TRNG I HC CN TH KHOA NNG NGHIP & SINH HC NG DNG B MN CHN NUI

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GIO TRNH

CHN NUI THBin son: PGs Ts Nguyn Vn Thu Ts Nguyn Th Kim ng

3/2009

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THNG TIN V TC GI PHM VI V I TNG S DNG CA GIO TRNH

I. THNG TIN V TC GI

1- H v tn: PGs Ts Nguyn Vn Thu Sinh nm: 16-02-1955 C quan cng tc: B Mn Chn Nui, Khoa Nng Nghip &SHD Trng i Hc Cn Th a ch Email lien h: nvthu@ctu.edu.vn

2- H v tn: Ts Nguyn Th Kim ng Sinh nm: 24-08-1956 C quan cng tc: B Mn Chn Nui, Khoa Nng Nghip &SHD Trng i Hc Cn Th a ch Email lien h: nvthu@ctu.edu.vn

II. PHM VI V I TNG S DNG - Gio trnh c th dung tham kho cho ngnh Chn nui-Th Y, Th Y, Nng hc v Sinh hc. - C th d ng cho cc Trng i Hc, Cao ng v Trung Cp Nng Nghip - Cc t kho : Chn nui th, k thut nui th, bnh thng thng ca th - Yu cu kin thc trc khi hc mn ny: Sinh l gia sc, Dinh dng gia sc v Ging gia sc. - xut bn v in nh xut bn: cha, ch in dng bi ging2

MC LC

THNG TIN V TC GI..........................................................................2I. THNG TIN V TC GI ..........................................................................................2 II. PHM VI V I TNG S DNG ....................................................................2

MC LC ......................................................................................................3 CHNG 1: TM QUAN TRNG V C IM SINH HC CA TH .........................................................................................................................8I. V TR V TM QUAN TRNG ...............................................................................8 II. NHNG LI CH CA NGH NUI TH..............................................................8 1. Th sinh sn nhiu v nhanh .....................................................................................8 2. Thc n ca th r tin d kim v t cnh tranh vi cc gia sc khc .....................9 3. Nui th u t vn t ................................................................................................9 4. Lao ng rt nh nhng: ............................................................................................9 5. Cung cp tht nhanh: ..................................................................................................9 6. Tht th c gi tr dinh dng tt:............................................................................10 III. C IM SINH HC ...........................................................................................10 1. Nhng tp tnh c bit ca th ...............................................................................10 2. S p ng c th vi kh hu .................................................................................10 3. Thn nhit, nhp tim v nhp th..............................................................................11 4. c im v khu gic ............................................................................................11 5. c im v thnh gic v th gic...........................................................................12 6. S tiu ha ...............................................................................................................12 a. C th hc h tiu ho...........................................................................................12 b. Sinh l tiu ha .....................................................................................................12 7. Sinh l sinh sn ......................................................................................................14 a. Cu to c quan sinh dc ......................................................................................143

b. Hot ng sinh l sinh dc ca th......................................................................15 8. Sinh l cho sa........................................................................................................16 IV. CU HI N TP ..................................................................................................17 V. TI LI U THAM KHO.........................................................................................17

CHNG 2: GING V CNG TC GING TH ...........................18I. S THUN HA .......................................................................................................18 II. CC GING TH.....................................................................................................18 1. Th Newzeland trng...............................................................................................19 2. Th Californian........................................................................................................19 3. Th Chinchilla .........................................................................................................20 4. Th English Spot .....................................................................................................21 5. Nhm th Vit Nam.................................................................................................21 a.Tnh sai con:......................................................................................................23 b.Tng trng v thnh phn c th: ..........................................................................24 c. S di truyn v c im ging ............................................................................24 d. Gen v mi trng sng .......................................................................................24 e. S lai ging cc nc nhit i .........................................................................25 III. PHNG PHP CHN LC V NHN GING TH ......................................25 1. Cc phng php chn lc ......................................................................................25 a. Chn lc qun th .................................................................................................25 b. Chn lc c th .....................................................................................................25 2. Phng php nhn ging th ...................................................................................27 a. Nhn ging thun..................................................................................................27 b. Lai ging ...............................................................................................................28 c. Thc hnh phi ging ...........................................................................................28 IV. CU HI N TP ..................................................................................................29 V. TI LI U THAM KHO.........................................................................................304

CHNG 3: DINH DNG V THC N CA TH .......................31A. NHU CU DINH DNG.......................................................................................31 I. Nhu cu nng lng .................................................................................................31 a. Nhu cu c bn .....................................................................................................31 b. Nhu cu duy tr .....................................................................................................31 c. Nhu cu sn xut...................................................................................................32 II. Nhu cu m v amino acid....................................................................................36 a. Nhu cu m .........................................................................................................36 b. Nhu cu amino acid ..............................................................................................36 III. Nhu cu cht x ca th ........................................................................................38 IV. Nhu cu khong v vitamin...................................................................................38 V. Nhu cu nc ung .................................................................................................39 B. CC LOI THC N CHO TH............................................................................40 I. Rau c.......................................................................................................................40 II. Cc loi h u v ph phm trng trt ..................................................................41 III. Thc n tinh bt.....................................................................................................49 IV. Thc n b sung m.............................................................................................49 V. Cch ch bin thc n cho th ................................................................................50 C. CU HI N TP ....................................................................................................51 D. TI LI U THAM KHO.........................................................................................51

CHNG 4: CHUNG TRI...................................................................53I. NHNG YU T CH KHI XY DNG CHUNG TRI TH .....................53 1. Kh hu.....................................................................................................................53 a. Nhit .................................................................................................................53 b. Gi ........................................................................................................................53 c. nh sng ...............................................................................................................53 d. m ...................................................................................................................535

2. V tr.........................................................................................................................53 II. NH NUI TH .......................................................................................................54 III. LNG TH ..............................................................................................................55 1. Lng nht ring tng con: .......................................................................................56 2. Lng th ci nui con ..............................................................................................56 3. Lng th nui tht ....................................................................................................57 4. Cc kiu lng: ..........................................................................................................57 a. Kiu lng 1 tng....................................................................................................57 b. Kiu lng 2 tng....................................................................................................58 c. Kiu lng 3 tng....................................................................................................58 5. Vt liu lm lng......................................................................................................59 6. Dng c trong lng ..................................................................................................59 a. Mng c: ...............................................................................................................60 b. Mng thc n b sung (TABS):............................................................................60 c. Mng ung: ...........................................................................................................61 d. :......................................................................................................................61 7. Kiu lng lin kt vi hang th ...............................................................................61 IV. CU HI N TP ..................................................................................................62 V. TI LI U THAM KHO.........................................................................................62

CHNG 5: K THUT NUI TH .....................................................64I. NUI TH THT........................................................................................................64 II. NUI TH SINH SN .............................................................................................68 1. Nui Th c ...........................................................................................................68 2. Chn Th c ..........................................................................................................68 3. Chn Th ci............................................................................................................69 4- Chn th con lm th ging ....................................................................................69 5. Tui cho th sinh sn ...............................................................................................696

6. Th ci ln ging: ....................................................................................................71 7. Cho th phi ging ..................................................................................................71 8. Chm sc th ci c thai ..........................................................................................71 9. Kim sot th ci c thai..........................................................................................72 10. Cho th ..............................................................................................................72 11. Mt s khu phn tham kho nui th sinh sn................................................72 III. NHNG BNH THNG THNG TH..........................................................74 1. Bnh Bi huyt: .......................................................................................................74 2. Bnh cu trng:........................................................................................................75 3. Bnh sn l gan:.......................................................................................................75 4. Bnh Gh: ................................................................................................................75 5. Bnh T Huyt Trng:.............................................................................................76 6. Bnh vim mi:........................................................................................................76 7. Bnh chng hi, tiu chy: ....................................................................................76 III. CU HI N TP...................................................................................................76 IV. TI LI U THAM KHO ......................................................................................77

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CHNG 1: TM QUAN TRNG V C IM SINH HC CA TH

I. V TR V TM QUAN TRNG Th nh l gia sc c bit nh l mt loi n c chuyn ho mt cch c hiu qu t rau c sang thc phm cho con ngi. Th c th chuyn ho 20% protein chng n c thnh tht so vi 16-18% heo v 8-12% b tht. Mt cch c bit chng tn dng tt ngun protein v nng lng t thc vt to ra thc phm, trong khi cc ngun thc n ny khng cnh tranh vi con ngi, heo, g ... so vi ng cc. Nh vy trong nhng nc hay vng khng c ngun ng cc d tha th chn nui th l mt trong nhng phng n tt nht sn xut ra ngun protein ng vt cn thit cho dinh dng con ngi mt cch kinh t. Trn th gii ngnh chn nui th kh pht trin. Trong nhng thp nin 80 theo c tnh t s sn xut tht th, mi nm mt ngi tiu th khong 200g tht th. Sn xut tht th cao cc nc Nga, Php, , Trung Quc, Anh, M, v..vMt cch chung nht ngh ny pht trin mnh Chu u v Chu M, tuy nhin km pht trin Chu v Chu Phi. Chu u s sn xut v mua bn tht th v th ging cng tng nhanh. C th l cc nc Nga, c, Php, an Mch, H Lan v Anh. Trung Quc cng l nc xut khu tht th c uy tnh th trng Chu u. Th trng da th v lng len th cng mnh m c bit l nhu cu da xut khu sang Anh, Nht, , M,v lng len ca th Angora xut sang M, Nht v c t cc nc sn xut chnh nh: Czechoslovakia, c, Anh, Ty Ban Nha, v.v Vit Nam mc d ngh chn nui th nc ta hin nay ni chung cn rt mi v cha pht trin so vi cc gia sc khc, tuy nhin ri rc ngi dn cng pht trin chng t thnh th n nng thn trn c nc cung cp tht cho cng ng ngi dn, cc nh hng, qun n, cung cp th cc phng th nghim, vin, trng hc, dng trong cng tc nghin cu v ging dy, v..v... Trong tng lai gn vi dn s ngy cng gia tng, nhu cu thc phm cho ngi dn ngy cng ln, nhu cu nghin cu khoa hc v ging dy cng tng ln. Do vy trong tng lai gn chng s pht trin thnh mt ngnh chn nui quan trng. Vic t mt nn tng khoa hc k thut nhm pht trin n th Vit Nam c vai tr quan trng c bit.

II. NHNG LI CH CA NGH NUI TH Chn nui th em li nhiu li ch v thun li cho ngi chn nui v nhng l do sau:

1. Th sinh sn nhiu v nhanh Th sinh sn nhanh, do tui sinh sn ch 6-7 thng v thi gian mang thai khong 1 thng. Do vy nu thng ging th m th thng 7 cng nm th con s v thng ging nm sau i chu s . Nh vy trong khong 13-14 thng c ba th h cng c8

th sn xut ra th con. Mi la th trung bnh 6-7 con, mi th ci trung bnh mi nm 6-7 la. Mi nm th c th sinh sn trung bnh 30 con th con.

2. Thc n ca th r tin d kim v t cnh tranh vi cc gia sc khc Thc n ch yu cho th l cc loi c rau, l cy l cc loi thc n d kim hay d trng trong iu kin gia nh, t hoc khng tn km nhiu tin. Thc n hn hp ca th dng nui trong iu kin tp trung khng i hi cht lng qu cao, chng ta c th tn dng cc loi sn phm nng nghip c sn b sung cng c nh l la, bp, cm, khoai c, Nu ch cho ton b l rau c th lng protein ca th cng c gii quyt phn ln, chng ta b sung khi cn thit. Dinh dng th khng i hi cu k, khng kh gii quyt nh cc loi gia sc khc. Ni chung hm lng m trong thc n xanh v cc ph phm khc cng p ng c protein ca th trong trong chn nui thm canh.

3. Nui th u t vn t Ni chung nui th u t rt thp t c khu con ging n thc n, lao ng chung tri khng nhiu m cng em li hiu qu kinh t nh cc ngnh chn nui khc tu theo quy m pht trin. L do l th sinh sn rt nhanh nn pht trin n ging rt l. T n ging ny c th nh hnh quy m pht trin mt cch c hiu qu v kinh t nht. Thc n c th tn dng lao ng trong gia nh (ct c t nhin, trng rau lang, rau mung) hay s dng thc n sn c nh la, cm, Do vy thu hi tin vn v sinh li rt nhanh. Tuy nhin iu quan trng nht vn l tm th trng tiu th th tht hay th con. Chng ta cn ch ng m rng th trng tiu th sn phm nh gii thiu cc mn n ch bin t tht th, vn ng vic s dng th trong cng tc ging dy, th nghim, to th lm cnh, v..v...

4. Lao ng rt nh nhng: Ngh nui th khng cn lao ng nng nhc, tn dng mi lao ng nhn ri trong gia nh nh ph n, tr em, ngi cao tui. c bit y l ngnh chn nui kh ph hp cho ngi ln tui cn lao ng nh nhng nhng chm sc t m v chu o.

5. Cung cp tht nhanh: Th sau 3 thng nui c trng lng xut chung 1,7-2kg. Mt nm th m c th sn xut khong 40 con v nh th s cung cp khong 70-75kg tht hi.

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6. Tht th c gi tr dinh dng tt: Tht th ngon cht lng tt (t m nhiu m) d tiu ha thch hp vi ngi g, tr em v ng bnh. Bng 1. Ga tr dinh dng ca cc loi tht (g/100g) Loi tht Th Heo Ngng Kcal 162 400 490 protein 22.5 14.5 16 bo 8 37 45 glucid 0.4 0.2 0.2

III. C IM SINH HC Th nh l loi gia sc tng i yu, kh nhy cm v d c phn ng c th vi nhng iu kin thay i ca mi trng bn ngoi nh nng, ma, m , nhit , thc n, nc ung, ting n v cc nhim mi trng khc. V vy ngi nui th cn phi hiu r v cc c tnh sinh hc, nhm bo m to cho th y cc yu cu ti u nht cho th sinh sng khi mi trng sng c s thay i, bng cch p dng cc bin php k thut chn nui.

1. Nhng tp tnh c bit ca th Th c mt s cc tp tnh nh sau: th sng bnh thng th o hang lm ni tr n v sinh sn, v d dng nhn bit mi ca chnh n, th sng thnh by v thng thng s ci nhiu hn c, thng thng s rng trng ca th ci xy ra trong lc phi ging, th ci thng dng cc vt liu kt hp vi lng bng lm trc khi , th n v ung bt k thi gian no trong 24 gi , chng khng n thc n d bn, ri xung t, v..v..

2. S p ng c th vi kh hu Nhit l yu t quan trng nht v nh hng trc tip i vi th. Khi nhit thp hn 100C th cun mnh gim din tch chng lnh, nhng khi nhit t 25300C th chng s nm di soi thn th ra thot nhit. Tuyn m hi th thng khng hot ng. Tai c xem l b phn pht tn nhit v nhp th cng c tng cng thot nhit khi nhit mi trng nng. Nu nhit mi trng trn 350C th s b stress nhit do thn nhit tng cao. Th c t tuyn m hi di da, thi nhit ch yu qua ng h hp, tri nng qu th th th nhanh nu nhit ln 450C th th c th cht nhanh. Th rt nhy cm vi m thp (40-50%), nhng m qu cao cng khng thch hp. m trong khng kh t 70-80% l tng i thch hp i vi th. Nu m qu cao v ko di th th d b cm lnh v vim mi. Th rt thch iu kin10

thng thong, thng gi s lu chuyn trong khng kh vo khong 0.3m/giy l thch hp nht, tuy nhin nu gi thi trc tip vo c th th th chng c th b bnh vim mi v cm lnh.

3. Thn nhit, nhp tim v nhp th Nhit c th ca th ph thuc v tng theo mi trng khng kh t 38-410C trung bnh l 39.50C. Nhp tim ca th rt nhanh t 120 n 160 ln/pht. Tn s h hp bnh thng l 60 - 90 ln/pht. Th bnh thng th nh nhng. Nu th lo s v ting ng, m thanh ln hay b chc ph hoc tri nng bc, chung tri cht hp khng kh ngt ngt th cc ch tiu sinh l u tng. Do vy s tng cc ch tiu sinh l l iu cn trnh bng cch to mi trng sng thch hp cho th nh thng thong, mt m v yn tnh. Bng 2. S thi nhit ra ngoi, thn nhit ca trc trng v nhit tai th da vo nhit khng kh Nhit khng Tng s nhit thi ra (W/kg) kh (0C) 5 10 15 20 25 30 35 5,3 4,5 3,7 3,5 3,2 3,1 3,7 Nhit thi ra t bn trong (W/kg) 0,54 0,57 0,58 0,79 1,01 1,26 2,0 Thn nhit (0C) 39,3 39,3 39,1 39,0 39,1 39,1 40,5 Nhit tai th (0C) 9,6 14,1 18,7 23,2 30,2 37,2 39,4

4. c im v khu gic C quan khu gic ca th rt pht trin, n c th ngi mi m phn bit c con ca n hay con ca con khc. Xoang mi th c nhiu vch ngn chi cht c th ngn chn c cc tp cht bn trong khng kh bi hoc t thc n. Cc cht d bn tch t ti y c th kch thch mi th, to iu kin cho vi khun pht trin gy vim nhim ng h hp. V th mi trng sng v thc n ca th cn c sch s nu cho thc n hn hp dng bt th cn phi lm cho m hoc ng thnh vin. Lng th phi dn sch s trnh bi bm, cn c v sinh lng chung thng xuyn. Ht sc ch n cc loi thc n rau c cn d li trong lng lm cho b m mc v m cao trong lng d gy bnh ng h hp cho th. Trng hp mun ghp th s sinh vo th m khc nui ta nn s dng mt s cht c mi thoa trn c th con ca th m v th con ghp vo th m khng phn bit c, sau mt gi nht chung m th m khng phn bit c th coi nh l s ghp thnh cng.11

5. c im v thnh gic v th gic C quan thnh gic th rt tt. Th rt nhy cm vi ting ng d l rt nh chng cng pht hin v chng cng rt nht d s hi, do vy trong chn nui trnh ting ng n o cho th. Trong m ti mt vn nhn thy mi vt, do vy th vn c th n ung ban m cng nh l ban ngy.

6. S tiu ha a. C th hc h tiu ho

Hnh 1. H tiu ho th trng thnh (4-4,5kg hay 2,5-3kg) chiu di h tiu ho c th 4,5-5,0m. Sau ng thc qun ngn l d dy n ca th cha khong 60-80g thc n. Rut non di khong 3m v c ng knh 1cm. Cui rut non l tip gip vi manh trng b phn tch tr v tiu ho thc n ny c chiu di khong 40-45cm vi ng knh 3-4cm. N cha c 100-120g mt hn hp cht cha ng nht vi t l cht kh khong 20%. K n l rut gi vi chiu di khong 1,5m. H tiu ho ca th pht trin rt nhanh trong giai on th ang tng trng. Hai tuyn chnh tit vo rut non l gan v ty tng. Dch mt th cha nhiu cht hu c nhng khng c enzyme. Dch ty cha nhng enzyme tiu ho protein (trypsin, chymotrypsin), tinh bt (amylase), v m (lipase). b. Sinh l tiu ha Thc n nhanh chng i vo d dy, y l mi trng acid v thc n lu li khong 3 6gi v c nhng thay i nh v mt ho hc. Bng nhng s co tht mnh cht cha trong d dy c y vo rut non. u tin cht cha s c ho tan vi dch mt v sau l dch ty. Sau tc ng ca enzyme cc nguyn t nh c gii phng ra v c hp thu qua thnh rut non. Nhng mnh thc n cha c tiu ho c th lu rut non khong 1 gi 30 pht. Sau chng c i vo manh trng v c12

th lu li 2 12gi v s c tiu ho bi cc enzyme ca vi sinh vt. Ch yu l cc thc n x c tiu ho ti y v to ra cc acid bo bay hi, ri chng c hp thu qua vch ca manh trng vo mu cho s s dng ca c th. Phn cht cha ca manh trng sau s c a vo rut gi. Khong phn na cn li c tiu ho v bao gm c vi sinh vt y. Phn u ca rut gi c hai chc nng l to ra phn mm v phn bnh thng ca th. S to ra phn mm l c im duy nht c th. Nu cht cha manh trng i n rut gi vo bui sng sm, n s tri qua t thay i v sinh ho hc, ri cc cht nhy ca rut gi tit ra s bao quanh cc cht cha ny gi l vin phn mm. Cn nu cht cha manh trng i n rut gi vo cc thi gian khc nhau trong ngy th nhng phn ng ho hc ca phn rut gi trc s hon ton khc. Trong trng hp ny s to ra cc vin phn cng do t nc. Cc vin phn cng s c y ra ngoi bnh htng trong khi phn mm s c th thu hi tr li bng vic th s nt cc vin phn ny khi chng ra khi hu mn ri th s nut m khng phi nhai li g c (Ceacotrophy). Th cng c th nhn bit phn mm ngay khi chng lt ra rt trn sn lng n tr li. Vin phn mm c gi tr protein v vitamin cao hn so vi vin phn cng. Lin quan n vn ny, mt s lng thc n ca th s c s dng tr li t 2-4 ln. Do vy tu theo loi thc n tin trnh tiu ho thc n ca th c th t 18 30 gi, trung bnh l 20 gi.

Bng 3. Thnh phn dng cht (% vt cht kh) ca vin phn mm v phn cng ca th cho n 10 loi thc n. Thnh phn Vin phn cng Trung bnh Nc Vt cht kh 41,7 58,3 Khong 34 52 8 66 Vin phn mm Trung bnh 72,9 27,1 Khong 63 82 18 37

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m th X Bo Khong Dn xut khng m

13,1 37,8 2,6 8,9 37,7

9 25 22 54 1,3 5,3 3,1 14,4 28 49

29,5 22,0 2,4 10,8 35,1

21 37 14 33 1 4,6 6 10,8 29 43

Manh trng ln gp 5 n 6 ln d dy v nhu ng ca rut yu do thc n ngho cht x hoc cha nhiu nc (thc n th xanh, c qu) d phn hu to thnh cc cht kh lm th d chng bng y hi, a chy. Th n nhiu thc n th xanh (rau, l, c) iu ny ph hp vi yu cu sinh l tiu ho, bo m thng xuyn cht cha trong d dy v manh trng trnh c cm gic i v gy ri lon tiu ho. Lng nc trong c th th chim khong 60 - 90% th trng, nc rt cn thit cho qu trnh trao i cht, pht trin thai v sn xut sa V vy cn phi cung cp nc ung y cho th.

7. Sinh l sinh sn a. Cu to c quan sinh dc - C quan sinh dc c

C quan sinh dc th c c cc phn chnh nh l cc loi gia sc khc nh dch hon, ng dn tinh, cc tuyn sinh dc v dng vt (hnh 2a). Tuy nhin th c vi c im sau: c th co rt dch hon khi s hi hay xung t vi cc con c khc v dch hon hin din r khi th c c khong 2 thng.14

- C quan sinh dc ci

con ci, bung trng c dng oval v khng vt qu 1 1,5cm, pha di bung trng (non so) l ng dn trng ni lin vi 2 sng t cung c lp 2 bn khong 7cm v thng vi phn trn m o bng c t cung (hnh 2b). Ton b b phn sinh dc c bi nhng si dy chng ln nh vo 4 im di ct sng. b. Hot ng sinh l sinh dc ca th - Th c: Tuyn sinh dc pht tin nhanh chng bt u t 5 tun tui, tuy nhin s sn xut tinh trng bt u khong 40 50 ngy tui. ng dn tinh s hot ng khong 80 ngy tui. Tinh trng c phng ra hin din ln u khong 110 ngy, nhng chng trong thi gian ny rt yu, sc sng km. S trng thnh sinh dc ca th Newzealand khong 32 tun tui trong iu kin n i, d vy nhng th c tr c th s dng cho s phi ging sinh sn khong 20 tun. Trong thc t s bc l nhng tp tnh phi ging ca th l khong 60 70 ngy tui khi th c biu hin u tin nhy ci trn nhng th khc. Thi gian c th cho th c nhy ci ln u nn l 135 140 ngy tui. Lng tinh dch ca th l 0.3 0.6ml trong mt ln phng tinh. Mt khong 150 500 x 108 tinh trng/ml. Lng tinh trng sn xut ra ti a khi s dng th c nhy ci 1 ln trong ngy. Nu s dng th c 2 ln trong ngy th mt tinh trng gim i phn na. Tuy nhin trong thc t th c c s dng 2 ln/ngy, hay 3 4 ln/tun mt tinh trng gy th thai. Nu s dng c phi nhiu ln trong ngy, trong tun qu mc ni trn c th nh hung km n s th thai. - Th ci: nang non xut hin ln u khong 65 70 ngy. Th ci c th phi ging 10 12 tun tuy nhin trong lc ny th cha c s rng trng. Nhng biu hin phi tnh ca th ging nh con v th trung bnh (4 6 thng) th sm hn th ging ln con (5- 8 thng). Chu u th ci c phi khong 120 130 ngy th cho thnh tch rt tt. S pht trin c th th ci lin h thun vi s thnh thc ca th. Nhng th ci t nu cho n y th c th dy th sm hn th nui trong iu kin ch nhn 75% vi15

khu phn tng ng khong 3 tun l, v nh th s pht trin c th s chm i 3 tun. Th bt u thnh thc tnh dc khi t th trng khong 75% trng lng trng thnh. iu ch l th ci t chp nhn cho th c nhy trc khi c kh nng rng trng. th ci th khng c chu k ln ging u u, cng nh khng c s rng trng ng thi trong thi gian ln ging nh cc loi gia sc khc (Lebas et al., 1986). Khc vi nhng gia sc khc, th nh c xung ng hng phn, khi giao phi mi xy ra rng trng. Sau khi phi 10 12 gi cc ti trng mi bt u ph v, trng qua loa kn vo ng dn trng v n v tr th tinh. Thi gian cn thit trng di chuyn gp tinh trng t khi rng l 4 gi, trn c s ngi ta p dng phng php b sung phi li ln th 2 sau ln th nht 6 gi, nhm tng thm s trng th tinh v nhiu con. Biu hin m h c mu c th xem nh l biu hin ln ging, thi im ny th ci chp nhn cho th c nhy v t l mang thai ln n 90%. Sau khi th ci ng dc sau 2 3 ngy, th c bn nng nht c, rc vo , co bi , t nh lng bng v chn lt lm m ri mi con, sau khi th m ph lng kn cho n con.

8. Sinh l cho sa S tng hp sa th ph thuc vo hormon prolactin v Lactogenic hormon. Trong giai on c thai Prolactin s b c ch bi estrogen v progesterone. Khi th mt s h thp mc progeterone nhanh trong mu. Oxytocin v prolactin s c tit t do v to nn s tng hp sa v thi sa ra ngoi. Sa s thi ra nh sau: th m vo cho con b, cc kch thch t s cho b s lm cho s tit ra oxytocin v nh th sa s c thi ra cho con b. Lng oxytocin tit ra t l thun vi s ln cho con b, tuy nhin th m s ch ng s ln cho b trong ngy. Thng th ci ch cho mt ln b trong mt ngy. S theo b m s khng to ra s tit oxytocin m tu theo th m c mun cho con b hay khng. Sa th c gi tr dinh dng cao (13%CP) hn sa b, sau khi 3 tun sa th tr nn giu m v m sa (tng 20 22%). Lng sa trong 2 ngy u khong 30 50g s tng n 200 300g vo tun l th 3. N s gim nhanh sau c bit l trong trng hp th c mang. Bng 4. Thnh phn dng cht ca sa th Thnh phn Sa th (4 21 ngy) Sa b

Vt cht kh Protein M Khong Lactose

26,1 26,4 13,2 137 9,2 9,7 2,4 2,5 0,86 0,87

13,0 3,5 4,0 0,7 5,0

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IV. CU HI N TP 1- Trnh by v tr v tm quan trng ca chn nui th trn th gii v ti Vit Nam 2- Nu nhng c im sinh hc ca th v ng dng chng cho pht trin ngnh chn nui th 3- Nu nhng c im tiu ho v sinh sn ca th khc vi cc loi gia sc khc.

V. TI LI U THAM KHO 1. Cheeke, P.R., 1987. Rabbit feeding and nutrition. Academic Press. INC. 1987. 2. inh Vn Bnh, Nguyn Quang Sc,1999. Nui Th v Ch Bin Sn Phm Gia nh. NXB Nng Nghip. 3. inh Vn Bnh, 2003. Ti liu k thut chn nui Th. NXB Nng Nghip. 4. F.A.O., 1986. The rabbit: Husbandry, health and production. Rome. 5. F.A.O., 1988. Raising rabbit. better farming series. Rome 1988 6. Hong Th Xun Mai.2005. K thut chn nui th .NXB Nng Nghip TP. H Ch Minh 7. Leng, R.A., 2008. Digestion in the rabbit a new look at the effects of their feeding and digestive strategies. In proceedings of International Rabbit Workshop on Organic farming based on Forages at Cantho University, Vietnam. 25-27 Nov. 2008. http://www.mekarn.org/prorab/content.htm 8. Nguyn Chu Chng, 2003. Hi p v nui th. NXB Nng Nghip, H Ni 9. Nguyn Ngc Nam, Nguyn Quang Sc v Phm Th Nga, 1983. Nui th tht. NXB Nng Nghip, H Ni. 10. Nguyn Ngc Nam. 2002. Hng dn k thut chn nui th. NXB Lao ng X Hi 11. Nguyn Quang Sc & inh Vn Bnh (2000), Cm nang chn nui th, thng tin trang wed-Vin Chn Nui Vit Nam, http://www.vcn.vnn.vn/vcn 12. Nguyn Vn Thu, 2003. Gio trnh Chn nui Th. Khoa Nng Nghip, i Hc Cn Th. 13. Sandford, J.C., 1996. The domestic rabbit. Fifth edition. Oxford. 14. Vit Chng.2003. Nui v kinh doanh th. NXB Tng Hp TP. H Ch Minh

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CHNG 2: GING V CNG TC GING TH

I. S THUN HA Cc ging th nh trn th gii hin nay u c ngun gc t th rng (Orytolaguc cuniculus) thuc H th nh v th rng (Leporidae), trong B gm nhm ring bit c rng ca kp (Lagomorpha), ca Lp ng vt c v (Mammalia) Ni chung s thun ho th rng thnh th nh ch khong vi trm nm gn y. Th rng Chu u c pht hin bi nhng nh ng m hc khi h n b bin Ty Ban Nha vo nm 1000 trc cng nguyn. Th l biu tng ca Ty Ban Nha vo thi k La M. T u th k 19 vic nui th pht trin khp Ty u v c ngi Chu u a th i du nhp tt c cc nc trn th gii. Cui th k 19 v nht l u th k 20 cng vi phng php nui nht cng vi cc ging th thch nghi vi iu kin nui nht c chn lc v thay i dn v ngoi hnh, sinh l thch nghi vi hon cnh c th v kh nng sn xut ph hp vi nhu cu thm canh cng vi cc k thut chn nui tin tin p ng nhu cu sn xut v li nhun, bnh tt ca th ngy cng c nghin cu v khng ch cng nh l c th iu tr v phng nga c cng ngy cng pht trin vi mc ch sn xut tht th lm ng vt th nghim v lm sinh vt cnh.

II. CC GING TH Hin nay chn nui th kh pht trin ch yu l nui th hng tht hoc nui th kim dng ly tht v lng len. Do vy c nhiu ging th ln con dng sn xut tht Chu u, Chu M v mt s ging th nh con cc nc nhit i pht trin ti a phng hay tng quc gia. Bn cnh cng c mt s ging chuyn sn xut lng len ch yu l nc n i. Nui th hng tht thng chn ging c tm vc kh lc trng thnh c trng lng 4,5 n 5 kg; cng ch nhng ging th ny c b xng nh c t l tht x cao. Mt cch chung nht ngi ta chia th da theo tm vc: nhm nng k (Trng lng trng thnh hn 5kg) nh Bouscat Giant White, French and French Giant Pabillon; nhm trung bnh (Trng lng trng thnh hn 3,5-4,5kg) nh Californian, New Zealand White, Grand Chinchilla, nhm th nh cn (trng lng trng thnh t 2,5-3kg) nh Small Chinchilla, Duch and French Havana, Himalayan, v nhm nh con (trng lng trng thnh hn 1kg). Di y l mt s ging th hng tht ch yu v ph bin Vit Nam:

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1. Th Newzeland trng

Ging th ny c nui nhiu nc v ph bin nhiu ni trn th gii Vit Nam do kh nng thch nghi vi cc iu kin sng cao. Ging th ny c ton thn mu trng, lng dy, mt nh hn ngc, c tm vc trung bnh, th trng thnh nng khong 4,5 - 5 kg. Mi nm th trung bnh 5 - 6 la mi la trung bnh t 6 -7 con. Nh vy i vi ging th ny mt th ci trung bnh cho 20 - 30 con/nm. Th cai sa thng c nui v bo n 90 ngy tui th git tht. Nh vy mt th m trong mt nm c th sn xut t 30 - 45 kg trng lng sng nu nui tt c th t 60 - 90 kg v thm t 20 30 tm lng da.

2. Th Californian

Ging th ny c to ra v pht trin t M (khong 1920) t 2 ging New Zealand White v Himalyan v sau c s tham gia ca ging Chinchilla vi mc ch to ra ging th c tht v len c cht lng cao. Chng c nhp vo t Anh ln u tin vo nm 1958. Tuy nhin n nm 1960 mi cng b chnh thc vi s lng 400 con.19

y l ging th to ra c li tc cao cho ngi nui th thng phm. c im ca ging th ny l c b lng mu trng tuyt, tr hai tai th c mu en, mi, ui v 4 chn c mu tro hoc mu en. Th trng thnh c trng lng 4 - 4,5 kg, con c nng t 3,6 - 4,5 kg con ci nng 3,8 - 4,7 kg. Mi nm th khong 5 la. Mi nm th khong 5 la mi la khong 5-6 con. Th ny nhp vo nc ta Sn Ty (1977) v thch nghi vi iu kin kh hu v nui dng chm sc. Th Californian c tm vc trung bnh, t l tht x cao t 55 - 58 % chng c nui ph bin trn th gii v tr thnh ging th tht ng th hai trn th gii (Sandford, 1996). Tuy nhin qua th nghim 3 nm nui BSCL vi cc loi thc n thng thng, ging th thun Californian tng i kh nui, km v t l th con hao ht cao so vi th thun New Zealand.

3. Th Chinchilla

Th Chinchilla ln u tin c trnh din ti Php 1913 bi J.J. Dybowski c to ra t th rng v 2 ging Blue Beverens v Himalyans c xem nh l ging th cho len. Ging th ny c 2 dng mt c trng lng 4,5 - 5 kg (Chinchilla giganta) v dng kia 2 - 2,5 kg lc trng thnh. Ging th ny trung bnh mi la t 6 - 8 con c kh nng thch nghi vi cc iu kin chn nui khc nhau. Th c lng mu xanh, lng ui trng pha ln xanh en, bng mu trng xm en.

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4. Th English Spot

Ging th English Spot c tm vc trung bnh trng lng trng thnh 2,5 - 3,5 kg ci v c, c chn lc v pht trin Anh quc. N c c im l thn c mu lng trng vi cc m mu xm trn c th, tai thng ng, mng rng trn v hi ln hn phn vai, chn di v mnh khnh. Ging ny c nhn bit vi cc m xm mu 2 vng mt, m v tai, sng lng v ui. Cc m ny c mu sc ph bin l en, xanh dng, s c la, nu, vng, v..v.. Ging th ny hin nay cng tham gia vo mu ca con th lai Vit Nam kh ph bin.

5. Nhm th Vit Nam

Th en v th khoang trng en Nhm th Vit Nam c du nhp t Php vo khong t 70 - 80 nm trc y. Chng c lai to gia nhiu ging khc nhau, nn c nhiu ngoi hnh v tm vc khc nhau, phn ln c mu lng ngn, mu en, trng mc, khoang trng en, trng vng, trng xm c th trng khong 2 kg, Ngi ta thng gi tn theo mu sc lng nh th D th nh con, nh cn, c trng lng 2,2-2,5kg. Nhn chung nhm th ny c mu lng khoang, lang hay m, trng, vng en, xm ring mu lng phn di bng, ngc, ui c mu xm nht hn hoc mu xm trng. Mu mt en, u nh lng khum trng lng trng thnh 2,5-3kg; v th en c lng ngn, c mu en tuyn, mu mt en, u to va, ming nh bng thon, bn chn di th, xng th. Trng21

lng trng thnh 2,6-3,2kg. Mt vi ni c cc ging th lng x mu trng do c mu ca ging Angora. c im sinh sn ca hai ging th mu xm v mu en ca Vit Nam c khc so vi th mi nhp ni v th lai thng phm khc. Chng vn cn bo tn tnh nng sn xut ca th rng xa xa nh ng dc sm 4,5 - 5 thng tui, mn sau khi t 1 n 3 ngy chu c phi ging li, th va tit sa va nui con v c cha nn nu gia nh c iu kin tt th th s lin tc, mi nm t 7 n 8 la v giao ng t 4 11con/ la. Mt trong nhng tp tnh ca th l nh lng lm , i vi tp tnh ny th en v xm ca Vit Nam th hin r hn so vi th nhp ni. Cc th trc khi thng t ly rc, rm c vo trong v t nh nhiu lng bng lng ngc trn thnh t m mm, con trong , t c trng hp con ngoi . Sc khng tt ca th Vit Nam v th Lai c th hin r nt hn th nhp ni iu ny th hin qua mt s ch tiu sinh l.

Nhm th Lai BSCL Nhm th lai vng BSCL c lai to t cc ging th ngoi nhp vo Vit Nam nhng nm 90 vi th lai a phng, chng c tm vc kh, mu sc a dng pha trn gia cc ging nh New Zealand, Chinchilla, Californian, English Spot, v..v Trong iu kin nui dng cn hn ch v dinh dng hin nay vi thc n th xanh v b sung cc loi ph phm th ci trng thnh ( la 3) t 3,2 - 3,8 kg. Th tht nui t 4 - 4,5 thng t 2,2 - 2,4 kg. y l nhm th c nui ch yu BSCL cho tht rt hiu qu v tn dng c ngun thc n rau c a phng.

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Bng 1. Cc ch tiu sinh l thng thng ca th Vit Nam v th New Zealand Ging th Thn nhit (oC) Xm en New Zealand 38.3-39.9 Nhp th (ln/pht) 60-72 Hng cu (triu/mm3) 3.76 3.84 5.25 15.5 13.7 8.1 Bch cu (ngn/mm3)

38.5-40.5 90-120

Ngoi ra cn mt s ging th khc c ting trong khu vc hay nhng chu lc khc nh nhm ging th cho lng len Angora, American Sable, Britannia Petite,v..v Tuy nhin chng cha ph bin nc ta.

Th French Angora Nhng c im ging v kh nng sn xut ca th ph thuc vo mi trng sng v kinh nghim pht trin ca nh nhn ging. S so snh nhng kt qu t nhng mi trng v a l khc nhau c th cho thy nhng c tnh chung ca ging. Tnh mn , mc tng trng v s pht trin cc c quan, t chc ca c th th t l 3 c tnh c bn ca ging. a.Tnh sai con: c o lng bng s th con sng hay tng s th s sinh. S lng con trong by tng khong 10-20% t la u tin cho n la th hai. Tuy nhin s khng c s khc bit t la th ba n la th t v t la th t tr i th s lng th s sinh trong by s gim. S ng huyt trong nhn ging cng s lm gim tnh sai con. N cn ph thuc vo ma v nng sut sinh sn ca th ci. Yu t u tin nh hng n s sai l s trng rng v sau l kh nng sng ca phi. Ging th khc nhau cng cho nng sut sinh sn khc nhau.23

V d: Caliornian S con sng trong S con cai sa trong b.Tng trng v thnh phn c th: Mc tng trng ca th t th tng quan cht ch vi tm vc v trng lng trng thnh ca chng trong trng hp khng c s khim khuyt dng cht trong khu phn ng ghi nhn. S bin ng v thnh phn c th th ln cc ging th c nui, v d ging th New Zealand White v Himalyan. Tng trng v mc tng trng ca nhng t chc chnh ph thuc vo c im sinh hc ca ging v s nui dng. Do vy ch tiu m t v ging trong mt mi trng sn xut nht nh nn l tui trng thnh. Nhng ging c ch trn quan im sn xut l t l tt nht gia tng trng v trng lng trng thnh m n n sm mt trng lng sng thch hp cho th trng. Nhng ging nh cn c th c tn dng nh l nhng ging thun hay tt hn l lai vi nhng ging c trng lng trung bnh sn xut ra quy tht c s pht trin c tt v tht c cht lng c nhu cu tiu th. 7,04 5.46 New Zealand White 7,23 5,72

c. S di truyn v c im ging S ci thin di truyn v c im ging thch hp cho mi trng sn xut ph thuc vo tnh bin ng di truyn c trng m n bc l ra mi trng. Tnh bin ng l s bc l v nhng khc bit di truyn m trong chn lc v nhn ging c gng khm ph chng. Cu hi t ra y l lm sau c th khm ph ra tnh bin ng di truyn trong sn xut qui m nh. Nng cao tim nng ca ging ph thuc vo c tnh sinh hc, u th ca s sinh sn v s tnh ton cc thng s di truyn cho s chn lc.

d. Gen v mi trng sng Hu ht nhng c tnh di truyn s lng nh th tinh, sc sng, tng trng th c quyt nh bi nhiu gen v chng cng b chi phi bi mi trng sng. Kiu hnh l kt qu ca nh hng kiu gen kt hp vi mi trng. Kiu gen l kt qu ca nh hng gen vi v tr ca n (locus). Mi trng bao gm kh hu, ch , tiu kh hu, nhit , m , tc gi dng c trang thit b, k thut phi ging v nui dng v kinh nghim ca nh nhn ging. Xc nh di truyn ca s bin ng ca cc tnh trng l s c li song hnh ca nh chn lc v ngi lm cng tc ging. u tin l s khm ph bin ng di truyn ca th cng ging v cng qun th; k n bng s lai ging khm ph tnh bin ng di truyn gia ging v cc qun th.

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e. S lai ging cc nc nhit i Nhng nn tng sinh hc to ra nhng con lai u tri v cc tnh trng. Chng nn c khm ph trong nhng qun th c nhn ging trong mi trng khc nhau. Nhng nghin cu qui m ln trn nhng ging lai cc nc nhit i t Cuba (m) v Mexico (kh) c tng trnh. Nhng nghin cu ny thc hin trn nhng ging th nhp ni. S sn xut sa c ci thin bng s s dng con lai tt nht. Kt qu c cho thy tm quan trng ca cc ging thun v ging lai sn sng cho qu trnh nghin cu th nghim.

III. PHNG PHP CHN LC V NHN GING TH Tin trnh chn lc v lai ging th tp trung trong mt qui m sn sut thng mi cc nc n i th khng cn thit. Tuy nhin qui m nh t 10 dn 60 th ci ca qun th th a phng c cho phi t nhng con c v ci nhp ca cc ging th khc nhau nhm tng cht lng n ging l cn thit. S ci thin di truyn mt cch hiu qu trong tin trnh chn lc v nhn ging nn l n lc theo nhm vi s h tr v khoa hc v k thut t cc t chc nghin cu v pht trin. Chng trnh ci tin c th tp trung mt x hay thch hp hn l mt nhm x, hay cng c th l mt s tri th mt s Tnh trn ton quc. Trong trng hp ny chng trnh i hi s chuyn ho k thut. Do vy nn c nhng nh nhn ging vi nhng n v c qui m ln t 100- 200 th ci sinh sn. Nhng nh chn lc v nhn ging ny nn c kinh nghim bng vic s dng cc h thng sn xut p ng tt vi iu kin v ngun lc ti a phng. Nhng phng tin s dng hin i v phc tp nn c trnh, tuy nhin cn c bit ch n vic tin hnh trong hon cnh nhng tri th thng phm tt nht. V sinh v sc kho ca th phi c c bit ch . n v chn lc phi c hiu qu hai mc l nhn ging v sn xut.

1. Cc phng php chn lc a. Chn lc qun th Cn c vo gi tr trung bnh ca cc tnh trng nh s la /nm, s con trn/la, trng lng s sinh ton v trng lng bnh qun/con chn lc theo gia nh, chng ta gi li nhng gia nh t gi tr trung bnh tr ln ca ging hoc loi thi nhng gia nh c thnh tch di mc trung bnh ca ging theo yu cu chn lc ca chng ta. V d i vi ging th Califonian, ngi ta thng chn nhng gia nh th t kt qu bnh qun kh v cc c tnh sn xut nh: Mt nm 5 la tr ln, mi la 6 con nui sng, trng lng con s sinh l 50gam v trng lng ton l t 300gam tr ln. b. Chn lc c th y l im quan trng c nhng c th tt a vo tin trnh nhn ging c th phi c ghi chp cc thnh tch y nh gi v quyt nh nn loi thi hay s dng tip tc trong tin trnh nhn ging. Cn ch nhng c tnh sn xut v c im25

ngoi hnh ca ging th m ta mun chn lc. V d ging th nui hng tht ni chung hai mng phi n nang, hai thng tht bn ct sng cng phi n nang. bo m ng c im ngoi hnh, nn chn th vo lc 5 - 6 thng tui l tt nht v lc ny ngoi hnh th pht trin kh hon thin. u tin phi ch n con ci v con c khng b khuyt im b phn sinh dc, con c hai dch hon phi u, con ci phi c 8 v tr ln. Vic la c th nn bt u khong 21 ngy tui, khi kho st lc 70 ngy tui nu th khng t yu cu t ra th phi loi thi ngay. Lc th t 6 thng tui nu khng tiu chun th vn tip tc loi. Chung nht vic chn lc ging th thng thng c tin hnh cc thi im nh s sinh, 21, 30, 70, 90, 180 ngy tui. Th nn c cn tt c cc thi im, nu l giai on s sinh v 21 ngy tui th cn c ri tnh trng lng bnh qun. Lc 21 ngy tui nh s cc con t tiu chun trng lng bng cch bm tai v chn th da vo c im ngoi hnh 6 thng tui. Thnh tch v th trng th phi t tiu chun nh trng lng s sinh trung bnh l 50g th nhp ni, 35 gam i vi th a phng; lc 21 ngy tui 200gam i vi th a phng, 250 gam i vi th nhp ni; lc 30 ngy tui 500 gam i vi th nhp ni v 350 gam i vi th a phng. Mc tng trng hng ngy lc 70 ngy tui phi t t 25 - 30 gam/ngy giai on 21 ngy tui n 70 ngy tui. Nhng con t mc tng trng trn 30 gam/ ngy l xut sc. Trng lng xut chung lc 6 thng tui thng t 3 kg i vi th nhp ni, 2 n 2,5 kg i vi th a phng. Phng php chn lc ging th nu trn thng cho kt qu nhanh chng, n trc tip kim tra nng sut c th, nng sut anh em trong mt gia nh v h hng. Nhng kt qu tt p c pht huy qua s ghp i giao phi gia nhng con c thnh tch tt vi nhau. Th d: C 10 th c v 50 th ci cho ghp i giao phi, mi gia nh c 1 c v 5 ci. Th c nh s t s 1 n s 10 v gi l gia nh s 1 n s 10. Sau mt nm th sinh sn thu c kt qu nh sau:

26

Bng 2. Kt qu sinh sn ca 10 gia nh th Gia nh s 1 2 3 4 5 6 7 8 9 10 S la/nm S con s sinh/la 5 6 4 6 5 3 6 5 5 4 6 6 6 5 7 5 7 5 6 7 Trng lng/con (g) 50 55 50 50 60 45 55 35 50 44 Trng lng ton lc s sinh (g) 300 330 300 250 420 225 385 175 300 310

Qua s liu thu thp bng trn cho chng ta thy nhng gia nh th s 3, 4, 6, 10 khng c chn lm ging phi loi thi. Cc gia nh th s 1, 2, 5, 7, 9 c tip tc chn v cho sinh sn lm ging. n con ca cc gia nh th ny s c tip tc chn lc c th cht ch cc giai on sau.

2. Phng php nhn ging th a. Nhn ging thun Nhn ging thun chng l phng php nhn ging trong cng mt ging to ra th con c c im tnh trng di truyn n nh ca ging. N c p dng khi n th b m c xc nh c nng sut cao n nh. Do vy nhng c tnh chc chn c li v mt k thut v kinh t s c chn lc v pht huy. S n nh v di truyn ging s cao. - Nhn ging trong dng L cch nhn ging nhm to ra tng nhm th chn lc c tnh di truyn n nh v phm ging cao hn bnh thng. to ra n th c nhng u im c bit cn phi tin hnh chn i giao phi v chn lc con ging qua nhiu th h v c nhiu c th tham gia trong qu trnh to ging. Nu s con a vo chn lc qu t v thi gian ngn th kt qu s rt hn ch. Phng php ny cng dn n mt mc ng huyt27

nht nh. Nu nh s lng th tham gia di mc cho php s dn n ng huyt nng sut s km, s con cht s tng ln do hin tng ng hp t gen xu xut hin. Kinh nghim cho thy nu dng th c di 40 con v 200 con ci th khng th duy tr dng thun c. Nu nh duy tr dng thun trong cng tc ging th phi c s lng th c v ci nhiu hn th hoc l t nht l bng s lng trn. y l phng php c tm quan trng c bit trong s to ra dng th va c phm cht tt c ci thin va m bo s n nh cao v tim nng di truyn, tuy nhin c nhiu tn km v ti chnh loi b nhng th c kh nng lm tng s ng huyt trong n ging. - Nhn ging khc dng L s cho phi ging nhng con th khc dng vi nhau nhm hn ch bt s ng huyt xy ra, tuy nhin vn n nh c nhng tim nng di truyn tnh trng c li ch ca ging.Ta c th cho phi ging cho giao phi ch hai dng hay lin tc cho phi nhiu dng vi nhau vi dng khc hoc sau cho phi vi th dng c n nh hay b sung c tnh mi c hnh thnh. Thng thng phng php ny c th to ra nhng dng mi thch nghi c nhng iu kin nui dng hay kh hu nhng c s khc nhau. b. Lai ging L s phi ging ca nhng th c v th ci khc ging, nhm to ra con lai c cc tnh trng cn thit trung gian hay tt hn c b ln m n, do hin tng u th lai c to ra t cc d hp t. y c th l phng php ph bin nhm mc ch to ra th lm ging sn xut th thng phm hay to ra nhng ging mi. Tin trnh ny dng sn xut con lai c nng xut cao. Th c v th ci dng to ging mi thng l ging thun chng khc nhau mi c th cho kt qu cao. Chng ta c th lai ch hai ging hoc trn hai ging, cng c th sau khi to ra ging mi ta cn phi n nh cc tnh trng di truyn ca chng bng cc phng php nhn ging thun. c. Thc hnh phi ging Cn thit cho th phi ging hp l nht khi n thnh thc v tnh dc v th trng. bo m t l th thai cao v duy tr ni ging tt nn ghp i giao phi 1 th c vi 5 th ci (i vi c s ging th). Chng ta cng c th ghp 1 th c vi 10 th ci i vi cc c s nui thng phm. Khi cho th giao phi nn a con ci n chung con c, khng nn lm ngc li. Mi th ci nn cho phi 2 ln vi 1 th c cch nhau khong 4 - 6 gi c kt qu chc chn v s con c nhiu. Cng c th tin hnh giao phi bng cch hai ln vi 1 con c sau 5 n 10 pht. Phng php ny t tn thi gian nhng t l th thai thp hn 10%. i vi cc c s thng phm cng c th phi ging hai th c khc nhau v th con ra u dng lm th thng phm. Sau 10 ngy phi ging nn kim tra thai th nu khng c cha th cho phi li. Trong chung th nn nht th c v th ci vo cc ngn ring qui nh theo ghp i giao phi

28

S phi ging: c 1 c 2 c 3 c 4 ci 4 Ci 3 ci 2 Ci 1 Ci 4 Ci 3 Ci 2 Ci 1 ci 4 Ci 3 ci 2 Ci 1 ci 4 Ci 3 ci 2 Ci 1 ci 4 Ci 3 ci 2 Ci 1

Trong chung th tp trung cn chia n th thnh 4 nhm thun tin cho vic giao phi hp l v trnh ng huyt. Theo s trn nguyn tc i vi i con s sinh lun lun phi ly k hiu nhm ca con c trnh ng huyt. Theo nguyn tc sau: c nhm 1 X ci nhm 4 c nhm 2 X ci nhm 3

Th h con

1 v 1

Th h con

2 v 2

Vic ghi chp nh du bo m cho s liu chnh xc khi phi ging l iu rt c bn trong s sch ghi chp y ngy phi ging, s tai th m, s tai th cha s ngn chung th. Phi c phiu theo di th c v th ci ngoi ngn chung. Sau y l mu ni dung theo di: Biu mu theo di cng tc ging Ngy phi S hiu c S hiu ci Ngy S con s trng lng s sinh sinh Cn sng s con trng lng Ghi ch 30 30 ngy ngy tui tui

IV. CU HI N TP 1- Nu nhng c im v kh nng sn xut ca cc ging th ph bin Vit Nam 2- Trnh by cc phng php chn lc ging th 3- Trnh by phng php nhn ging v lai ging th 4- Hy ngh nh hng cho vic pht trin ging th Vit Nam.

29

V. TI LI U THAM KHO 1. Cheeke, P.R., 1987. Rabbit feeding and nutrition. Academic Press. INC. 1987. 2. inh Vn Bnh, Nguyn Quang Sc,1999. Nui Th v Ch Bin Sn Phm Gia nh. NXB Nng Nghip. 3. inh Vn Bnh, 2003. Ti liu k thut chn nui Th. NXB Nng Nghip. 4. F.A.O., 1988. Raising rabbit. better farming series. Rome 1988 5. Hong Th Xun Mai.2005.Th k thut chn nui.NXB Nng Nghip TP. H Ch Minh 6. Nguyn Chu Chng, 2003. Hi p v nui th. NXB Nng Nghip, H Ni 7. Nguyn Ngc Nam, Nguyn Quang Sc v Phm Th Nga, 1983. Nui th tht. NXB Nng Nghip, H Ni. 8. Nguyn Ngc Nam. 2002. Hng dn k thut chn nui th. NXB Lao ng X Hi 9. Nguyn Quang Sc & inh Vn Bnh (2000), Cm nang chn nui th, thng tin trang wed-Vin Chn Nui Vit Nam, http://www.vcn.vnn.vn/vcn 10. Nguyn Vn Thu, 2003. Gio trnh Chn nui Th. Khoa Nng Nghip, i Hc Cn Th. 11. Sandford, J.C., 1996. The domestic rabbit. Fifth edition. Oxford. 12. Trung tm Khuyn Nng Quc Gia, 2008. Cm nang nui th. http://www.nhabe. hochiminhcity.gov.vn/DetailNews.asp?ID=735 13. Trung Tm nghin cu D Th Sn Ty, 2002. Nui th gia nh. Nh xut bn nng nghip.

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CHNG 3: DINH DNG V THC N CA TH

Ti liu v nhu cu dinh dng ca th dng hng dn trong thc tin chn nui hin nay cn nhiu hn ch, do cc nghin cu v dinh dng th cn t, cng nh s bin ng v nhu cu dng cht ca cc ging th theo mc ch sn xut.

A. NHU CU DINH DNG I. Nhu cu nng lng Mt cch chung nht, nhu cu v nng lng i vi gia sc thng thay i theo t l nghch vi tm vc ca c th. Nu th cng nh con th nhu cu nng lng trn mt n v th trng cng cao. V d nh th l mt trong nhng loi ng vt c v c nhu cu nng lng tng i cao, so vi tru b n c nhu cu nng lng gp 3 ln. Nhu cu nng lng gm c 3 phn: a. Nhu cu c bn Nhu cu ny c th xc nh trong tnh trng th khng sn xut v hot ng trong 24 gi theo nghin cu ca Lee (1939) cc loi th c trng lng khc nhau: Bng 1. Nhu cu c bn ca Th Th trng (kg) Nhu cu c bn (Kcal) Th trng (kg) Nhu cu c bn (Kcal)

_______________________________________________________________________ 1,5 2,0 2,5 80 100 120 3,0 3,5 4,5 140 180 200

_______________________________________________________________________ b. Nhu cu duy tr c xc nh l nhu cu c bn v cng thm vi mt s nng lng cn thit nh n ung, tiu ho v nhng hot ng sinh l khc nhng khng sn xut. Nhu cu ny c th tnh bng cch nhn i nhu cu c bn, nn kt qu nh sau:

Bng 2. Nhu cu duy tr ca Th

31

Th trng (kg)

Nhu cu duy tr (Kcal)

Th trng (kg)

Nhu cu duy tr (Kcal)

_______________________________________________________________________ ______ 1,5 2,0 2,5 160 200 240 3,0 3,5 4,5 280 360 480

_______________________________________________________________________ ______

c. Nhu cu sn xut Nhu cu sn xut ca th thng bao gm: Nhu cu sinh sn, nhu cu sn xut sa v nhu cu tng trng - Nhu cu sinh sn: Nhu cu ny th cho c th c c th phi con ci v nhu cu th ci c mang. Mt s nghin cu ngh l nhu cu ca th c ging v th ci c mang chim khong t 5-10% nhu cu duy tr. Th ci c thai trong khong 30 ngy th . S ngy c mang c th tng hay gim cht t tu theo ging th hay s lng thai c mang trong c th. Trong 20 ngy u trng lng bo thai pht trin chm, sau trng lng thai tng rt nhanh trong 10 ngy cui. iu ny s cho thy l trng lng s sinh ca th ty thuc rt nhiu vo dng cht cung cp cho th m trong giai on ny, v lc ny nhu cu mang thai c th tng ln khong 30-40% nhu cu duy tr. - Nhu cu sn xut sa: Nhu cu ny ty thuc rt nhiu vo khu phn thc n. Lng sa trong 5 ngy u c th thay i khong 25g/ngy/con ci. Mc ch trong giai on ny l m bo cho th con tng trng tt v th m khng b gy m do nui con. Sn lng sa sn xut cao khong 35g/ngy/con ci thng t ngy 12 n ngy 25. Lng sa s gim nhanh sau khi sanh 30 ngy v chu k cho sa trung bnh ca th ci l 45 ngy. Cht lng ca khu phn ca th s nh hng ln n khng nhng sn lng m cn cho cht lng sa. Thnh phn ho hc sa ca th nh sau:

32

Bng 3. Thnh phn ho hc ca sa Th v cc loi GS n c khc _______________________________________________________________________ Nc m M ng Khong Ngun ti liu

(%) (%) (%) (%) (%) _______________________________________________________________________ Th 69,5 69,5 54,3 B D Cu Tru 87,3 86,9 82,2 88,3 15,5 12,0 8,5 3,40 3,80 5,20 4,40 10,4 13,5 22,8 3,70 4,10 7-10,0 11,9 1,95 2,0 1,40 4,90 4,60 5,20 4,40 2,50 2,50 3,0 0,70 0,80 0,71 1,0 Konig (1919) Moris (1930) Krause (1956) Moris (1936) Moris (1936) Thc (1963) Thu (1997)

Chng ta thy rng do nc t hn nn vt cht kh ca sa th cao hn cc loi sa khc, v t l m v bo cao hn mt cch r rt so vi sa ca loi gia sc n c khc. Trong lc t l ng sa (ch yu l lactose) th thp hn cc loi sa khc. Mt cch tng qut l dng cht ca sa th rt cao so vi cc loi sa khc, do vy thc n s c mt vai tr rt quan trng trong vic cung cp y v s v cht lng dinh dng cho th con. Trong trng hp thc n ngho nn th dn n th m d b gim trng v nh hng n kh nng sinh sn trong chu k sinh sn k tip v cng s nh hng khng nh n th trng ca th con v sc sng ca chng sau khi sinh ra. Theo Axelsson (1949) nhu cu v nng lng i vi th ci cho sa nu tnh theo % so vi nhu cu duy tr theo thi gian th kt qu nh sau: Tun l 1-2: 200% Tun l 3-4: 330% Tun l 5-6: 370% Tun l 7-8: 400%

Trong lc c tc gi th cho rng tun l 3-4 l 350% v 7-8 l 600%. Trong cc ngh trn cho thy l tun l th 3-4 nhu cu nng lng cc tc gi u tng cao r rt ph hp vi s sn xut sa gia tng. - Nhu cu tng trng: i vi th th cc ging c trng lng chnh lch nhau khi trng thnh do vy kh nng tng trng cng s rt khc nhau. S bin ng v33

trng lng trng thnh c th trong khong t 1 - 9 kg ty theo ging th. V d s l 1 kg i vi ging Dwaft v 9 kg i vi Flenishgeant. S thay i ny ch yu l do di truyn tuy nhin trong mt s trng hp yu t dinh dng cng gp phn vo . Khi gn t n th trng trng thnh th tc tng trng s chm li. Ty theo ging th m thi gian trng thnh v th trng khc nhau. Th d, ging th nh con c th trng 2,3 kg 210 ngy, v ging th ln con c th t 4,7 kg lc 322 ngy tui. Bng 4. Th trng v tc tng trng ca th Ta _______________________________________________________________________ Ngy tui Th trng (kg) Tng trng/ngy (gam)

_______________________________________________________________________ 0-14 14-30 30-45 45-60 60-75 75-90 90-105 105-120 120-135 135-150 150-165 165-180 180-195 195-210 210-225 225-240 240-450 60-225 225-400 400-700 700-1050 1050-1400 1400-1750 1750-2000 2000-2200 2200-2350 2350-2500 2500-2650 2650-2750 2750-2825 2825-2875 2875-2925 2925-2950 2950-3000 11,8 10,9 20,0 23,3 23,3 23,3 16,7 13,3 10,0 10,0 10,0 6,7 5,0 3,3 3,3 1,7 0,2

34

Bng 5. Th trng v tc tng trng ca th New Zealand _______________________________________________________________________ Tui Th trng (g) Tng trng (g/ngy)

_______________________________________________________________________ S sinh - 3 tun 3 tun - 8 tun 8 tun - 14 tun 14 tun- 20 tun 45,4 - 363,2 363,2 - 1816 1816 - 3268 3269 - 4086 15,1 41,5 33,2 16,5

_______________________________________________________________________

Nhu cu nng lng v tng trng c tnh theo tui: _______________________________________________________________________ Tun tui: kCal/g tng trng 8 3,9 10 4,7 12 5,5 14 6,3 16 7,2 18 7,9 20 8,7 22 9,5 24 10,3

Nng lng trao i trong khu phn khuyn co bi Lebas et al. (1986) th tng trng (4-12 tun) l 2400 kCal ME/kg, th mang thai l 2400 kCal ME/kg, th ang nui con l 2600 kCal ME/kg v th v bo 2410 kCal ME/kg. Cch tnh nng lng trao i ca thc n c ngh nh sau: ME (kCal/Kg) = 37 x %CP + 81x %EE + 35.5 x %NFE (Pauzenga, 1985 & Igwebuike et al., 2008) CP = Crude protein (m th) EE = Ether extract (chit cht Ether) NFE = Nitrogen-free extract

35

II. Nhu cu m v amino acid a. Nhu cu m Lng m trong khu phn c xem l quan trng v n m bo cc hot ng duy tr v sn xut ca th, tuy nhin cc nghin cu trn th ngoi nhp thun v th lai Vit Nam c nhng kt qu kh bin ng, mt s cc ti liu cho bit: - Th ci c thai 3kg c nhu cu hng ngy l 20g DP (m tiu ho). - Th nui con cn 30-35 g DP mi ngy. - Th c sinh sn hoc th ci kh c nhu cu 10-12 g DP/ngy Theo Lebas (1979) v Lang (1981) ghi nhn bi Lebas et al. (1986) nhu cu m trong khu phn phn theo loi sn xut nh sau th tng trng (4-12 tun tui) l 16%CP (m th), th ci mang thai l 16%CP, th ci cho sa nui con l 18%CP, th ci sinh sn v th v bo 17%CP. Cng theo Lebas et al. (1986) nhu cu m th tht trong khu phn t 15-16%CP (m th) v th ci sinh sn l t 17-18%CP cho d l c trng hp tng ln n 21%CP th nui con cho nhiu sa, tuy nhin iu ny khng c khuyn co do hiu qu kinh t v s con cai sa km. Tuy nhin theo ngh INRA (1989) ghi nhn bi Sandford (1996) th nhu cu m th trong khu phn l 15.5% cho th tng trng t 4-12 tun l, th ci trong giai on ln ging l 16% v th ci ang tit sa nui con l 18%. Trong cc nghin cu gn y i vi th lai BSCL th sinh sn l 15-18%CP ty theo cht lng ca ngun thc n m l ph phm (b u nnh, b bia, ) hay chnh phm (u nnh, thc n hn hp cng nghip), trong khi vi th tng trng l t 13-16% ty vo ngun thc n m (Nguyen Van Thu & Nguyen Thi Kim Dong, 2005, 2008 and 2009). Bng 6. H s tiu ho (%) mt s dng cht ca th _______________________________________________________________________ Loi thc n m th m tng s M th X th Khong

_______________________________________________________________________ Thc n th ging Thc n th v bo Thc n th hu b 81,14 79,4 74,06 79,46 76,6 72,06 84,11 80,46 87,03 28,41 30,86 37,9 52,88 44,93 31,75

_______________________________________________________________________ Ngun ti liu: Hungary (Nguyn Ngc Nam v ctv, 1983) b. Nhu cu amino acid Trong nhiu nm, cht lng protein khng c quan tm trong dinh dng th bi v c hin tng n phn. Tuy nhin, nhng bo co gn y cho thy phn mm ch36

chim khong 14% tng DM n vo v khong 17-18% protein n vo. V vy, mc d phn mm c gii thiu l ngun m cho th c phm cht tt v amino acid gii hn, nhng s lng ca chng khng m bo nhu cu trong khu phn v vy cn b sung ngun amino acid gii hn ny (Santoma et al., 1987). Cc nh nghin cu cho bit l th tng trng cn trong thc n cha 10 trong s 21 amino acid thit yu to nn protein ca th gm c arginine, histidine, leucine, isoleucine, lysine, phenylalanine vi tyrocine, methionine vi cystine, threonine, trytophane v valine (Lebas et al., 1986). Nhu cu v cc loi amino acid th sinh sn cng cn bng tng t nh l th tht (Lebas et al., 1986). Bng 7. Nhu cu amino acid (%) ca th Loi amino acid Spreadbur y (1978) Tng trng Methionin + cystine Lysin Arginnine Threonine Tryptophan Valine Leucine Isoleucine Histidine Phenylalanine + tyrosine Glysine DE (MJ/kg) 0,62 0,94 0,56 13 Colin (1988) Tng trng 0,62 0,68 0,69 10,25 Cho sa 0,8 0,73 0,88 10,67 AEC (1988) Tng trng (4-12 tun) 0,6 0,65 0,9 0,55 0,18 0,7 1,05 0,6 0,35 1,2 10,45 Cho sa 0,6 0,75 0,8 0,7 0,22 0,85 1,25 0,7 0,43 1,4 10,9 Th m nui con 0,6 0,7 0,9 0,6 0,2 0,8 1,2 0,65 0,4 1,25 10,45

Ngun: Santoma et al., 1987

37

III. Nhu cu cht x ca th Vic xc nh mc x ti u trong khu phn th l mt trong nhng mc tiu chnh ca vic nghin cu v dinh dng th. Th c cho n khu phn x thp th c nhng biu hin xo trn trong h thng tiu ha vi nhng biu hin nh tiu chy km vi t l cht cao. iu ny c th gii thch l do khu phn c mc x thp s ko di thi gian lu gi ca thc n trong h thng tiu ha (Hoover & Heitmann, 1972). Hn th na, khu phn x thp hn 12% s thay th cht cha trong manh trng s thp hn. Tnh trng ny dn n hai trng hp: s ln men khng mong mun trong manh trng v s gia tng ca nhng vi sinh vt gy bnh (Carabano et al., 1988). T c im sinh l tiu ha ca th ta thy thc n x th va l cht cha y d dy v manh trng va c tc dng chng i m bo sinh l tiu ha bnh thng. Cht x nh l ngun cung cp nng lng, tc ng tt n qu trnh ln men ca vi khun manh trng. Nhiu kt qu nghin cu cho thy: nu cho th n thc n ngho x (di 8%) th th s b tiu chy. Nhu cu ti thiu v x th l 12% trong khu phn n ca th. Hm lng x ph hp nht l 13-15%. Thc n ny s kch thch s hot ng ca ng tiu ha v nhu ng rut bnh thng. Nhng nu tng t l x th trn 16% th s gy cn tr tng trng v kh nng s dng thc n ca th. Ring th ging trng thnh c th s dng c khu phn n cha thnh phn x th cao hn (16-18%). Cung cp x th c th theo dng c, l xanh, kh hoc dng bt nghin nh 2-5mm trn vo thc n hn hp ng vin hoc dng bt (Nguyn Quang Sc & inh vn Bnh, 2000). BSCL cc nghin cu cho thy mc 38-42% x trung tnh (NDF, neutral detergent fiber) trong khu phn gm c lng Para v rau lang, v lng 25-35g x trung tnh/ngy/con i vi th ang tng trng c trng lng 1,3kg 1,5kg l thch hp cho s tiu ho v tng trng (Nguyen Thi Kim Dong and Nguyen Truong Giang, 2009).

IV. Nhu cu khong v vitamin Cc nhu cu khong v vitamin hin nay cc ti liu thng bo c nhng bin ng v khc bit nhau. Nhng nghin cu v nhu cu v calcium v phospho cho thy th tng trng cn t hn rt nhiu so vi th ci nui con. Th ci nui con chuyn 78g khong vo sa mt ngy. Bt k s mt cn i v Na, K, Cl c th gy ra vim thn v sinh kh. Khi bn rau c c hm lng cao K khi cho th n c th gy ra nhng ri ro (Lebas et al., 1986). Trong chn nui th rt cn thit phi cung cp vitamin c bit l th nui nht v c nng sut cao. i vi th sinh sn cn thit phi c cung cp vitamin A v E nu y th t l c th t 70-80%, nu thiu t l ny c th l 4050% v t l nui sng l 30-40%. C xanh, c rt, b v la ln mng l nhng ngun cung cp vitamin rt tt cho th. Th c th t tng hp vitamin nhm B trong h tiu ho. Ngi ta cng c th cung cp vitamin tng hp dng bt cho th vo trong thc n hn hp.

38

Bng 8. Khuyn co v vitamin trong khu phn thc n ca cc loi th Khu phn thc n gi nh cha 85% vt cht kh (DM) Vitamin A Vitamin D Vitamin E Vitamin K Vitamin C Vitamin B1 Vitamin B2 Vitamin B6 Vitamin B12 Folic acid Pantothenic acid Niacin Biotin UI/kg UI/kg ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm 6000 900 50 0 0 2 6 2 0.01 5 20 50 0.2 12000 900 50 2 0 0 n v tnh Th (4-12 tun) Th ci ang nui con Th ci cha khng nui con 12000 900 50 2 0 0 0 0 0 0 0 Th c trng thnh Th ci sinh sn v th v bo 10000 900 50 2 0 2 4 2 0.01 5 20 50 0.2

6000 900 50 0 0 0 0 0 0 0 0 -

Ngun: Lebas, 1979; Lang, 1981

V. Nhu cu nc ung Th nui trong chung s dng hai ngun nc t nc trong c xanh v nc ung cung cp. Nhu cu nc ph thuc vo nhit khng kh v hm lng vt cht kh trong thc n hng ngy. Nc cn tiu ha thc n v cc hot ng sng ca c th th. Ma h th n nhiu thc n th th cn lng nc gp ba ln so vi nhu cu bnh thng. Th c tm vc trung bnh th cn 0,4-0,6 lt/ngy (Sandford, 1996). Nhu cu nc ph thuc vo la tui v cc thi k sn xut khc nhau: - Th v bo - hu b ging: 0,2-0,5 lt/ngy - Th mang thai: 0,6-0,8 lt/ngy39

- Khi tit sa ti a: 0,8-1,5 lt/ngy Nu cho n thc n th xanh, c qu nhiu c b sung thc n tinh th lng nc thc vt p ng c 60%-80% nhu cu nc tng s. Nhng vn cn cho ung nc, th thiu nc nguy him hn thiu thc n. Th nhn kht n ngy th hai l b n. Trong thc t chn nui nu cho th lai n cc loi rau c c nhiu nc ngi ta khng cho ung nc th vn sng bnh thng, tuy nhin nn cho th c nc ung sn sng th th s tng trng v sc kho tt hn.

B. CC LOI THC N CHO TH I. Rau c Th c th n nhiu loi c trong iu kin BSCL cc loi rau c c th cho th n nh rau lang, rau mung, rau trai (Commelina palidusa), lc bnh (Eichhornia crassipes), bm bm (Operculina turpethum), a cc (Wedelia spp), v.v.., v cc loi c nh c lng ty (Brachiaria mutica), c l tre (Paspalum conpressum), c mm (Hymenache acutigluma), c ch (Cynodon dactylon), c s (Panicum maximum), c ng (Panicum repens), c voi (Penisetum purpureum), v.v.. Ch l nn ct c trc khi ra hoa v c ra hoa th cht lng gim i do dn xut khng m gim trong lc hm lng x v cc cht kh tiu ho tng ln nh lignin, cutin, silic, v.v Cn thit ht sc ch i vi: * C h thi * C t nn phi dn mng ra cho kh, khng nn cht thnh ng. iu ny c th to iu kin cho mt s vi khun ln men S lng c cho th n nhiu hay t cn ph thuc vo khu phn ca th c cho n thm thc n tinh hay khng, thng thng th ci n khong 1,0 - 1,5 kg/ngy.

C Lng ty

C Mm

40

Dy Bm bm

a cc

Lc bnh II. Cc loi h u v ph phm trng trt

Chun b Lc bnh cho th n

Mt s cc loi c h u nh stylo, clover, bnh linh (Leuceana lecocephala), so a (Sesbania grandiflora), in in (Sesbania sesban), c u l nh (Spophocarpus scandn), c u l ln (Macana pruriens), u Bng bic (Centrosema pubescens) v.v Cc loi c kh, l u kh v cc ph phm ch nh l ci, xu ho, rau m, c ci, c rt, v tri cy cng c th cho th n, ngay c cc loi rau c mi thm nh s, ta t, rau hng th cng n c. Bng 9. Thnh phn dng cht (%DM) ca mt s loi thc n dng trong chn nui th BSCL THC N Rau c t nhin C lng ty C mm C mn tru 18,5 15,0 22,5 89,9 89,5 92,0 9,5 11,8 13,641

DM

OM

CP

CF

EE

NFE

NDF

Ash

25,7 30,9 27,7

3,7 5,1 4,5

50,9 41,7 46,2

67,1 68,0 67,3

10,2 10,5 8,0

Rau mung a cc Bm bm Rau da Rau trai L du tm Cy ch Cy n C sa Rau dn Rau du Lc bnh Trichantera gigantica Rau c trng L dm bt Dm bt C voi C s C Ruzi Paspalum atratum C h u u l nh u l ln u Macro Ph phm trng trt Rau lang L bng ci

9,25 10,4 11,9 10,0 9,8 26,9 20,2 19,8 21,9 12,9 18,5 8,1 15,1

87,8 83,9 87,9 90,2 84,9 83,5 92,4 78,9 90,2 82,2 84,8 86,2 86,4

20,2 12,7 15,5 15,4 16,6 24,4 11,9 15,1 11,9 24,8 13,4 13,7 23,9

15,6 15,5 21,2 12,3 18,8 14,5 24,9 18,2 20,8 26,5 16,2 20,1 13,9

4,5 8,9 6,5 5,4 5,5 6,9 8,7 3,6 9,1 3,0 3,8 3,9 7,7

47,5 46,8 44,7 57,1 44,0 37,7 46,9 42,0 48,4 27,9 51,4 48,5 40,9

36,3 38,2 38,8 36,1 45,3 31,1 42,3 45,9 39,2 42,1 45,4 59,2 34,2

12,2 16,1 12,1 9,8 15,1 16,5 7,6 21,1 9,8 17,8 15,2 13,8 13,6

17,7 20,5 26,0 18,3 19,6 20,1

87,5 88,1 87,5 89,2 89,7 92,4

18,5 17,2 9,8 10,2 9,9 9,5

14,9 22,8 27,4 31,2 29,5 32,8

6,9 6,2 5,2 2,7 4,1 3,8

47,2 41,9 45,1 45,1 46,2 46,3

35,7 36,8 59,6 69,3 67,5 69,5

12,5 11,9 12,5 10,8 10,3 7,6

15,7 17,8 17,8

89,1 88,1 90,7

19,3 20,9 15,7

24,1 27,6 21,9

7,0 7,1 6,2

38,7 32,5 46,9

49,1 48,5 47,8

10,9 11,9 9,3

9,1 8,8

86,2 82,1

19,7 17,042

15,0 13,4

9,4 6,1

42,1 45,6

32,1 24,3

13,8 17,9

L bp ci Ci bc tho L rau mung

7,6 6,9 10,9

84,5 85,9 86,9

14,8 16,1 28,9

15,3 14,9 11,3

5,3 5,4 8,3

49,1 49,5 38,4

21,6 23,8 25,9

15,5 14,1 13,1

Thc n b sung nng lng v m La ht Tm Cm Thc n hn hp B bia Ht u nnh B u Nnh 88,4 84,2 87,9 89,8 19,8 92,5 10,5 95,2 97,8 89,9 80,0 95,9 92,8 96,3 7,4 9,2 12,3 19,6 24,5 45,1 16,6 10,6 1,1 7,4 4,6 16,3 10,1 17,2 1,8 2,4 11,3 5,9 10,5 18,1 10,0 75,4 85,1 58,9 45,9 44,6 19,5 52,5 26,4 3,4 26,7 29,1 21,7 32,3 47,6 4,8 2,2 10,1 20,0 4,1 7,2 3,7

Ngun: Nguyen Van Thu & Danh Mo (2009)

u Macana pruriens

u Spophocarpus scandn

43

u Bng bic

L rau Mung (cng lm da chua)

Qua vic tm hiu v thnh phn dng cht ca tng loi thc n ta thy: hu ht cc loi thc n trn u c thnh phn dng cht ph hp dng nui th. V CP ca cc loi thc n xanh th ngoi mt s loi c CP cao nh rau mung, l du tm, rau dn, Trichanteria gigantica, u l nh, u l ln, rau lang, l rau mung s dng rt tt khi cho th n m lng x cng ph hp vi th; c mm, c mn tru, c voi, c s, c Ruzi, c Paspalum atratum c hm lng NDF, CF cao v CP mc thp nn ch v t l tiu ha vi lng dng cht m th s dng c trong khu phn. V vy nn hn ch cc loi c ny trong khu phn mc hp l m bo s tn dng thc n ca th. Mt vi loi thc n c DM thp (lc bnh, ci bch tho, l bp ci, l bng ci, rau lang, rau mung, rau trai) nn ch khi s dng nn kt hp vi loi thc n c DM cao hn cn i s tip thu dng cht. Nhm thc n b sung m v nng lng: nu s dng dc nhm thc n ny khi nui th th rt tt v tin li. La, tm, cm, khoai c b sung nng lng rt tt cho th khi khu phn thiu nng lng. Cm, thc n hn hp, b bia, b u nnh l nhng loi thc n c CP cao b sung vo khu phn s tng lng CP ln khi cn thit l tt v tin li (Nguyen Van Thu & Danh Mo, 2008).. Bng 10. Kt qu tiu ho vt cht hu c in vitro (%OM) ca mt s thc n dng trong chn nui th bng cch s dng dch manh trng th Tn thc n Rau c t nhin a cc Bm bm Rau trai Cy ch Rau dn 52,7 52,3 53,1 62,3 70,044

Thi gian 0 gi 24 gi 48 gi 96 gi

65,8 68,1 65,0 65,9 78,4

72,4 72,3 73,3 72,4 80,7

73,5 72,8 77,3 76,1 85,2

Lc bnh C lng ty C mn tru Rau c trng L dm bt Dm bt C s C Ruzi C Paspalum atratum C h u u l nh u l ln Ph phm trng trt Rau lang L rau mung L bng ci L bp ci

51,8 23,1 29,2

52,0 40,4 45,6

56,1 49,4 50,6

58,4 53,5 57,5

65,3 66,7 29,5 31,4 29,0

90,2 86,8 32,1 38,4 34,1

91,8 87,2 36,7 42,1 37,6

91,7 88,0 39,0 43,8 41,8

50,4 53,7

64,8 62,9

69,4 70,6

71,2 72,2

57,8 68,7 58,1 50,9

68,0 82,2 70,8 71,1

88,2 85,8 74,0 89,0

90,6 91,4 77,6 91,0

Ngun: Danh Mo and Nguyen Van Thu, 2009 T kt qu ca bng trn ta thy Nhm thc n rau c t nhin: cc loi thc n u c t l tiu ho in vitro ln hn 50%. c bit rau dn c TLTH rt cao: 85,2%. a cc 73,5%, bm bm 72,8%, rau trai 77,3%, cy ch 76,1%, l TLTH cao. Cc thc n ny th tiu ho rt tt. Lc bnh 58,4%, c lng ty 53,5%, mn tru 57,5% l TLTH kh tt. Cc v bm bm tiu ha n 48 gi th ht do lc ny dng cht cn thit c s dng hu nh hon ton. Cc thc n cn li th tiu ha n 96 gi lc u t l tiu ha nhanh cng v sau TLTH chm li do dng cht cn thit c s dng cng lc cng gim dn. Cc cy c t nhin u c th lm thc n cho th, th tiu ha cc loi thc n ny kh tt (ln hn 50%OM) c bit l rau dn, a cc, bm bm, rau trai, cy ch . Nhm thc n rau c trng: l dm bt v dm bt t l tiu ha in vitro (TLTH) rt cao ln lt l 91,7%, 88,0%. L dm bt v dm bt tiu ha n 24 gi th hu nh khng cn tiu ha na do n lc 24 gi th dng cht cn thit c s dng ht. C s, c ruzi, c Paspalum atratum c t l tiu ho thp v tng ng nhau (nh hn45

50%): c s thp nht 39,0%, c Paspalum atratum 41,08%, c Ruzi 43,8%. Do x kh cao nn th kh tiu ho. TLTH n 96 gi lc u t l tiu ha nhanh cng v sau TLTH chm li do dng cht cn thit c s dng cn kit dn. Nn b sung dm bt v l dm bt vo khu phn n ca th l tt v t l tieu ha cao. Nhm thc n h u: c TLTH cao vi u l ln 72,2%, u l nh 71,2%. Cc thc n ny th tiu ho kh tt. TLTH n 96 gi lc u t l tiu ha nhanh cng v sau TLTH chm li do dng cht cn thit c s dng gim dn. Qua TLTH trn ta thy u l ln v u l nh tiu ha tt th v lng CP ca 2 thc n ny kh cao v vy s dng b sung vo trong khu phn n ca th l rt tt. Nhm ph phm trng trt: t l tiu ho rt cao (ln hn 90%) vi rau lang 90,6%, l rau mung 91,4%, l bp ci 91,0%, l bng ci tiu ho cao 77,6%. TLTH n 96 gi lc u t l tiu ha nhanh cng v sau TLTH chm li do dng cht cn thit c s dng gim dn. T 48 gi 96 gi TLTH hu nh khng ng k. Nhm thc n ny th tiu ho rt tt, nn tn dng cc ph phm trng trt ny lm thc n cho th l rt tt, Nhng ch vn cht lng ca ph phm v lng thuc bo v thc vt. TLTH vt cht hu c trong in vitro th hu ht cc thc n ny u tt. Cc thc n rau trai, dm bt, l dm bt, rau dn, ph phm trng trt TLTH l rt cao nn dng cc loi thc n ny d nui th l rt tt. Ngoi ra cc loi thc n khc (tr c s, c Ruzi, c Paspalum atratum) u c t l tiu ha ln hn 50% nn dng nui th c. u l nh, u l ln c t l tiu ha cao (72%), c hm lng CP, DM kh, NDF v CF mc trung bnh nn dng trong khu chn nui th l tt. Bng 11. Kt qu theo di lng sn xut kh (ml/gOM) in vitro ca mt s thc n dng nui th bng cch s dng dch manh trng th. Tn thc n Rau c t nhin a cc Bm bm Rau trai Cy ch Rau dn C lng ty L du tm C sa Cy n 155 128 46,3 76,3 90,1 81,9 124 106 31,0 232 183 97 121 127 125 177 150 69,546

Thi gian 12 gi 24 gi 48 gi 72 gi 96 gi

272 211 150 147 157 183 202 174 108

275 222 180 173 176 201 234 202 146

276 229 194 187 187 214 248 213 166

Rau da Rau mung Rau c trng C s C Ruzi C Paspalum atratum C h u u l nh u l ln u Macro Ph phm trng trt Rau lang L rau mung L bng ci L bp ci

68,2 143

93,2 184

120 208

149 215

161 218

52,1 57,9 59,3

60,2 69,8 63,2

68,2 75,0 74,8

74,2 77,0 85,8

78,2 81,0 89,7

101 124 105

144 180 151

186 215 176

198 223 206

215 233 220

155 176 172 222

194 230 214 264

220 258 227 274

229 266 234 288

239 271 238 298

Ngun: Danh Mo and Nguyen Van Thu, 2009350 300 V kh, m l/g O M 250 200 150 100 50 0 30.0 y = 3.29x - 28.18 R2 = 0.80

40.0

50.0

60.0

70.0

80.0

90.0

100.0

OMD, %

Biu . Mi quan h gia lng kh sinh ra (ml/gOM) vi t l tiu ha in vitro (%OMD)

47

Qua biu trn ta thy lng kh sinh ra (ml/gOM) c mi quan h cht ch vi t l tiu ha in vitro (%OMD) R2 = 0.80. Qua ta c th t lng kh sinh ra (%OMD) m bit c t l tiu ha (%OMD) v ngc li vi R2 = 0.80. Vic dng lng kh sinh ra dnh gi TLTH in vitro cn kh mi m v cn ang dc nghin cu nhiu. Tuy nhin gia chng c mi quan h vi nhau. TLTH tng theo thi gian lng kh sinh ra cng tng theo thi gian. TLTH v lng kh sinh ra ti mt thi im c quan h mt thit vi nhau. TLTH v lng kh sinh ra ti cc thi im ca mt loi thc n th khc nhau v khc nhau cc loi thc n khc nhau. Bng 12. Cc tham s ca phng trnh Orskov (1979) theo di lng kh sinh ra ca mt s loi thc n dng trn th. Tn thc n C lng ty a cc u l ln u l nh L bng ci L rau mung Rau lang Hm Orskov (a, b) Y = a + b (1-e-ct)x a 214,8 276,3 222,8 203,6 233,0 256,9 221,6 b 0,04 0,07 0,07 0,06 0,11 0,10 0,11 0,977 0,990 0,960 0,989 0,997 0,980 0,980 R2

T kt qu bng 9 ta thy hm Orskov l hm dng xc nh mi quan h gia lng kh sinh ra vi thi gian ph bin trn b. Tuy nhin khi s dng hm ny nh gi mi quan h gia lng kh sinh ra vi thi gian trn th cng chnh xc a cc vi R2 = 0,990, l bng ci vi R2 = 0,997, u l ln vi R2 =0,960, rau lang vi R2 = 0,980, c lng ty, u l nh, l rau mung vi R2 ln lt l 0,977, 0,989, 0,980. T chng ta c th s dng hm ny c lng th tch kh sinh ra theo thi gian. Lng kh sinh ra cng nhiu chng t dng cht c s dng cng cao. T kt qu phn tch thnh phn dng cht, theo di TLTH vt cht hu c v sinh kh trong in vitro nhn thy cc thc n trn c th dng nui th trin vng tt: Nhm rau c t nhin: c lng ty, rau mung, a cc, bm bm, Trichanteria gigantica, rau trai. Nhm c h u: u l nh v u l ln. Nhm ph phm trng trt: rau lang, l bng ci, l bp ci, ci bc tho, l rau mung. Nhm thc n b sung m v nng lng: tm, cm, la ht b sung nng lng trong khu phn rt tt v tin li; cm, thc n hn hp, b bia, b u nnh dng b sung m rt ph hp cho th.

48

III. Thc n tinh bt Gm c la, ng, khoai, sn,.. dng b sung thm cho th. Bp v la thng c ngm nc cho mn trc khi cho n. La mc mm cho n rt tt, thng la ngm t chiu ngy hm trc n chiu hm sau, ri tri ra mt nn c bng mt v sng hm k th ly la ny mm cho th n, ch no cha dng ti th c bao v ti nc mi ngy mt ln. Tuy nhin khng nn mm ln qu 1cm. Mm la c nhiu vitamin E, B1, B6, B2, PP v C. 1 kg la ngm 24 gi s cho 1,7kg v 48 gi s nng l 2,3 kg.

C Khoai lang IV. Thc n b sung m

La

Bt c, bt tht v cc loi bnh du (u nnh, da, bng vi, phng) cng c dng trn vo hn hp thc n cho th ty theo yu cu cht lng ca hn hp thc n. Vic b sung thc n hn hp tu thuc vo gi c thc n v gi bn tht hay th ging v gi thc n hn hp cao. Kinh nghim cho thy nu b sung thc n hn hp 20%CP cho th tht th mc 20-30g/ngy con tu giai on, trong lc th mang thai l khong 40g/ngy v th nui con l 60g/ngy trong iu kin khu phn c b sung thm l rau mung v b u nnh (Nguyen Thi Kim Dong & Nguyen Van Thu, 2008). Tuy nhin nu khu phn ch cho n c lng ty th thc n hn hp c th b sung tng ln n 100g/ngy th nui con (Nguyn Th Xun Linh, 2008). Cn thit cho n thm c kh vo ban m cho th gm nhm cng nh cung cp thm nc ung cho th. Cc loi b bia, b u nnh, b u xanh c th b sung m tt v tn dng c ngun dng cht vi gi r.

49

B bia

B u nnh

Thc n hn hp (dng vin)

V. Cch ch bin thc n cho th i vi thc n xanh thng c thu hoch lc cn non hay va phi nn khng cn phi ch bin g, tuy nhin nu qu di hay th th cn phi ct ngn 20-30 cm. Cc loi khoai, qu th st nh dy khong 5-8mm. Bp hay la ht th xay b hay xay nhuyn, tuy nhin la hay ht u cng c th cho n nguyn ht. Nu thc n dng bt th cn phi vy t nc trnh bi thc n bay vo mi th v cng trnh hao tn thc n. Cc dng thc n ht cng c th ngm nc v cho ny mm cho th n nh l bp, la v u. C xanh lc c nhiu c th thu hoch v lm c kh d tr, c phi kh c b li thnh tng bnh cht c 2 u ri gc ln sn cao cch mt t khong 1m. Vic phi hp thc n s lm tng khu v v tng kh nng tiu ho chng. Khng nn cho th n n iu mt loi c hay mt loi thc n tinh di ngy v nh vy s lm gim tnh thm n ca th, dn n lng thc n tiu th gim lm nh hng n nng sut tng trng v sinh sn ca chng.

50

C. CU HI N TP 1. Trnh by vai tr v nhu cu ca nng lng v m i vi th tht v th sinh sn. 2. Trnh by vai tr v nhu cu ca cht x, khong, vitamin v nc i vi th. 3. Nu mt s thc n ph bin c th chn nui th ti a phng ca anh ch v xut s pht trin ca chng.

D. TI LI U THAM KHO 1. Cheeke, P.R., 1987. Rabbit feeding and nutrition. Academic Press. INC. 1987. 2. inh Vn Bnh, Nguyn Quang Sc,1999. Nui Th v Ch Bin Sn Phm Gia nh. NXB Nng Nghip. 3. inh Vn Bnh, 2003. Ti liu k thut chn nui Th. NXB Nng Nghip. 4. F.A.O., 1986. The rabbit: Husbandry, health and production. Rome. 5. F.A.O., 1988. Raising rabbit. better farming series. Rome 1988 6. Hong Th Xun Mai.2005.Th k thut chn nui.NXB Nng Nghip TP. H Ch Minh 7. Nguyn Chu Chng, 2003. Hi p v nui th. NXB Nng Nghip, H Ni 8. Nguyn Ngc Nam, Nguyn Quang Sc v Phm Th Nga, 1983. Nui th tht. NXB Nng Nghip, H Ni. 9. Nguyn Ngc Nam. 2002. Hng dn k thut chn nui th. NXB Lao ng X Hi 10. Nguyn Quang Sc & inh Vn Bnh (2000), Cm nang chn nui th, thng tin trang wed-Vin Chn Nui Vit Nam, http://www.vcn.vnn.vn/vcn 11. Nguyen Quang Suc, Dinh Van Binh, Le Viet Ly and TR. Preston, 1994. Studies on the use of dried pressesed sugarcane stalk or peeled sugarcane stalk for rabbit. In proc. Of Natioanal Seminar-Workshop. Sustaianable Livestock production on local feed resources. Nov. 22-27, 1993 in Ho Chi Minh city. pp 53-56. 12. Nguyen Thi Kim Dong and Nguyen Thanh Van, 2009. Effect of different levels of cabbage waste (Brassica olerea) replacement in para grass (Brachiaria mutica) basal diet on growth performance and nutrient digestibility of crossbred rabbits in Mekong delta of Viet Nam. In proceedings of International Rabbit Workshop on Organic farming based on Forages at Cantho University, Vietnam. 25-27 Nov. 2008. http://www.mekarn.org/prorab/content.htm. 13. Nguyen Thi Kim Dong and Nguyen van Thu, 2006. Effect of supplement level of water spinach leaves in diets based on para grass on intake, nutrient utilization, growth rate and economic returns of crossbred rabbits in Mekong delta, Vietnam.51

MEKARN Proccedings of Workshop on Forages for Pigs and Rabbits Phnom Penh, Cambodia, 22-24 August 2006. Agricultural Publishing house Hanoi 14. Nguyen Thi Kim Dong and Nguyen van Thu, 2006. Effect of dietary protein supply on reproductive performance of crossbred rabbits. MEKARN Proccedings of Workshop on Forages for Pigs and Rabbits. Phnom Penh, Cambodia, 22-24 August 2006. Agricultural Publishing house Hanoi. 15. Nguyen Van Thu & Nguyen Thi Kim Dong, 2009. A study of associated fresh forages for feeding growing crossbred rabbits the Mekong delta of Vietnam. In proceedings of International Rabbit Workshop on Organic farming based on Forages at Cantho University, Vietnam. 25-27 Nov. 2008. http://www.mekarn.org/prorab/content.htm. 16. Nguyen Van Thu and Danh Mo, 2009. A study of nutritive values of forages as rabbit feed resources by using in vitro digestibility and gas production techniques. In proceedings of International Rabbit Workshop on Organic farming based on Forages at Cantho University, Vietnam. 25-27 Nov. 2008. http://www.mekarn.org/prorab/content.htm 17. Nguyen Van Thu and Nguyen Thi Kim Dong, 2005. Effect of replacement of different levels of paragrass (Brachiaria mutica) and sweet potato vines on feed utilization, growth rate and carcass quality of crossbred rabbit in the Mekong delta. BSAS Proceedings Khon Kaen, Thailand. Vol.2. T51. 18. Nguyen Van Thu and Nguyen Thi Kim Dong, 2008. Effect of psophocarpus scandens replacing para grass in the diets on feed utilization, growth rate and economic return of growing crossbred rabbits in the mekong delta in Vietnam. In Proc. of 9th World rabbit Congress. Verona, Italy. P 759-762. 19. Nguyen Van Thu and Nguyen Thi Kim Dong, 2008. Effect of water spinach and sweet potato vine associated with 2 other natural plants, on growth performance, carcass values and economic return of growing crossbred rabbits in the mekong delta of Vietnam. In Proc. of 9th World rabbit Congress. Verona, Italy. P 763-767. 20. Nguyn Vn Thu, 2003. Gio trnh Chn nui Th. Khoa Nng Nghip, i Hc Cn Th. 21. Sandford, J.C., 1996. The domestic rabbit. Fifth edition. Oxford. 22. Santoma G, J. C. De Blas, R. Carabano and M. J. Fraga (1987), Animal Production, (45), 291-300. 23. Trung tm Khuyn Nng Quc Gia, 2008. Cm nang nui th. http://www.nhabe. Hochiminhcity.gov.vn/DetailNews.asp?ID=735 24. Trung Tm nghin cu D Th Sn Ty, 2002. Nui th gia nh. Nh xut bn nng nghip. 25. Vit Chng.2003. Nui v kinh doanh th. NXB Tng Hp TP. H Ch Minh52

CHNG 4: CHUNG TRI

I. NHNG YU T CH KHI XY DNG CHUNG TRI TH Th l loi gia sc tng i chu ng c nhiu loi kh hu khc nhau. Tuy nhin th kh nhy cm vi mi trng sng. Chung tri nh hng n s thch nghi, nng sut v sc kho ca th, do vy khi xy dng tri th phi ch n cc c im sau: 1. Kh hu a. Nhit Nhit tt cho s sng ca th trong khong t 15-200C. Thng thng th th chu lnh tt hn l chu nng. Trnh nhng ni qu chnh lch gia ngy v m, gia thng lnh v thng nng. Nhit thp qu hay cao qu s lm thay i, dn n xo trn sinh l v bin dng cn bn, t s c tc ng xu n tng trng v sinh sn ca th cng nh l d nhim bnh do sc khng c th th b km. Ta c th to ra mt tiu kh hu trong chung th tt vi iu kin xy dng chung tri th vi vt liu v phng cch thch hp. b. Gi Th d cm ng vi nhng cn gi la, lm thay i kh hu trong chung, d dn n th b cm lnh v cht. V th lp tri th nn la nhng ni no trnh c hng gi c gi lung trc tip vo tri v d hng Ty Nam, Bc Tuy nhin tri rt cn thong kh, khng kh trong tri cn thit phi c trao i vi bn ngoi. c. nh sng nh sng nhiu qu s khng thch hp cho th, v th lp tri th nn la ni no c bng mt, nh di nhng bng cy to, c bit l nhng ni c c ma h qu nng. d. m m ph hp cho th c th nm trong khong t 60-90%. Th d b cm nhim vi iu kin m t, hay c nc thng xuyn. c bit ch trnh nhng ni qu m t, m ly, sng m, nht l nhng ni c nhiu mui.

2. V tr Cn thit phi ct ni cao ro, d thot nc, thun tin cho vic di chuyn ti lui, yn tnh, t c ngi, gia sc qua li v nn chn nhng ni t tng i thch hp cho vic trng cc loi cy thc n. Nu c nn chn nhng ni t mi cha nhim bnh tt.

53

II. NH NUI TH Nh nui th l nh m cc lng th c t trong . Nh c th c ct bng cc loi vt liu thun li v r tin ti ch v t dn nhit nhng ch cc yu cu sau: - Phi c trn nh cch nhit tt chng nng vo ma h, vch nh trnh c gi la vo ma lnh v ma tt vo. Cn phi c h thng ca ra vo hai u nh (Bc - Nam) v h thng ca s m bo nh thong, sng sa, kh ro. - Nn nh phi c h thng rnh thot phn v nc tiu hp l, d dng dn qut v sinh. Nn nn lm bng xi mng, phng v c dc thot nc d dng. - Mi nh nn lm bng vt liu khng dn nhit c th l l hay ngi, nu lm bng tole hay tole xi mng th phi c trn. -Vch nh c th lm bng tre, l, g hay gch, nn trnh lm bng tole hay thit v sn c th l g hoc tre. - Kch thc nh nui th ph thuc s th c nui v kch thc lng th b tr.

Hnh 1. Nh nui th Tnh Tin Giang

54

Hnh 2. Nh nui th Italy III. LNG TH C th lm bng tre, g, st thp. Kch thc lng th phi ph hp vi tm vc ca th, thng thng ta c th p dng nhng phng php xc nh kch thc ca lng th theo 3 chiu di, ngang, cao ca mi ngn lng nht th. + o chiu ngang ngn lng: t th trn 1 bn rng v ko di 2 chn sau ra, v o khong cch t mi th n cui hai chn sau, y l chiu rng ti thiu ca ngn lng. + o chiu di ca ngn lng: Cho th di chuyn (nhy), o khong cch ti a: gia chn sau khi th cha nhy v chn trc khi th phng ti. + o chiu cao ngn lng: Chiu cao va phi, cho th chm ln n c trn cao, tu th ln nh m c chiu cao ngn lng khc nhau, bnh qun l 60cm.

Hnh 3. Kiu lng th ca Italy

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Hnh 4. Lng c mng c di ng trn Lng th c th chia lm nhiu loi:

1. Lng nht ring tng con: Thng dng cho th c ging v th ci c thai hoc th ci cha phi. - Th to con: c din tch t 0,81m2 - 1,0m2/ con ( (0,9x0,9) (1x1m)) - Th trung bnh: 0,61 m2 - 0,80 m2 - Th nh con: 0,45m2 - 0,6 m2

2. Lng th ci nui con Phi m bo nui c mt th ci v 10 th con n khi cai sa. Mi th con kho ng 2dm2/con. * Ging th to con: 1,5 m2 * Ging th trung bnh 1,2 m2 * Ging th nh con 0,8 m2 Khi cai sa th th tch th ci v th c nui ring, n 4 thng th tch nui ring tng con.

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3. Lng th nui tht Kch thc lng th nn thay i theo s th nui trong mi ngn lng. Thng ngi ta tnh din tch cho 10 th tht, c chiu ngang 0,7m, chiu di 1,5m v chiu cao l 0,5 m. Khi ng lng th th cn thit cc lng phi ng nht nhau v kch thc tin vic b tr v sp xp trong nh nui th cng nh to ra v m quan. S lng nui th c tnh ton ty theo s pht trin s th trong tri v da theo s th hin ti. V d: 9 th ci v 1 th c cn s lng nh sau: - 9 lng th ci nui con - 5 lng th nht ring (3 cho th ci c mang thai, 1 cho th c v mt lng th cch ly (bnh tt hoc v sinh lng) * i vi th nh con: cao 0,6m, ngang 0,7m, chiu di c th thay i. * i vi th nht tng con: 0,6 x 0,7 x 0,8m (di) * i vi th ci nui con: 0,6 x 0,7 x 1,0m * i vi th tht 10 con: 0,6 x 0,7 x 1,5 m

4. Cc kiu lng: C th dng kiu lng: 1, 2 hay 3 tng, nu dng lng nhiu tng th tit kim c din tch. Tuy vy b tr sao cho s thao tc lm vic ca cng nhn c thun li, nu dng lng nhiu tng th phi c vt che gia, trnh th trn tiu, tiu xung tng di. a. Kiu lng 1 tng

0,6m

1,0m

0,7m

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b. Kiu lng 2 tng

0,6m

0,5m 0,5m

0,6m 0,45m

0,45m

c. Kiu lng 3 tng Kiu ny t c p dng trong nc v tng th 3 cao qu, cng nhn rt kh khn cho s chm sc v nui dng, v mt cu trc cng tng t nh cu trc lng 2 tng. Ngoi cc kiu lng nu trn cn c cc kiu lng khc nh kiu lng di ng, c th di chuyn lng i nhiu ni, thng c nui trong cc sn c v ch nui 1 s t th thi. Kiu lng c cng khing i hoc l lng treo bng kim loi.

Hnh 5. Kiu lng c mng c gia

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5. Vt liu lm lng Thng c th l g bo lng v sn dng c lu v tin cho v sinh chung, c th lm chung bng st v sn. Chung quanh lng thng ng li, kch thc cc l li cng quan trng i vi li lm nn lng, l qu to th th lt chn, cn qu nh th phn khng lt dn n phn ng thnh lp v mt v sinh. L li ny thng l 1,25 x 1,25 cm i vi th nh con, hoc 1,25 x 2cm cho th ln con. Ngoi ra c th lm vch lng bng nhng song st hay l g. Tuy nhin i vi song g th thng gm mn dn, v th sau mt thi gian phi thay.

6. Dng c trong lng Ni chung trong lng th c mt s dng c sau: mng c, mng thc n b sung mng ung v cho th ci.60cm

45cm

50cm 90cm

Mng Thc n b sung

Mng c

Hnh 6. Kch thc lng v b tr mng c v mng thc n b sung

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Hnh 7. B tr mng n v nc ung

a. Mng c: phn phi c cho th, mng c phi cao th khng th dm ln c n, trnh nhim bnh cu trng v nc tiu, phn dnh ln c lm cho c mau h. Mng thng b tr bn ngoi lng th khng li ko c ri trong lng. Bn trong phn nh vo lng phi c song theo khong cch thch hp (3-4cm), nu dng thanh st th ch 2 cm th ko c n. Mng c c th lm bng g, tre, hay cc thanh st. Chiu di mng ph thuc kch thc ca lng v s th nui. Kch thc t vch lng ra khong 20 cm, mng c t cch lng 10 cm v chiu cao c th t t 3-4 cm (tu chiu cao lng). b. Mng thc n b sung (TABS): i vi cc loi th nh th c ging, th ci mang thai, th v bo th cn phi b sung thc n dng thc n hn hp, la ny mm, bnh du, khong... Thng thng trong chn nui th cng nghip ta dng thc n vin (c th gm bt c v cc thnh phn khc), vic dng thc n vin c li l th c th gm nhm, trnh gy bnh nht l cu trng.

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c. Mng ung: Nhu cu nc i vi th l kh cao. Nu cho th n ton c xanh c th tho mn nhu cu nc. Nu nui bng thc n vin, th trong lng th phi c mng ung cung cp nc. Ngoi ra mng ung cn l phng tin cung cp thuc ung tr bnh hay nga nh l cu trng. C nhiu kiu mng ung thng ta t ch mng ung bng chai nc bin treo ln. d. : Trc khi th 3-4 ngy th vo lng cho th ci . c hnh dng nh ci hp, c kch thc tu theo tm vc th. y ca th nn d thot nc, trnh nc tiu ca th lm cho th con b cm lnh. Bng 1. Kch thc ca th _______________________________________________________________________ Loi th chiu cao chiu rng chiu di din tch

_______________________________________________________________________ - Nh con - Trung bnh - Ln con 25cm 30cm 35cm 25cm 30cm 30cm 35cm 40cm 45cm 885cm2 1200cm2 1350 cm2

_______________________________________________________________________ Trong tri th phi c hng ro cch ly hn ch xm nhp ca ngi l v cc loi gia sc khc trong tri trnh bnh truyn ly hay lm cn ph th hay lm h hi lng th. Phi b tr h tiu c trc khi vo tri th v gia cc ngn chung cng c h tiu c (vi bt). Chng ta cn thit phi v sinh lng th thng xuyn.

7. Kiu lng lin kt vi hang th Th l loi vt nht nht thch sng t nhin trong hang do vy Tin S A. Finzi (Italy), ngi gii thiu kiu 1 lng kt hp vi 1 hang ring bit (bng ciment hay t st nung) th sng mt m, m hnh ny c pht trin Chu u, c bit l cc nc Chu Phi c nhit ngoi tri nng. Lng th lin kt vi hang bng 1 ng thng bng t st nung, ciment hay nha. Th s c tp n, tiu tiu lng bn ngoi vi ngy u v sau quen vi iu kin sng trong hang. M hnh ny thng p dng cho th ci sinh sn.

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Hnh 7. Kiu Lng lin kt vi hang

IV. CU HI N TP 1. Nu vai tr quan trng ca chung tri i vi chn nui th. Gii thch l do ti sao? 2. Nhng yu cu ca nh nui th, nn lm nh nui th nh th no thch hp vi iu kin a phng? 3. Nu cc kiu lng th v nhng dng c cn thit ca lng th. Cch b tr cc dng c nh th no cho hp l?

V. TI LI U THAM KHO 1. Cheeke, P.R., 1987. Rabbit feeding and nutrition. Academic Press. INC. 1987. 2. inh Vn Bnh, Nguyn Quang Sc,1999. Nui Th v Ch Bin Sn Phm Gia nh. NXB Nng Nghip. 3. inh Vn Bnh, 2003. Ti liu k thut chn nui Th. NXB Nng Nghip. 4. F.A.O., 1988. Raising rabbit. better farming series. Rome 1988 5. Hong Th Xun Mai.2005.Th k thut chn nui.NXB Nng Nghip TP. H Ch Minh 6. Nguyn Chu Chng, 2003. Hi p v nui th. NXB Nng Nghip, H Ni 7. Nguyn Ngc Nam, Nguyn Quang Sc v Phm Th Nga, 1983. Nui th tht. NXB Nng Nghip, H Ni.62

8. Nguyn Ngc Nam. 2002. Hng dn k thut chn nui th. NXB Lao ng X Hi 9. Nguyn Quang Sc & inh Vn Bnh (2000), Cm nang chn nui th, thng tin trang wed-Vin Chn Nui Vit Nam, http://www.vcn.vnn.vn/vcn 10. Nguyen Van Thu and Nguyen Thi Kim Dong, 2008. Effect of pso