VIEN CHAN NUOI - Tap chi Khoa hoc Cong nghe Chan nuoi - S6 15-Thang 12-2008
Slf DUNG TRAU
DLTCGIONG NGOAI HINH TO NHAM CAI TAG
T A MVOC VA KHA NANG SINH TRUONG CUA DAN TRAU DIA PHUONG TAI
XA NGOC SON - THANH CHUONG - NGHE AN
•. , .'l . . - M . •. . 1 ! J | I
Mai van Sanh '*, Nguyen Cong Dinli' vci Trinh Vein Trung'
'Phong Dao Tao Va Thong tin - Vien Chan nuoi
Bo mon Di truyen - Giong vat nuoi uii.,'i 4 i l
*Tac gia lien he: Mai Van Sanh - - , - . : T Tel: (04)38.386.125/0912.585.495; Fax: (04).38 389.775; Email: [email protected]
ABSTRACT
Use of big size bulls to improve the body size and growth rate of local buffalo
in Ngoc Son - Thanh Chuong - Nghe An • , ! ; u''.') Eight Swamp buffalo bulls (4 big size and 4 local bulls) and 240 buffalo cows (120 selected and 120 non- selected) were used to evaluate the effects of bull size and selected buffalo cows on body weight and growth of calves. Experimental animals were allocated into 4 groups: 1- big size bulls and selected cows; 2 - big size bulls and non-selected cows; 3 - local bulls and selected cows and 4 - local bulls and non-selected cows (control group). Each bull was used to breed with 15 selected cows and 15 non-sclectcd cows.
Body weight of calves at 3, 6, 12, 24 and 36 months of age was highest in calves of group 1, following group 2 and group 3 and the lowest was found in control group. Body weight of calves in big size bull groups was higher than that of calves in local bull groups at all ages. Calves weight of big size bulls and selected cows group was 9 - 20% higher than calves in local bulls and non-selected cows group at all ages. The figures of body sizes were similar to that of body weight. It is concluded that use of big size bulls and selected buffalo cows are the good solution for improving body size and growth of calves.
Kay words: Big size bull, selected buffalo cows, birth weight, growth, body size. _' •'' •• ]y- -.u! •,-•,•'_.''
DAT VAN DE
Nudi trau la mot nghe truyen thdng cua nhan dan ta. Dieu kien sinh thai ciia nude nhiet ddi ndng am va nghe trdng lua nude la co sd de hinh thanh va phat trien quan the trau nude ta.
Con trau cd tam quan trgng dac biet trong nen san xuat ndng nghiep. la ngudn cung cap sire keo (cay biia va van chuyen d ndng thdn), cung cap lugng Ion phan hiru co cho trdng trot ddng thoi ddng gdp iiidt phan khdng nhd thit cho nhu cau con ngudi, ngoai ra nd cdn mot sd san pham phii nhu da, sirng. Idng cho che bien dd dimg gia dung va hang my nghe.
Trau ndi thich u'ng va phat trien tdt trong dieu kien sinh thai nude ta, nhung chiing cd nhugc diem la tam voc nhd. sinh trudng cham, thanh thuc mugn, khoang each lira de dai, kha nang cho thit thap. Nhirng nam qua, do cdng tac gidng trau ciia ta chua tdt dan den dan trau dang cd hien lugng ddng huyet va bi chgn Igc ngugc do trau to bi ban di giet thit, trau nhd dugc giir lai cho cay keo ddng thoi lam gidng ludn va dan trau cai thi khdng dugc chgn Igc. Nhieu noi tam vdc dan trau da cd chieu huong giam siit.
Theo nhieu nghien cim cho thay tam vdc trau Viet Nam cd the dugc chia lam 3 loai hinh la trau tam vdc to (trau Ngo) cd khdi lugng 450-500kg (due), 400-450kg (cai); trau tam vdc trung binh cd khdi lugng 400-450kg (due), 350-400kg (cai) va trau tam vdc nhd (trau Gie) khdi lugng 350-400kg (due), 300-350kg (cai). Ciing qua cac nghien ciru ve trau loai hinh to, Nguyen Diic Thac (1983) de xuat sir dung trau due ngoai hinh to lam gidng se gdp phan cai tao tam vdc \'a kha nang san xuat ciia trau ngoai hinh nhd cac dia phuong. Xuat phat tir thuc tien tren chiing tdi tien hanh de tai: "Sii' dung trau due giong ngoai hinh to ndng cao tam voc vd kha ndng sinh trwd'ng ciia dan trau dia phuong tai xd Ngoc Son - Thanh Chuong - Nghe An".
MAI V A N S A N H - Sir dung trau dice giong ngoai hinh to
VAT LIEU VA PHLf^ONG PHAP NGHIEN CUU Noi dung nghien ciiu
Dieu tra. daiili gia chat lugng dan trau tai diem nghien cim. tuy^n chgn trau due gidng ngoai hinh to lam gidng. Theo ddi khdi lugng va kha nang sinh trudng dan nghe sinh ra qua cac nidc tudi.
Phuong phap nghien ciiu I'htnni}.^ phup dieu tra
Dieu ira chat lugng va tuyen chgn dan trau dia phuang: can khdi lugng trau bang can dien tu.
do mgt sd chieu do chinh cua trau (VN. DTC. CV) bang thudc da\'. thudc ga\. Phong vdn ndng dan ve tinh hinh sinh san. nudi duong dan trau bang cac bd cau hoi da chuan bi trudc.
Fhirong phc'tp thi nghiem
Chgn Igc dan trau cai: chgn nhirng trau cai sinh san cd khdi lugng truang thanh tren trung binh cua dan, tudi de lira dau va khoang each hai lira de tir trung binh tro Ien.Tuyen trau due ngd til' Tuyen Quang cd du lieu chuan cua trau due gidng (5-6 tudi. dep \4 ngoai hinh, da cd nghe sinh ra), khdi lugng co the binh quan 528 kg. Dan trau due dia phuang cung chgn nhirng con tdt nhat trong dan theo tieu chuan tren va cd khdi lugng trung binh la 400 kg de dua vao thi nghiem. Thi nghiem dugc tien hanh vdi hai yeu id anh huong la trau due \a trau cai o hai mirc do khac nhau la chgn va khdng chgn, cac Id TN dugc bd tri nhu sau:
Ld TN 1: trau due Ngd vdi trau cai da chgn Ld TN 2: trau dire Ngd vdi trau cai dai tra Ld TN 3: trau due dai tra vdi trau cai da chgn Ld ddi chii'ng: trau due dai Irii vdi trau cai dai tra
Tong sd trau thi nghiem la 8 trau due gidng (trong dd cd 4 trau due ngd ngoai hinh to \'a 4 trau due dai tra), va 240 trau cai sinh .san. Mdi trau due se cho phdi vdi 15 trau cai chgn loc va 15 trau cai dai tra. Trau due gidng va trau cai dugc danli sd, cd sd theo ddi tirng nhdni, timg Id. Khi trau cai dgng due dugc phdi gidng va giir tai iilia den khi bet ddng due. Trau thi nghitMii dugc nudi dudiig theo dieu kien ciia dan la chan tha ket hgp bd sung thirc an lai chudng vao ban dem.
Trau nghe thi nghiem deu dugc tiem phong dinh ky, nghe sinh ra dugc lay giun theo quy trinh cua thii y. Nghe dugc theo me tu bii den khi tu cai sira. Theo ddi kha nang sinh truong phat trien cua dan nghe smh ra sau chgn Igc: can khdi lugng va do kich thudc co the o cac moc tudi so sinh, 3. 6, 12, 24 va 36 thang tudi bang can dien tir va thudc day, thudc gay.
Phuong phap xii' ly so lieu
So lieu dugc xir ly thdng ke sinh vat hgc bang chuong trinh Excel va Minitab.
KET QUA VA THAO LUAN Dieu tra danh gia chat luong dan trau
Hien Intng clan Iran Irifc'rc ihi nghiem
KCn qua di^u tra dan trau tai xa Nggc Son huyen Thanh Chuong tinh Nghe An nhu sau: Tir 402 trau cai va 59 con trau due d cac lira tudi nudi trong 350 hd dugc dieu tra cho thay ly le de thSp, tudi de lira dSu cao trung binh tren 4,5 tudi (cao nhat la 72 thang, thap nhat la 36 thang). Dan trau a day cd khdi lugng trung binh dugc the hien qua Bang 1
VIEN CHAN NUOI - Tap chi Khoa hoc Cong nghe Chan nuoi - S6 15-Thdng 12-2008 Cd the thay rang khdi lugng trau dja phuong la loai trau cd khdi lugng co the thap. thudc loai hinh nhd (thuong ggi la trau Gie). Mac dii dan trau d day van tang deu qua cac nam nhung trau cai khdng dugc chgn Igc, trau due giir lai tir trong dan sinh ra qua nhieu ddfi. trau due gidng vira cd tam vdc be vira khdng cd su hoan ddi vi vay cd the xay ra hien tugng ddng huyet trong dan: trau due liic 12 thang dat 135,5 kg trau cai 130.5 kg; liic 24 thang cd khdi lugng d trau due 218 kg. con cai 204 kg; trau due trudng thanh chi dat 353 kg cdn trau cai dat 327 kg.
Bang 1. Khdi lugng dan trau trudc thi nghiem Tudi (thang)
6 12 24 36 48 60 tro Ien
n 15
9 6 6 15
8
Trau due
(Mean ±SD) 80,14 ± 12,25
135,50 ±9,78
• 218.43 ±11,36 298,12 ± 13,46 330,50 ±25,51 353,27 ±35,87
n 26 59 48 64 52 153
Trau cai (Mean±SD) 78,35 ± 19,27 130,50± 11.15 204.22 ± 23,33 271,09 ± 10,29 305,14 ± 14,25 327,89 ±25,43 Theo Vii Duy Giang va cs, (1999) cho biet trau Sdc Son cd khdi lugng luc 12 thang tudi a e o n due la 147 kg va con cai la 140 kg; khi d 24 thang tuong tu la 234 kg va 183 kg, cdn trau d Ham Yen liic trudng thanh d con due va con cai la 397 kg ; 378 kg. Nhu vay dan trau cua Nggc Son cd tam vdc nhd hon.
Qua dieu tra ta thay khdi lugng co the trau cai chgn Igc binh quan la 366,5 kg va dan dai tra binh quan la 329,4 kg. Da dua 4 trau due gidng cd khdi lugng co the trung binh 580 kg (nhd nhat 552 kg, Idn nhat 628 kg) tir Chiem Hoa, Tuyen Quang chuyen ve diem nghien cim.
Qui ino vd tap qucin chan nuoi trau a Ngoc San
Qui iiid chan nudi trau: qua dieu tra chiing tdi thay 100% sd trau dugc nudi trong cac hd gia dinh ndng dan san xuat nhd. Trau d day dugc nudi chu yeu theo phuang thirc chan tha tan dung, cdng viec cham sdc hau nhu chua dugc quan tam. chinh vi le dd ma chan nudi trau d day chua mang lai hieu qua cho ngudi dan. mac dii day la viing cd nhieu bai chan tha. Theo sd lieu dieu tra trong 350 hd ndng dan ciia xa Nggc Son chiing tdi thay chan nudi trau chii yeu la lay sire keo va ket hgp voi sinh san nen cd den 283 hd nudi 1 trau chiem 80,85% nudi 1 trau va sd hd nudi 2 trau chieni 19,15%.
Tap quan chan nudi trau d day do dieu kien tu nhien. dieu kien sinh thai nen phuong thiic chan nudi Irau chii yeu la chan nudi quang canh. tan dung ngudn thirc an tu nhien, chua biet su dung, che bien phe phu pham lam thirc an cd gia tri.
Khoi luong va kha nang sinh truffng cua dan nghe qua cac moc tuoi ' Khoi liamg (kg) cua dan nghe thi nghiem
Khdi lugng co the la nidt trong nhirng chi tieu quan trgng de danh gia su sinh trudrng va phat due, ddng thoi nd cung bieu hien kha nang san xuat ciia chiing. Qua khdi lugng co the se phan anh dugc tdc do sinh trudng ciia gia sue d timg giai doan khac nhau.
Qua kcl qua d Bang 2 tren ta thay, khdi lugng ciia nghe due so sinh d Id 1 la 25,3 kg, d Id 2 la 24,8 kg va d Id 3 la 22,7 kg cdn d Id ddi chimg la 21,1 kg, sir sai khac nay cd y nghTa thdng ke (p < 0.05). Tuong tu nhu vay khdi lugng nghe o cac nidc tudi deu cd xu hudng tang dan: thap nhat la Id ddi chimg. tiSp dd den Id thi nghiem 3. Id thi nghiem 2 va cao nhat la nghe a Id thi
MAI V A N S A N H - Sir dung trau dire giong ngoai hinh to ...
nghiem 1 (trau due gidng ngoai hinh to ghep phdi vdi trau cai dugc tuyen trgn). So vdi khoi lugng dan trau 6\cu tra trudc khi thi nghiem thi khdi lugng nghe cua cac Id thi nghiem va doi chimg deu cao hon. Dd la do ba con ndng dan da cd y thirc hon trong viec lira trgn va cho trau cai phdi vdi trau due gidng tdt. ngoai hinh to. Ben canh dd cac hd chan nudi trau d^u dugc tham gia cac Idp tap huan ve ky thuat chan nudi trau nen da ap dung ky thuat chan nudi trau va cac phuong phap che bien du trii: thirc an miia ddng. Vi vay, da lam giam dang ke cac anh huong ciia ngoai canh va khdi lugng dan nghe dugc cai thien rd ret.
Bang 2: Khdi lugng nghe tir so sinh den 36 thang tudi Tuoi va
tinh biet nghe Sa sinh
+ due + cai 3 thang
+ dire + cai 6 thang
+ dire + cai 12 thdng + due + cai 24thdng + due I- cai 36thang
+ due + cai
n 40 50 40 50 40 50 36 46 32 41 20 26
L6TN1 (Mcan±SD)
25,3" ±3,1 2 4 , 7 " ! 1,9 6 1 , r ± 3 , 3 58,9' ± 3.8 89,2" ± 4,7 87,7" ±5,9 155,4" ±9,8 152,1" ±9,5 257,1" ±9,5 252,7" ±7,1 319,1"± 12,4 3 12,4" ± 11,2
n 34 53 34 53 34 53 31 51 24 40 14 22
Lo TN2 (Mcan±SD)
24,8" ± 1,8 23,9" ± 1,6 59,1" ±4,9 57,6" ±5,4 87,1" ±5,7 85,3" ±5,3 150,5"'±9,8 149,5"'±10,1
250,6" ± 11,2 247,5"''± 10,2 312,4"± 10,8 307,5"''± 13,4
n 24 21 24 21 24 21 24 21 24 20 14 17
L6TN3 (Mcan±SD)
22,7''± 1,6 2 1 , 6 ' ± 2 , 1 53,3'±2,1 5 1 , 6 ' ± 3 , 2 82,2' ± 4,0 8 0 , 7 ' ± 3 , 9 144,5'^ ±9,4 142,3''-± 8,1 240,7' ± 9,8
236,6''±9,l 299,6'± 13,4 295,7''±14,7
n 20 22 20 22 20 20 20 20 19 20 II 16
L6DC (Mcan±SD)
21,1'±2,3 20,4'± 1,8 52,6'±3,2 4 9 , 1 ' ± 4 , 0 79,8'±3,3 78,4'±3,6 140,3'± 7,8 1.37,2'±8,7 234,4' ± 9,3 229,6'±8,1 291, l'± 13.7 287,8'± 12,2 Mai van Sanh va cs, (1995). di^u tra trau d Binh Son. Thai Nguyen cho thay khdi lugng trau viing nay thip, trau due truong thanh 326 kg, trau cai trudaig thanh 312 kg. Vu Duy Giang va cs. (1999) diiim tra danh gia linh hinh phat trien dan trau mien Bac thay rang khdi lugng dan trau cua nhiau dia phuong d 2 nam tudi trau due chi dat 234 kg. trau cai 183 kg. Sd lieu khao sat cua Ha Phiic Mich. (1985) la khdi lugng nghe so sinh la 21 kg, liic 6 thang la 79,5 kg va 12 thang la
132 kg chi tuong duong vdi khdi lugng nghe d Id dai tra va thap hon cac Id thi nghiem.
Mai van Sanh. (2005) cho biet, sir dung trau due gidng ngoai hinh to lam gidng cho phdi vdi trau cai dia phuong d xa Van Hoa, Ba Vi, Ha Tay da cho kk qua nghe so sinh due dat 24,2 kg va nghe cai dat 23.3 kg; 24 thang tudi nghe due dat 254,8 kg, nghe cai dat 248,4 kg. Neu so voi cac sd lieu tren thi khdi lugng nghe thi nghiem or Nggc Son cd phan cao ban.
Tdc do sinh truang va khoi lugng tich luy la nhirng chi tieu quan trgng de danh gia chat lugng gidng va dieu kien chain sdc nudi duong.
Nhin vao kk qua Bang 3 ta thSy. kha nang tang khdi lugng ciia nghe giam dan theo tudi, d giai doan so sinh d^n 12 thang tudi la cao nhat (tang trgng tuyet ddi o Id TNI la 361,3 g/ngay.
Id TN2 349,1, Id TN3 338,7 so vdi Id DC la 330,9 g/ngay)
VIEN CHAN NUOI - Tap chi Khoa hoc Cong nghe Chan 111,61 - S6 15-Thang 12-2008
Thang tuoi
Bang 3: Tang trgng ciia nghe qua cac nidc tudi (g/con/ngay) Tang trong cua nghe (g/con/ngay)
L6TN1 L6TN2 Lo TN3 L 6 D C
SS 1 2 - 2 4
S S - 2 4 2 4 - 3 6 S S - 3 6
Due Cai Due
Cai Due Cai Due Cai Due Cai
361,3 354,1 282,3 279,4 321,8 316.7 172,4 167,6 272,0 266,4
349,1 348,8 278.0 272.2 313,5 310,5 171,8 166,5 266,3 262,5
338,7 335,4 267,1 261,9 302,9 298,6 167,5 164,6 256,3 258,2
330,9 324.6 261,2 256,5 296,1 290,5 157,6 161,9 249,9 247,7
)uri
Kich ihit'&c mot so chieu do ca the ciia nghe thi nghiem
Bang 4: Kich thudc mot sd chieu do cua nghe thi nghiem ^>\\.-J\\
Tinh biet va tuoi nghe
(thang)
L6TN1
n (Mcan±SD) r
L6TN2
1. (Meaii±SD)
L 6 T N 3
n (Mean±SD)
L6DC
n (Mean±SD Cao vay
So Dire 40 63,8 ±2,1 sinh Cai 50 63,3 ± 1,8
12 Due 36 97,5 ± 3 , 0 thang Cai 46 96,9 ± 2,9 24 Due 32 11 1,5 ± 3 , 3 thang Cai 41 111,1 ± 2 , 9 36 Due 20 119,3 ± 2 , 7 ihang Cai 26 118,5 ± 3 , 0
34 63,5 ± 2 , 9 53 62,9 ± 3 , 3 31 96,8 ±2,1 51 96,6 ± 2 , 6 24 109,9 ±3,4 40 109,3 ±2,3 14 119,1 ±2,9 22 117,3 ±3,1
24 6 0 , 9 + 1 , 6 21 59,2 ±2,1 24 95,8 ± 2,2 21 94,6 ±2,1 24 109,2 ± 3 , 9 20 108,1 ± 2 , 9 14 118,9 ± 2 , 3 17 116,9±3,7
20 58,2 ±2,3 22 57,9 ±1,9 20 95,5+1,1 20 93,9 ±2.4
19 108,3 ±2,3 20 107,6 ±3,0 11 116,1 ±2,3 16 115,3 ±3,1 Vong nguc
So- Due 40 68,9 ± 4 , 4 sinh Cai 50 68,6 ± 3 , 2 12 Du-c 36 130,8 ± 4 , 7 thang Cai 46 128,5 ±5,1 24 Due 32 158,2 ± 3 , 2 thang Cai 41 157,5 ± 4 , 0 36 Due 20 172,4 ±3,5 thang Cai 26 170,9 ± 3 , 0
34 67,0 ±3,5 53 66,6 ± 4 , 8 31 129,9 ± 4 , 5 51 127,8x5,9 24 156,9 ± 5 , 3 40 156,0 ±4,7
14 171,6±4,4 22 170,8 ± 5 , 4
24 67,6 ± 5 , 3 21 65,3 ± 3 , 7 24 127,9 ± 5 , 0 21 125,0±5,1 24 152,9 ±4,1 20 151,5 ± 4 , 8 14 169,4 ± 4 , 8 17 168,3 ± 5 , 3
20 65,2 ±5,8 22 64,6 ±3,2 20 125,3 ±4,3 20 123,1 ±4,6 19 151,5 ±6,4 20 150,7 ±4,2 11 169,2 ±3,1 16 167,6±4,1 Dai than cheo
So Due 40 55,1 ± 3 , 3 smh Cai 50 54,2 ± 2,8 12 Due 36 97,3 ± 3 , 3 thang Ciu 46 96,7 ± 2.4 24 Due 32 123,6 ± 2 , 7 thang Cai 41 123,1 ±3,1 36 Due 20 132,2 ± 3 , 9 Ihimg Cai 26 131,6 ±4,1
34 54,5 ±3,1 53 53,8 ± 2 , 6 31 96,1 ± 3 , 0 51 95,5 ± 3 , 8 24 123.1 ± 3 , 2 40 122,5 ± 3 , 5
14 131,8±4,2 22 130,1 ±4,5
24 54,2 + 3,1 21 52,8 + 3,2 24 94,0 ±3,1 21 93,6 ± 4 , 0 24 122,5 ± 3 , 5 20 120,3 + 3,4 14 130,6 ± 3 , 4 17 129,4 ± 3 , 8
20 53,9 ±4,2 22 52,7 ±3,1 20 93.8 ±1,7 20 92,9 ± 2,0
19 121,7±4,2 20 120,0 ±3,2
11 129,9 ±5,5 16 126,8 ±4,8
eia MAI VAN S.ANH - Su dung trau dire gi'ing nguai hinh to ...
Ciing voi khdi lugng co the. kich thudc cac chiki do cung gdp phin the hien tim vdc ciia ..„
sue. Kich thudc cac chieu do cd lien quan chat che ddn hudng san xuat ciia gia siic. su bFc-n linen cac chieu do la mot trong nhirng chi lieu danh gia sir phat trien ciia gia siic.
Tam vdc cua gia siic dugc the hien qua khdi lugng co th^ va kich thudc cac chilu do. Khdi lugng CO the ludn ludn cd tuong quan thuan vdi kich thudc cac chieu do co the. Khi kich thudc CO the tang^thi khdi lugng tang. Trong trudng hgp the trang binh thuong thi khdi lugng gia siic die hien tam vdc. Tuy nhien, d liing giai doan sinh truong cua gia siic non kich thudc cac chieu do co the tang nhung khdi lugng tang khdng theo ty le cua kich thudc. do la giai doan phat trien xuong. con khi gia sue gia thi cd xu hudng ngugc lai, khdi lugng cd the tang nhung kich thudc khdng lang theo ly le do chu veu la tich luy iiio.
Cling cd ket qua tuong tu nhu khdi lugng cua nghe. cac chii^u do cao va>'. vdng nguc \a dai than cheo cua nghe so sinh, 12, 24 va 36 thang tudi cung cao nhat a Id trau due is'gd ngoai hinh to phdi vdi trau cai dugc chgn Igc, ti§p theo la nghe cua Id trau due ngoai hinh to phdi vdi trau cai dai tra, rdi den nghe cua Id trau due dai tra phdi vdi trau cai chgn Igc va cudi ciing thap nhat la nghe ciia Id trau due dai tra phdi \ di trau cai dai tra.
Trong thi nghiem nay, kich thudc cac chi^u do co th8 nghe a tdt ca cac Id dugc theo ddi tir so sinh den 36 thang tudi, ket hgp vdi khdi lugng co the tha> rang nghe phat trien theo qu\ luat sinh truong gia siic ndi chung. dd la quy luat phat trien khdng ddng diSu giira cac giai doan.
nghe phat trien manh nhat a thoi ky mdi sinh, sau dd giam din, tuong tu nhu nhung kk qua thu dugc cua Nguyen Dire Thac (1983), Le Dang Danh va cs (1995) tren trau ndi. cua Mai Van Sanh (1996) tren trim Murrah va trau lai Fl.
Qua kich thudc 3 chieu do chinh la: Cao vay, vdng nguc. dai than cheo ta thdy khi so sinh vong nguc la vdng Idn nhat. den liic 36 thang tudi trai tu nay cung van khdng thay ddi. Nhung tdc do phat trien ciia cac chieu do la khac nhau. Ciing vdi su Uing Ien ve the \dc \a khdi lugng qua cac lira tudi la thay chieu cao vay cua trau due ludn cao hon Iriiu cai cimg luoi. Chieu dai than cheo ndi Icn sir phiit Iricn ciia he xuong true (xirong song), cimg vdi su phat trien cua cao vay chieu din than cheo nd lien quan dial che den sir tang trgng cua triiu. Vdng nguc la chi lieu phan anh sir phiil Iricn chu \ i cua trau \'a no cd luong quan chat che den khdi lugng cua trau. qua bang tren ta thay nhung Irat lu tren cimg khdng lha\ ddi. chimg to trau o viing Nggc Son phat trien co the hoan loan theo qui luiil sinh truang cua trau.
Khoi luang nghe cua cc'ic 16 ihi nghiem so vai nghe 16 d6i chiing (%J
Bang 5: Khdi lugng nghe ciia cac Id thi nghiem so vdi nghe Id ddi chimg (%)
Tudi nghe Ld TN 1 Ld TN2 Ld TN3 Ld ddi chirng
Nghe due So sinh
3 thang 6 thang 12 thang 24 thang 36 thang So sinh 3 thang 6 thang 12 thanu ' 24 ihium 36 thang
119,4 116,1 113,0 110,7 109,7 109,5 121,1 1 19,9 112,8 110,8 110,1 108,5
117.3 112,4 110,3 107,4 106,9 105,3 Ntihe cai
117,5 117,3 109,8 108,9 107,8 106,8
107,1 105.6 104,1 103.1 102,7 102,0 105,8 105,5 103,8 103.7 103,5 102,5
100 100 100 100 100 100 100 100 100 UK) 100 100
VIEN C H A N N U O I - Tap chi Khoa hgc Cong nghe Chan mid, - S6 15-Thang 12-2008
Ket qua thi nghiem nay chirng td nghe ciia trau due Ngd voi trau cai dugc chgn la tdt nhat, tiep theo la nghe ciia trau due Ngd vdi trau cai dai tra, rdi den nghe ciia trau due dai tra vdi trau cai chgn Igc va thap nhat la nghe ciia trau due dai tra voi trau cai dai tra. Nhu vay. anh huong cua trau due den khdi lugim con sinh ra Idn hon so vdi anh buong ciia me. Ndi each khac su dung trau due Ngd lam gidng da cai thien dang ke khdi lugng so sinh va sinh trudng cua nghe.
So vdi nghe dai tra (Id DC) thi khdi lugng so sinh. 3, 6. 12. 24 va 36 thang tudi ciia nghe Id TN cao hon ban. Cao nhat d Id TNI tiep dd den Id TN2 va cudi ciing la Id TN3 nghia la khdi lugng nghe hai Id cd bd la due Ngd cao hon dai tra nhieu hon so vdi nghe Id cd me dugc chgn. qua dd ta cd the thay dugc anh huang ciia trau due bd den khdi lugng con Idii hon anh hudng cua trau cai me.
Su khac biet giira cac Id thi nghiem so vdi ddi chiins cd xu huong giam dan khi tudi nghe tang Ien la do anh hudng ciia yeu td ngoai canh tang dan da lam giam anh huong ciia yeu td di
truyen. tuy vay su khac biet dd van rat rd ret. .' Tuang quan ve khoi luang nghe giira cac giai doan so voi khoi hcang nghe sa sinh
Khdi lugfng so sinh ciia trau ciing tuong q^uan thuan vdi khdi lugng co the chung o nhirng liia tudi ke tiep. Trong dieu kien nudi duong tdt va dn dinh, ngudi ta cd the dua vao khdi lugng so sinh ciia nghe de danh gia va du doan kha nang sinh trudng giai doan sau. va nd ciing la chi tieu quan trgng trong chgn gidng. Tuong tu nhu vay khdi lugng d cac moc tudi khac cung cd tuong quan thuan va chat che vdi nhau P<0.01.
He sd tuong quan giam dan theo tudi ciia nghe chimg td nghe cang Idn anh hudng ciia yeu td ngoai canh cang tang va da lam giam anh huong ciia cac yeu td di truyen. Nhu tren da neu, nghe thi nghiem nudi trong dieu kien ciia dan, khdng kiem soat bet dugc dieu kien nudi duong, nhieu trudng hgp khdng dap img dugc nhu cau ciia nghe nen chiing sinh trudng khdng diing nhu tiem nang sinh hgc. Vi vay de phat buy bet tiem nang di truyen can phai nudi du nhu cau dinh duong cua nghe.
Bang 6: Cac phuong trinh hdi quy va he sd tuong quan giira khdi lugng nghe so sinh vdi • khdi lugng nghe cac giai doan sau
Tudi nghe (thang) 3 6 12 24 36
Phuong trinh So vdi khdi Y = 19,2+ 1,58 PSS Y = 54,2+ 1,30 PSS
Y = 108+ 1,74 PSS Y = 2 0 5 + 1,84 PSS Y = 2 7 0 + 1,63 PSS
He sd tuong quan lugng nghe so sinh
r = 0,65 r = 0,51 r = 0,42 r = 0,38 r = 0,28
Do tin cay
P<0,01 P<0,01 P<0,01 P<0,01 P<0,01
* Y la khoi luong nghe cac thang tuoi giai doan sau so vol nghe so sinh.
KET LUAN VA DE NGHI Ket luan
Sir dung trau due gidng ngoai hinh to lam gidng da nang cao dugc tam vdc ciia dan trau dia phuang lan hon so vdi dan trau dai tra khdng dugc chgn Igc: nghe so siiiJi due df Id TNI la 25,3 kg con due. 24.7 con cai; due 12 thang tudi la 155,4 kg, cai 152,1 kg, so vai Id DC chi dat: so sinh due 21,1 kg va cai la 20,4 kg; liic 12 thang due 140,3 kg va cai la 137,2 kg.
MAI V A N S A N H - Su dung trdu due giong ngoai hinh lo ...
Tugng tu nhu vay o mdc 36 thang tudi Id TNI due la 319,1 kg, cai 312,4 kg so vdi Id ddi chung la 291,1 kg due va 287,8 kg cai. Nhu vay cd th^ thiy khdi lugng nghe cac mdc tudi cua lo trau due gidng ngoai hinh to vdi trau cai dugc chon Igc Idn hon ban so vdi Id trau due dai tra vdi trau cai dai tra (9 - 20%), Sir sai khac nay cd y nghia thdng ke (p < 0,05).
Kich thudc cac chieu do co the nghe so sinh. 3. 6. 12. 24 va 36 thang cung tuan theo quv luat tuong tu nhu khdi lugng nghe.
1 ugng quan giua khdi lugng nghe giiia cac giai doan sau so vdi khdi lugng nghe so smh la thuan va chat che (r = 0,28 - 0,65) tir dd cd the can cir vao khdi lugng nghe so sinh de du doan khdi lugng nghe o cac mdc tudi tilp theo.
Hien nay viec su dung trau due gidng ngoai hinh to lam gidng dugc coi la bien phap tdt d^
nang cao tam vdc trau. neu ket hgp vdi chgn loc thuong xuyen dan trau cai va cd phuang thirc cham sdc nudi duong tdt thi hieu qua tir chan nudi trau se cao ban.
De nghj
Tiep luc nghien cim va phd bien rgng rai trong san xuat nham cai tao va nang cao tini \'dc dan trau ndi.
TAI LIEU THAM KHAO
Ha Phuc Mich. (1985), Mot so nhan xet buoc dau ve kha nSng sinh trudng cua trau lai Fl Murrah x Viet nam.
Khoa hoc va ky thuat nong nghiep, 1985. trang 424-426
Le Dang Danh, Chau Chau Hoang, Nguyen Kim Cuong. Pham Trong Nghia. Tran Van Chinh. Nguyen Van Phat and John Perkins, (1995). Management and performance of village cattle and buffalo - a case study from Phuoc Thanh village. Exploring Approaches to Research in the Animal Sciences in Vietnam.
A Workshop held m Hue. 31 Jul.-3 Aug,, 1995, pp 90-93,
Mai Van Sanh, Nguyen Due Thac, Dao Lan Nhi and R, J, Petheram, (1995), Buffalo rearing in a mountainous village of Vietnam, Exploring Approaches lo Research in the Ammai Sciences in Vietnam, A Workshop held in Hue, 3 1 Jul,-3 Aug., 1995, pp 161 -166.
Mai van Sanh, (1996), Kha nang sinh trudng, sinh san. cho s&a thit ciia trau Murrah nuoi a Song Be va ket qua lai tao voi trau noi. Luan an PTS nong nghiep.
Mai Van Sanh, (2005), Anh huong cua chpn loc dan trau cai va sir dung trau due co khoi lucrng Ion lam giong den khoi luong so sinh va sinh truong cua nghe. TC Chan nuoi so 1 1. tr 8-9,
Nguyin Diic Thac, (1983). Mot so dac diem ve sinh truong, cho thit sira cua loai hinh trau to mien Bac va kha nang cai tao nd voi trau Murrah. Luan an PTS khoa hoc NN,
Vii Duy Giang, Nguyen Trong Tiin, Nguyin Xuan Trach va cs (1999), Bao cao ket qua thuc hien de tai: Dieu tra danh gia va djnh hirong phat trien dan trau mien Bac Viet nam.
Ngu'oi phan bien : TS. Nguyen Van Due ; TS. Vu Van Noi
