安格斯肉牛与本地黄牛杂交试验

应用安格斯肉牛杂交改良青海省本地黄牛,经试验测定,杂一代犊牛初生重28.6kg,比青海本地黄牛15.09kg提高89.53%,1月龄、3月龄、6月龄平均体重分别为39.22kg、72.90kg和101.51kg,比同龄当地黄牛分别提高83.27%、109.45%和56.53%,杂交优势明显(P<0.01)。     

安格斯肉牛杂交改良青海黄牛效果分析

青海省首次引进安格斯肉牛细管冻精,利用人工授精技术杂交改良青海黄牛,并对安本F1牛进行试验测定,结果表明：安本F1牛初生重平均为29.21kg,比本地黄牛初生重15.00kg相对提高了94.73%,安本F1牛3月龄、6月龄、12月龄、18月龄平均体重分别为73.63kg、112.78kg、195.85kg、268.50kg,比同龄本地牛分别提高了111.58%、109.23%、113.34%、156.45%,各阶段体尺指标比同龄本地牛相应提高。安本F1牛18月龄日增重为0.44kg,比本地黄牛日增重0.17kg,相对提高了158.8%。安本F1牛表现出了较强的杂种优势,杂交效果显著。     

安格斯肉牛改良沿河本地黄牛效果研究

应用安格斯肉牛细管冻精改良沿河本地黄牛。经观测：安本F_1牛体型趋向父本、毛色呈显性遗传,多为黑色或黑褐色;平均初生重为20．80±2．63kg,6月龄体重为111．08±5．02kg,12月龄体重为172．91±12．47kg,18月龄体重为229．56±14．67kg,比同龄的沿河本地黄牛分别提高46．99%、43．55%、45．81%和47．79%,差异极显著(P＜0．01);各月龄阶段的体尺指标均显著高于本地黄牛(P＜0．05),增长幅度大多在10%～20%之间。结果表明：安格斯肉牛改良沿河本地黄牛、杂种优势明显,能显著改善本地黄牛体形不足的缺陷,安本F_1牛生长发育快,且抗病力强,耐粗饲,适应能力强,是改良山区黄牛的理想肉牛品种,值得推广。     

安格斯肉牛杂交改良青海黄牛效果分析

安格斯肉牛是英国著名的小型早熟肉用品种，该牛体躯低矮，深宽结实，头小而方，四肢短而直，全身肌肉丰满，具有生长快，耐寒、耐粗饲，易育肥，肉质好，肌肉大理石纹理明显等特点，是世界上优秀的肉牛品种。青海省互助县自2005年引进安格斯肉牛细管冻精，对本地黄牛进行杂交改良，其杂交后代安本F1牛生长发育快，适应性能好，表现出了明显的杂交优势。     

安格斯肉牛冻精与隔年产犊牦牛杂交改良效果分析

通过对上年未产犊牦牛采用补饲与同期发情处理技术,并采用安格斯肉牛细管冻精开展牦牛杂交,出生的犏牛犊采用犊牛培育技术,对不同培育条件对犏牛犊牛生长发育的影响,研究结果表明,采用上年未产犊母牦牛补饲技术,与对照组相比,试验组隔年产犊母牦牛的发情率、受胎率、产犊率及犊牛成活率分别为86.67%、82.23%、78.34%和96.46%,分别提高22.84%、27.59%、33.03%和7.62%,差异显著(P<0.05)。采用犏牛犊牛培育技术,与传统对照组相比,犊牛培育组和培育对照组公、母犏牛初生的体高、体斜长、胸围、管围体重明显增加,差异显著(P<0.05)。上年未产犊母牦牛补饲与同期发情处理技术结合犏牛犊牛培育技术,显著提高其杂交一代犏牛的生长发育速度,提高犊牛的繁殖成活率。     

安格斯肉牛改良门源县本地黄牛的效果观察

在我省门源县应用安格斯肉牛细管冻精改良当地黄牛,经观测其杂种F1代生长发育快,表现出了明显的杂交优势.     

安格斯肉牛杂交改良青海黄牛的效果

南门峡镇位于青海省互助县西北部,平均海拔2875m,年平均气温2～3℃,昼夜温差大,主要农作物有小麦、青稞、油菜、蚕豆,燕麦、马铃薯等,可利用天然草场7．6万hm^2,是理想的养牛基地。     

安格斯肉牛胚胎移植试验报告

〔目的〕为探讨和研究安格斯肉牛胚胎移植在武威市的应用前景,指导我市的高档肉牛养殖,〔方法〕我们以西杂母牛为受体,进行了10头安格斯双胚、6头输精后7天移植单胚、389头单胚、10头移植前注射黄体酮和促黄体素a3共4项试验研究。〔结果〕双胚移植受孕2头,产犊结果都为单胎;移植加输精0头、单胚移植受孕率为16.8%、注射激素受孕率为10%。〔结论〕使用体内胚胎,加强妊娠牛的饲养管理,可能会提高产双犊几率,在以后生产中可以推广和应用;输精后牛各项激素和生殖受孕环境发生变化不适合于胚胎移植,在生产中利用不大;胚胎移植同步注射黄体酮和促黄体素a3在提高牛体外胚胎妊娠率的利用中作用不大。     

安格斯肉牛胚胎移植试验

应用胚胎移植技术，对当地9头母牛进行了安格斯肉牛胚胎的移植试验，结果受胎4头，受胎率为44．4％。     

西门塔尔牛、安格斯牛杂交生产利用研究

为了探讨西门塔尔牛和安格斯牛杂交改良本地黄牛效果,采用西门塔尔牛和安格斯牛作为肉牛终端父本,分别与本地黄牛开展二元经济杂交,对杂交F1体重变化、屠宰性能数据进行了统计分析研究。结果表明：两者杂交F1均比本地黄牛生长速度快且产肉率高,可有效提高本地黄牛的屠宰性能。说明西门塔尔牛和安格斯牛改良本地黄牛杂交优势明显,可有效增加本地黄牛养殖的经济效益,值得推广。     

娟姗牛改良牦牛效果浅析

本文测定了娟姗牛改良牦牛的效果,分析了牦牛改良繁活率低的原因,提出了牦牛乳用改良的措施。     

不同肉牛品种杂交西门塔尔杂种牛效果的研究

为了研究不同肉牛品种杂交改良西门塔尔杂种牛的效果,筛选出产肉量高、肉质好、抗逆性强的品种杂交组合,为大规模开展杂交提供依据,试验采用红安格斯、利木赞、夏洛莱(法系)、德国黄牛4个品种牛,分别杂交西门塔尔杂种母牛,产犊后从每个杂交组合中选择11头断奶小公牛,在相同饲养管理条件下持续育肥至18月龄,并进行屠宰和肉质评定。结果表明:红安西杂组合杂交效果最好,其次是利西杂及夏西杂,德黄西杂组合杂交效果较差。说明在生产实际中,如果采用断奶小公牛持续育肥至18月龄时出栏、屠宰,应优先选择红安格斯×西门塔尔杂交组合。     

加系纯种肉牛改良本地黄牛效果的调查研究

选用西门塔尔、夏洛来、利木赞3个品种公牛48头,用来改良本地黄牛,培育优质肉午。对种公牛后裔的出生、6月龄、12月龄体重、体尺进行测定及屠宰试验。经统计分析,对引进种公牛的种用价值进行评定,比较了西门塔尔、夏洛来、利木赞3个品种及品种内个体的改良效果。     

Two-, three- and four-breed rotational crossbreeding of beef cattle: reproductive traits

Reproductive data were collected on 4,596 cow exposures in a rotational crossbreeding study that spanned four generations (1970 through 1988). Angus (A), Brahman (B), Charolais (C) and Hereford (H) breeds were included in three two-breed (A-B, C-B and H-B), three three-breed (A-B-C, A-B-H and C-H-B) and one four-breed (A-B-C-H) rotational mating system. Contemporary straightbreds were produced each generation. Reproductive traits of interest were calving rate, calf survival, weaning rate, calf birth date and calving assistance. Overall means and standard errors for calving rate, calf survival, weaning rate, calf birth date and calving assistance were 82.1 +/- .6%, 92.8 +/- .4%, 76.2 +/- .6%, 50.4 +/- .3 d and 4.2 +/- .3%, respectively. Rotational mating systems had similar calving and calf survival rates that were greater (P less than .01) than those of straightbreds. Three- and four-breed rotation systems had similar weaning rates (81.5 +/- 1.1 and 80.8 +/- 2.0%) that were higher than those for two-breed rotations (77.1 +/- 1.2%). Two- and three-breed rotation systems had fewer assisted births (3.5 +/- .6 and 2.2 +/- .6%) than straightbreds (5.5 +/- .6%) and the four-breed rotation (5.4 +/- 1.0%). Three-breed rotation calves were born earlier in the calving season (46.8 +/- .6 d; P less than .05) than straightbred, two-breed or four-breed rotation calves (51.8 +/- .6, 52.1 +/- .6 and 51.1 +/- 1.0 d). Hereford-Brahman two-breed rotation cows had higher (P less than .05) calving and weaning rates than A-B or C-B two-breed rotation cows (87 +/- .4 vs 81.9 +/- 1.9 and 81.5 +/- 1.8%; 81.7 +/- 2.0 vs 76.4 +/- 2.1 and 74.1 +/- 2.0%). All three-breed rotation combinations had similar calving, calf survival and weaning rates, assistance at calving and calf birth dates. Rotational combinations tended to be more superior (P less than .05) to weighted purebred means for calving, calf survival and weaning rates than for calf birth date and calving assistance.     

Growth characteristics in crosses of Angus, Santa Gertrudis and Gelbvieh beef cattle

A total of 343 calves (males and females) were evaluated for preweaning average daily gain, weaning weight (WW), feedlot average daily gain to slaughter (ADGF), slaughter weight (SW), pelvic height (PH), pelvic width, pelvic area, weaning conformation score (WS) and ratio of weaning weight to the dam's weight at weaning (R). Mating types included straight-bred Angus (A) and Santa Gertrudis (S), the reciprocal crosses of these two breeds and Gelbvieh (G) X Angus. Straightbred S and A X S crosses had the heaviest WW, followed by S X A and G X A crosses; straightbred A had significantly smaller WW than all other mating types. The crossbreds and the straightbred S had higher WS than straightbred A. The ratio of WW to cow weight was largest for S X A. The straightbred S and A X S crosses had significantly lower R values than the other mating types. Weaning weight per cow exposed, computed as the product of weaning rate and weight, indicated that straightbred A had an advantage over the other mating types (156.5 kg), whereas S and S X A were intermediate (147.9 and 147.6 kg, respectively) and A X S was lowest (128.9 kg). Feedlot gain was highest for A X S, though not significantly greater than for straightbred S or G X A. Straightbred A gained significantly less than other mating types except S X A. Straightbred A were found to be significantly smaller at slaughter than the other mating types. The S X A and G X A were intermediate; the straightbred S and A X S were significantly larger for SW.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reproductive performance in crosses of Angus, Santa Gertrudis and Gelbvieh beef cattle

Angus (A), Santa Gertrudis (S), and Gelbvieh (G) sires were mated to A and S dams to produce five mating types (A X A, S X S, S X A, A X S and G X A) in each of four calf crops. The study involved 501 matings. Overall means for the traits measured (calves born/cows exposed, Julian birthdate, calving ease, percentage of live calves at 24 h, birth weight, survival to weaning and gestation length) were 74.2%, 48.8 d, 96.4%, 33.2 kg, 95.4% and 283.8 d, respectively. Angus dams had a 14 percentage point (P less than .05) advantage over S dams for percentage of calves born/cows exposed. The effect of heterosis in crosses of A and S for percentage of calves born/cows exposed was negative (-11.1%) and approached significance. The percentage of calves born/cows exposed were 84.4, 70.4, 76.1 and 62.3 for the A X A, S X S, S X A and A X S mating types, respectively. Matings involving A sires and dams produced calves significantly earlier in the calving season than did matings involving S sires and dams. Matings involving S sires and dams produced calves with significantly longer gestation periods than matings of A sires and dams. Calving ease score and survival to weaning were not affected by breed of sire, breed of dam, age of dam, sex of calf, or the interaction of breed of sire X breed of dam. Percentage of live calves at 24 h indicated that straightbred S calves were significantly less viable at birth than the other four mating types.(ABSTRACT TRUNCATED AT 250 WORDS)     

发酵棉粕对安格斯肉牛生长性能和血清生化指标的影响

试验旨在研究饲喂发酵棉粕对安格斯肉牛生长性能和血清生化指标的影响。试验选用10月龄健康初始体重[(259.11±22.62)kg]无明显差异的黑安格斯肉牛(公牛)18头,随机分成两组(每组9头),即试验组和对照组。试验组添加6%的发酵棉粕,对照组添加6%的未发酵棉粕。试验期共42 d,预饲期10 d,正饲期32 d。试验结果表明:(1)试验组平均日增重和平均日采食量与对照组相比较有明显的差异(P<0.05),相较于对照组,试验组平均日采食量提高了31.51%(P<0.05),平均日采食量提高了9.1%(P<0.05);对照组与试验组的料重比相比有极显著差异,和对照组相比料重比下降了16.58%(P<0.01)。(2)对照组和试验组血清中总蛋白、尿素氮、钙、磷、铁、免疫球蛋白A等含量均差异不显著(P>0.05)。血清中总蛋白、葡萄糖及免疫球蛋白G含量,试验组相较于对照组有显著差异,分别提高36.64%(P<0.01)、37.5%(P<0.01)和36.99%(P<0.05)。因此,饲喂发酵棉粕可改善安格斯肉牛的生长性能。