鲁西黄牛和渤海黑牛MRF家族基因编码区DNA多态性分析

由鲁西黄牛和渤海黑牛主要产区随机采集牛颈静脉血样,采用酚-氯仿法提取基因组DNA,用覆盖基因序列全长的15对引物扩增MRF家族4个基因MyoD、MyoG、Myf5和Myf6并测序,应用相关分子生物学软件对测序结果进行分析,以揭示其DNA多态性.通过对1 54条序列测序、比对,共发现36个核苷酸突变位点,其中7个位点与已...     

Changes in Serum Macro-mineral Concentrations in Growing Yak Throughout a Year

Concentrations of serum calcium, phosphorus, sodium, chlorine and potassium of growing yak born from a nuclear breeding herd in 1995,1996 and 1997(classified as groups G3, G2 and G1) were determined bimonthly from September 1997 to July 1998. The result showed that the concentrations of serum macro-minerals demonstrated a month/season pattern and both calcium and phosphorus reached the highest in September(11.36mg/dl and 6.82 mg/dl, respectively). The animals in G1 had a very high serum phosphorus concentration due to their young age and incomplete weaning in the early times of sampling. The ratio of calcium to phosphorus was generally higher than that recommended for cattle and demonstrated a great variation in month/season. The results indicated that the deficiencies of phosphorus, sodium and probably calcium were common in the pasture on the Qinghai-Tibetan Plateau.     

Yak Calving Interval and Calving Efficiency

The results of 439 times of calving interval(CI) from 161 yak cows showed that the average CI is 459(se=131)d. The CI with 3 to 6 calving numbers is 25～48 d shorter than that of 1 to 2 and above 7 calving numbers. Although slaughtering a great number of calves during the late September and early October do bring about relatively higher calving rate that is mos yak cowst can give 3,4,5 and 6calves during 4,5,6 and 7 years old respectively. This makes major calving months shift from April or May to June.     

青年牦牛不同年龄体重鲜皮重与皮张面积关系浅析

本文测定了６０头牦牛的０．５岁，１．５岁和２．５岁三个年龄段牦牛的鲜皮面积，它们分别为０．９０３ｍ＾２，１．２２９ｍ＾２和１．５３９ｍ＾２，从而得出从半岁到２．５岁牦牛皮张面积的增长幅度。在该年龄段内，牦牛体重与皮张面积的关系为：Ｙ＝０．３１６２＋０．００８２Ｘ；牦牛鲜皮重与皮张面积的关系为：Ｙ＝０５３９＋０．０８２７Ｘ；并得出在用主要体尺估测皮张面积时缺乏统计意义，是不可取的。     

野牦牛×家牦牛F1代近亲横交试验报告

在牦牛育种过程中,采用有计划的F1近交(近交系数介于0.03125～0.125),不仅能使复壮的牦牛新群体在体型、外貌、毛色等外观性状方面快速趋于一致,而且横交牛展现了良好的生产性能和生态适应能力.初生重较家牦牛大2.23 kg,6月龄较家牦牛重14.88 kg,胴体较家牦牛重7.43 kg,越冬保活率较家牦牛高5个百分点.瘤胃、瘤胃容积亦较同龄家牦牛分别大0.39 kg、4.98 L.     

野、家牦牛的精液特性和冷冻试验及人工授精效果(Ⅰ)

研究家畜冻精的目的在于选择和推广良种,充分发挥最优秀种公畜在育种和改良中的作用,有效而极大限度地使种公畜的品质通过冷冻精液得到利用,从而迅速繁殖数量多、质量高的后代.     

牦牛育种繁育体系的结构及作用

家畜选育、复壮及育种措施的实施,完全依赖于繁育体系的建立.对于终年放牧粗放管理的牦牛,要施以复壮及育种措施,繁育体系的建立更是必不可少.