Abstract: Objective]Through the estimation of Hutubi Holstein cattle farm first 305 days milk yield of genetic parameters and breeding value,this paper aims to set up the genetic evaluation system and evaluate the advantages and disadvantages of the genetic evaluation system and the evaluation of the breeding bulls.[Meth-od]The milk yield of Xinjiang Hutubi cattle farm 1 ,145 Holstein dairy cow fetal and pedigree data were used for SAS software statistical analysis.The effects of 4 factors:the field,calving year,calving month and the primip-arous month age on milk yield were observed to study the seasonal variation of milk yield in 305 days.And mo-reover,the heritability and breeding value of milk yield in 305 days were estimated by BLUPf90 program.[Re-sult]Pasture,calving year and calving month affected 305 day milk yield significantly (P<0.01 ),effects of primiparous months on 305 day milk yield were not significant (P>0.05 );The milk yield changed significantly with the change of the seasons.In winter and spring,milk yield was higher than other seasons.The heritability of milk production was 0.268.The estimated breeding value of each individual and ancestor was obtained and the scope was 1,967.04 to -1,042.78.The difference was 3,009.82 kg.[Conclusion]In this dairy herd,Ani-mal genetic gap were larger,the individual genetic ability were better,to provide a reliable scientific basis for se-lection accuracy and improved efficiency for reference for the rational organization of dairy production and im-prove.

摘要： 【目的】通过估计呼图壁种牛场荷斯坦头胎305 d产奶量的遗传参数和育种值，为该场选留核心母牛群，建立遗传评估体系以及评价种公牛的优劣。为合理的组织奶牛生产和提高选种准确率及改良效率提供可靠的科学依据供参考。【方法】对新疆呼图壁种牛场1426头荷斯坦奶牛头胎305 d产奶量及系谱资料，运用SAS软件进行统计分析，观察场、产犊年份、产犊月份、初产月龄等4种因素对产奶量的影响，研究305 d产奶量的季节性变化规律，并用BLUPf90程序估计305 d产奶量的遗传力及育种值。【结果】牧场;产犊年份;产犊月份对305 d产奶量均影响极显著（P＜0.01），初产月龄对305 d产奶量影响不显著（P＞0.05）；产奶量随季节的变化而发生明显的变化，冬、春季产奶量相对于其他季节要高；产奶量的遗传力为0.268，获得个体及各祖先产奶量的估计育种值，其范围为1967.04～－1042.78，其差值为3009.82 kg。【结论】在这个奶牛群体里，遗传差距较大，个体遗传能力较好，为合理的组织奶牛生产和提高选种准确率及改良效率提供可靠的科学依据供参考。