不同泌乳阶段和胎次对广东地区奶牛泌乳性能的影响及变化规律研究

The Effect and Correlation of Different Lactation Stages and Parity on Lactation Performance of Dairy Cows in Guangdong Province

本文通过分析广东省某规模化奶牛场2022年生产性能测定(DHI)数据,研究不同泌乳阶段、胎次对奶牛泌乳性能的影响及其变化规律。结果显示,随着泌乳天数的增长,奶牛产奶量、乳中尿素氮和脂蛋比呈现先上升后下降的变化规律,乳蛋白率和乳脂率为先下降后上升,而体细胞数为逐步升高;随着胎次的增加,奶牛产奶量、乳脂率和脂蛋比表现出先上升后下降的趋势,而体细胞数逐步升高;奶牛产奶量与乳品质各指标之间存在一定相关关系。因此,生产中应以奶牛的泌乳阶段和胎次为依据,对奶牛进行合理分群和饲料配制,进而提高奶产量、乳品质和奶牛场经济效益。

In this paper,the effects of different lactation stages and parity on the lactation performance of dairy cows,as well as their change rules and correlation were studied by analyzing the Dairy Herd Improvement(DHI)data of a large-scale dairy farm in Guangdong Province in 2022.The results showed that,with the increase of lactation days,the milk yield,urea nitrogen and fat-protein ratio of dairy cows increased first and then decreased,the milk protein rate and milk fat rate decreased first and then increased,while the somatic cell count increased gradually.With the increase of parity,the milk yield,milk fat rate and fat-to-protein ratio of dairy cows showed a trend of increasing first and then decreasing.Milk urea nitrogen increased first,then decreased and then increased,milk protein increased first,then decreased,then increased and then decreased,while somatic cell count increased gradually.Therefore,based on the lactation stage and parity,dairy cows should be reasonably grouped and feed formulated,so as to improve the milk quality and the economic benefits of dairy farms.