不同养殖模式及存栏规模牛场奶牛生产性能分析

对山东省86家奶牛群体改良(DHI)参测牛场的生产性能数据进行了综合统计,采用最小二乘分析法探究了养殖模式(规模化牧场和小区)及饲养规模对牛只生产性能是否存在影响,同时比较了近年来不同规模奶牛场生产性能变化情况。结果表明,山东省DHI参测奶牛场以规模化牧场为主,牧场的存栏规模以300～600头最多,其次为300头以下、600～1000头、1000头以上。不同养殖模式和养殖规模牛场之间在各项生产性能指标上存在显著差异(P<0.05):牧场养殖模式下牛群平均胎次、生奶产量和质量水平显著高于小区模式;不同养殖规模牛场生产性能比较显示,日产奶量、校正奶量和305天奶量均以300头以下牛场为最高(P<0.05),乳脂率以1000头以上牛场为最高(P<0.05),乳蛋白率以600～1000头存栏规模的牛场最高(P<0.05)。从近7年校正奶量变化情况看,存栏600～1000头的奶牛场校正奶量上升趋势最为明显。

Analysis on Production Performance of Dairy Cow under Different Culture Model and Population Size

The production performance of dairy cattle was collected from 86 DHI(dairy herd improvement) farms.The effects of culture model and population size on dairy performance were studied by using the least square analysis.The variation trend of milk yield for dairy cattle was also compared between herds with different population size.The results suggested that large-scale cattle farms contributed to the largest proportion of all dairy farms enrolling on DHI.The population size of most cattle farms was 300~600 heads,followed by less than 300,600~1 000 and more than 1 000.There were significant differences(P<0.05) in production performance of dairy cows under different culture patterns and scales: the mean parity,raw milk yield and quality for cows in large-scale farm were significantly higher than those in dairy breeding plot.According to the comparison results for cow herds with different raising scale,the daily milk yield,the corrected milk and 305-day milk production were the highest for cows in herds with the raising scale less than 300 heads(P<0.05).The milk fat percentage was the highest for cow herds with the raising scale more than 1 000 heads(P<0.05),while the milk protein percentage was the highest for those with the raising scale of 600~1 000 heads(P<0.05).The upward trend of corrected milk yield of cow herds with the raising scale of 600~1 000 heads was the most obvious in the recent 7 years.