通过对全国2020年18 个省份201 个规模奶牛场月度繁殖和产奶量数据进行分析,旨在确定不同月份下奶牛繁殖和产奶性能表现。结果表明：（1）5—6月成母牛受胎率、怀孕率开始下降,7、8月明显下降,9月仍较低,其中7—9月,2胎、3胎及以上牛只受胎率明显低于1胎（平均低4.3~5.1 个百分点）;（2）1—12月后备牛怀孕率、受胎率相对稳定,6—8月未出现明显下降趋势;（3）泌乳牛单产在6月之后呈缓慢下降趋势,平均下降0.50~0.90 kg,泌乳牛峰值产量在6月之后呈较明显下降趋势,其中经产牛下降幅度较大,头胎牛下降幅度较小。因此,为减少奶牛受不同月份热应激影响而导致生产性能下降,建议不同地区奶牛场根据实际情况做好防暑降温工作,优化配种方案,改善营养与饲养管理。
关键词：
奶牛; 受胎率; 单产; 温度; 热应激
The objectives of current study were to ensure the performance of dairy cow reproduction and milk production in different months,by analyzing 201 scaled dairy farms' monthly reproduction and production data from 18 provinces of China in 2020.Results showed that: (1) Cows' conception rate and pregnancy rate began to decline in May and June,decreased significantly in July and August,but remained low in September. From July to September, second and more than second parity cows'conception rate was significantly lower than first parity (average 4.3 to 5.1 percentage points lower);(2) Heifers' pregnancy rate and conception rate were relatively stable within 12 months,and no significant decrease from June to August;(3) After June,lactating cows' yield decreased slowly with an average around 0.50 to 0.90 kg,peak yield decreased obviously after June.Peak yield was largely decline in multiparous cows and less decline in primiparous cows.Therefore, in order to reduce the influence of heat stress on dairy cows' production performance in different months and improve the production performance of dairy cows,it is suggested that the dairy farms in different areas should take measures to prevent heat stress,optimize breeding program and improve nutrition and feeding management.
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