高产奶牛适宜干奶期长度研究进展

Advances in optimal dry period length of high-producing dairy cows

为分析缩短或取消干奶期在高产奶牛生产中的可行性和经济性,本文主要分析了2003—2020年有关干奶期长度对奶牛的泌乳、健康、繁殖力和经济效益影响的研究文献。结果表明:1)缩短干奶期至30d或取消干奶期可导致下一周期泌乳量下降,但分娩前额外的产奶量可部分弥补产奶损失。2)缩短或取消干奶期可显著改善奶牛泌乳初期的能量负平衡问题,且缓解由能量负平衡导致的代谢紊乱,提高奶牛繁殖力。奶牛健康水平和繁殖力提高带来的收益,可部分弥补产奶量降低带来的经济损失。3)缩短或取消干奶期对犊牛健康水平无显著影响。目前该干奶策略在实际生产中推广和应用仍需要更多的研究数据支撑,未来研究可聚焦于30或0d干奶期相匹配的饲养管理策略研发,适宜干奶期长度预测模型的建立和干奶期乳腺退化和乳腺组织更新的分子机制探究,为将来奶牛适宜干奶期长度的研究提供参考,也为实际生产中奶牛干奶期长度选择提供依据。

To analyze the feasibility and economic efficiency of shortening and canceling the dry period in the production of high-yield dairy cows,this study summarized and analyzed the research progress on the effects of dry period length on milking,healthy,fertility and economic benefit of dairy cows based on the literature published from 2003 to 2020.The results showed that:1)Shortening the dry period to 30 days or canceling the dry milk period can lead to the decrease of milk yield in the subsequent lactation,whereas the milk yield precalving in cows with a 30 dor 0 ddry period can partly compensate the milk yield loss post calving.2)Shortening or canceling the dry period can significantly improve the negative energy balance in early lactation,alleviate the metabolic disorder caused by negative energy balance and improve the fertility of dairy cows.The benefits obtained from the improvement of health and fertility of dairy cows can partly make up for the economic losses caused by the reduction of milk yield.3)Shortening or canceling the dry period had no effect on the health of calves.However,further researches are needed for the application and promotion of the strategy in practice.In the future,the researches could focus on the improvement of management strategies to match 30 or 0 ddry milk period,the prediction mode of the proper dry period length for individual cow,and the molecular mechanism of the mammary gland involution and regeneration in order to provide a reference for the future research on the suitable dry period length of dairy cows,and also provide scientific basis for the selection of the suitable dry period length of dairy cows in practice.