中国规模化牧场初乳管理与新生犊牛被动免疫现状

Calves and Heifers Management in China Large-Scale Dairy Farms:Descriptive Characteristics of Colostrum Quality and Passive Transfer Status of Dairy Calves

初乳关系着犊牛的生长和健康,饲喂过程中应注重对初乳巴氏杀菌、初乳质量、初乳饲喂量以及饲喂时间的管理。笔者所在团队先后于2017年、2019年在全国范围开展了两次后备奶牛培育现状调研,调研结果显示,我国96.4%的规模化牧场都会进行初乳质量检测,91.8%的牧场会对初乳进行巴氏杀菌,且有83.6%的初乳质量达到了优质水平(初乳折光率大于22%)。另外发现,采用“4+2+0”或“4+2+2”初乳饲喂模式的牧场占比最多,达79.5%。86.4%的牧场能够在犊牛出生1 h内饲喂初乳。新生犊牛被动免疫是否成功是判断牧场初乳管理效果的关键性指标。调研表明,97.5%的犊牛血清总蛋白含量大于5.2g/dL,并且,随着年份的增加,血清总蛋白大于5.5g/dL的犊牛数量逐渐增多,到2019年占比达98.2%。基于调研数据,本研究提出,犊牛被动免疫水平可划分为“优秀”(血清总蛋白≥6.7g/dL)、“良好”(6.0g/d≤血清总蛋白<6.7g/dL)、“合格”(5.2g/dL≤血清总蛋白<6.0g/dL)和“不合格”(血清总蛋白<5.2g/dL);群体标准中被动免疫“优秀”犊牛占比大于40%,“良好”犊牛占35%左右,“合格”犊牛占25%左右,“不合格”犊牛占比小于5%。从调研结果可以看出,目前我国规模化牧场初乳管理水平较高,犊牛群体被动免疫成功率较高,为犊牛后期生长健康打下了坚实基础。

The management of colostrum plays a key important role in the health and growth of dairy calves.The results showed that colostrum quality was measured in 96.4%of farms and colostrum was pasteurized in 91.8%of farms.83.6%of colostrum were excellent(Brix>22%).Moreover,most of farms(79.5%)fed calves with 4L colostrum for the first time and then 2 L for the second time,and colostrum could be fed to calves within 1 hour after birth in 86.4%of farms.Besides,calves that experienced failure of passive transfer decreased annually and accounted for 0.75%in 2019.Based on data collected,the passive transfer of calves could be divided into 4 levels:excellent total serum protein>6.7g/dL,good(6.0g/dL≤total serum protein<6.7g/dL),fair(5.2g/dL≤total serum protein<6.0g/dL)and poor(total serum protein<5.2g/dL).This study indicated that colostrum quality and passive transfer status of dairy calves in China large-scale dairy farms was better.