宁夏地区荷斯坦牛后备牛健康问题及淘汰情况分析

为揭示宁夏地区荷斯坦牛后备牛在周岁前的健康问题和淘汰情况,收集了2013—2020年宁夏地区12 个规模化牧场的后备牛出生记录、健康问题记录和淘汰记录,统计了后备牛周岁前发生的主要健康问题,重点分析了后备牛腹泻和肺炎的发生情况随后备牛月龄和自然月份的关系;此外,还分析了后备牛周岁前的淘汰情况,以及淘汰风险与后备牛月龄和自然月份的关系。宁夏地区的荷斯坦牛中,腹泻和肺炎是后备牛在周岁前最易发生的健康问题,占所有健康问题的75%。后备牛腹泻集中发生在2月龄以内的犊牛中,肺炎病例在周岁前的各生命阶段中均有分布,总体上随着后备牛月龄的增加而减少。不同自然月份中,后备牛腹泻和肺炎的发生情况存在较大差异,腹泻在1~2月发生较多,肺炎在1~6月发病较多,冬季是宁夏地区规模化牧场健康管理的重点季节。周岁前的后备牛淘汰时,其平均淘汰日龄为160.21±110.00 天;随着后备牛月龄的增加,后备牛淘汰风险逐渐降低;不同自然月份中,8~12月淘汰的后备牛较多。结果揭示了宁夏地区荷斯坦牛后备牛周岁前的健康事件和淘汰发生情况,为该地区规模化牧场的后备牛管理提供了有用信息。

A Study on Health Problem and Culling in Holstein Replacement Cattle in Ningxia Area

To reveal the characteristics of health problem and culling for dairy calves and replacement heifers in Holstein population in Ningxia area,the birth,health,and culling records of 12 large-scale dairy farms from 2013 to 2020 were collected. The main health problem of dairy cattle until yearling and the relationships between case number and month age,and calendar month were investigated. Furthermore,the culling characteristics and the relationships between culling risk and calendar month age,month were investigated,respectively. In Holstein population in Ningxia,diarrhea and pneumonia with the highest case number were the main health problem in dairy calves and replacement heifers before yearling,which accounted for a proportion of 75% in all health events. Diarrhea occurs mainly in calves less than 2 months old,while pneumonia cases were distributed in all stages before yearling,and a decrease trend of case number with the increase of age was found for pneumonia. Among different months within a year, there were large differences on the case number for diarrhea and pneumonia. The diarrhea has more cases from January to February,and pneumonia has more cases from January to June,which means that winter is a high-risk season for the health management in dairy farms in Ningxia. When dairy cattles were culled before yearling, the average culling age was 160.21 ± 110.00 day, and the culling risk gradually decreases as the age increase of dairy calves and replacement heifers. Among various months within a year,more dairy calves and replacement heifers were culled from August to December. This study reveals the characteristics of health events and culling for replacement calves and dairy heifers before yearling in Ningxia Holstein population,and provides useful information for the management of dairy calves and replacement heifers in large-scale dairy farms in this area.