Alvåsen Karin, Dohoo Ian, Roth Anki, Emanuelson Ulf
Department of Clinical Sciences, Swedish University of Agricultural Sciences, P.O. Box 7054, 75007, Uppsala, Sweden.
Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, C1A 4P3, Canada.
Acta Vet Scand. 2018 Jun 19;60(1):38. doi: 10.1186/s13028-018-0390-8.
Longevity is an important trait for increasing the profitability of dairy production. Long cow longevity is also essential to reduce the environmental impact of milk production, and to maintain positive consumer attitude. Genetic selection for increased longevity has been effective, but the phenotypic trend of longevity in Swedish dairy cows has not been improved. The objective of this study was to identify herd characteristics and management routines that are associated with the average cow longevity in a herd. To obtain this information, a questionnaire was developed and sent out to 661 Swedish dairy farmers.
The response rate was 35%. Seventeen of the 62 characteristics investigated had either a univariable association with the outcome (days from birth to culling) at P < 0.15, or were identified as confounders in the causal diagram and were therefore considered as candidates for the multivariable analysis. Multiple imputation was used to fill in the missing data from the questionnaires, and this increased the number of usable observations in the multivariable modeling from 156 to 228. Only a few of the investigated herd characteristics and management routines were associated with average cow longevity. The results demonstrated that using herd health advisory services shortened the average longevity, while using breeding advisory services prolonged the average longevity in the herd. Furthermore, having a greater interest in animal breeding (i.e. genetic selection) decreased the longevity, and calling the veterinarian when discovering an unhealthy cow increased the average longevity. Higher age of the farmer was also associated with longer average herd longevity.
The herd average cow longevity was only associated with some of the farm characteristics and management routines studied. The results demonstrate that the use of advisory services and farmers' attitudes could be targeted for increasing the herd longevity. Further, the results indicate that other e.g. qualitative factors influencing farmers' decisions play an important role.
长寿是提高奶牛生产盈利能力的重要性状。奶牛的长寿对于降低牛奶生产的环境影响以及保持消费者的积极态度也至关重要。通过基因选择来提高奶牛长寿已见成效，但瑞典奶牛的长寿表型趋势并未得到改善。本研究的目的是确定与牛群中奶牛平均寿命相关的牛群特征和管理惯例。为获取这些信息，设计了一份问卷并发送给661位瑞典奶农。
回复率为35%。在调查的62个特征中，有17个特征与结果（从出生到淘汰的天数）存在单变量关联（P<0.15），或者在因果图中被确定为混杂因素，因此被视为多变量分析的候选因素。采用多重填补法来填补问卷中的缺失数据，这使得多变量建模中可用观测值的数量从156个增加到228个。只有少数被调查的牛群特征和管理惯例与奶牛平均寿命相关。结果表明，使用牛群健康咨询服务会缩短平均寿命，而使用繁殖咨询服务则会延长牛群的平均寿命。此外，对动物育种（即基因选择）兴趣较高会降低奶牛寿命，发现奶牛不健康时联系兽医则会增加平均寿命。农民年龄较大也与牛群平均寿命较长有关。
牛群中奶牛的平均寿命仅与所研究的一些农场特征和管理惯例相关。结果表明，可针对咨询服务的使用和农民的态度来提高牛群寿命。此外，结果表明其他例如影响农民决策的定性因素也起着重要作用。
