Martin-Collado D, Hely F, Byrne T J, Evans R, Cromie A R, Amer P R
1AbacusBio Limited, Ground Floor, PublicTrust Building 442 Moray Place, PO Box 5585, Dunedin 9016,New Zealand.
2Irish Cattle Breeding Federation,Highfield House, Shinagh,Bandon, Co. Cork, Ireland.
Animal. 2017 Feb;11(2):318-326. doi: 10.1017/S1751731116001567. Epub 2016 Jul 27.
Calving difficulty (CD) is a key functional trait with significant influence on herd profitability and animal welfare. Breeding plays an important role in managing CD both at farm and industry level. An alternative to the economic value approach to determine the CD penalty is to complement the economic models with the analysis of farmer perceived on-farm impacts of CD. The aim of this study was to explore dairy and beef farmer views and perceptions on the economic and non-economic on-farm consequences of CD, to ultimately inform future genetic selection tools for the beef and dairy industries in Ireland. A standardised quantitative online survey was released to all farmers with e-mail addresses on the Irish Cattle Breeding Federation database. In total, 271 farmers completed the survey (173 beef farmers and 98 dairy farmers). Both dairy and beef farmers considered CD a very important issue with economic and non-economic components. However, CD was seen as more problematic by dairy farmers, who mostly preferred to slightly reduce its incidence, than by beef farmers, who tended to support increases in calf value even though it would imply a slight increase in CD incidence. Farm size was found to be related to dairy farmer views of CD with farmers from larger farms considering CD as more problematic than farmers from smaller farms. CD breeding value was reported to be critical for selecting beef sires to mate with either beef or dairy cows, whereas when selecting dairy sires, CD had lower importance than breeding values for other traits. There was considerable variability in the importance farmers give to CD breeding values that could not be explained by the farm type or the type of sire used, which might be related to the farmer non-economic motives. Farmer perceived economic value associated with incremental increases in CD increases substantially as the CD level considered increases. This non-linear relationship cannot be reflected in a standard linear index weighting. The results of this paper provide key underpinning support to the development of non-linear index weightings for CD in Irish national indexes.
产犊困难（CD）是一个关键的功能性状，对牛群的盈利能力和动物福利有重大影响。育种在农场和行业层面管理产犊困难方面都起着重要作用。确定产犊困难惩罚的经济价值方法的一种替代方法是，通过分析农民所感知的产犊困难对农场的影响来补充经济模型。本研究的目的是探索奶牛和肉牛养殖户对产犊困难在农场层面的经济和非经济后果的看法和认知，最终为爱尔兰肉牛和奶牛行业未来的遗传选择工具提供信息。向爱尔兰牛育种联合会数据库中有电子邮件地址的所有养殖户发放了一份标准化的定量在线调查问卷。共有271名养殖户完成了调查（173名肉牛养殖户和98名奶牛养殖户）。奶牛和肉牛养殖户都认为产犊困难是一个非常重要的问题，涉及经济和非经济因素。然而，奶牛养殖户认为产犊困难问题更大，他们大多倾向于略微降低其发生率，而肉牛养殖户则倾向于支持提高犊牛价值，即使这意味着产犊困难发生率会略有上升。研究发现，农场规模与奶牛养殖户对产犊困难的看法有关，大型农场的养殖户比小型农场的养殖户认为产犊困难问题更大。据报道，产犊困难育种值对于选择与肉牛或奶牛交配的种公牛至关重要，而在选择奶牛种公牛时，产犊困难的重要性低于其他性状的育种值。养殖户对产犊困难育种值的重视程度存在很大差异，无法用农场类型或所使用种公牛的类型来解释，这可能与养殖户的非经济动机有关。随着所考虑的产犊困难水平的增加，养殖户感知到的与产犊困难增量增加相关的经济价值大幅上升。这种非线性关系无法在标准线性指数加权中体现。本文的结果为爱尔兰国家指数中产犊困难的非线性指数加权的发展提供了关键的基础支持。
