Shi R, van der Linden A, Oosting S, Wang Y, Ducro B
Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, National Engineering Laboratory of Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China.
Animal Breeding and Genomics Group, Wageningen University & Research, Wageningen, The Netherlands.
J Anim Breed Genet. 2025 Sep;142(5):513-527. doi: 10.1111/jbg.12922. Epub 2025 Jan 8.
Holstein cattle account for the largest proportion of dairy cattle in China. The current China Performance Index (CPI) consists mainly of production traits. To derive economic values (EV) of additional traits for balanced breeding programs, a bio-economic model is necessary. Landless and intensive dairy farms are dominant in China, wherein all feed is purchased, and in-farm technicians and veterinarians are employed. Therefore, in the present study, a tailored bio-economic model was developed using the parameters of a typical dairy farm in North China. The typical farm had 1500 cows and 1400 youngstock, with a replacement rate of 33.5% per year and a productive life of 1090 days. The bio-economic model was on a per cow per year basis and described the revenues and costs from different animal categories. The EVs of 17 traits, including production, calving, fertility, longevity, and health traits, were derived and used to develop a more balanced selection index. Results showed that the bio-economic model can represent the typical dairy farm system in North China. The EVs of production traits were 2.39 Chinese Yuan (CNY), 32.85 CNY, and 89.60 CNY per kg milk yield, fat yield and protein yield, respectively. The EVs of production traits were two to three times higher than those in some European countries, due to the higher prices on milk volume and milk solids in China. The EVs of health traits ranged from -0.45 CNY to -11.95 CNY and were nearly half of those in other countries, due to the lower in-farm veterinarian labour costs. The EVs of most other functional traits were in line with the published values of other countries with similar economic assumptions in the model. Using the calculated EVs, a more balanced selection index was derived by including functional traits. This index had higher relative weight (46.8%) on functional traits than the current CPI (12.5%). With the high milk prices, it is still most profitable to allow for a decline in functional traits, although the decline is considerably smaller with the developed balanced index than with the CPI. Collectively, the bio-economic model and EVs provided the foundations for implementing balanced breeding programs in the Chinese Holstein population.
荷斯坦奶牛在中国奶牛中占比最大。当前的中国性能指数（CPI）主要由生产性状构成。为了得出用于平衡育种计划的其他性状的经济价值（EV），需要一个生物经济模型。在中国，无土地的集约化奶牛场占主导地位，所有饲料都需购买，并且雇佣场内技术人员和兽医。因此，在本研究中，利用中国北方一个典型奶牛场的参数开发了一个定制的生物经济模型。该典型奶牛场有1500头奶牛和1400头幼畜，年更新率为33.5%，生产寿命为1090天。生物经济模型以每头奶牛每年为基础，描述了不同动物类别的收入和成本。得出了17个性状的经济价值，包括生产、产犊、繁殖力、长寿和健康性状，并用于制定一个更平衡的选择指数。结果表明，该生物经济模型能够代表中国北方的典型奶牛养殖系统。生产性状的经济价值分别为每千克牛奶产量2.39元人民币（CNY）、每千克脂肪产量32.85元人民币和每千克蛋白质产量89.60元人民币。由于中国牛奶产量和乳固体价格较高，生产性状的经济价值比一些欧洲国家高出两到三倍。健康性状的经济价值在-0.45元人民币至-11.95元人民币之间，由于场内兽医劳动力成本较低，几乎是其他国家的一半。大多数其他功能性状的经济价值与模型中具有类似经济假设的其他国家公布的值一致。利用计算出的经济价值，通过纳入功能性状得出了一个更平衡的选择指数。该指数在功能性状上的相对权重（46.8%）高于当前的CPI（12.5%）。尽管牛奶价格较高，但允许功能性状下降仍最有利可图，不过与CPI相比，采用制定的平衡指数时功能性状的下降幅度要小得多。总体而言，生物经济模型和经济价值为在中国荷斯坦牛群体中实施平衡育种计划奠定了基础。
