Optimization of purebred and crossbred dairy calf performance, health, and welfare

每年，在奶牛场出生的部分小牛犊要么不适合，要么不需要取代奶牛群。这些犊牛通常被称为“剩余奶牛犊”，最常见的是公犊牛。多头小牛是传统意义上的纯种荷斯坦小牛，在市场上被当做小牛肉或“乳牛肉”出售。最近，全球范围内在奶牛群中使用牛肉精液的情况有所增加，以改善屠体特征和增加过剩公犊的价值。这导致了进入加拿大小牛肉和牛肉行业的40%以上的小牛被杂交；然而，在如何管理杂交小牛以最大限度地提高它们的生产潜力、产品质量和在饲养系统中的弹性方面，存在着巨大的知识缺口。这项研究建议的目标是确定策略，通过关注遗传、营养以及缓解压力和疾病的影响来优化纯种和杂交奶牛的管理，以提高加拿大乳制品、小牛肉和牛肉行业的生产率、健康、福利和可持续性。该项目将侧重于多个目标，并取得切实的成果。首先，该项目将确定产生经济高效杂交小牛的肉牛的遗传属性。该项目还将制定关于早期生命管理的有效和可行的指导方针，包括初乳和牛奶营养、运输、缓解压力和疾病以及断奶后对杂交和纯种剩余小牛的营养，以最大限度地提高它们作为小牛肉和牛肉动物的成功。最后，将进行生命周期分析，以确定实施具体管理和饲养做法的经济价值，并确定影响纯种和杂交剩余小牛价值的主要经济投入。因此，该项目将最大限度地提高剩余小牛的生产价值，并向行业利益攸关方提供知识，通过实施新技术和协议来提高经济效益、健康和福利。因此，这一NSERC联盟不仅将增加消费者的信任，还将增加加拿大乳制品、牛肉和小牛肉行业的盈利能力和可持续性。

Every year a portion of calves born on dairy farms are either unsuitable or not required to replace the dairy herd. These calves are commonly referred to as "surplus dairy calves" and are most commonly male calves. Surplus calves were traditionally purebred Holstein calves marketed as veal or "dairy beef". Recently, there has been a global increase in the use of beef semen in the dairy herd to improve carcass characteristics and the value of surplus male calves. This has resulted in more than 40% of the calves entering the Canadian veal and beef industries being crossbred; yet, there are large knowledge gaps regarding how to manage crossbred calves to maximize their productive potential, product quality, and resiliency in the system which they are raised in. The goal of this research proposal is to determine strategies to optimize the management of purebred and crossbred dairy calves by focusing on the influence of genetics, nutrition, and mitigation of stress and disease, in order to improve productivity, health, welfare, and the sustainability of the Canadian dairy, veal, and beef industries. This project will focus on multiple objectives with tangible and practical outcomes. Firstly, this project will identify genetic attributes in beef sires that produce economically efficient crossbred calves. This project will also create effective and actionable guidelines on early life management - including colostrum and milk nutrition, transport, mitigation of stress and disease - and post-weaning nutrition of crossbred and purebred surplus calves to maximize their success as veal and beef animals. Lastly, a life cycle analysis will be performed to identify the economic value of implementing specific management and feeding practices and determine the major economic inputs that impact the value of purebred and crossbred surplus calves. Thus, this project will maximize the production value of surplus calves, and will deliver knowledge to industry stakeholders that will improve economic efficiency, health, and welfare through implementation of new technologies and protocols. As such, this NSERC Alliance will increase not only consumer trust, but also, the profitability and sustainability of the Canadian dairy, beef and veal industries.