Machado Vinicius S, Ballou Michael A
Department of Veterinary Sciences, Texas Tech University, Lubbock, TX, USA.
Transl Anim Sci. 2022 Jan 7;6(1):txab234. doi: 10.1093/tas/txab234. eCollection 2022 Jan.
In this literature review, we overview some of the common management practices associated with calf rearing in specialized operations of the United States. Given the growing importance of dairy-beef calves entering the beef production of the United States, we overview aspects related to housing, nutrition, and health events during the pre- and post-weaning period. Based on data on dairy animals, we hypothesize how early life experiences could impact the feedlot performances of dairy-beef animals. Most of the large calf raising operations, where the majority of dairy-beef animals are raised, are located in the Central Great Plains and West regions of the United States. Approximately 80% of calves are individually housed, but the type of housing (e.g., outside hutch, inside a barn) varies based on location of calf-raising facilities. Milk-replacer is fed in more than 80% of operations, while milk (saleable or nonsaleable) is fed in approximately 30% of calf raising facilities (some operations fed more than one type of liquid diet). In addition to liquid feed, water and calf starter are offered ad libitum to calves. Adequate starter intake at weaning is crucial for feed transition from pre- to post-weaning period, which occurs at approximately 2 months of age. Then, calves are mainly housed in group pens and transition from calf-starter to total mixed ration (TMR). Health challenges such as scours and bovine respiratory disease (BRD) can hinder the performance of calves and are major causes of morbidity and mortality in calf ranches. Transportation at a very young age and comingling with animals from other dairies can increase the risk of diseases. Current research efforts are focusing on determining individual factors such as body weight (BW) at arrival or biomarkers of inflammation and stress that can be predictive of disease morbidity, mortality, and performance of calves. Future research should focus on how to utilize this information to optimize management and to develop targeted preventative strategies to reduce incidence of diseases and mortality and improve performance during the pre-weaned period. Also, more research is needed to understand how colostrum management, housing, and nutrition can impact the adult performance of dairy-beef animals.
在这篇文献综述中,我们概述了美国专业化养殖场犊牛饲养的一些常见管理做法。鉴于进入美国肉牛生产领域的奶肉兼用犊牛的重要性日益增加,我们概述了断奶前后时期与圈舍、营养和健康状况相关的方面。基于奶牛的数据,我们推测早期生活经历如何影响奶肉兼用动物在饲养场的表现。大多数饲养奶肉兼用动物的大型犊牛养殖场均位于美国中部大平原和西部地区。大约80%的犊牛单独圈养,但圈舍类型(如室外犊牛栏、 barn内)因犊牛养殖设施的位置而异。超过80%的养殖场饲喂代乳粉,而约30%的犊牛养殖设施饲喂牛奶(可销售或不可销售的)(一些养殖场饲喂不止一种类型的液体饲料)。除了液体饲料外,还向犊牛自由提供水和犊牛开食料。断奶时摄入足够的开食料对于从断奶前到断奶后时期的饲料过渡至关重要,断奶通常发生在大约2月龄。然后,犊牛主要饲养在群养栏中,并从犊牛开食料过渡到全混合日粮(TMR)。腹泻和牛呼吸道疾病(BRD)等健康挑战会阻碍犊牛的生长性能,并且是犊牛养殖场发病和死亡的主要原因。幼龄时的运输以及与其他奶牛场的动物混群会增加疾病风险。目前的研究工作集中在确定个体因素,如到达时的体重(BW)或炎症和应激的生物标志物,这些因素可预测犊牛的疾病发病率、死亡率和生长性能。未来的研究应侧重于如何利用这些信息来优化管理,并制定有针对性的预防策略,以降低疾病发病率和死亡率,并提高断奶前时期的生长性能。此外,还需要更多的研究来了解初乳管理、圈舍和营养如何影响奶肉兼用动物的成年性能。