100 Management Strategies to Optimize Health and Performance of Pre-weaned Calves

Abstract In the United States, 1 in each 10 dairy replacement heifers were raised in a calf raising facility, and that at least half of farms with 500 or more lactating animals raised some of their calves in a specialized calf ranch. 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 operations. Generally, the benchmark for optimal growth of calves is to double their birth weight by weaning. Such benchmark can only be achieved with consistent management and nutrition. Hence, it is not surprising that in large operations, up to 90% of facilities receive regular visits of both veterinarians and nutritionists. Milk-replacer is fed in more than 80% of operations, while milk (sealable or non-sealable) is fed in approximately 30% of calf raising facilities. Health challenges such as scours, and bovine respiratory disease (BRD) can hinder the performance of calves and are major causes of mortality in calf ranches. In addition to optimal colostrum management, vaccination and early diagnosis/ treatment can prevent major economic losses caused by these diseases. Compared to calves raised in their original dairies, calves raised in off-site operations are exposed to additional stressors that can lead to impairment of their immune system and weaken their resistance against pathogens. For instance, transportation at a very young age and comingling with animals from other dairies can increase the risk of diseases. Current research efforts are focusing in determining individual factors such as body weight at arrival or biomarkers of inflammation and stress that can be predictive of disease morbidity, mortality, and performance of calves. Such information could be used in the future to optimize management and to develop targeted preventative strategies to reduce incidence of diseases and mortality during the pre-weaned period.