Complexed versus amino acid-chelated trace mineral programs in high-risk calves during receiving

摘要

It is widely recognized that the postweaning and feedlot-receiving periods are high-stress times in the life of a calf. Stress due to commingling, transport, and exposure to new diets and environments can negatively affect calf health and feedlot performance ( ). During receiving is also when calves become susceptible to bovine respiratory disease (BRD). Even when calves have been vaccinated against viral and bacterial pathogens associated with BRD, they may not be able to mount an adequate immune response against BRD pathogens due in part to a lack of adequate nutrition ( ). Trace minerals are essential nutrients for immune system development and for antibody response to pathogens ( ). Previous research where inorganic trace minerals were replaced with organic forms have resulted in higher blood infectious bovine rhinotracheitis (IBR) titer levels and reductions in BRD-associated morbidity in feedlot cattle ( ). However, very little research has been reported where different organic trace mineral sources and/or levels have been directly compared with one another in the same feedlot-receiving experiment. Therefore, we hypothesized that supplementing two different commercial organic trace mineral products (Zinpro Availa-4 or Tracer Micro Maxx) would produce different health and growth performance outcomes in high-risk calves during receiving.