Early life after birth is challenging for beef calves, but a successful transition from the uterus to the outside environment is necessary for calves to survive and thrive pre-weaning. Despite this, limited research has investigated how maternal undernutrition during pregnancy affects the vigor and metabolism of beef calves during early life. Beef females in their first pregnancy were fed to meet their energy and protein requirements, or were fed 70% of these requirements, during late pregnancy. Their calves were monitored closely, and data were collected intensively during early life. Calves born to nutrient restricted females were less vigorous at birth, taking longer to attempt to stand and stand successfully for the first time, and having lower vigor scores at 20 min of age. These calves also showed more signs of calving trauma and stress (elevated aspartate aminotransferase, creatine kinase, and creatinine) and had less red blood cells, but they had successful transfer of passive immunity and minimally affected energy metabolism. Overall, the effects of nutrient restriction observed may have decreased neonatal calf health and survival in a normal production environment, but not through reduced passive transfer.

Read the full article in the Journal of Animal Science.