Effect of calving assistance and supplementation of colostrum with sodium bicarbonate on newborn calf vigor, success of passive transfer, health, and growth of dairy calves

Abstract

The objective of this research was to examine the efficacy of supplementing colostrum with sodium bicarbonate for improving passive transfer, health, and growth. An additional objective was to evaluate the effects of calving difficulty on calf vigor. A total of 543 heifer and bull calves from 9 commercial dairy herds were enrolled in this randomized double-blind field trial. At birth, calves were assessed for vigor by the dairy producer, using a prototype calf vigor assessment tool which rated Visual appearance, Initiation of movement, General responsiveness, Oxygenation, and Rates of heartbeat and respiration (VIGOR). Subsequently, calves were fed colostrum supplemented with either 20 g of sodium bicarbonate (SB) or placebo powder. Blood was collected from each calf between 1 and 8 days of age for serum total protein (STP). Each calf was assessed with a standardized clinical score for general health, and measured for growth using a heart girth weight tape at 1, 2, 3, and 6 weeks of age. The findings suggest that calves born with assistance, or that were malpositioned at calving, had lower vigor than those born unassisted. Yet, calf vigor improved with time following birth. Measures from the VIGOR score, including slower responsiveness and a higher heart rate, were associated with reduced health. There was a significant interaction between sex of the calf and SB supplementation of colostrum with STP. Sodium bicarbonate supplementation of colostrum was not significantly associated with improved passive transfer, and had no significant effect on weight gain. Assessment of calf vigor in calves born with assistance may be an important management tool for dairy producers as an indicator that further intervention may be needed to improve health.