Abstract
This study aimed to determine the optimal feeding time of microencapsulated sodium butyrate (SB) in whole milk (WM) and starter feed on growth performance and health in dairy calves. Forty-eight Holstein calves (age = 4 d; body weight [BW] = 39.45 ± 2.48 kg) were randomly allocated to 1 of 4 treatment groups (12 calves per treatment) in a completely randomized block design and fed (1) WM without microencapsulated SB (SB0) supplementation; (2) 4 g/d SB added to WM since d 4 to 32 (SB4); (3) 4 g/d SB added to WM since d 61 to 74 and equal amount was added to starter since d 75 to 88 (SB60); and (4) 4 g/d SB added to WM (since d 4 to 74) and the starter (since d 74 to 88) throughout the experiment (SBT). Calves fed SB4 and SBT had lower fecal score during pre-weaning, transition period, and overall period (P = 0.043, P = 0.05, and P = 0.015; respectively). In addition, calves in SB4 and SBT groups decreased the number of days with scours during pre-weaning period, and throughout study (P = 0.035 and P = 0.025; respectively). SB60 calves had greater serum total protein (P < 0.001) during post-weaning period. Post-weaning and overall albumin concentrations were greater in SB4 and SBT calves (P = 0.011), and tended to increase in pre-weaning period compared to control calves (P = 0.06). Based on these results, addition of SB in WM is recommendable for the first month of milk-fed calves life.