| Popis: |
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. |
