Effect of feeding starter containing butyrate salt on pre- and post-weaning performance of early or normally weaned calves

Two experiments were conducted to examine the influence of the starter supplemented with butyrate salts on the performance of Holstein calves. Twenty-three and thirty-five male calves were used in the Experiment I and II, respectively. Total duration of the experiments are 70 d (35 d pre-weaning and 35 d post-weaning) and 100 d (60 d pre-weaning and 40 d post-weaning), respectively. In both of the experiments, all calves were kept together with their dam and fed colostrum for the first 3 days after calving and then housed in calf hutches. Calves were fed individually whole milk (4 l/d) with two meals and starter diets ad libutum in pre-weaning period, while total mixed ration contained starter (60%) and alfalfa hay ground (40%) were used in post-weaning period. The starter diets contained 0 (without butyrate salt, CON), 1.5 g/kg sodium butyrate (NaB15), and 3.0 g/kg sodium butyrate (NaB30) in the experiment I, 0 (without butyrate salt, CON), 2.5 g/kg calcium butyrate (CaB25) and 5.0 g/kg calcium butyrate (CaB50) in the experiment II. Live weight, live weight gain and feed intake of calves were determined weekly in each experiment. Feeding starter containing NaB increased significantly (P< 0.05) live weight, live weight gain, and feed conversion efficiency of calves during pre-weaning period, but did not post-weaning period. On the other hand, feeding starter supplemented with CaB did not affect performance of calves in both periods. The present results suggest that the inclusion of NaB in starter feeds could be recommended for calves in early weaning program.