Effect of Lactobacillus acidophilus supplementation of milk replacer on preweaning performance of calves.

Forty Holstein-Friesian calves were used to evaluate the effect on young calves of daily dietary supplementation with Lactobacillus acidophilus. Calves were randomly assigned at 2 d of age to one of two treatments; 1) milk replacer with no additives or 2) milk replacer supplemented with 1 ml (5 x 10(7)) of viable L. acidophilus bacteria at each of two feedings per day. Milk replacer was reconstituted to 12% DM and fed at 10% of BW/d for the duration of the 6-wk trial. A commercial starter pellet was offered for ad libitum intake from 7 d of age. Treatment had no effect on actual BW at any stage or on total BW gain; however, average daily gain during wk 2 was affected by L. acidophilus supplementation. Calves receiving L. acidophilus maintained initial BW, and the control calves lost BW until 2 wk of age, at an average rate of 112 g/d. Starter intake, total DMI, feed efficiency, and occurrence of diarrhea were unaffected by treatment. Therefore, L. acidophilus supplementation for calves fed milk replacer may be beneficial during the first 2 wk of life.