Effect of a Direct-Fed Microbial Product on Calf Performance and Fecal Flora

Abstract Thirty-eight Holstein bull calves were used to evaluate the effect on young calves of daily dietary supplementation with a direct-fed microbial. Calves were randomly assigned at birth to one of two treatments; 1) milk replacer with no direct-fed microbial or 2) milk replacer supplemented once daily with 0.25 tsp of a microbial product. The microbial product contained a mixture of Streptococcus faecium, Lactobacillus acidophilus, Saccharomyces cerevisiae, Bacillus subtilis, and Aspergillus oryzae fermentation products. The dose given provided 8.8 × 10 8 cfu of lactic acid producing bacteria and 8.8 × 10 8 cfu live yeast cells. Calves were on their respective treatments for 8 wk. Milk replacer was not medicated and was fed at 5% of BW twice daily. A commercial calf starter was offered for ad libitum intake. Treatment had no effect on actual BW, total BW gain, average daily gain or wither height. Starter intake, total DMI, and feed efficiency were unaffected by treatment. Fecal coliform, and lactobacilli counts on d 0, 14, and 28 were similar between treatments. No appreciable effects on Cryptosporidium parvum occyst shedding were detected by the feeding of a microbial product.