Effects of bacterial inoculants in milk on the performance of intensively reared calves

The aim of this study was to evaluate the effects of probiotics on the feed intake, body weight gain (BWG), feed efficiency (FE) and fecal microbiota of intensively reared calves fed milk inoculated with probiotic bacteria in a computerized milk feeder system. Thirty Holstein calves were allocated into three groups: group A, supplemented with an inoculum comprising Lactobacillus casei DSPV 318T, Lactobacillus salivarius DSPV 315T and Pediococcus acidilactici DSPV 006T; group B, supplemented with an inoculum comprising Lactobacillus plantarum DSPV 354T; and group C, control without probiotics. The calves were examined for 21 days. Inocula were added to the tank milk, and the daily dose for each calf was approximately 10 log CFU. The total Lactobacillus, inoculum strains, coliforms, yeast and enterococci in the stool and the total Lactobacillus, inoculum strains and pH in the tank milk were determined weekly. The lactic acid bacteria (LAB) in groups A and B produced enough acid to bring the milk to a pH lower (P < 0.05) than that of the control milk. Fermentation increased the shelf life of the milk, thereby avoiding the need to frequently discard the milk and reducing the costs for the use of the computerized milk feeder system. The probiotics-stimulated milk intake (P < 0.05) was compared with that of the control group. L. casei DSPV 318T, L. salivarius DSPV 315T, P. acidilactici DSPV 006T and L. plantarum DSPV 354T were present in the gastrointestinal tracts of the calves in the probiotics groups. In addition, the Lactobacillus/coliform ratio was greater than 1 in the probiotics groups and lower than 1 in the control group. BWG and FE were higher for group B than for group C. The presence of L. plantarum DSPV 354T and its dominance over coliforms in the fecal microbiota might have positive effects on the growth performance of calves.