The effects of mannan oligosaccharide and Streptococcus faecium addition to milk replacer on calf health and performance

The objective of the current study was to examine the effects of offering calves milk replacer containing either mannan oligosaccharide (MOS), a probiotic (PRO) in the form of Streptococcus faecium, or a combination of both, on the health and growth performance of dairy bred calves in a group housed situation using computer controlled milk feeders. A total of 80 calves (40 heifers, 40 bulls) were assigned at 5 days of age to one of 4 treatments: 600 g/calf/day of a 23% crude protein milk replacer with no supplement added (C); C with the addition of 10 g MOS/calf/day (MOS); C with probiotic included in the milk replacer (PRO); and C with both MOS and PRO included (MOS + PRO). Treatments were balanced for ZST score, birth weight and gender. Mannan oligosaccharide was added automatically using additive dispensers attached to the automatic milk feeders. Calves remained on the treatments until weaning which occurred when a concentrate intake of 0.6 kg/day was achieved for 4 consecutive days. Despite calves offered MOS or PRO consuming significantly more concentrate at 4 weeks of age, no differences in calf growth above that achieved by the control treatment were found during the study. MOS, PRO, and MOS + PRO addition to the diets reduced the faecal score of calves compared with unsupplemented calves. However, no reduction in the number of scour episodes was found. In summary, MOS or PRO inclusion in the diet of pre-wean dairy calves increased concentrate intake in early life without affecting calf performance although calves offered these supplements had improved faecal consistency.