Authors : J.M. Graves, S.H. Ward and B.J. Rude
Abstract: Total 40 (n = 8) Holstein heifers were used to evaluate growth and health when supplemented with coccidiostat, mannanoligosaccharide or β-glucan in milk replacer. Calves were randomly assigned to one of five treatments at birth: CX (1 g day-1 Deccox), MOS (10 g day-1 MOS), β-g (0.5 g day-1 β-glucan), CX+MOS (1 g day-1 Deccox+10 g day-1 MOS) and MOS+β-g (10 g day-1 MOS + 0.5 g day-1 β-glucan). Heifers received 3.8 L milk replacer (22% CP, 20% fat) once daily until 6 weeks of age but remained on trial for 56 days. Calves were fed a non-medicated starter (18% CP) at 0.9 kg day-1 and increased by 0.9 kg day-1 when orts = 0. Orts were collected and weighed daily and pooled by week within treatment. Calves had ad lib. access to clean water. At birth, calves were fed colostrum via esophageal tube, weighed and measured. Fecal and respiratory scores were recorded daily body measurements, blood and fecal samples were collected weekly. Fecal samples analyzed for coccidia bi-weekly after 21 days at 2, 4 and 8 weeks fecal samples were analyzed for E. coli. Blood samples were analyzed for CBC weight/differential. There were no significant differences in DMI (p<0.93), FE (p<0.95), ADG (p<0.79) or blood analysis (p>0.10) among treatment groups. Given similar diets fed, no changes in growth or intake were expected. No differences in fecal or respiratory scores, CBC or other health measures indicated that supplementation with MOS, β-g or a combination supported immune function similarly to CX. Fecal shedding of E. coli was not different across treatments (p<0.23), however orthogonal contrasts showed greater E. coli from MOS+β-g (80.4 x 104 CFU μL-1 feces) compared to β-g (23.2x104 CFU μL-1 feces; p<0.04). There was also a trend for calves fed MOS to shed more E. coli compared to the calves fed β-g (70.3 vs. 23.2x104 CFUs μL-1 feces, respectively, p<0.06). E. coli shedding decreased over time (114.6, 49.4 and 5.0x104 CFU μL-1 feces at weeks 2, 4 and 8, respectively; p<0.01).
J.M. Graves, S.H. Ward and B.J. Rude, 2013. Performance of Neonatal Holstein Heifers Fed Yeast Derivatives in Milk Replacer. Research Journal of Dairy Sciences, 7: 1-5.