Effects of YANG (multi-strains yeast) supplementation effects on health and performances in male Holstein calves

The objective of this study was investigate the effects of a multi-strains yeast (S. cerevisiae and C. jadinii) fractions product, YANG, on the health and performance of young male dairy calves (17±3d). At a commercial farm, 158 veal calves were enrolled and divided in two groups: a control group (CTR) 57 animals (no supplementation) and a treated one (TRT) 101 animals (YANG supplementation), both balanced for live weight. TRT received YANG through the milk replacer: 5g/h/d during the first 30d, then 3g/h/d until d90. From d90 to 190 (slaughter) the diet was the same for both groups. For all animals, individual carcass weights, mortality and morbidity (veterinary treatments) were collected. Blood parameters (Hg, RDW, MCV; d30, 73, 115, 150) and electrophoresis for blood protein characterization (d47, 118) were analysed in 23 randomly selected animals (12 CTR and 11 TRT). On sampled animals, body weights were measured (d0, 47, 82). No differences were observed on carcass weights at slaughter and carcass classification between the two groups. However, sampled animals’ ADG was impacted. ADG from d0 to 47 and 47 to 82 was 263g/d and 321g/d higher, in TRT than in CTR (0.47kg/d, P=0.01; 1.01kg/d, P<0.01 respectively). No difference was observed in mortality, however health of calves was improved. Morbidity was reduced from 56% in CTR to 38% in TRT (P=0.02), with a reduction of number of chronic animals (≥2 treatments per animal) by 50% (P=0.03). Numerically, the reduction of veterinary treatments was mainly due to reduction of enteric treatments in TRT (-25.6%). TRT animals showed higher content of total proteins (P<0.01), with higher percentage of γ-globulins (P<0.01) and higher percentage of α1-globulins (P<0.01). These analyses are in favour of a better activated immune system of veal calves in TRT. No differences were observed on RDW and MCV. No differences in Hg average concentration, but more homogeneity in TRT. This study demonstrates that the health of veal calves was improved during their whole lifecycle with the addition of YANG in the milk replacer during the first 90d. These results are in line with reduction in use of antimicrobial treatments in farms.