Impact of Saccharomyces Cerevisiae and/or Its Cell Wall Supplementation in Dairy Cow Diet on Passive Immunity Transfer in their Calves

Early detection of failed transfer of passive immunity (FTPI) is crucial to prevent neonatal diseases and mortality. This study evaluates the effect of supplementing dairy cows with Saccharomyces Cerevisiae and/or a yeast wall during the last month of pregnancy on the transfer of passive immunity to calves. Forty-five Montbeliarde dairy cows were divided into four groups: a control group (CON; n=13) with no supplementation, an SC group (n=12) receiving 5 g/day of S. Cerevisiae yeast, a YW group (n=10) receiving 5 g/day of yeast wall (20% mannans, 20% β-glucans), and an SCYW group (n=10) receiving a combination of 5 g SC and 5 g YW. At calving, colostrum and blood samples were collected to measure calf serum IgG concentration using radial immunodiffusion (RID) and compare results with the %Brix refractometer. A one-way ANOVA assessed the effects of supplementation type, colostrum quality, and calf sex. A Spearman correlation test evaluated the %Brix refractometer as an indirect tool for IgG estimation. Results showed a significant improvement in passive immunity transfer with supplementation (P<0.001), particularly in the SC and SCYW groups (P<0.01). Colostrum quality had a significant effect, whereas calf sex had no impact. A positive correlation (r=0.536) was observed between RID and %Brix. In conclusion, supplementing dairy cows with yeast during the last month of pregnancy enhances passive immunity transfer. The %Brix refractometer is a viable alternative to RID for estimating serum IgG concentration and detecting FTPI cases.