Improvement of serum B12, certain biochemical variables and rumen function indicators after live yeast feeding with or without cobalt in dairy cattle with signs of impaired digestion

Résumé 0

The objective of this study was to evaluate under field conditions the effect of live yeast feeding with or without cobalt on rumination time, manure score and serum concentrations of vitamin B12, blood urea nitrogen (BUN), total protein (TP), albumin and fructosamine in dairy cattle with impaired rumen function. The study was conducted in a commercial dairy herd in a commercial dairy herd of 94 milking cows and lasted for for 75 days. The first 15 days (Day -15 to Day -1) the animals were fed the basal total mixed ration without supplementation of live yeast or Co and served as control period. The evaluation period lasted for sixty days (Day 0 to Day 60). During days 0 (D0) to 30 (D30), the cows were fed the basal ration supplemented with a commercial live yeast product (4gr/cow/day), and during days 31 to 60 (D60) were fed the same ration supplemented with live yeast and cobalt (cobalt carbonate; 6mg/cow/day). Rumination time was evaluated daily using a commercial monitoring system. Prior to the onset (D0) and at the end of the first (D30) and second month (D60) of the study manure was scored and blood samples were obtained. Rumination time was higher and manure scores were improved on D60 than D0. Serum B12 concentration was higher on D30 and even higher on D60 compared to D0. BUN was unaffected on D30 but significantly lower on D60 than D0 and D30. Serum albumin was lower on D30 and D60 compared to D0 whereas serum globulins concentration was significantly different between all sampling days and the highest value was recorded on Day 30. Serum fructosamine was significantly higher at the end of the study than D0. Combined in-feed inclusion of live yeast and cobalt improves digestion, serum B12 levels, and energy status of dairy cows with impaired rumen function and provide evidence for possible acute phase reaction by live yeast feeding