EFFECTS OF DIETS WITH INACTIVE DRY YEAST ADDITION ON PRODUCTIVITY AND HEALTH STATUS IN DAIRY COWS

This study evaluated the influence of inactive dry yeast in diets of dairy cows on productivity, blood-urine parameters, and faecal score. The research was carried out on a number of 30 Romanian Black and Spotted lactating dairy cows, with 583 +/- 16.99 kg live weight, divided into three groups (n=10), two experimental E-1 and E-2 groups, and one control group (C). The experimental group E1 received 120g inactive dry yeast/head/day, while the experimental group E-2 received 150g inactive dry yeast/head/day during a 28 days trial. Dietary treatment effects were determined using analysis of variance (ANOVA) for repeated measures (mixed model). Supplementation of the diet with inactive dry yeast generated an increase of milk yield (P<0.10) for the E-1 and the E-2 groups, compared with the C group. For the milk lactose percentage, a treatment influence (P<0.05) and period influence (P<0.10) between the studied groups were observed. Also, for some blood indicators, a dietary treatment influence was recorded. There were no significant effects of the treatments on the other studied parameters. Dry yeast addition in dairy cows diets can have a positive effect on milk yield performance.