EFFECTS OF YEAST (SACCHAROMYCES CEREVISIAE) FEED SUPPLEMENT ON MILK PRODUCTION AND ITS COMPOSITION IN TUNISIAN HOLSTEIN FRIESIAN COWS

A 105-day feed trial was conducted to evaluate the effect of probiotic feed supplement containing Saccharomyces cerevisiae on milk yield and its composition in Holstein Friesian cows. The trial was conducted in the region of Sidi Bouzid in the west of Tunisia. Effects of Saccharomyces cerevisiae have been investigated on eight Holstein Friesian cows randomly divided into two groups of four animals on the basis of age, body weight, average milk yield, and lactation number. The first group was supplemented with 2.5 g/cow/day of probiotic yeast Saccharomyces cerevisiae (2.5 1010 CFU/day) and the second group (control) was without the yeast. The study showed that supplementation with 2.5 g of yeast Saccharomyces cerevisiae per cow per day or 2.5 1010 CFU/day tended (P 0.06) to increase milk production by 1.1 kg/cow. By cons, there was a significant increase of fat (P 0.01; 52.8 and 46.9 g/cow/day) and protein (P 0.05; 41.7 and 38.7 g/cow/day) content both for treated and control group, respectively. It is concluded that supplementation of Saccharomyces cerevisiae at 2.5 1010 CFU/day in the diet of dairy cows may have positive influence on milk fat and protei n yield (g/cow/day).