Effects of dietary Saccharomyces cerevisiae live yeast culture supplementation on ruminal digestion and protozoa count in rams fed with diets with low or high ratio forage/concentrate

Abstract

In this study, 4 male one year old Kivircik rams with permanent rumen cannula were used. Feeding of the animals was performed according to 4 x 4 Latin square designs with 20 days periods (15 days adaptation period, 5 days collection period). Animals were fed with two different diet types : Diet 1 consisted of 70 % alfalfa hay and 30 % concentrate diet while Diet 2 consisted of 30 % alfalfa hay and 70 % concentrate. Diet 1 and 2 were supplemented with or without a daily dose of 4 g Yea-Sacc(1026) (20.10(9) CFU/day) Saccharomyces cerevisiae live yeast culture (YS). Rumen contents collected at 0 (before morning feeding), 2 and 4 h (after morning feeding) on days 1 and 5 in each collection period were analyzed for pH, protozoa counts, total volatile fatty acid (VFA) concentration, NH3-N, ruminal cellulolytic activity. When YS was added to the forage-enriched ration (Diet 1), ruminal pH was significantly decreased at 2 hours (P < 0.05) and in parallel, ruminal VFA concentrations tended to increase (P < 0.01). Ruminal NH3-N concentrations were significantly increased at 4 hours (P < 0.05) by dietary YS supplementation whatever the ratio forage/concentrate of the diet. By contrast, protozoa counts and cellulolytic activity were not significantly affected in the presence of YS. These results suggest that the ruminal digestion would be more easily affected by dietary YS addition when rams consumed a diet rich in forage.