Effect of saccaromyces cerevisiae supplementation on rumen characteristics in awassi lambs fed diets with different roughage to concentrate ratios

الملخص EN

Thirty two Awassi male lambs with initial body weight(27±1.78 kg), and four to five months old, were allocated into four equal groups in factorial experiment to study the effect of two roughage to concentrate rations (R:C, 60:40 and 40:60) supplemented with two levels of Saccharomyces cerevisiae (0 and 5 g S.

cerevisiae / head / day) on rumen fermentations rate[Total volatile fatty acids(TVFA) ,pH and ammonia concentration (NH3-N)] .

The diets were offered in quantity to achieve 150 g daily gain .Results shown no differences in daily dry matter intake(DMI) and daily gain across treatments.

As well as no significant effect for R: C ratio on TVFA and pH whereas, propionic, butyric acids and NH3-N increased significantly (P<0.05) with high concentrate diets, but the molar proportion of acetic significantly (P<0.05) decreased with high levels of concentrate diets.

S cerevisiae supplementation showed significantly (P<0.05) increased in TVFA, propionic and butyric acid, whereas, significantly (P<0.05) decreased acetic acid and NH3-N.

Significant(P<0.05) interaction were shown between high level of concentrate and S cerevisiae supplementation in TVFA, propionic, butyric acid ,acetic acid and NH3-N whereas, no significant effect on pH .In conclusion ,S cerevisiae supplementation to high concentrate diet significantly (P<0.05) increased TVFA, propionic and butyric acid, whereas, significantly (P<0.05) decreased acetic acid and NH3-N