Effect of adding dry bread yeast Saccharomyces cerevisiae on nutrient digestibility, pH and some blood Characteristics in Awassi rams
The aim of the study was to find out the effect of adding several levels of yeast on digestibility of nutrients, some characteristics of rumen fluid and a number of blood parameters. It was achieved in the animal house of the College of Veterinary Medicine / University of Tikrit from 15/7/2017 until 01/10/2017. 16 Awassi rams were used with (36±0.34 kg) initial weight, and (10-12 months) of age. The animals were distributed into four experimental groups (4 lambs per group), and fed on four diets to which the yeast was added. The diets were included in the second groups T2, the third T3 and the fourth T4 on the yeast at rates of 3 g, 5 g and 7 g head /day respectively. It was provided with wheat hay as roughage feed in libtum form, and concentrated feed at a rate of 2.5% of the live weight measured weekly for a period of 75 days. The digestibility of organic matter increased with an upturn in the percentage of yeast in the diet (56.022, 60.529, 64.402 and 63.843), as well as the fiber digestibility factor (59.461, 62.325, 68.568 and 67.413). While the protein digestibility index decreased in T2 and T3 compared with the control group (56.403, 64.955, and 68.853 respectively) while the differences were not significant for the digestibility of dry matter and fatty matter. Rumen pH was increased to 9.675 after hours after eating the feed for the group that added 5 g / day of yeast to its diets. As for the blood parameters, the protein level decreased to 4.825 mg / 100 ml blood for the group that added 5 g / day. A day of yeast to its diet, compared to the control group, which was 5.550 mg / 100 ml of blood.