Effect of dry live yeast as feed additive on lactating cows and growing sheep performance

Abstract

Dry live yeast, Saccharomyces cerevisiae, (SC) as feed additive in cows and sheep rations were nutritionally evaluated through three trials of digestibility, lactation for cows and growth for sheep. The levels of yeast supplemented were 0, I 0, 20 and 30 g/head/day for cows and sheep to find out the best level of dry live yeast. Accordingly, the tested rations were R 1 , R2 and R3 along with the control ration (C) forming 4 treatments. The control ration (C) was composed of 50% concentrate mixture, 40% clover plus I 0% wheat straw. At the end of lactation and growth trials. simple economic evaluation was estimated. The results showed that the yeast contained 45.62% CP, 2.25% EE, 3.0% CF, 42.23% NFE and 6.9% ash. Nutrient digestibilities of the tested rations were insignificantly improved by adding yeast. The feeding values of the tested rations were better wheri yeast was added. Feed intake of lactating cows was significantly higher (p :'0 0.0 I) by adding yeast. Moreover, milk

yield and milk composition were improved with yeast supplementation. From economical point of view use ofR 1 (I 0 g/yeast/cow/day) could be recommended to improve milk production and feed conversion. Lambs body weight gain and feed conversion were significantly improved (p :'0 0.05) by adding dry live yeast. It could be concluded that R 1 (I0 g yeast/lamb/day) could be used• as growth promoter for •growing sheep ration.