Effect of Yeast Supplement to The Rations Differed in Degradable Protein in Milk Production and Components in Cow.

Abstract

This study was conducted in the animal farm college of agriculture and forestry/ Mosul university by using three multiparous Friesian dairy cows in the 95 ± 12 of DIM, average body weight 399.67 kg, using latin square design (3 × 3) with three period each was lasted 21 days. The cows was placed in individual pen and fed with three rations; first one was control consist of barley, wheat bran, soybean meal and contained 10% rumen degradable protein as dry matter base (T1), second ration was similar to the control with addition 35 g / cow per day of yeast (Saccharomyces Cerevisiae) T2, while in the third, rumen degradable protein was increased to 12% of dry matter by urea with addition 35 g / cow per day (T3). Cows were fed with 7.5 kg of concentrate and 2.25 kg wheat straw ,with grazing for 5 – 6 hr daily. Results showed no significant increase in milk yield in T2 and T3 11.109 and 11.029 kg/ day, fat corrected milk 4% 9.365 and 9.795 kg/ day as compared with T1 9.826 and 8.402 kg/ day respectively. Also it was noted no significant differences in milk fat 3.05, 2.96, 3.20%, protein 2.85, 2.78, 2.81%, lactose 4.25, 4.15, 4.20% and energy 605, 589, 616 kcal/ kg. It was noted that the differences was not significant in blood parameters.