EFFECf OF GnRH TREATMENT AND YEAST SUPPLEMENTATION ON PE.RFORMANCE OF FHEISIAN CATTLE

Abstract

The present study was carried out at EI-Gemmezah Experimental •l Statioh; Animal Production l{esearch Institute, agricultural Research Center, Ministry or Agriculture. In this concept, three experiments were

conducted during the period II om November 2003 to December 2004 in order to evaluate the eJTect of dry baker's yeast (DUY) either added to diets combined with or without GniZI-1 on growth performance, nutrients digestibility, calving performance, milk yield and composition, postpartum reproductive traits of Friesian heifers and lactating cows as well as rumen parameters of nuns feu the experimental rations. Experiment 1: This experiment was conducteu on 14 Friesian female calves aged I 0-13 months anu wcighcu 205 kg on the average. Animals were diviued into 2 comparable groups (control and DUY supplemented (8g/h/d). Growth performance, nutrients uigestibility and nutritive values were studied. The animals were fed '10'% concentrate feed mixture (CFM) and 60% berseem hay (UI-Jj as well as ad libitum intake of rice straw (RS). Feed intake as total OM was uaily recorded and Iced conversion was computed. Two digestibility trials were carried out using three calves from each experimental group selected at random using the acid insoluble ash (AlA) technique as an internal marker.