Abstract

ElObied G. H. and Ali J. A

A study was conducted in Rahad Agricultural Corporation with the objective to find the optimum level of concentrate that can offset live weight (lwt) loss during summer. Thirty Kenana x Friesian 1-1.5 year old calves were allocated to five levels of concentrate supplement (CS); 0, 0.5, 1.0, 1.5 % of animal body weight and CS 100%. In treatment groups, where CS was proportionate to body weight, ad libitum sorghum straw was offered as basal roughage. Feed DM, OM, CP and CF were evaluated. Rumen fluid was analyzed for pH, NH3 and protozoal count. In blood, haemoglobin (Hb) and heamatocrit (PCV%) was examined. The results showed that the digestibility of DM, OM, CP, CF and total dry matter intake (DMI) increased significantly with increasing level of CS in the ration. Rumen fluid pH was not affected by supplementation but was significantly decreased (P0<05) in exclusively concentrate fed calves (100% CS). Rumen NH3 was not affected by the level of supplement except in 100% CS feeding. Total protozoal count was unaffected by the different levels of CS. Both Hb and PCV% were significantly (p<0.01) increased with higher levels of CS. Optimum levels of CS was found at 0.34% of animal body weight. It could be concluded that CS of 0.5 % of body weight of calves improved feed digestibility, blood Hb and PCV% and prevented live weight loss. Increased CS levels of 1% and 1.5% increased significantly (P<0.1) MR compared to full concentrate feeding.