Abstract
In the first of two experiments, liveweight gain responses and carcass characteristics were investigated using two breeds of growing male goats, local (Dhofari) and exotic (Cashmere), fed on a whole pelleted-high fiber date by-products' based diet at 32.5% level (As-fed) supplemented with 12% fish (sardine), (HF-Fish) and a commercial concentrate diet (conc.). The (HF-Fish) diet was formulated to be iso-nitrogenous to the (conc.) diet, supplying 14% CP (DM-basis). Both diets together with Rhodes grass hay (Chloris Guyana) were fed ad libitum. The experimental design was a complete random arranged in a $2{\times}2$ factorial with breeds and diets as the main factors, using six animals per treatment. The experiment lasted for 84 days and goats were penned individually. At the end of the feeding trial, three animals from each treatment group were slaughtered for carcass evaluation. In experiment 2, diets' digestibility and N-balance were determined using 3 sheep per diet. The (HF-Fish) diet significantly(p < 0.05) improved liveweight gain. There was also a significant difference(p < 0.01) between breeds, with Cashmere gaining more than local goats. Feed conversion efficiency, dressing percent and longissimus dorsi area were not significantly affected by diet or breed(p > 0.05). Digestibility of the proximate components and N-balance for both diets were similar and not significantly different(p > 0.05). Fish supplementation greatly improved the digestibility of CF, ADF, NDF, cellulose and hemicellulose. Meat production ost was decreased by 31% due to feeding of the (HF-Fish) diet.