Growth and body composition in meat production of Omani Batina goats
Mahgoub, O.; Lodge, G.A.
Small Ruminant Research 19(3): 233-246
ISSN/ISBN: 0921-4488 DOI: 10.1016/0921-4488(95)00762-8
Forty-five Omani Batina buck, wether and doe goats were reared from birth until slaughter at 11, 18 or 28 kg BW. They were fed ad libitum on a concentrate diet (16.5% CP) and Rhodesgrass hay (8.8% CP). Bucks were heavier than does at birth, had the fastest growth rates (118 g day-1) and reached slaughter weights earlier than wethers and does (85 g day-1 and 87 g day-1), respectively. Goats of all sexes had the maximum growth rates during the first month of age. At 28 kg BW, dressing-out percentages (DO) for bucks, wethers and does were 54.4%, 55.9% and 55.5%, yielding carcasses of 14.1 kg, 14.7 kg and 14.0 kg, which contained 68.2%, 61.0% and 59.8% of muscle, 13.9%, 12.4% and 12.5% of bone and 12.1%, 20.2% and 19.1% of fat, respectively. Weights of total body fat were 13.0%, 19.9% and 20.0% of empty body weight (EBW). Proportion of bone in carcass decreased, that of fat increased, whereas that of muscle was isometric in relation to EBW. Over the 11-28 kg BW range the proportion of total edible and total saleable portions of Batina goat increased from 58 to 62% and from 66 to 70%, respectively. Bucks had less fat and more muscle and bone than wethers or does at 28 kg slaughter weight. Over a range of 11-28 kg BW, within the total musculature of the carcass, the proportions of those towards the rear of the body and in distal limbs decreased with increasing BW. Bucks had higher muscle weight in the fore quarters than does which had more muscle in the proximal hind limb and those surrounding the spinal column. Some intrinsic muscles of the neck region were better developed in bucks than wethers and does. Ribs, pelvis and scapula of Batina goats grew at a rate relatively faster than other bones of the skeleton whereas limb bones grew at a slower rate than EBW. Bucks had higher proportions of fore and hind limbs but lower proportions of the axial skeleton than does at 28 kg BW. They also had longer humerus, radio-ulna and femur than does but there were few differences between the various sexes in width or circumference of bones. In general, the magnitude of change in proportions of individual muscles and bones between 11 and 28 kg BW or sex differences was small. Batina goats raised under a closed intensive system performed better than reported for this breed under traditional systems. They yielded lean carcasses (particularly intact males) and had high total edible and saleable proportions of the body.