Slaughter Characteristics of Feedlot-Finished Premium South African Lamb: Effects of Sex and Breed Type.

This study compared the carcass characteristics of ram and ewe lambs from South African wool, dual-purpose, meat, and fat-tailed sheep types, reared to produce premium lamb carcasses. The lambs were reared on a feedlot diet (10.41 MJ ME/kg feed and 19.06% crude protein) from weaning (30 kg live weight) until they attained a back-fat depth of ~4 mm, measured using ultrasound. After slaughter, the carcasses were assessed for retail cut yields, composition, and physical meat quality. Later, maturing lambs attained heavier carcass weights than early maturing breeds (~20.7 kg vs. 16.9 kg, respectively; p ≤ 0.05), and differences in carcass composition and retail cut yields were ascribed to differences in the frame size and pattern of fat deposition of the respective breeds. Small differences in physical meat quality were observed, with meat from Dormer and Namaqua lambs having notably higher shear-force values (~46 N) than that from Meatmaster carcasses (~34 N). These differences though are expected to have little influence on the perceived quality of the meat.

Effect of the g.98535683A>G SNP in the CAST gene on meat traits of Nellore beef cattle (Bos indicus) and their crosses with Bos taurus.

The objective of this study was to estimate allele frequencies of the g.98535683A>G:BTAU7 SNP in the CAST gene in different genetic groups of beef cattle produced in Brazil (Nellore and their crosses with Bos taurus), and to evaluate associations between this polymorphism and meat traits. Five hundred animals from six different genetic groups were genotyped and phenotyped for shear force (SF), myofibrillar fragmentation index (MFI), rib eye area, backfat thickness, and total lipids. Alleles A and G of the SNP were detected in all genetic groups and the frequency of A was higher than G. Significant association (P<0.05) was observed between the polymorphism and meat tenderness (SF and MFI), in which genotype AA exhibited the best values. These results demonstrate for the first time the occurrence of the studied SNP in a Zebu breed and its potential application to the genetic improvement of meat tenderness in the Nellore breed (Bos indicus) and its crosses with Bos taurus.

Effect of including linseed in a concentrate fed to young bulls on intramuscular fatty acids and beef color.

The effect of varying concentrate composition to include 5% linseed and 200 IU of vitamin E on the growth performance, fatty acid composition, and muscle color during shelf life was assessed in 46 young Pirenaica bulls finished to two fatness levels. Adding 5% linseed lowered the dressing rate without altering daily gain or carcass classification. It likewise did not alter the total saturated, monounsaturated, or polyunsaturated fatty acids in the intramuscular fat, though the percentage of α-linolenic acid and n-3 fatty acids increased significantly while the n-6 fatty acid to n-3 fatty acid ratio decreased. Higher subcutaneous fat cover depth at slaughter increased the total percentage of oleic acid and monounsaturated fatty acids without affecting the percentage of saturated or polyunsaturated fatty acids. Adding 200 IU of vitamin E in addition to linseed did not alter the color of film-wrapped fresh meat during storage in darkness.