The effects of feeding system and breed on the performance and meat quality of weaned lambs

Selecting proper animal genotype that suits particular environment, management systems, market requirements and food processing is a fundamental step to achieve efficiency in livestock operations. Thus, this study compared the performance and meat quality of the fat-tailed, Akkaraman (AKK) and crossbred, Anatolian Merino (AMR) lambs under the feeding systems of annual forage mixture (AFM), perennial pastures (PAS) or concentrated-based (CON). There were no consistent breed differences for liveweight gain (LWG) but AKK lambs that were fed AFM had greater NDF intake and digestibility than AMR lambs (P < 0.01). Lambs that consumed forage-based diets had lower slaughter weights and weight-related carcass traits than lambs on CON (P <0.05). Dressing percentage was greater for AKK compared to AMR across all diets (P < 0.05). However, AMR had a greater meat to bone ratio and more intermuscular fat in the thoracic region than AKK (P < 0.01). The ratio of n6 to n3 fatty acids was lower with forage-based diets compared to CON (3.9 and 5.4, respectively). However, CLA isomers (C18:2, cis-9 trans-11 and C18:2 trans-10 cis-12c) and alpha-linolenic acid (C18:3 cis-9, cis-12, cis-15) composition of the fatty acids were all greater with forage-based feeding (P < 0.01). Ratios of n-6/n-3 FA were lower in PAS and AFM groups compared to CON indicating the superiority of forage based diets on producing higher meat quality. High CLA content of meat from pasture-fed fat tailed AKK lambs suggest positive human health benefits given tail fat is widely used in traditional cultural dishes.