46 The effects of forage-based and a concentrate feeding system on lamb production.

摘要

This study compared the performance and meat quality of the weaned lambs of the fat-tailed, Akkaraman (AKK) and Central Anatolian Merino (CAM) breeds under forage and concentrate-based feeding systems in Central Turkey. A total of 54 lambs of both genotypes were fed indoor either daily harvested triticale-Hungarian vetch (T-HV) mixture (rainfed) or concentrated feed. Another group of lambs grazed perennial pasture (irrigated) that consisted of tall fescue, perennial ryegrass, orchard grass, white clover and birdsfoot trefoil. The experiment was commenced in spring 2016 and continued for 63 days in three, 21-day periods. All lambs were slaughtered to determine their carcass characteristics and meat quality traits at the end of the fattening period. Lambs that were fed concentrate had greater( <0.05) dry matter intake than those had forage-based diets. In relation to the feed intake and digestibility of the diets, the liveweight gains of the lambs that consumed T-HV and pasture were lower ( <0.05) than those were fed on concentrate. In addition, the in vivo digestibility of T-HV mixture and pasture decreased ( <0.01) as the season progressed. Consequently, the lambs consumed forage based diets had lower ( <0.05) final liveweights at the slaughter than the lambs consumed concentrate diet. Similarly, weight-related carcass traits were greater ( <0.05) for the lambs that consumed concentrate than those were fed on forage-based diets. The results indicated that the n63 ratio of fatty acids was lower ( <0.05) with forage-based feeding system as compared to concentrate-based feeding. However, C18:2, cis-9 tran-11 and C12:2 trans-10 cis-12 and α-linolenic acid (C18:3n3) composition of the fatty acids were greater (P <0.05) with forage-based feeding. There was no major difference between AKK and CAM lambs for performance and meat quality parameters except, AKK had lower tallow contents than CAM under concentrate feeding system.