日粮中添加亚麻籽对羔羊产肉性能和肉品质的影响

Effects of Dietary Linseed Supplementation on Performance,Carcass Characteristics and Meat Quality of Lamb

本试验旨在研究日粮中亚麻籽水平对羔羊产肉性能和肉品质的影响及其调控机理。本试验选取2月龄健康萨福克(♂)×小尾寒羊(♀)F1代羔羊32只随机分为4组,每组8只。日粮为试验处理,分别为含0%(对照组)、5%、10%和15%亚麻籽(干物质基础)的日粮,各组蛋白及能量水平相同,试验期60d。结果表明,羔羊日粮中添加5%和10%亚麻籽可以提高羔羊的生产性能和产肉能力,改善羔羊日增体质量(P<0.05)、胴体质量及料重比(P<0.01)。随着添加亚麻籽水平的提高,肌肉中水分含量下降(P<0.01),粗脂肪含量上升(P<0.01);血液中总胆固醇、甘油三酯和游离脂肪酸的含量依次上升,但未达显著水平(P>0.05);脂肪酶活力随着亚麻籽添加量的增加而减小。添加5%～10%亚麻籽改善了羔羊肉品质,随着亚麻籽添加量的增加,熟肉率、肌内脂和肌小节片断化指数(MFI)均显著提高(P<0.01),提高了肉的嫩度,而肌肉的抗氧化能力降低,但对肌肉肉色无显著影响(P>0.05)。日粮中亚麻籽的添加增加了肌肉中PUFA(P<0.01)、CLA(P<0.01)和亚麻酸(P<0.01)的含量,以及PUFA中n-3与n-6的比例(P<0.01)。结果提示,羔羊日粮中添加5%～10%亚麻籽能够提高生长性能,通过提高羊肉中不饱和脂肪酸,尤其是CLA含量,改善羊肉品质。

This experiment was conducted to study the effects of feeding different linseed level diets on performance, carcass characteristics and meat quality of lamb, and its mechanism. Thir- ty-two F1 lambs （two months old） of Suffolk sheep（ ♂） × Small-Tailed Han sheep（♂） were allo- cated into four groups with eight replicates in each group. Lambs were fed the diet with 0% （con- trol group）, 5%, 10% or 15% linseed （DM basis）. The experiment lasted 60 days. All the diets were designed to contain similar contents of crude protein and digestible energy. The results showed that feeding diet containing 5% and 10% linseed could improve the performance, ADG（P〈0.05） and carcass weight（P〈0.05）of lambs, and decrease the ratio of Feed/Gain（P〈0.01）. With the increasing of linseed content in the diet, water content of muscle was decreased （P〈 0.01） and the fat content in the muscle was increased（P〈0.01）. The contents of total cholester- ol, TG and free fatty acid in the blood tended to increase （P〉0. 05）. The activity of lipase decreased. The diet containing 5% to 15% linseed significantly modified meat quality of lamb. Linseed improved cooking percentage, intramuscular fat and MFI （P〈0. 01）of muscle, so it improved the muscle tenderness. Linseed in diet declined the oxidation resistance, but had no effect on the meat color（P〉0.05）. Linseed supplement improved the fatty acid profile, especial- ly increased the amounts of PUFA（P〈0.01）, CLA（P〈0.01）, linolenic acid（P〈0.01） and the ratio of n-6 to n-3 PUFA（P〈0.01）. Diet containing 50% to 10% linseed could increase growth performance and improve the meat quality through optimizing fatty acid profile and increasing PUFA content, especially CLA content of meat.