日粮添加过瘤胃赖氨酸对利木赞杂交肉牛胴体性状和肉质的影响

Effect of dietary rumen-protected lysine supplementati on level on carcass characteristics and meat quality of Limousin crossbred beef cattle

研究添加过瘤胃赖氨酸对肉牛胴体品质及肉质性状的影响。选用24头利木赞F1杂交公牛分别饲喂添加不同含量的过瘤胃赖氨酸(0、5、10和15 g/d)的日粮。饲喂14周后全部屠宰,测定胴体品质和肉质性状相关指标。结果显示:随着赖氨酸添加量的增加,背膘厚呈线性降低(Y=-0.016X+0.585),其中15 g/d赖氨酸组显著低于对照组(P<0.05)。日粮中过瘤胃赖氨酸的添加量对肌肉肉色b*(P=0.048)产生二次曲线规律的影响。15g/d赖氨酸组的滴水损失和肉样蛋白质的含量显著高于对照组(P<0.05)。随着赖氨酸添加量的增加肉样中天冬氨酸(Y=0.015 2X+7.831)和异亮氨酸(Y=0.008 4X+4.317)含量呈线性升高,但其他氨基酸含量、必需氨基酸、非必需氨基酸及总氨基酸的含量没有显著变化。结果表明,在低赖氨酸日粮中补充适量的赖氨酸,可以降低肉牛背膘厚,增强肉质中蛋白质的合成,同时也会降低牛肉的系水力,但对其他肉质形状没有影响。

Twenty-four Limousin crossbred bulls were used to test the effects of rumen-protected lysine（RPL） supplementations on the carcass characteristics and meat quality.Animals were randomly divided to four groups,where 6 bulls per group receiving one of the following 4 dietary treatments：the control diet,control diet plus 5 g RPLys/bull/day,control diet plus 10 g RPLys/bull/day,and 15 g RPLys/bull/day.All the bulls were slaughtered after 14 weeks at the end of the trial.Results showed that supplementing dietary RPLys caused linearly（Y=-0.016X＋0.585） decreased backfat（BF） depth,i.e.,the treatment with no RPLys supplementation exhibited a higher（P〈0.05） backfat depth than 15 g/d g supplementation.Increasing lysine supplementation resulted in a quadratic effect（P=0.048） in b^＊.15 g/d lysine supplementation exhibited a greater dressing percentage（DP） and meat protein than 0 g/d supplementation（P〈0.05）.ASP（Y=0.015 2X＋7.831） and ILE（Y=0.008 4X＋4.317） of meat increased linearly as lysine supplementation increased.However,lysine supplementation had no effect on the other amino acids,essential amino acids（EAA）,nonessential amino acids（NEAA） and total amino acids（TAA）.