苜蓿草粉对育肥猪肉品质、肌肉氨基酸和脂肪酸含量的影响

Effects of Alfalfa Meal on Meat Quality,Muscle Amino Acids and Fatty Acids Contents of Finishing Pigs

本试验旨在探讨饲粮添加苜蓿草粉对育肥猪生长性能、肉品质、肌肉氨基酸和脂肪酸含量的影响。选择平均体重(60.28±0.73)kg的健康"长×大"或"大×长"二元育肥猪130头,随机分为5组,每组26个重复,每个重复1头猪。对照组饲喂基础饲粮,试验组在基础饲粮中分别添加5%、10%、20%和30%的苜蓿草粉。预试期7 d,正试期72 d。结果表明:1)5%苜蓿草粉组育肥猪的平均日增重(ADG)最高,增重成本最低。2)饲粮添加苜蓿草粉对育肥猪的肌肉p H45 m in、熟肉率、大理石纹和肉色无显著影响(P>0.05);与对照组相比,各苜蓿草粉组的肌肉p H24 h极显著降低(P<0.01);30%苜蓿草粉组的肌肉滴水损失显著低于对照组和5%苜蓿草粉组(P<0.05)。3)与对照组相比,20%苜蓿草粉组育肥猪的肌肉鲜味氨基酸(DAA)(天冬氨酸、谷氨酸、甘氨酸、丙氨酸)、必需氨基酸(EAA)(蛋氨酸、缬氨酸、异亮氨酸、苯丙氨酸、亮氨酸、苏氨酸、赖氨酸)、组氨酸、精氨酸、酪氨酸、丝氨酸、脯氨酸及总氨基酸(TAA)含量显著提高(P<0.05)。4)随饲粮苜蓿草粉添加水平的增加,育肥猪的肌肉饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)含量逐渐减少,肌肉不饱和脂肪酸(UFA)、多不饱和脂肪酸(PUFA)、n-6 PUFA和n-3PUFA含量逐渐增加。与对照组相比,20%和30%苜蓿草粉组的肌肉M UFA、油酸含量显著降低(P<0.05),肌肉UFA含量显著提高(P<0.05);20%和30%苜蓿草粉组的肌肉PUFA、亚油酸、α-亚麻酸、n-6 PUFA和n-3 PUFA含量均显著高于对照组、5%和10%苜蓿草粉组(P<0.05);肌肉n-6 PUFA/n-3 PUFA含量极显著低于对照组、5%和10%苜蓿草粉组(P<0.01)。综上,饲粮添加20%苜蓿草粉可使育肥猪的肌肉DAA、EAA含量以及PUFA中亚油酸、α-亚麻酸含量提高,n-6 PUFA/n-3 PUFA降低,有利于n-3 PUFA在肌肉中的富集,可以提高猪肉品质和营养价值。

This experiment was conducted to investigate the effects of dietary alfalfa meal on growth performance, meat quality, muscle amino acids and fatty acids contents of finishing pigs. One hundred and thirty healthy “Landrace×Yorkshire” or “Yorkshire ×Landrace” finishing pigs with average body weight of （60.28±0.73） kg were randomly assigned to 5 groups with 26 replicates per group and 1 pig per replicate. Pigs in control group were fed a basal diet, and the others were fed the basal diet supplemented with 5%, 10%, 20% and 30% alfalfa meal, respectively. The pre-experiment lasted for 7 days, and the experiment lasted for 72 days. The results showed as follows： 1） average daily gain （ADG） of finishing pigs in 5% alfalfa meal group was the highest and the weight gain cost was the lowest. 2） Dietary alfalfa meal had no significant effects on muscle pH 45 min , cooked meat percentage, marbling score and meat color of finishing pigs （ P 〉0.05）. Compared with control group, muscle pH 24 h in all alfalfa meal groups was significantly decreased （ P 〈0.01）. Muscle drip loss in 30% alfalfa meal group was significantly lower than that in control group and 5% alfalfa meal group （ P 〈 0.05 ）. 3） Compared with control group, the contents of delicious amino acid （DAA） （aspartic acid, glutamic acid, glycine, alanine）, essential amino acid （EAA） （methionine, valine, isoleucine, phenylalanine, leucine, threonine, lysine）, histidine, arginine, tyrosine, serine, proline and total amino acid （TAA） in muscle of finishing pigs in 20% alfalfa meal group were significantly increased （ P 〈0.05）. 4） With dietary alfalfa meal supplemental level increasing, the contents of saturated fatty acid （SFA） and monounsaturated fatty acid （MUFA） in muscle of finishing pigs were gradually decreased, while the contents of unsaturated fatty acid （UFA）, polyunsaturated fatty acid （PUFA）, n-6 PUFA and n-3 PUFA in muscle were gradually increased. Compared with control group, the contents of MUFA and oleic acid in muscle in 20% and 30% alfalfa meal groups were significantly decreased （ P 〈0.05）, and the content of UFA in muscle was significantly increased （ P 〈0.05）. The contents of PUFA, linoleic acid, α-linolenic acid, n-6 PUFA and n-3 PUFA in muscle in 20% and 30% alfalfa meal groups were significantly higher than those in control group, 5% and 10% alfalfa meal groups （ P 〈0.05）, and the ratio of n-6 PUFA to n-3 PUFA was significantly lower than those in control group, 5% and 10% alfalfa meal groups （ P 〈0.01）. This research shows that diet supplemented with 20% alfalfa meal can improve the contents of DAA, EAA and linoleic acid, α-linolenic acid of PUFA in muscle, decrease the ratio of n-6 PUFA to n-3 PUFA, which is benefit to enrich n-3 PUFA in muscle, and improve pork quality and nutrient value.