初生和成年黑藏羊肉品质与肌纤维特性差异分析  

Difference Analysis of Meat Quality and Muscle Fiber Characteristics between Newborn and Adult Black Tibetan Sheep

作　　者：周力 高占红 侯生珍[1] 杨葆春[1] 王志有[1] 桂林生 ZHOU Li;GAO Zhanhong;HOU Shengzhen;YANG Baochun;WANG Zhiyou;GUI Linsheng(College of Agriculture and Animal Husbandry, Qinghai University, Xining 810016, China)

机构地区：[1]青海大学农牧学院,西宁810016

出　　处：《畜牧兽医学报》2022年第3期700-710,共11页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：青海省农业农村厅项目(CK2035907);青海省林草局项目(K992138);青海大学校地合作项目(2020GN118);省部共建项目(2018ZZ08)。

摘　　要：旨在比较放牧条件下不同年龄间黑藏羊肉品质与肌纤维组织学特性的差异。本研究选择青海自然放牧条件下体况良好的初生黑藏羊(平均体重(2.31±0.49)kg)和12月龄黑藏羊(平均体重(36.58±1.26)kg)各5只,依据年龄分为2组,即羔羊组(lamb)和成年羊组(adult)。通过三磷酸腺苷酶(ATPase)染色、酶联免疫吸附(enzyme-linked immunosorbent assay,ELISA)法以及实时荧光定量PCR(real-time qPCR)技术分析羔羊和成年羊背最长肌营养成分、抗氧化能力、肌纤维类型及其肌球蛋白重链(myosin heavy chains,MyHCs)基因表达的变化情况。结果显示:1)2组间背最长肌水分、粗蛋白、粗脂肪和粗灰分等营养指标差异不显著(P>0.05);同时,过氧化氢酶(catalase,CAT)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、超氧化物歧化酶(superoxide dismutase,SOD)活性,总抗氧化能力(total antioxidant capacity,T-AOC)和丙二醛(malondialdehyde,MDA)水平差异均不显著(P>0.05)。2)羔羊Ⅰ型、ⅡA型、ⅡB型肌纤维直径与横截面积均显著小于成年羊(P<0.05),而肌纤维密度则相反(P<0.05);羔羊Ⅰ型肌纤维数量比例和Ⅰ型、ⅡA型肌纤维面积比例均显著高于成年羊(P<0.05)。3)羔羊MyHCⅠ和MyHCⅡA基因的mRNA表达量显著低于成年羊(P<0.05),而MyHCⅡB型mRNA表达量则相反(P<0.05)。结果提示,随着年龄的增长,黑藏羊背最长肌营养成分与抗氧化能力没发生显著变化,但肌纤维类型由氧化型向酵解型转化,在一定程度上影响机体生长发育。This experiment was conducted to study the differences of meat quality and muscle fiber characteristics of black Tibetan lambs at different ages under grazing conditions.Five newborn black Tibetan lambs(average weight(2.31±0.49)kg)and five 12-month-old black Tibetan sheep(average weight(36.58±1.26)kg)were selected under natural grazing conditions in Qinghai.They were divided into two groups according to age,namely lamb group and adult sheep group.Via ATPase staining,ELISA and real-time qPCR,the variation of the nutrient composition,antioxidant capacity,muscle fiber type and myosin heavy chain(MyHCs)genes expression in longissimus dorsi were analyzed between lamb and adult sheep groups.The results showed as follows:1)There were no significant differences in nutrient indexes of longissimus dorsi such as moisture,crude protein,ether extract and ash between the two groups(P>0.05).Similarly there were no significant differences in catalase(CAT),glutathione peroxidase(GSH-Px),superoxide dismutase(SOD)activities,total antioxidant capacity(T-AOC)and malondialdehyde(MDA)levels(P>0.05).2)The diameter and cross-sectional area of typeⅠ,ⅡA andⅡB muscle fiber in lambs were significantly lower than those of adults(P<0.05),but the muscle fiber density was the opposites(P<0.05).The proportion of typeⅠmuscle fiber quantity and the proportion of typeⅠand typeⅡA muscle fiber area of lambs were significantly higher than those of adult sheep(P<0.05).3)The mRNA expression levels of MyHCⅠand MyHCⅡA in lambs were significantly lower than those in adults(P<0.05),but the mRNA expression level of MyHCⅡB was the opposite(P<0.05).These results indicated that,with the increase of age,the nutrient composition and antioxidant capacity of longissimus dorsi of black Tibetan sheep had no significant changes,but the muscle fiber dramatic changed from oxidized type to glycolysis type,which influenced the body growth and development to a certain extent.

关 键 词：黑藏羊 营养成分 肌纤维类型 抗氧化指标 MyHCs基因 肉品质 

分 类 号：S826.2[农业科学—畜牧学]