不同草原类型对乌珠穆沁羔羊生产性能和肉品质的影响

Effects of Different Grassland Types on Performance and Meat Quality of Ujumqin Lambs

将3~3.5月龄、体重相近的16只乌珠穆沁羔羊随机分为2组,一组在锡林浩特市毛登牧场典型草原放牧,另一组在四子王旗乌兰花镇荒漠草原放牧,放牧99d后屠宰并采集背最长肌测定理化性质和营养品质,分析不同草原类型对放牧羊产肉力和肉品质的影响。结果表明:(1)两种草原类型对放牧羔羊的宰前活重、胴体重、屠宰率没有显著影响,但典型草原放牧组干物质采食量和眼肌面积显著高于荒漠草原放牧组(P<0.05),采食行走里程显著减少(P<0.05)。(2)荒漠草原放牧组肉色较浅而剪切力较大(P<0.05),且蒸煮损失显著低于典型草原放牧组(P<0.05)。(3)荒漠草原放牧组粗蛋白含量显著高于典型草原放牧组(P<0.05),而肌内脂肪含量显著低于典型草原放牧组(P<0.05);荒漠草原放牧组氨基酸总量、必需和非必需氨基酸总量、鲜味氨基酸总量及赖氨酸、天冬氨酸、脯氨酸和谷氨酸含量均显著高于典型草原放牧组(P<0.05),其饱和脂肪酸(SFA)总量、单不饱和脂肪酸总量及C10∶0、C12∶0、C14∶0、C15∶0、C16∶0、C17∶0、C18∶0、C20∶0、C14∶1、C16∶1、C18∶1trans-11和C18∶1cis-9均显著低于典型草原放牧组(P<0.05);多不饱和脂肪酸(PUFA)在组间没有显著差异,但典型草原放牧组CLAcis-9 trans-11含量显著提高(P<0.05),而荒漠草原放牧组PUFA/SFA比例显著提高(P<0.05)且达到理想推荐值0.44以上。由此可见,荒漠草原有效提升放牧羊肉中粗蛋白质、必需氨基酸和有益脂肪酸组分沉积。

The aim of this study was to clarify the differences of productivity and meat quality of Ujumqin lambs after grazing in the typical and desert grassland of Inner Mongolia.Sixteen Ujumqin lambs(3-3.5 months old with similar body weight)were randomly divided into two groups.One group was grazed in typical grassland of Maodeng pasture in Xilinhot City,and the other group was grazed in desert grassland of Wulanhua Town,Siziwang Banner.All lambs were slaughtered after continuously grazing for 99d.The Longissimus thoracis muscle samples were collected to determine the physicochemical properties and nutritional quality.The results showed as follows:(i)There were no differences in slaughter weight,carcass weight,and dressing rate between two groups,but lambs grazing on typical grassland had higher dry matter intake and Longissimus thoracis muscle area than lambs grazing on desert grassland(P<0.05),and the feeding walking distance was significantly reduced than lambs grazing on desert grassland(P<0.05).(ii)Meat color of the lambs grazing on desert grassland was lighter and meat shear force was greater(P<0.05),and the cooking loss was significantly lower than that of typical grassland grazing group(P<0.05).(iii)Lambs grazing on desert grassland had higher level of meat protein and lower level of intramuscular fat than lambs grazing on typical grassland(P<0.05).Meat of the lambs grazing on desert grassland had greater amounts of total amino acids,total essential and non-essential amino acids and flavor amino acids,as well as Lys,Asp,Pro and Glu contents(P<0.05);meat of the lambs grazing on desert grassland had less amounts of total saturated and monounsaturated fatty acids,as well as C10∶0,C12∶0,C14∶0,C15∶0,C16∶0,C17∶0,C18∶0,C20∶0,C14∶1,C16∶1,C18∶1trans-11 and C18∶1cis-9(P<0.05).There was no significant difference in polyunsaturated fatty acids between two groups,but the content of CLAcis-9 trans-11 in typical grassland grazing group increased significantly(P<0.05),while the proportion of PUFA/SFA in desert grassland grazing group increased significantly(P<0.05)and reached the ideal recommended value of more than 0.44.It was concluded that grazing in desert grassland can effectively improve the deposition of crude protein,essential amino acids and health-promoting fatty acids in lamb meat.