不同月龄湘西黄牛的生产性能和屠宰性能及肉品质

Characterization of production performance, slaughter performance and nutritional quality in beef of Xiangxi cattle at different months of age

选取湘西黄牛国家级保种场内不同月龄(6、18、30月龄)的黄牛各10头,进行体尺、屠宰性能、肉品质的测定。结果显示:除6月龄与18月龄间的管围、尾周长、尾长及18月龄与30月龄的尾长外,不同月龄阶段湘西黄牛生产性能指标间的差异有统计学意义(P<0.05);随着月龄的增加,湘西黄牛的屠宰性能逐渐提高,在30月龄时屠宰率可达49.98%;湘西黄牛肉的水分、粗蛋白、粗脂肪和灰分质量分数分别为73.80%~76.55%、20.45%~23.05%、1.18%~3.75%和1.00%~1.10%,Cu、Fe和Zn的含量分别为0.49~0.65、10.26~17.85、25.45~34.78 mg/kg,6月龄与18月龄湘西黄牛肉中的水分质量分数及Cu、Fe、Zn含量间的差异有统计学意义(P<0.05),6月龄与30月龄湘西黄牛肉中的粗蛋白、灰分、粗脂肪质量分数及Fe、Zn含量间的差异有统计学意义(P<0.05),除Fe含量外,18月龄与30月龄湘西黄牛肉的常规营养成分含量间的差异均有统计学意义(P<0.05);6月龄与18月龄湘西黄牛肉中总氨基酸含量间的差异无统计学意义(P>0.05),而6月龄与30月龄间的差异有统计学意义(P<0.05),总氨基酸含量为18.43~19.60 g/(100 g),8种必需氨基酸含量为7.75~8.34 g/(100 g),所有月龄阶段必需氨基酸总量在氨基酸总量中的占比均在42%以上,均达优质肉品质要求;湘西黄牛肉中饱和脂肪酸含量为52.17%~52.59%,单不饱和脂肪酸含量为39.37%~40.82%,多不饱和脂肪酸含量为4.35%~4.50%。综上所述,湘西黄牛肉富含蛋白质和氨基酸,必需氨基酸含量较丰富,脂肪含量适宜,营养较全面。

To characterize the production performance and meat quality of Xiangxi cattle at its different ages,three age groups(6,18 and 30 months)were selected from the national conservation farms,with 10 cows in each group.Body size,slaughter performance,meat quality,amino acid and fatty acid contents were measured.The results showed that there were significant differences in production performance indexes at different ages(P<0.05)except for 6 and 18 months tube circumference,tail circumference,tail length and 18 and 30 months tail length.With the increase of the monthly age,the slaughter performance of cattle improved gradually,and the slaughter rate reached 49.98%at the age of 30 months.The moisture,crude protein,crude fat and ash mass fraction of Xiangxi cattle beef were 73.80%-76.55%,20.45%-23.05%,1.18%-3.75%and 1.00%-1.10%,respectively.The contents of Cu,Fe and Zn were 0.49-0.65,10.26-17.85,25.45-34.78 mg/kg,respectively.The differences in the contents of moisture,Cu,Fe and Zn between the 6 months and 18 months were statistically significant(P<0.05).There were statistically significant differences in crude protein,ash content,crude fat mass fraction and Fe and Zn contents between 6 months and 30 months(P<0.05).Except for Fe content,there were statistically significant differences in the contents of conventional nutrients between 18 months and 30 months(P<0.05).The total amino acid content was no significantly different between 6 months and 18 months(P>0.05),but was significantly different between 6 months and 30 months(P<0.05).The total amino acid contents were 18.43-19.60 g/(100 g)and 8 kinds of essential amino acid contents were 7.75-8.34 g/(100 g).The proportions of the essential amino acid contents in total amino acid contents were above 42%for all ages,and met the requirement of high quality meat.The contents of saturated fatty acids in the beef were 52.17%-52.59%,the contents of monounsaturated fatty acids were 39.37%-40.82%and the contents of polyunsaturated fatty acids were 4.35%-4.50%.In summary,through the detection of various performance indicators and meat quality,the beef of Xiangxi cattle contained sufficient proteins,amino acid including essential amino acid and proper fatty acids.