不同月龄安格斯母牛屠宰性能、肉品质及卵巢发育比较

Comparison on slaughter performance,meat quality and ovary development of Angus cows of different months of age

【目的】比较分析不同月龄阶段安格斯母牛屠宰性能、肉质品质及卵巢发育的差异,为进一步丰富安格斯牛育种数据和开展湖南本地肉牛品种改良及新品种(系)培育提供科学依据。【方法】选取国家核心肉牛育种场内6、18和30月龄体况良好的安格斯母牛各10头分为3组,在标准饲养条件下对其进行屠宰性能、肉质品质和卵巢卵泡发育的测定。【结果】随着月龄的增加,安格斯母牛的屠宰性能逐渐提高,在30月龄时屠宰率达49.08%,较6月龄屠宰率显著增加4.98%(P<0.05,下同);胴体重185.63 kg、眼肌面积4942.77 mm2、剪切力44.13 N,分别较6月龄显著增加139.55%、45.86%和114.43%,且各月龄阶段间均存在显著差异;熟肉率和含水量在各月龄阶段差异不显著(P>0.05,下同)。粗蛋白、粗脂肪和铁(Fe)含量随月龄的增加呈先降后升的变化趋势,30月龄时含量分别为18.83%、1.03%和15.10 mg/kg。安格斯母牛3个月龄的总氨基酸含量在18.58%~19.06%,必需氨基酸含量在7.70%~7.93%,必需氨基酸含量在氨基酸总量中的占比均在41.00%左右;其中总氨基酸和必需氨基酸含量在6月龄和18月龄间差异不显著,二者与30月龄间存在显著差异。3个月龄阶段的安格斯牛肉中饱和脂肪酸含量在44.51~49.10 mg/g,单不饱和脂肪酸含量在32.00~37.72 mg/g,多不饱和脂肪酸含量在13.03~22.86 mg/g,各月龄阶段间均存在显著差异;卵巢重量和卵泡数量也随着月龄的增加而增加,各月龄阶段间均存在显著差异,但卵巢的厚和宽在18月龄与30月龄间差异不显著,30月龄与6月龄间存在显著差异。【结论】不同月龄阶段安格斯母牛肉质品质和卵巢发育差异明显,引种安格斯牛进行地方品种改良及新品种(系)选育时应根据不同月龄阶段的特征进行合适选择。

【Objective】In order to further enrich the Angus cattle breeding database and meet the needs of Hunan local cattle breed improvement and new breeds(lines)culture,the differences in the slaughter performance,meat quality and ovarian development of Angus cows at different ages were compared and analyzed.【Method】Each 10 Angus cows of 6,18 and 30 months old with good body condition were selected from the national core beef cattle breeding site and divided into 3 groups.The slaughter performance,meat quality and ovarian follicle development of Angus cows were measured under standard feeding conditions.【Result】The results showed that with the increase of month age,the slaughter performance of Angus cows gradually improved,and the slaughter rate was up to 49.08%at the age of 30 months,which was significantly increased by 4.98%compared with 6 months old(P<0.05,the same below).And the carcass weight was 185.63 kg,which was significantly increased by 139.55%compared with 6 months old.The area of eye muscle was 4942.77 mm2,which was significantly increased by 45.86%compared with 6 months old,and the shear force was 44.13 N,which was significantly increased by 114.43%compared with 6 months old.There were significant differences between each age group.There were no significant differences in cooked meat rate and water contentat each age group(P>0.05,the same below).The contents of crude protein,crude fat and iron(Fe)increased first and then decreased and increased finally,at the age of 30 months,and the contents were 18.83%,1.03%and 15.10 mg/kg respectively.The total amino acid content was 18.58%-19.06%,and the essential amino acid content was 7.70%-7.93%.The proportion of the total essential amino acid in the total amino acid was about 41.00%in all the stages of the month.However,the differences in total amino acid and essential amino acid between the ages of 6 and 18 months were not significant,and there were significant differences between the two and the age of 30 months.The content of saturated fatty acids in Angus beef at 3 months was 44.51-49.10 mg/g,the content of monounsaturated fatty acids was 32.00-37.72 mg/g,and the content of polyunsaturated fatty acids was 13.03-22.86 mg/g,and there was significant difference among different month ages.The ovarian weight and the number of follicles also increased with the increase of age,and there were significant differences among different month ages.However,there were no significant differences in the thickness and width of the ovaries between the ages of 30 and 18 months,and significant differences was found between the ages of 30 and 6 months.【Conclusion】The differences in meat quality and ovarian development of Angus cows at different stages are large,the characters of Angus cows at different month ages can be considered for the introduction of Angus cows to local breed improvement and breeding of new breeds(lines).