不同基因型和营养对山羊生长性能、胴体品质及肉质的影响

【目的】探讨不同基因型和营养物质在改善老挝山羊的生长性能、胴体特征和肉质中的效果。【方法】采用2×2双因素试验，以本地山羊品种Lat为对照，对Lat与越南Bach Thao公山羊的杂交F1（BT×L）进行比较。从每个基因型中选择30头7月龄的成长公山羊并分成两组，其中一组采用传统饲喂方法即自由放牧，另一组采用改良饲喂方法，即放牧并任意采食木薯渣和矿物砖。试验期间测量山羊平均日增重（ADG），在后期每组选择3只山羊宰杀并测定胴体特性（胴体组成和初分切肉）、肉质（剪切力、肉色、pH、滴水损失率和蒸煮损失率）。【结果】杂交山羊F1的平均日增重（60．02g／头）明显高于本地山羊（38．45g／头），增幅为56．09％；饲喂补充木薯渣和矿物砖的山羊平均日增重（55．45g／头）则显著高于未添加对照组（43．02g，头），增幅为28．89％。杂交繁育和饲喂补充物对山羊胴体品质如屠宰率、前肢百分率、后肢百分率及胸肌率没有显著影响，但杂交F1山羊的脖子极显著大于本地山羊，而其腰腹部切口极显著小于本地山羊。在两种不同饲喂管理条件下，Lat和杂交F1山羊的肉质特性没有显著差异。【结论】老挝本地山羊Lat与Bach Thao公山羊杂交及在饲料中补充木薯渣和矿物砖，可提高山羊肉产量且对其肉质无任何负作用。

Effects of genotype and nutrition on growth performance,carcass characteristics, and meat properties of goats in Laos

Objective]A 2×2 factorial trial was carried out to determine effects of genotype and nutrition on improved growth performance, carcass characteristics, and meat properties of goats in Laos. Method ]The indigenous goat breed （Lat） was used as the control in comparison with F1 （BT×L） as a result of crossbreeding Lat does with Bach Thao bucks imported from Vietnam. For each genotype, 30 growing male goats at age of 7 months were chosen and equally divided into 2 groups, one was raised according to the traditional feeding regime （free ranging only） and the other with an improved feeding regime including cassava hay and mineral block provided ad libitum in addition to free ranging. The animals were observed for the average daily gain （ADG） and at the end, three animals per group were slaughtered to determine carcass characteristics （physical composition, primal cuts）, and meat properties （shear force, color, pH, drip loss, and cooking loss）. Result]The results showed that the ADG of F1（60.02 g/head/day） was very much higher （56.09%） than that of the indigenous goat （38.45 g/head/day）. The ADG of goats supplemented with cassava hay and mineral block （55.45g/head/day） was also significantly higher （28.89%） than that of those not supplemented （43.02 g/head/day）. No significant （P〉0.05） effects of the crossbreeding and supplementation were found for dressing percentage and percentages of shoulder-foreleg, rump-rearleg, and breast-rip cuts in the carcass; however, the F1 had a bigger neck （P〈0.01） but a smaller loin-abdomen cut （P〈0.01） compared with the indigenous goat. No significant differences were observed for the parameters of meat characteristics between Lat and F, goats under the two different feeding regimes. Conclusion]h was therefore concluded that crossbreeding with Bach Thao bucks and supplementation of cassava hay and mineral block improved meat yield without negative effects on meat quality of goats in Laos.