Carcass characteristics and fatty acid profile of Santa Inês lamb fed banana leftovers

ABSTRACT: The use of new feed resources, particularly local agroindustrial byproducts, such as banana, may be an option for replacing those traditionally used for sheep feed to reduce production costs. Thus, the aim of this study was to evaluate the dietary effects of replacing corn bran with banana leftovers on performance, carcass, non-carcass components, meat traits, and fatty acid profile of Santa Inês lambs. Twenty-four Santa Inês female lambs with an average weight of 23.73 kg were fed diets containing 60 % coast cross hay and 40 % concentrate (30 % corn bran and 10 % soybean meal). Treatments consisted of corn bran replaced by banana leftovers at rates of 0, 25, 50, and 75 % on a dry matter basis. The experiment lasted 120 days. Animals were slaughtered and carcasses and non-carcass components were evaluated. The half-carcasses were weighed and sectioned into commercial cuts. The 12th and 13th ribs were dissected to collect bones, muscle and fat proportions. Cooking loss, color, shear force and sarcomere length were measured. Fatty acid profiles were obtained by gas chromatography. Hot and cold carcass weight, leg, neck, lung, loin eye area, fat thickness, initial sample weight of the 12th and 13th ribs, fat and bone, presented a negative linear effect of banana leftovers replacing corn in the diet. Loin, fat thickness, cooking loss and carcass redness showed a negative quadratic effect, while full and empty abomasum, full omasum, sarcomere length and yellowness presented a positive quadratic effect. Replacement of up to 75 % of corn bran by banana leftovers did not interfere in the intake, performance, meat traits and the fatty acid profile of lambs. The use of banana leftovers may be an alternative for reducing animal production costs.

摘要：新型饲料资源，尤其是香蕉类本地农工副产品，或可替代传统绵羊饲料原料以降低养殖成本。为此，本研究旨在评估以香蕉残渣替代玉米麸皮，对圣伊内斯羔羊（Santa Inês lambs）生长性能、胴体及非胴体组分、肉品质性状与脂肪酸组成的饲喂效果。试验选取24只平均初始体重为23.73 kg的圣伊内斯母羔羊，饲喂含60%海岸杂交干草（coast cross hay）与40%精料（其中30%为玉米麸皮、10%为豆粕）的日粮。试验组以香蕉残渣按干物质基础分别以0%、25%、50%、75%的比例替代玉米麸皮，试验周期为120天。试验结束后对羔羊实施屠宰，测定其胴体与非胴体组分：对半胴体称重并分割为商业屠宰切块；切取第12、13肋条进行解剖，分离收集骨骼、肌肉及脂肪组分；同时测定蒸煮损失、肉色、剪切力及肌节长度，并采用气相色谱法分析脂肪酸组成。结果表明：热胴体重、冷胴体重、腿部重量、颈部重量、肺部重量、眼肌面积、脂肪厚度、第12、13肋条初始样本重量、脂肪占比及骨骼占比，均随日粮中香蕉残渣替代玉米麸皮比例升高呈现负线性效应；腰肉占比、脂肪厚度、蒸煮损失及胴体红度呈现负二次效应；而皱胃净重与空重、瓣胃净重、肌节长度及肉色黄度则呈现正二次效应。研究显示，以香蕉残渣替代最高75%的玉米麸皮，不会对羔羊的采食量、生长性能、肉品质性状及脂肪酸组成造成不良影响，香蕉残渣可作为降低畜牧养殖成本的新型替代饲料原料。