Partially Dehulled Sunflower Seeds in Diets for Grazing Chickens: Effect in Meat Quality

ABSTRACT The effect of including partially dehulled sunflower seeds in the diet of grazing chickens in meat quality was evaluated. Two hundred and forty, one-day-old, Ross 308 chickens were used, randomly distributed into four treatments with six replicates of 10 birds each. Seventy-two birds were slaughtered at seven weeks of age, 18 per treatment, extracting the Pectoralis major muscle to analyze meat quality. The treatments were completely randomized in a 2x2 factorial arrangement, where type of rearing (confinement or grazing) and diet (base diet or base diet substituting 10% soybean meal for partially dehulled sunflower seeds) were the independent variables. The grazing chickens spent 8 hours a day in a white clover (Trifolium repens) paddock. Including sunflower seeds improved (p<0.05) the color and crude protein (CP) in breast meat (p<0.05), while grazing increased (p<0.05) CP, dry mater (DM), and shear force (SF), and the percentage of breast fat decreased (p<0.05) by up to 50%. Additionally, grazing increased (p<0.05) saturated fatty acids (SFA) and reduced (p<0.05) lipid oxidation by up to 50%. Partially replacing soybean meal with partially dehulled sunflower seeds in the diet of grazing chickens with white clover improves the physicochemical characteristics and nutritional quality of the breast meat; it also decreases lipid oxidation, extending the shelf life of the meat.

摘要 本试验旨在评估日粮中添加部分脱壳葵花籽对放牧肉鸡肉品质的影响。试验选用240只1日龄罗斯308肉鸡，随机分为4个处理组，每组设置6个重复，每个重复10只鸡。于7周龄时屠宰72只肉鸡，每个处理组18只，采集胸大肌进行肉品质指标检测。试验采用2×2因子设计的完全随机试验方案，以饲养方式（笼养或放牧）与日粮类型（基础日粮，或用10%部分脱壳葵花籽替代基础日粮中的豆粕）作为两个自变量。放牧肉鸡每日在白三叶（Trifolium repens）牧场上放牧8小时。结果表明，日粮添加葵花籽可显著改善胸肉的色泽与粗蛋白（crude protein, CP）含量（p<0.05）；而放牧可显著提升胸肉的粗蛋白、干物质（dry matter, DM）与剪切力（shear force, SF）含量，并使胸肉脂肪占比最高降低50%（p<0.05）。此外，放牧可显著提升胸肉的饱和脂肪酸（saturated fatty acids, SFA）含量，并使脂质氧化水平最高降低50%（p<0.05）。在以白三叶为牧地的放牧肉鸡日粮中，用部分脱壳葵花籽部分替代豆粕，可改善胸肉的理化特性与营养品质，同时降低脂质氧化水平，延长肉品货架期。