State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, PR China.
Poult Sci. 2011 Sep;90(9):1992-8. doi: 10.3382/ps.2010-01298.
This study was conducted to investigate whether the free fatty acid (FFA) content of yellow grease would influence the performance and carcass characteristics of broiler chicks. A total of 432 one-day-old, male Arbor Acres broilers were randomly allotted to 1 of 4 treatments, with each treatment being applied to 6 pens of 18 chicks. The dietary treatments were based on corn and soybean meal and were supplemented with either soybean oil (2.86% FFA) or yellow grease with a low (2.74%), medium (12.59%), or high (19.05%) FFA content. The fat sources were supplemented at 1.5% of the diet during the starter phase (0 to 21 d) and at 3.0% of the diet during the grower phase (22 to 42 d). From d 0 to 42, the BW gains of chicks fed diets containing soybean oil and yellow grease with 2.74% FFA were similar. As the FFA level in the yellow grease increased, the BW gain of chicks decreased (P < 0.01). The reduction in BW gain appeared to be mediated by a reduction in feed intake. The dressing percentage and the percentage of breast muscle in the carcass were significantly (P < 0.01) lower for broilers fed any yellow grease diet compared with birds fed soybean oil. In contrast, abdominal fat was significantly increased in diets containing yellow grease. These results demonstrate that the performance of birds fed yellow grease with a low content of FFA was essentially equal to that of birds fed soybean oil. However, because yellow grease samples containing FFA levels greater than 2.74% negatively affected bird performance, producers should exercise caution with regard to feeding broilers yellow grease with an elevated FFA content. In 42-d-old broilers, serum total cholesterol and low-density lipoprotein cholesterol levels were elevated in birds fed yellow grease, regardless of the dietary level. In contrast, serum high-density lipoprotein cholesterol and triglyceride levels were unaffected by dietary treatment. Although dietary FFA may influence triglyceride-rich lipoprotein metabolism in broilers, an explanation for the observed effects remains elusive.
本研究旨在探究黄油脂中的游离脂肪酸（FFA）含量是否会影响肉鸡雏鸡的生产性能和胴体特征。共选用 432 只 1 日龄雄性 Arbor Acres 肉鸡雏鸡，随机分成 4 个处理组，每个处理组设 6 个重复，每个重复 18 只鸡。基础饲粮以玉米和豆粕为主，分别添加 2.86% FFA 的豆油或 FFA 含量分别为 2.74%、12.59%和 19.05%的黄油脂。在育雏期（021 日龄）饲粮中添加 1.5%的脂肪源，在生长期（2242 日龄）饲粮中添加 3.0%的脂肪源。0~42 日龄时，饲粮中添加豆油和 FFA 含量为 2.74%的黄油脂对肉鸡雏鸡的 BW 增重影响相似。随着黄油脂 FFA 水平的增加，肉鸡雏鸡的 BW 增重降低（P＜0.01）。BW 增重的降低似乎是由于采食量减少所致。与饲粮中添加豆油的肉鸡相比，饲粮中添加任何一种黄油脂的肉鸡的屠宰率和胴体中胸肌比例显著（P＜0.01）降低，而腹脂比例显著增加。这些结果表明，饲粮中添加 FFA 含量低的黄油脂对肉鸡的生产性能影响基本等同于饲粮中添加豆油。然而，由于 FFA 含量大于 2.74%的黄油脂样品会对鸡的生产性能产生负面影响，因此生产者在给肉鸡饲粮中添加 FFA 含量较高的黄油脂时应谨慎。在 42 日龄时，饲粮中添加黄油脂可提高肉鸡血清总胆固醇和低密度脂蛋白胆固醇水平，无论饲粮添加水平如何。相反，饲粮处理对血清高密度脂蛋白胆固醇和甘油三酯水平没有影响。虽然饲粮 FFA 可能影响肉鸡富含甘油三酯的脂蛋白代谢，但仍难以解释观察到的效果。
