Effects of Bile Acids and Lipase Supplementation in Low-Energy Diets on Growth Performance, Fat Digestibility and Meat Quality in Broiler Chickens

ABSTRACT The aim of this study was to investigate the effect of bile acids and lipase supplementation in low energy (LE) diets on growth, fat digestibility, serum lipid profile and meat quality of broilers. Seven hundred one-day-old broiler chicks were divided into 5 dietary treatments with five replicates of 28 birds each. The five treatments were: i) high energy diet (HE; metabolizable energy (ME) = 3,000 and 3,170 kcal/kg for starter and finisher diet), ii) low energy diet (LE; ME = 2,900 and 3,070 kcal/kg for starter and finisher diet), iii) LE diet supplemented with 300 g/ton bile acids (LEB), iv) LE diet supplemented with 180 g/ton lipase (LEL), v) LE diet supplemented both with bile acids (300 g/ton) and lipase (180 g/ton). The experiment lasted 35 days having starter phase from days 1-21 and finisher phase from days 22-35. Dietary inclusion of both bile acids and lipase in LE diet had no effect (p>0.05) on body weight (BW) gain and feed intake. High energy diet reduced feed intake and BW gain during starter and overall period; however, during finisher phase BW gain was similar in all dietary treatments. Dietary energy level had no effect on feed conversion ratio. Fat digestibility (p>0.05) both in the starter and finisher phase was not affected by the dietary treatments. Concentration of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides were not affected by the dietary treatments (p>0.05). Meat quality of breast and thigh muscle was unaffected due to the dietary treatments (p>0.05). It is concluded that the supplementation of bile acids alone or in combination with lipase in low-energy diets did not improve broiler performance, fat digestibility, serum lipid profile and meat quality.

摘要
本研究旨在探究低能（LE）日粮中添加胆汁酸与脂肪酶对肉用仔鸡生长性能、脂肪消化率、血清脂质谱及肉品质的影响。试验选取700只1日龄肉用仔鸡，随机分为5个日粮处理组，每组设5个重复，每个重复28只鸡。5个处理组分别为：①高能日粮组（HE：育雏期与育肥期日粮代谢能（ME）分别为3000与3170 kcal/kg）；②低能日粮组（LE：育雏期与育肥期日粮代谢能（ME）分别为2900与3070 kcal/kg）；③添加300 g/吨胆汁酸的低能日粮组（LEB）；④添加180 g/吨脂肪酶的低能日粮组（LEL）；⑤同时添加300 g/吨胆汁酸与180 g/吨脂肪酶的低能日粮组。试验周期为35天，其中育雏期为1~21日龄，育肥期为22~35日龄。在低能日粮中同时添加胆汁酸与脂肪酶对肉用仔鸡的体增重（BW）与采食量无显著影响（p>0.05）。高能日粮组在育雏期及全试验期的采食量与体增重均显著降低；但育肥期各日粮处理组的体增重无显著差异。日粮能量水平对饲料转化率无显著影响。育雏期与育肥期的脂肪消化率均不受日粮处理的影响（p>0.05）。血清总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇及甘油三酯浓度均不受日粮处理的影响（p>0.05）。胸肌与腿肌的肉品质均不受日粮处理的影响（p>0.05）。综上，在低能日粮中单独添加胆汁酸，或同时添加胆汁酸与脂肪酶，均未能改善肉用仔鸡的生产性能、脂肪消化率、血清脂质谱及肉品质。