Emulsifier and enzymatic complex in diet for free range broiler chicken in the western amazon

Abstract This study aimed to evaluate the effects of adding levels of emulsifier based on soy lecithin and enzymatic complex (xylanase, β-glucanase, galactosidase, protease, amylase, and β-mannanase) on the basal diet during the raising of free-range broiler chickens. The experimental design was completely randomized, with five treatments and six replications. Treatments were: T1: control diet, without enzymatic complex and emulsifier; T2: 0.2 kg t-1 of enzymatic complex; T3: 0.5 kg t-1 of emulsifier; T4: 0.2 kg t-1 of enzymatic complex + 0.5 kg t-1 of emulsifier; and T5: 0.3 kg t-1 of enzymatic complex + 1 kg t-1 of emulsifier. Performance data were collected every 14 days, and the animals were euthanized at 70 days to obtain carcass, breast, drumstick, and thigh yield and intestine collection for pH analysis and morphometry. The periods from 1 to 56 and 1 to 70 days showed a difference (P<0.05) in the parameters of zootechnical performance, the feed intake was lower in T4 and T5, and weight gain was better in T1, T2, T3, and T4. Feed conversion was better in T1, T2, and T4. No difference (P>0.05) was observed for poultry livability, carcass yield, viscera, and pH of duodenum and cecum. A difference was found for intestinal morphometry (P<0.05), and T5 showed the best villus/crypt ratio. The level with 0.3 kg t-1 of enzymatic complex and 1 kg t-1 of emulsifier indicated a better relationship between villi and crypts. However, the level with 0.2 kg t-1 of enzymatic complex and 0.5 kg t-1 of emulsifier added to the commercial diet led to benefits such as decreased feed intake, without affecting weight gain, thus inducing a good feed conversion.

摘要 本研究旨在评估在散养肉鸡饲养过程中，于基础日粮中添加不同水平的以大豆卵磷脂为基质的乳化剂与复合酶制剂（含木聚糖酶、β-葡聚糖酶、半乳糖苷酶、蛋白酶、淀粉酶及β-甘露聚糖酶）的应用效果。本试验采用完全随机设计，设置5个处理组，每组6个重复。处理组具体如下：T1：空白对照日粮，不添加复合酶制剂与乳化剂；T2：添加0.2 kg·t⁻¹复合酶制剂；T3：添加0.5 kg·t⁻¹乳化剂；T4：添加0.2 kg·t⁻¹复合酶制剂+0.5 kg·t⁻¹乳化剂；T5：添加0.3 kg·t⁻¹复合酶制剂+1 kg·t⁻¹乳化剂。每14天采集一次生产性能数据，试验肉鸡于70日龄时实施安乐死，采集胴体、胸肉、鸡腿及大腿的出肉率指标，并采集肠道样本用于pH值分析与形态学检测。在1~56日龄及1~70日龄两个饲养阶段，肉鸡的畜牧生产性能参数均存在显著差异（P<0.05）：T4、T5组的采食量显著降低，T1、T2、T3、T4组的增重表现更佳；T1、T2、T4组的饲料转化率更优。各组肉鸡的存活率、胴体出肉率、内脏器官重量及十二指肠、盲肠的pH值均无显著差异（P>0.05）。但肠道形态学指标存在显著差异（P<0.05），其中T5组的肠绒毛高度/隐窝深度比值最优。当添加0.3 kg·t⁻¹复合酶制剂与1 kg·t⁻¹乳化剂时，可获得最佳的肠绒毛与隐窝比例关系。而在商品日粮中添加0.2 kg·t⁻¹复合酶制剂与0.5 kg·t⁻¹乳化剂，可在不影响增重的前提下降低采食量，从而实现优良的饲料转化率，展现出良好的应用效益。