Performance, gut morphometry and enzymatic activity of broilers fed neonatal supplementation in housing

ABSTRACT. The objective was to evaluate the performance, relative organ weight, morphometry, intestinal length and pancreatic enzyme activity of broilers receiving neonatal supplementation. A total of 900 Cobb 500 broiler chicks was housed in 30 boxes of 2.5 m². The treatments were divided in a completely randomized design with six replications, and consisted of five inclusion levels (0.0, 2.5, 5.0, 7.5 and 10 grams per bird). The supplement used was based of amino acids, vitamins and minerals, which was provided on the ration on the first day in the housing. Statistical analysis was performed using SAS (2008) and when significant broken down using a polynomial regression. Due to the inclusion of the neonatal supplement in the period from one to seven and one to 21 days of age, the feed intake presented a linear effect and the weight gain, a quadratic effect. The relative weights of the gizzard and liver showed a quadratic effect, and the inclusions of 4.18 and 3.41 grams/bird provided the lowest weights, respectively. The jejunum villi height decreased with supplementation as well as the activity of pancreatic lipase. It can be concluded that neonatal supplementation benefited the performance of birds up to 21 days of age.摘要。本研究旨在评估新生期补饲对肉鸡生产性能、相对器官重量、形态计量学指标、肠道长度及胰腺酶活性的影响。试验共选取900羽Cobb 500肉鸡雏鸡，饲养于30个面积为2.5㎡的栏舍中。试验采用完全随机设计，设置6个重复，共包含5个补饲添加水平（每羽鸡分别添加0.0、2.5、5.0、7.5及10克补饲剂）。本次试验所用补饲剂以氨基酸、维生素及矿物质为核心成分，于雏鸡入舍首日按日粮比例添加。统计分析采用SAS（2008）软件完成，差异显著时通过多项式回归进行多重比较。在1~7日龄及1~21日龄阶段添加新生期补饲剂的条件下，肉鸡采食量呈线性变化效应，而日增重则呈二次曲线变化效应。肌胃与肝脏的相对重量均表现出二次曲线变化效应，当每羽鸡添加量分别为4.18克与3.41克时，二者相对重量达到最低值。随着补饲剂添加量的提升，空肠绒毛高度及胰腺脂肪酶活性均呈下降趋势。综上可知，新生期补饲可改善肉鸡在21日龄前的生产性能。