Performance and carcass yield of female broilers fed with diets containing probiotics and symbiotics as an alternative to growth enhancers

ABSTRACT. An experiment was carried out with female broilers, aiming to evaluate the effect of using probiotics and symbiotics on growth performance and yield of carcasses and of the main commercial cuts and edible viscera. A total of 720 one-day-old Cobb chicks, distributed in a completely randomized experimental design with four treatments and six replicates of 30 birds each at a stocking density of 10 birds per square meter (m2). At 42 days old two broilers of each experimental unit were sacrificed to evaluate the carcass yield and its parts. The carcass yield was not affected by the inclusion of probiotics and symbiotics in the diet being equivalent to the antibiotic group. No significant difference was observed among the treatments, even in the controls that did not receive any additive factor. All the performance parameters were similar for the four treatments, with the exception of weight gain, that was significantly lower in probiotic treatment. It was concluded that these additives are important alternative to replace antibiotics as growth enhancers, which have already been banned in many countries.

摘要：本研究以雌性肉鸡为试验对象，旨在评估益生菌（probiotics）与合生制剂（symbiotics）对肉鸡生长性能、屠宰率及主要商业分割肉块、可食用内脏产量的影响。共计选用720羽1日龄科布（Cobb）肉鸡，采用完全随机试验设计，设置4个处理组，每组设6个重复，每个重复饲养30羽肉鸡，饲养密度为10羽/平方米（m²）。于试验第42日龄时，从每个试验单元中选取2羽肉鸡进行屠宰，以评估其屠宰率及各分割部位产量。日粮中添加益生菌与合生制剂对肉鸡屠宰率无显著影响，该指标与抗生素组相当；各处理组间未观察到显著差异，未添加任何添加剂的对照组亦无明显差异。4个处理组的其余生长性能参数均无显著差异，仅益生菌组的增重显著低于其他组。综上，此类添加剂可作为生长促进剂的重要替代方案，用以替代已在多国禁用的抗生素。