Sugarcane yeast inclusion for broilers at post-hatch

ABSTRACT A total of 450 one-day-old male broiler chicks were used to evaluate the effect of the sugarcane yeast on performance, body composition, and development of the intestinal mucosa. The experiment was carried out in a completely randomized design with five treatments and six replicates of 15 birds. Sugarcane yeast was included in the experimental diets at the levels of 0, 12.5, 25.0, 37.5, and 50.0 g kg−1. Body weight, weight gain, feed intake, and feed conversion were determined. At the end of the experiment, four broiler chicks were slaughtered per experimental unit: two were used for evaluation of moisture content, crude protein, fat, and body ash and the other two were used in the collection of small-intestine segments for evaluation of villus height and crypt depth. The increasing yeast levels resulted in a linear increase in feed intake and feed conversion. Inclusion of more than 14.4 g kg−1 yeast resulted in a reduction of body ash content. Villus height and crypt depth in the jejunum showed maximum values at the sugarcane yeast levels of 20.9 and 20.6 g kg−1, respectively. In the ileum, the crypt depth reduction at the level of 25.6 g kg−1 also resulted in an increase in villus:crypt ratio. Yeast inclusion increases feed intake and feed conversion, improves body mineral absorption, and increases villus height in the jejunum and the villus:crypt ratio in the ileum of broiler chicks.

摘要：本试验选用450只1日龄雄性肉用雏鸡，旨在评估甘蔗酵母（Sugarcane yeast）对受试鸡生产性能、体成分及肠黏膜（intestinal mucosa）发育的影响。试验采用完全随机设计，设置5个处理组，每组6个重复单元，每个重复单元包含15只雏鸡。试验日粮中添加甘蔗酵母的水平分别为0、12.5、25.0、37.5及50.0 g·kg⁻¹。测定指标包括体重、增重、采食量及饲料转化率。试验结束后，每个试验单元屠宰4只雏鸡：其中2只用于测定水分含量、粗蛋白质、脂肪及体灰分，剩余2只用于采集小肠节段，以测定绒毛高度（villus height）与隐窝深度（crypt depth）。结果显示，随着甘蔗酵母添加水平的提升，受试鸡的采食量与饲料转化率呈线性升高趋势。当日粮中酵母添加量超过14.4 g·kg⁻¹时，体灰分含量显著降低。空肠（jejunum）的绒毛高度与隐窝深度分别在酵母添加水平为20.9 g·kg⁻¹与20.6 g·kg⁻¹时达到最大值。回肠（ileum）中，当酵母添加水平为25.6 g·kg⁻¹时，隐窝深度降低，同时绒毛隐窝比（villus:crypt ratio）显著升高。综上，在肉用雏鸡日粮中添加甘蔗酵母可提升采食量与饲料转化率，改善机体矿物质吸收，并提高空肠绒毛高度及回肠绒毛隐窝比。