Dietary levels of soluble and insoluble fibre sources for young slow-growing broilers

This study aimed to evaluate the effects of dietary levels of soluble and insoluble fibre on the performance and digestive development of slow-growing broilers during the starter period. A total of 400 one-day-old Isa LabelTM male chicks were used that were distributed in a completely randomized factorial design 2 x 2 + 1 (inclusion of 2% or 4% of corncobs as a source of insoluble fibre IF and citrus pulp as a source of soluble fibre (SF); and a control treatment) with eight replicates of 10 birds each. The addition of IF to diets improved the weight gain and feed conversion of broilers at 7 and 21 days of age. Both fibre sources added to diets resulted in higher relative weights of proventriculus + gizzard, liver, small and large intestine. The diets containing an SF source presented positive effects on the duodenal mucosa. In addition, positive effects on the caecal villus to crypt ratio were observed in broilers fed diets containing different types of fibre. It is concluded that dietary inclusion of IF up to 4% maintains the performance, nutrient metabolism and improves the development of the proventriculus + gizzard in slow-growing broilers. However, for improving the morphological and histomorphological parameters of slow-growing broilers in the starter phase the addition of SF sources is recommended.