Effect of crushed sugarcane on performance, bone characteristics and intestinal morphology of free-range chicken lines

Abstract

The objective of this study was to evaluate the effect of different levels of crushed sugarcane in the diet on the performance, bone characteristics and intestinal morphology of slow-growing broiler strains. A total of 448 chickens at 35 days of age were allotted to two randomized blocks in a 4×2 factorial arrangement (levels of feed replacement with crushed sugarcane, on a fresh-matter basis: 0, 15, 30, and 45%) and two strains (Pesadão and Label Rouge (LR)). Two replicates were used per block over time (containing the treatments and the strains), and 14 individuals were used per experimental unit. Weight gain and feed intake decreased linearly in response to the increasing sugarcane levels. Feed intake was higher in the Pesadão strain than in LR. Chicken foot weight was lower in Pesadão than in LR. There were no effects of sugarcane levels or strains on the tarsometatarsal bone weight, breaking strength, maximum load and deformation. The dry matter (DM) content of the tarsometatarsal bone was lower in LR than in Pesadão. The replacement of feed with sugarcane induced a linear increase in bone ash content and a decrease in bone phosphorus and calcium contents. Label Rouge chickens showed a greater crypt depth and lower values of villus/crypt ratio and mucosal layer thickness. The performance and intestinal morphology of broiler chickens are negatively affected by increasing sugarcane levels in the diet. In addition, the increasing intake of sugarcane changes the bone mineral composition without reducing mechanical resistance, in both the Pesadão and Label Rouge strains.