Dry residue of cassava as a supplementation in broiler feed with or without addition of carbohydrases

Abstract

The objective of this study was to evaluate the inclusion of dry residue of cassava (DRC) with or without supplementation of carbohydrases on performance, carcass yield, cuts and organs, blood parameters and meat quality of broiler chickens. Birds were distributed in a completely randomised design in a 2 x 5 factorial scheme, with or without addition of carbohydrases and five levels of DRC inclusion, resulting in 10 treatments with 5 replicates of 22 birds each. At 21 days of age, two birds of each treatment were fasted for 6 hours for blood brachial puncture. At 42 days, four birds per pen were slaughtered to determine carcass yield, cuts, organs, percentage of abdominal fat and meat quality. Between 1-21 days of age, there was an interaction (P < 0.05) between carbohydrase and DRC supplementation on weight gain (WG) and feed intake, which showed a decreasing linear effect without the inclusion of carbohydrases. In the period from 1 to 42 days, there was an interaction (P < 0.05) between carbohydrase supplementation and DRC inclusion on the variables WG and feed conversion. Carbohydrase inclusion provided an increase (P < 0.05) in the concentrations of cholesterol, triglycerides, creatinine, gamma GT and blood glucose. Concentrations of gamma GT were increased and levels of alanine aminotransferase and creatinine were decreased (P < 0.05) with DRC inclusion. At 24 hours post mortem, there was a significant interaction (P < 0.05) for breast meat between carbohydrase supplementation and DRC inclusion for the variable L. The analysed values of pH, water holding capacity and shear force of the breast meat were not affected (P > 0.05) by DRC inclusion and carbohydrase addition. However, cooking loss was influenced (P < 0.05) by levels of inclusion of DRC. The L and a* variable and the feet of broiler chickens were not affected (P > 0.05) by DRC levels and carbohydrase addition. The colour variable b* showed a decrease (P < 0.05) from 5% level of inclusion. The results of this study show that DRC can be used in the diets of broiler chickens from 1 to 21 days old to the assessed level of 10%, provided that carbohydrase is added.