Effect of Mannanases-predigested Palm Kernel Meal in the Diets on Nutrient Digestibilities and Broiler Performance

Abstract

Two studies were conducted to determine the efficacy of using mannanase treated and untreated palm kernel meal (PKM) with different commercial mannanases in various broiler diets. Forty five birds and 160 birds were used for digestibility and performance studies respectively. Three different diets (PKM with no enzyme and PKM pretreated with mannanase A or B) were offered to the birds for digestibility study. In contrast, 7 different diets containing 0% PKM as control (T1), 10% PKM (T2), 10% mannanase A-treated PKM (T3), 10% mannanase B-treated (T4) were offered for performance study. The pre-treated PKM was heated in the oven at 90oC for 15 minutes to inactivate the enzyme prior to its mixing with the diets. The study was conducted for 42 days and the birds were fed their respective diets ad libitum. Faecal discharge was collected for three consecutive days for faecal coefficient of digestibility and ileal digesta was taken from Mackel’s diverticulum to 1 cm before caeca for ileal amino acid digestibility. Data indicated that pre-digested PKM with both mannanases increased digestibility of crude fibre and AME of PKM (P<0,05). However, an increased ileal protein digestibility and a decreased moisture content of faeces were only found in birds fed the mannanase A treated PKM. Addition of 10% PKM in the broiler diet negatively affected body weights of birds when compared with the birds fed the control diet (T1). Predigestion of PKM with mannanase A improved feed intake and body weight gain significantly. In conclusion, Predigested PKM with mannanase could be effectively used to improve the nutritive value of PKM.