Dietary fat and oil are potential alternative energy sources for fast growing broiler chickens (Meng et al., 2004). Nevertheless, hampered fat digestion and absorption were reported in young broiler chickens with incompletely developed digestive tract (Al-Marzooqi and Leeson, 2000). Addition of emulsifier and lipases to a diet is one strategy to improve energy utilization and subsequent growth performance in broiler chickens when fed a high fat diet (Siyal et al., 2017). Studies demonstrating growth performance benefits with the addition of microbial lipases and emulsifiers in broiler chickens are limited. Therefore, the objective of the present study was to examine the effects of supplementation of two different microbial lipases and emulsifier in combination, into a reduced energy diet, on growth performance and nutrient digestibility in broiler chickens from hatch to 35 days.
Two hundred and seventy one-day-old Ross male broiler chickens were randomly allocated to 30 pens. Each pen was assigned to one of five treatments to give six replications with nine birds in each cage. Five dietary treatments were; 1) Standard (STD) diet formulated to meet the Ross 308 nutrition specification without adding any emulsifier or lipases, 2) negative control with 100 kcal/kg lower energy than STD (NC), 3) Emulsifier treatment (EMF): NC + 0.1% Polysorbate-20 and 4) Lipase treatment 1 (TLL): EMF + 0.1% TLL (Thermomyces lanuginosus lipase), 5) Lipase treatment 2 (CRL): EMF + 0.1% CRL (Candida rugosa Lipase). Corn and soybean-meal-based control diets containing beef tallow were formulated to meet the Ross 308 nutrition specification. Diets were provided on an ad-libitum basis in a mash form. Emulsifier and lipases were top-dressed onto the basal diet. Growth performance was measured on days 21 and 35. Ileal digesta was collected on day 35 to measure the nutrient digestibility. Our results revealed that NC lowered (P < 0.05) the body weight and average daily gain of the broilers compared to broilers fed STD diet from hatch to 35 days. Broilers fed CRL showed higher body weight and average daily gain compared to NC and TLL fed broilers from hatch to 35 days. Moreover, broilers fed CRL tend to have improved (P< 0.1) feed efficiency compared to the broilers fed other treatment diets from hatch to day 35. Improved crude fat and energy digestibility (P < 0.05) were observed in broilers fed with CRL compared to NC fed broilers on day 35. In conclusion, our results indicated that CRL have the ability to maintain growth performance and nutrient digestibility of broiler chickens by curtailing the negative impact of low energy in the diets.
Presented at the 31th Annual Australian Poultry Science Symposium 2020. For information on the next edition, click here.