Effects of dietary protein level on protein deposition in broilers: 2. Body composition, plasma metabolic profile and litter composition.

Abstract

The aim of study was to evaluate the effects of three dietary protein levels on body composition, plasma metabolic profile and litter composition of broilers at 42 days of age. One-day-old unsexed Cobb 500 broilers (n=600) were randomly assigned in 3 groups with 4 replications per treatment. Three diets were formulated for each growth phases, to contain 3 levels of protein: high protein (HP), medium protein (MP) and low protein (LP). The diets were isocaloric, with similar content of digestible sulphur amino acids, lysine, calcium and available phosphorus. The empty body weight (BW) of broilers was influenced by the dietary treatments (+ 8% in HP, respectively - 7.7% in LP vs. MP; P 0.05). In general, plasma biochemical parameters were not influenced by the dietary protein levels (P>0.05). In conclusion, low protein diets can support similar quality performance that high or medium diets when the quality ingredients are used. The lower dietary protein level resulted in reduced nitrogen excretion, which is an important advantage for environmental safety.