Amino Acids Fortification of Low-protein Diet for Broilers Under Tropical Climate. 2. Nonessential Amino Acids and Increasing Essential Amino Acids

Abstract

A three-week trial was carried out to evaluate the effect of nonessential amino acids (NEAA) supplementation to a low-crude protein (CP) diet with adequate essential amino acids (EAA) level on growth performance, blood metabolites, and relative weights of abdominal fat, breast yield, and internal organs in broiler chickens raised under tropical hot and humid environment. Five isocaloric (3000 metabolisable energy/kg) corn-soybean diets were administered (1 to 21 days) to 5 groups of broilers (60 birds/group) as follows: i) 22.2% CP (positive control; PC); ii) 16.2% CP+all EAA to meet or exceed the National Research Council (1994) recommendations (negative control; NC); iii) NC+further EAA to equal the levels in the PC diet; iv) NC+NEAA to equal the levels in the PC; v) NC+EAA and NEAA to equal the amino acids levels in the PC diet. The results showed that the fortification of EAA alone, only improved feed intake (FI), whereas, addition of NEAA or EAA+NEAA significantly enhanced body weight, daily weight gain, and FI and decreased the feed conversion ratio to the same levels as in PC. Serum uric acid was significantly reduced and serum triglyceride increased in NC group. Dietary treatments had no significant effect on relative weights of heart, liver, abdominal fat, breast meat yield, serum albumin, and serum total protein. In conclusion, these results suggest that NEAA fortification may improve the growth performance of broilers fed an excessive low-CP diet under tropical hot and humid condition.

Effects of protease supplementation of low protein and/or energy diets on growth performance and blood parameters in broiler chickens under heat stress condition

“…Interestingly, no reduction in FI and WG, and elevation in FCR were observed when either protein (LPRE and LPREP) or energy (RPLE and RPLEP) was reduced. These results are in agreement with previous findings that a reduction of dietary CP (in essential AA fortified diet) up to 3% (Bregendahl et al 2002;Si et al 2004;Namroud et al 2008;Awad et al 2014) or energy up to 100 kcal/kg ME (Zaman et al 2008;Dairo et al 2010) had no adverse effects on growth performance in broiler chickens.…”

“…The CP content of the diets was determined following the procedure of AOAC (1990). The AA content was determined using high-performance liquid chromatography, as described in details by Awad et al (2014).…”

Effects of feeding male and female broiler chickens on low-protein diets fortified with different dietary glycine levels under the hot and humid tropical climate

“…Crude protein (ingredients, experimental diets and litter samples) and amino acid contents (ingredients and experimental diets) were determined according to the procedure of AOAC (1990) and using high-performance liquid chromatography as described previously (Awad et al 2014b), respectively. Litter samples were dried in a drying oven at 105 C for 24 h to determine the dry matter following the AOAC (1990) procedure.…”

The effects of low-protein diets and protease supplementation on broiler chickens in a hot and humid tropical environment

“…However, usage of LP diets in some excessive levels still has a negative impact on growth performance, carcass traits [ 1 ], morphology of intestinal villi [ 4 ] and profitability. The scenario is more challenging when broilers are raised under high-temperature conditions, either during summer in temperate regions or in a tropical climate [ 5 ]. Although one study suggested LP diets as a means of reducing metabolic heat production associated with protein catabolism [ 6 ], others suggested the use of higher dietary crude protein (CP) mainly due to lower feed intake (FI) and protein digestibility under high-temperature conditions [ 7 ].…”