Screening of Commonly used feed ingredients for digestible amino acids, metabolizable energy and their effects on three different broiler Strains

Abstract

The present study was planned to examine digestible amino acids (DAA) and apparent metabolizable energy corrected for nitrogen (AMEn) of the commonly used indigenous poultry feed resources, and their effects on the performance of Cobb (500), Arbor Acre and Hubbard (Classic). The study comprised of three phases. In the first phase, standardized ileal amino acid digestibility (SIAAD) of 3 samples of each feed ingredient was determined in broilers at the age of 21 days. The test ingredients served as sole source of AAs in their respective diets. The diet based on each sample of each ingredient was fed to 36 birds in 6 replicates, each containing 6 birds. The acid insoluble ash (AIA), at the rate of 2% of the diet, was used as an external marker to determine digestibility. Among cereals, the corn had the highest SIAAD (90.11%) and among cereal by-products, wheat bran exhibited higher SIAAD (76.86%). Among protein meals, soybean had the highest digestibility but it was the lowest in guar meal. In the second phase, the AMEn of 3 sample of each feed ingredient was determined by substitution method in 21 days old broilers using AIA, at 1% of the diet, as an external marker. Among cereals, rice broken had the highest AMEn (3372 kcal/kg). Similar in cereal byproducts, rice polishings supplied the highest AMEn (1936 kcal/kg). The fish meal exhibited highest AMEn (2802 kcal/kg) in protein meals. In the third phase, 3 diets for each strain were formulated using DAA coefficients and AMEn values determined in first two phases to examine the growth performance of three broiler strains. The control diet (C) had standard DAA according to each strain’s requirement. The second diet (HDAA) supplied 10% more DAA and the third diet (LDAA) had 10% less DAA than C. Data were analyzed using Completely Randomized Design (CRD) having levels of DAAs nested within broiler strains. The growth performance of Arbor Acre at 42 days of age was better (P<0.05) followed by Hubbard and Cobb. All 3 strains of broilers fed LDAA diet ate more (P>0.05) feed and gained numerically more (P>0.05). Similarly, improved feed conversion ratio (P>0.05) was noticed in Cobb fed HDAA diet. However, Arbor Acre and Hubbard performed better on C diet. Dressing percentage remained similar among all diets in all strains; but, breast meat percentage improved (P>0.05) when fed HDAA diet in all strains. In conclusion, determining nutrient availability of locally available feed ingredients will not only help maintain national database repository but will also help cost-effective broiler production in the country.