Determining the appropriate level of metabolic energy, protein and essential amino acid standardized ileal digestibility (SID) in diet of TN broiler chickens
The objective of this study aimed to investigate the response of growth and meat quality yield of TN broiler chickens to the levels of metabolic energy, crude protein (CP) and standardized ileal digestible amino acids (SID-AA) in the diet based on the balance of other essential amino acids (AA) according to lysine. The experiment was carried out on 810 with 1-day-old TN chickens. At the 8th day of age, all chickens were designed using a completely randomized design with two factors, included 3 levels of energy (ME), CP and 3 levels of SID-lysine (other essential AAs such as methionine + cysteine, threonine, tryptophan, agrinine are balanced according to SID-lysine), with 5 replicates/treament. Experimental chickens were distributed evenly according to the ratio of males and females among treatments. The results showed that increasing energy-protein and SID-lysine levels in the diet had a positive effect on growth performance, feed efficiency and meat quality yield of TN chickens raised for meat. When considering each growth stage separately, it can be concluded that the requirements for metabolized energy, protein and SID-lysine of TN chickens raised for meat is expressed in content and ratio (%) in 1kg of feed containing 89% dry matter is as follows: Metabolizable energy (Kcal/kg): 3000, 3050 and 3100; crude protein (%): 21; 19.5 and 17.5%; SID-lysine (%): 1.2; 1.05 and 0.95 correspond to the stages 8-28 days old, 29-56 days old and 57-84 days old.
