Abstract
An experiment was conducted to evaluate the effect of different digestible amino acid profiles on the performance of broilers in two phases: from 1 to 21 days and from 22 to 42 days of age. At the end of the experiment, carcass yield and cut percentages were evaluated. Nine hundred and sixty AgRoss birds were distributed in a randomized block design with four treatments (four digestible amino acid profiles): Rostagno et al. (2000), Baker & Han (1994b), Degussa (1997) and those recommended by AgRoss (2000), with six repetitions and 40 birds per repetition (20 males and 20 females). The results showed that the four diets were able to provide the requirements of the birds, since no significant differences were seen among the treatments on the performance in the two phases and on the carcass yield and cuts at 42 days of age. Males had better yields of feet, head and neck, and lower percentage of abdominal fat (p<0.05). The best cost/benefit ratio was seen for the profile established by Rostagno et al. (2000) when diets were evaluated in an ideal protein situation.
Highlights
Broiler diet formulation has been based on crude protein requirements for a long time, frequently resulting in diets containing amino acid levels above the real requirements of birds
No effect of treatment was seen on weight gain (WG), feed intake (FI), feed conversion (FC), mean daily weight gain (DWG), energy conversion (EC) and protein conversion (PC) from 1 to days and from to 42 days (Table 4)
Few data are available about the different profiles of digestible amino acids in broiler chickens based on lysine nutritional requirements, which is used as a reference for establishing the levels of the other amino acid
Summary
Broiler diet formulation has been based on crude protein requirements for a long time, frequently resulting in diets containing amino acid levels above the real requirements of birds. Many studies have directed animal nutritionists to formulate diets based on the ideal protein concept. This is defined as the ideal amino acid balance in the diet, without deficiencies or excesses, providing the requirements of all amino acids needed for maintenance and production of the birds (Baker & Chung, 1992). According to Penz (1996), amino acid should be added in levels that are as close as possible from the requirements of the birds in each production phase and amino acid excess would be minimized in the diets
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
