Abstract
The addition of tryptophan (TRP) in diets for broilers can meet the requirement, reducing the crude protein content of the feed, in addition to maintaining the homeostasis and the consumption control, these factors are relevant to increase the productivity. Therefore, this study aims to estimate the requirements and tryptophan utilization efficiency for broilers. Will be three dose responses in test phases (starting at 14 -1 growing - 15 to 28 and finishing - 29 to 42 days of age). In each test, the experimental design will be completely randomized, consisting of 16 treatments in a factorial 2 x 8 (eight amino acid levels and sexes) with four replicates of 20 birds each. The experimental diets will be formulated through the "Dilution Technique". The variables are: performance (weight gain, feed intake, feed conversion), yelled of cuts (carcass, breast, thigh and drumstick), body protein deposition (DPB) in feather (DPF) and efficiencies of using tryptophan (k). The data will be subjected to regression analysis to fit the LRP models, quadratic polynomial, quadratic and exponential + LRP will also be elaborated factorial model: TRP = [(AATRP.PBm0,73.u) + (0,01.WPF. AAF)] + [(AAB.DPB / k) + (AAF.DPF / k), where AATRP is the requirement for maintenance of TRP protein defeathering body (mg / PBm0,73 u / day.); PBm is the weight of body protein at maturity (kg); u is the degree of maturity of body protein (u = PBt / PBm); WPF is the protein weight of the feathers (g); AAF and AAB is the tryptophan content in protein pen and fleeced body (g / mg) respectively. Statistical analyzes will be conducted with SAS 9.2. The expected results will establish optimal levels of tryptophan and its utilization efficiency for body protein deposition and develop models to estimate tryptophan requirements in broilers of lineage Cobb.
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