Abstract
This study will determine the requirements of threonine for laying hens in the growth phase based on the methods dose-response and factorial. In factorial design, using performance data and comparative slaughter, different models are used to estimate requirements for threonine. The threonine requirements estimated for the three phases: initial (2-6 weeks), creates (8-12 weeks) and growing (13 to 17 weeks) through three trials to be undertaken separately. The trials will be mounted on a CRD, with eight treatments, six replicates of eight chicks each, except the initial phase, which will be 15 chicks each. The diets are formulated according to the technique of dilution. The variables used to estimate demand for methods and dose response factor (comparative slaughter) will be: GP (g), CR (g), threonine intake (g/bird/day), CA (g/g) and protein deposition and fat (g/bird/day) in the body free of feathers and feathers. Another methodology based on results of N balance and using factorial equations is used. This methodology allows us to estimate the maximum theoretical potential for deposition of N at different phases, requirements for maintenance and N use efficiency and requirements for threonine. To this end, four tests will be conducted N balance in the ages between 15-30, 45-60, 75-90 to 105 days. Will use a total of 56 broilers from Dekalb White in the growth phase, distributed in DIC, 7 treatments, 8 replicates were housed individually in metabolism cages. Each test will last 15 days, five for adjustment and 10 for excreta collection. The diets will be formulated by the dilution technique. Statistical analysis of data to determine the optimum level of threonine by the dose-response method and the parameters of the factorial method will be performed in computer program SAS 9.1.
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