Threonine requirement for gilts from 15 to 30 kg

[摘要] - Forty gilts, averaging 15,47 kg initial weight, allotted to a randomized complete block design, with five treatments: .49, .54, .59, .64 and .69% of total threonine, four replicates and two animals per experimental unit, were used to determine the threonine requirement for gilts from 15 to 30 kg. The experimental diets were formulated with corn, sorghum, and soybean meal and corn gluten meal, supplemented with minerals, vitamins and amino acids and supplied ad libitum to the animals. At the end of the experiment, with the animals averaging 33,36 kg live weight, blood samples were collected for serum blood urea analysis. The total threonine requirement determination was based on the performance and serum urea levels parameters, and was estimated by the quadratic and/or the broken line models. In the determination of the true digestible threonine requirement, a threonine basal diet coefficient of true ileal digestibility of 84,6% was used, where the synthetic threonine digestibility coefficient was considered to be 100% digestible. Quadratic effects of dietary threonine levels on feed intake, feed: gain and blood serum urea were observed. However, for urea blood serum, the broken line model showed a better adjustment for threonine levels according to the observed results. The total threonine requirement was estimated in .60% and the true digestible threonine requirement was estimated in .53%.

[学科分类] 兽医学

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