02513naa a2200385 a 450000100080000000500110000800800410001902400300006010000170009024501000010726000090020752014930021665000090170965000150171865000190173365000160175265000110176865000140177965000100179365000250180365000110182865000080183965300130184765300230186065300130188370000240189670000210192070000230194170000210196470000200198570000170200570000250202270000240204777300560207121008012019-01-14       2018    bl uuuu     u00u1 u    #d7 a10.3382/japr/pfy057.2DOI1 aLELIS, G. R.  aDigestible threonine-to-lysine ratio in diets for brown egg-laying hens.h[electronic resource]  c2018  aAbstract: he objective of this study was to evaluate the levels of digestible threonine to determine the ideal digestible threonine-to-lysine ratio in the diet of brown egg-laying hens aged 42?54 wk. A total of 270 Dekalb Brown hens were used in a Completely randomized design (5 treatments × 9 replicates × 6 birds = 270 birds). Five different ratios of digestible threonine-to-lysine were evaluated: 66% (0.435% Thr dig), 70%, 74%, 78%, and 82%. The diets were formulated to satisfy the animals? nutritional requirements and amino acid relationships (2,950 Kcal/Kg ME and 14.81% CP), with the exception of threonine and lysine. The ratio of digestible threonineto-lysine was obtained by L-Threonine (98%) supplementation in place of starch. Parameters such as feed intake (g/bird/d), egg production (%), egg weight (g), egg mass (g), feed (kg/dz and g/g), relative weight of egg components (% yolk, albumen, and eggshell), and weight gain (g) were evaluated. As a result, feed intake, egg weight, relative weight of egg components, and weight gain were found not to be influenced by the digestible threonine-to-lysine ratio used. Egg production, egg mass, and feed conversion (kg/dz and g/g) displayed a quadratic effect for the different ratios used. Based on the results, the digestible threonine-to-lysine ratio recommended in the diets of laying hens between 42 and 54 wk of age is 72%, which corresponds to 0.478% of digestible threonine or 460 mg/bird/d of digestible threonine.  aDiet  aEgg masses  aEgg production  aLaying hens  aLysine  aThreonine  aDieta  aGalinha Para Postura  aLisina  aOvo  aPoedeira  aProdução de ovos  aTreonina1 aTAVERNARI, F. de C.1 aCALDERANO, A. A.1 aDALLA COSTA, F. A.1 aALBINO, L. F. T.1 aROSTAGNO, H. S.1 aBRITO, C. O.1 aARAÚJO, V. A. G. de1 aRIBEIRO JÚNIOR, V.  tJournal of Applied Poultry Research, pfy 057, 2018.