Utilizating various levels of metionine+cystine on rations of laying hens up 45 weeks of age Níveis de metionina+cistina no desempenho de poedeiras comerciais leves com

An experiment was carried out in the Aviary of Experimental Farm of Iguatemi of the State University of Maringá (FEI/UEM), with the objective of studying the needs in sulfur amino acids for hens. 200 hens were used above 45 weeks, in 4 cycles of 28 days each. The treatments consisted on a basal ration with 16.0% PB and 2,850 kcal EM/kg, supplement with 5 TSAA levels (0.52; 0.57; 0.62; 0.67 and 0.72%). The variables studied were ration consumption and of TSAA; production, weight, and internal quality of the eggs, weight of the peel of the eggs, specific gravity and feed conversion. The completely randomized design, was used with 5 treatments, 5 repetitions and 8 birds for experimental unit. The data were submitted the regression analysis by the system SAS®. In the conditions in that the experiment was accomplished, there was a growing lineal increase in the medium weight of the eggs, when were increased the levels of sulfur amino acids in the ration. For eggs quality, peel percentage and Haugh units (UH), there was not significant difference (P>0.05). Production of eggs was converted for posture percentage and alimentary conversion (kg/kg and kg/dz), they didn't also have difference (P>0.05).Objetivando-se estudar as necessidades em aminoácidos sulfurados para poedeiras comerciais leves, utilizaram-se 200 poedeiras leves com 45 semanas de idade, em 4 períodos de 28 dias cada. Os tratamentos consistiram em uma ração basal com 16,0% PB e 2.850 kcal EM/kg, suplementada com 5 níveis de metionina+cistina (met+cis) (0,52; 0,57; 0,62; 0,67 e 0,72%). As variáveis estudadas foram consumo de ração (CR), consumo de met+cis (CM), conversão alimentar (CA), produção de ovos (PO), peso dos ovos (PE), qualidade interna dos ovos (QI), peso da casca dos ovos (PC), porcentagem de casca dos ovos (CO), gravidade específica (GE) e Unidades Haugh (UH). O delineamento experimental foi o inteiramente casualizado, com 5 tratamentos, 5 repetições e 8 aves por unidade experimental. Os dados foram submetidos à análise de regressão pelo sistema SAS®. Houve um aumento linear crescente no PE com o aumento dos níveis de met+cis na ração. A CO, UH, PO e CA não diferiram nos tratamentos utilizados