Investigou-se o efeito de dieta baseada no trigo (DBT) e suplementada com xilanase e vitamina A sobre o desempenho, digestibilidade dos nutrientes, morfologia intestinal e viscosidade digesta de frangos de corte. Baseado num esquema aleatório, frangos de 240 dias foram divididos em grupos de seis dietas experimentais, com quatro repetições, com 10 frangos cada. As dietas foram: T1 = dieta baseada em trigo; T2 com DBT com vitamina A (9000 IU kg-1); T3 = T2 sem vitamina A; T4 = T2 + 6000 IU kg-1 vitamina A; T5 = T2 + 420 IU kg-1 xylanase; T6 = T2 + 6000 IU kg-1 vitamina A + 420 IU kg-1 xylanase. Para a Taxa de Conversão de Dieta entre dia 1 e 21 e entre dia 21 e 42 DBT suplementada com vitamina A e enzima foi menor do que DBM (p < 0,05). Suplementacão sozinha de vitamina A e vitamina A + enzima melhoru a digestibilidade de proteina bruta (DPB) e gordura bruta (DGB) do que DBT com a quantidade rotineira de vitamina A (p < 0,05). As vilosidades (duodeno, jejuno e íleo) eram mais compridas (p < 0,05) em frangos de corte alimentados com dieta suplementada com vitamina A e enzima do que os frangos alimentados com DBM. Conclui-se que a suplementação de DBT pela enzima e vitamina A poderá melhorar os parâmetros acima.
The effect of wheat-based diet (WBD), supplemented with xylanase and surplus vitamin A, on performance, nutrient digestibility, intestinal morphology and digesta viscosity of broiler chickens was investigated. Based on a completely randomized design, 240-day-old chickens were randomly divided into six experimental diets and four replications with 10 chickens each. Experimental diets consisted of corn-based diet (CBD) (T1), WBD with routine amounts of vitamin A (9000 IU kg-1) (T2), T2 without vitamin A in premix (T3), T2 + 6000 IU kg-1 vitamin A (T4), T2 + 420 IU kg-1 xylanase (T5), and T2 + 6000 IU kg-1 vitamin A + 420 IU kg-1 xylanase (T6). For Feed Conversion Rate (FCR) between day 1 and 21 and between day 21 and 42 WBD supplemented with vitamin A and enzyme was less than CBD (p < 0.05). Also, supplementation of surplus vitamin A singly, and vitamin A and enzyme improved digestibility of crude protein (CPD) and crude fat (CFD) than WBD with routine amounts of vitamin A (p < 0.05). The villus (duodenum, jejunum and ileum) was longer (p < 0.05) in broilers fed on diet supplemented with vitamin A and enzyme than those with CBD. It may be concluded that enzyme and vitamin A supplementation to WBD may improve mentioned parameters.