ABSTRACT. The objective of this study was to investigate the effects of alpha-amylase supplementation on performance and carcass and cuts yield in broilers during finishing phase (21 to 42 days). A completely randomized experimental design with six treatments and eight replications was used: Positive Control (PC): no enzyme; Negative control (NC): without enzyme formulated with 6.34% less energy (- 6.34% ME); NC1: with 250 g ton-1 of alpha-amylase; NC2: with 500 g ton-1 of alpha-amylase; NC3: with 750 g ton-1 of alpha-amylase; NC4: with 1000 g ton-1 of alpha-amylase. Significant differences in weight gain, feed intake and feed conversion were reported with the inclusion of alpha-amylase. The NC treatment with inclusion of amylase provided improvement values of weight gain, feed conversion and feed intake, but do not was similarly in comparison to those obtained in broilers fed a diet that completely met the requirements during this phase. There was no dietary influence on carcass parameters. The use of alpha-amylase was effective in improving performance in broilers fed a diet of 200 kcal kg-1 of reduced metabolizable energy.

O objetivo desta pesquisa foi avaliar o efeito da suplementação de colecalciferol (D3) e 25 hidroxicolecalciferol (25-OHD3) como fontes isoladas ou associadas (100%-0%; 75%-25%; 50%-50%; 25%-75%; 0%-100%) de vitamina D sobre o desempenho, a qualidade de casca e as características ósseas, em galinhas poedeiras de ovos brancos de 24 semanas de idade alimentadas com duas concentrações de cálcio (Ca) e fósforo disponível (Pdisp) na dieta basal (DB) (DB1 = 0,38% Ca - 0,36% Pdisp e DB2= 3,2% Ca - 0,30 % Pdisp), durante um período experimental de 16 semanas. Foram utilizadas 960 galinhas Dekalb White em delineamento inteiramente casualizado, com oito repetições e doze aves por unidade experimental. Os tratamentos foram constituídos de um fatorial (5x2), associações de vitamina D e concentrações de Ca e Pdisp. As fontes de vitamina D associadase a maior concentração de Ca e Pdisp diminuíram o consumo de ração e a conversão alimentar. Além disso, a maior concentração de Ca e Pdisp incrementou a produção e massa de ovo. A suplementação a partir de 50% de 25-OHD3 entre as associações de vitamina D aumentou a porcentagem de casca do ovo. Houve interação entre as fontes de vitamina D e as concentrações de Ca e Pdisp. As fontes de vitamina D na DB1 com pelo menos 50% de 25-OHD3 incrementaram a porcentagem de cinzas e a densitometria óssea radiográfica (BRD). A suplementação de 25-OHD3 na DB2 como fonte isolada de vitamina D aumentou a BRD.

The effect of cholecalciferol (D3) and 25-hydroxycholecalciferol (25-OHD3) as isolated or associated sources of vitamin D (100%-0%, 75%-25%, 50%-50%, 25%-75%, 0%-100%) on the productive performance, egg quality, and bone characteristics was evaluated in white egg-laying hens fed two levels of calcium (Ca) and phosphorus (P) in the basal diet (BD) (BD1 = 0.38% Ca - 0.36% available P and BD2 = 3.2% Ca - 0.30% available P). Nine hundred and sixty Dekalb White hens (24 weeks old) were distributed into 80 cages, under a completely randomized factorial design for 16 weeks. The use of associated sources of vitamin D reduced the feed intake and feed conversion ratio, as well as BD1, which also increased the egg production and egg mass. The association of vitamin D sources with up to 50% 25-OHD3 increased the eggshell percentage. There was interaction (p<0.05) between the sources of vitamin D and the concentrations of Ca and available P, sources with at least 50% 25-OHD3 increased ash percentage and bone radiographic densitometry (BRD) with BD1; in BD2 the use of 25-OHD3 as isolated vitamin D source increased BRD. The association of D3 and 25-OHD3 improved the productive performance, increased the percentage of eggshell and had different positive effects on the bone characteristics that depend on the concentrations of Ca and available P in the balanced feed of white egg-laying hens.