ABSTRACT The objective of this study was to evaluate the effects of supra-nutritional level of selected B vitamins in different types of diet on broiler performance. Two experiments were conducted using male and female one-day-old chicks (n=288 each; initial body weights in experiment I and II was, respectively, 47.57 ± 0.43, and 47.98 ± 0.31) reared in batteries up to 18 days. In experiment I, the chicks were fed a corn and soybean meal-based diet and, in experiment II, a diet containing oxidized animal by-product meals and soybean oil was used. Both experiments followed a completely randomized design in a 3 × 2 factorial arrangement, consisting of the factors: i) supplementation levels of selected B vitamins (control, 3- or 6-times control of the vitamins riboflavin, pantothenic acid, niacin, folic acid and vitamin B12); ii) dietary nutritional density (low or high), totaling 6 treatments and 8 replicates of 6 birds each (3 males and 3 females). As result of this study, in Exp. I, chicks showed higher weight gain (741.1 g vs. 697.3 g) and feed intake (920.2 vs. 878.5 g) when fed low-nutritional density diet with supra-nutritional vitamin level 6-times higher than the control. However, this effect was not found in the performance of chickens fed high-nutritional density diet. Despite the poor quality of the ingredients used in Exp. II, no statistical effect was shown of the use of vitamin super-dose in rations with different dietary nutrient density. Feed conversion ratio (FCR) was significantly improved for chickens fed high-nutritional density diet (1.191 vs. 1.246 in experiment I, 1.244 vs. 1.275 in experiment II, p<0.01). We conclude that birds fed a vegetable diet formulated with low-dietary density improved body weight (BW) and feed intake (FI) when receiving supra-nutritional levels of vitamins 6-times higher than the control.

ABSTRACT The purpose of this trial was to supplement commercial broiler diets with optimum vitamin programs and higher availability of mineral sources, and to evaluate the effect on performance, yield and meat quality of broilers. The study used 1800 male broiler chicks randomly distributed in a 2 x 2 factorial design (vitamin programs - optimum and commercial vs. mineral sources - inorganic (sulfates) and carbo-amino-phospho-chelate (CAPC)). Supplementation associating optimum vitamin levels and mineral source CAPC resulted in better feed conversion and higher carcass weight at 42 days of age (p<0.05). Supplementation of diets with optimum vitamin levels resulted in higher absolute and relative breast weight, lower abdominal fat deposition, and reduction (p<0.05) of broiler breast water loss by dripping. Supplementation with CAPC minerals resulted in higher breast weight, lower abdominal fat deposition, less elastic muscle tissue, that is, a higher level of tenderness resulting in less resistance of muscle fibers and skin with higher tear strength than the skin of birds fed inorganic sources. Associating optimum vitamin programs and CAPC mineral source resulted in lower (p<0.05) lipid peroxidation levels in thighs and drumsticks after 10 and 40 days freezing. No difference (p>0.05) was found in the association of vitamin programs and mineral sources on the occurrence of white striping and dorsal myopathy. Supplementing the diets with optimized vitamin programs associated with a more bioavailable mineral source resulted in a positive contribution to the meat quality of broilers.

ABSTRACT This study aimed to evaluate the effect of different reductions in digestible amino acids content (lysine, methionine, and threonine), according to two nutritional requirements in corn, soybean meal, and meat and bone meal based diets, with protease supplementation, on performance parameters and carcass characteristics. A total of 1080 day-old chicks, male, Cobb 500, were allotted to a completely randomized design, in a factorial arrangement 3 x 2, three reductions in digestible amino acids content (lysine, methionine, and threonine) and two nutritional requirements (Rostagno et al. 2005 and Cobb-Vantress Guidelines 2008), and all diets were supplemented with protease (200 ppm) with 6 replicates of 30 birds per pen. There was no significant interaction (p<0.05) between digestible amino acid reductions and both nutritional requirements for the performance variables and carcass yield and cuts. There was an effect of amino acid reduction and protease supplementation only on slaughter weight (p<0.05). Broilers fed according to the nutritional requirements of Rostagno et al. (2005) showed better (p<0.05) performance when compared to broilers fed as specified by the nutritional requirements of Cobb-Vantress (2008) with no significant differences in carcass characteristics. Protease supplementation of corn, soybean meal, and meat and bone meal based diets allows a reduction in the inclusion of crystalline amino acids (lysine, methionine, and threonine).

Abstract This study evaluated the effects of the dietary inclusion of an enzyme blend and a direct-fed microbials in broiler diets on litter production and quality. In total, 900 Cobb 500(r) broiler chicks were distributed according to a completely randomized design into 4 treatments and 9 replicates of 25 birds each. Broilers were reared from 1 to 42 days of age. The treatments consisted of the following diets: NC: negative control; DFM: NC + 500 ppm of direct-fed microbials product (DFM), containing Bacillus subtilis and Bacillus licheniformis; ENZ: diet formulated with an enzyme blend (20 ppm phytase, 200 ppm protease and 200 ppm of xylanase); DFM+E: ENZ + DFM. Birds and litter were weighed at the start and end of the rearing period, for litter production and waste ratio (Rw) determination. Litter samples were analyzed for dry matter (DM) content, total and thermotolerant coliform counts, nutrient composition (nitrogen (N), phosphorous (P) and potassium (K)), and fiber fraction (neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin). The dietary inclusion of the evaluated additivesdid not influence litter production or Rw; however, ADF (%), NDF (kg and kg/kg DM litter), and total and thermotolerant coliform counts were reduced, and N content increased in the litter. The diets containing enzymes (ENZ and DFM+E) reduced litter P content. The addition of exogenous enzymes and their combination with a DFM based on Bacillus spp .Did not affect waste production, and reduced litter microbial load, and the contents of P and insoluble fiber in the litter.

A trial was conducted to evaluate the effects of adding an exogenous α-amylase-β-glucanase complex produced from Bacillus amyloliquefaciens on the growth performance, carcass yield, and relative AME bioequivalence in broilers fed corn-soy diets from 1 to 40 d of age. One thousand seven hundred and fifty one-day-old Cobb x Cobb 500 slow-feathering male broilers were randomly allotted to seven treatments with 10 replicates of 25 birds each as follows: control diet (C); C diet with reduction of 60 (C-60), 90 (C-90), or 120 (C-120) kcal AME/kg; C diet with reduction of 120 kcal AME/kg and supplemented with 200 (C-120-200), 300 (C-120-300), or 400 (C-120-400) mg of the enzyme complex/kg. Each g of the enzyme complex corresponded to 200 kilo-Novo α-amylase and 350 fungal β-glucanase units. On d 40, eight birds were randomly taken from each pen and processed to evaluate carcass and commercial cuts yields. Percent mortality was not affected by the treatments (p > 0.05). Live performance, as indicated by BW gain (BWG) linearly decreased (p < 0.05) and FCR linearly increased with the reduction in AME. Birds fed diets supplemented with the enzyme complex showed weekly improvements in BWG and FCR. There were no effects of the treatments on the yield of the carcass or of commercial cuts; however, abdominal fat was significantly lower (p < 0.0343) in birds fed the C-120-400 compared to the C-120 feeding program (1.67% vs. 1.90%); all other treatments were intermediate. Average AME equivalence of the enzyme complex varied weekly. Estimations for the entire period were 40, 46, and 56 kcal for BWG and 58, 76, and 99 kcal AME/kg for FCR (p < 0.001) for the diets containing 200, 300, and 400 mg enzyme complex/kg, respectively.