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 The objective was to evaluate the performance, intestinal morphology and carcass yield of broilers fed corn-soybean meal (SBM) diet or corn-SBM-soybean hull (SH) with or without b-mannanase supplementation. Thousand four hundred and forty Cobb Slow-male- chicks were housed design following a factorial scheme 2 x 2 (corn-SBM diet and corn-SBM-SH diet vs with and without b-mannanase), composing 4 treatments and 9 replicates each treatment, with 40 birds each replicate. At 21 days, corn-SBM diet supplemented with b-mannanase resulted in better (p<0.05) feed conversion. At 42 days, the weight gain (p<0.05) and feed intake (p<0.05) of the birds fed diets containing SH was 2.6% and 2.9% higher than that of birds fed corn-SBM diets, respectively, independent of b-mannanase supplementation. Birds supplemented with b-mannanase had a lower length of villi (p<0.05) and absorption area (p<0.05) of jejunum mucosa, and higher (p<0.05) relative liver weight. Diets with SH and without addition of b-mannanase resulted in higher relative liver weight (p<0.05) and lower percentage of fat in the carcass. It was not found statistical differences (p>0.05) in the quality of the poultry litter with the inclusion of the enzyme in the diet. The use of b-mannanase in diets with higher concentration of fiber improves the feed conversion of broilers from 1 to 21 days and can be an important nutritional and economic strategy in situations of unavailability of raw material of better quality. Corn-SBM-SH diet resulted in greater weight gain at 42 days than corn-SBM diet.

ABSTRACT The objective of this study was to evaluate the supplementation of guanidinoacetic acid (GAA) and L-arginine (L-Arg) as creatine precursors to vegetable diets on the carcass yield and meat quality of broilers subjected to two days of heat stress before slaughter. A total of 1260 broiler chicks were distributed according to a completely randomized design into four treatments with nine replicates of 35 birds each. The treatments consisted of: T1 - vegetable diet based on corn and soybean meal (control diet); T2 - control diet with the inclusion of meat meal (3%); T3 - control diet supplemented with GAA (0.08%); and T4 - control diet supplemented with L-Arg (0.8%). The birds were submitted to heat stress for two days before slaughter (from 42 to 44 days of age). The birds fed the diets supplemented with GAA or L-Arg presented heavier carcasses (p<0.0035), higher breast yield (p=0.0685), and lower of abdominal fat deposition (p=0.0508) than those fed the control diet and the control diet with meat meal. The cooking loss of the breast fillets of broilers fed the control diet supplemented with meat meal, GAA or L-Arg was lower (p<0.0068) compared with those fed the control diet. Thawing and pressure-driven breast fillet weight losses, and pH, luminosity, redness (a*value), and yellowness (b* value) values were not influenced by the treatments. When GAA is less expensive than commercially-available Arg, the dietary supplementation of GAA is more advantageous, based on the meat yield improvements observed in the present study.

RESUMO O objetivo deste estudo foi avaliar o efeito do fornecimento de dietas pós-eclosão suplementadas com diferentes fontes de gordura insaturada e adicionadas ou não de taurina e glicina sobre o desempenho produtivo, a biometria e a morfometria do intestino delgado de pintos de corte de um a 21 dias de idade. Foram utilizados 480 pintos de corte machos de um dia de idade da linhagem Cobb. O delineamento foi inteiramente ao acaso, em esquema fatorial 2 x 4, com e sem suplementação de taurina e glicina e quatro dietas (controle, óleo de peixe, de soja e de girassol), totalizando oito tratamentos com seis repetições de 10 aves cada. As rações experimentais foram fornecidas de zero a quatro dias de idade. O desempenho zootécnico foi avaliado ao alojamento e aos quatro, sete e 21 dias de idade. Nestas mesmas datas, foram sacrificadas duas aves por unidade experimental para biometria do intestino e histomorfometria da mucosa do intestino. A adição de diferentes fontes de gordura e a suplementação de glicina e taurina às dietas de transição não influenciaram o desempenho produtivo de um a 21 dias. A suplementação das dietas com glicina e taurina alterou a morfologia da mucosa intestinal, principalmente do duodeno, resultando em maior comprimento do vilo e relação vilo:cripta. Entretanto, parte dos efeitos positivos depende do tipo de óleo adicionado, mostrando que dietas pós-eclosão acrescidas de fontes de lipídios podem ser benéficas no desenvolvimento da capacidade funcional do intestino de frangos de corte.

ABSTRACT The aim of this study was to assess post-hatch diets supplemented with different sources of unsaturated fat and added or not with taurine and glycine on the productive performance, biometry and morphology of small intestine of chicks from 1 to 21 days of age. Four hundred and eighty (480) one day old male broiler Cobb chicks were used. The experimental design was completely randomized in a factorial 2 x 4, with and without supplemental taurine and glycine and 4 diets (control, fish, soy and sunflower oil), totaling six treatments with six repetitions of 10 birds each. The experimental diets were supplied from 0 to 4 days old. The performance was evaluated in housing and 4, 7 and 21 days of age. On these same dates, 2 birds per experimental unit were sacrificed for gut biometrics and histomorphometry of intestinal mucosa. The addition of different sources of fat, glycine and taurine supplementation on transition diets did not influence productive performance from 1 to 21 days. Supplementation of diets with glycine and taurine altered the morphology of the intestinal mucosa, mainly of the duodenum, resulting in greater length of villi and villi: crypt ratio. However, the positive effects depend on the type of oil added, showing that post-hatch diets increased with lipid sources may be beneficial in the development of the functional capacity of the intestine of broilers.