RESUMOForam utilizados 1600 pintos de corte de um dia de idade, distribuídos em delineamento, em blocos ao acaso, com esquema fatorial 4×2 (quatro linhagens, sendo uma delas comercial (Ross-308) e as demais específicas para a produção colonial (Caipirinha, Pescoço Pelado e Paraíso Pedrês) e dois sistemas de criação (confinado e com acesso a piquete), com quatro repetições de 50 aves cada. A ração não continha promotores químicos de crescimento e produtos de origem animal. Avaliaram-se o ganho de peso, o consumo de ração, a conversão alimentar, a mortalidade e os rendimentos de carcaça e das partes (peito, pernas, asas e dorso) aos 56, 63, 70, 77 e 84 dias de idade. O comprimento e a porcentagem (em relação ao peso vivo) dos intestinos e o peso e a porcentagem (em relação ao peso vivo) do fígado, moela e pâncreas foram avaliados aos 84 dias de idade. Houve efeito (P<0,05) da linhagem para as características de desempenho e da linhagem e do sexo para rendimentos da carcaça e das partes, assim como para as características do sistema digestório (P<0,05). O sistema de criação não influenciou as características avaliadas.Palavras-chave: frango de corte colonial, desempenho, rendimento de carcaça, produção semi-extensiva ABSTRACTOne thousand and six hundred day-old-chicks were randomly assigned to a 4×2 factorial design (4 strains and 2 production systems) with 4 replicates of 50 birds each. A commercial strain Ross and three strains (Caipirinha, Pescoço Pelado and Paraíso Pedrês) for free range chicken production systems were used. The production systems were confined and semi-confined supplemented with grass paddock (3m 2 /bird). The diets did not contain chemical growth promoters and animal by products. Weight gain, feed consumption, feed conversion, mortality and carcass yield and parts were evaluated at 56, 63, 70, 77 and 84 days. Length and percentage of gut, liver, gizzard and spleen were evaluated at 84 days. Differences (P<0.05) among strains for performance, carcass yield and parts and gut characteristics and no differences (P>0.05) among production systems were observed.

This experiment studied the effect of four calcium (3.0, 3.5, 4.0, and 4.5%) and four available phosphorus levels (0.25, 0.30, 0.35, and 0.40%) in the diet of semi-heavy commercial layers after molting. Hisex Brown® layers between 90 and 108 weeks of age were distributed in a completely randomized experimental design with a 4x4 factorial arrangement with 16 treatments of five replicates of eight birds each. mortality, egg production, feed intake, egg mass, average egg weight, calcium and phosphorus intake, feed conversion ratio (per dozen eggs and per kg eggs), eggshell percentage and thickness, eggshell strength, eggshell weight per surface area (ESWSA), yolk percentage and color, albumen percentage, albumen and yolk heights, and blood and excreta calcium and phosphorus concentrations. There was no interaction (P>0.05) between dietary Ca and avP for any of the studied parameters. There were linear increases in Ca intake (P<0.01), eggshell percentage (P<0.05); ESWSA (P<0.05); yolk color (P<0.05); Ca concentration in the blood (P<0.05) and excreta (P<0.01) as dietary Ca level increased. The intake of avP linearly increased (P<0.01) with dietary avP levels. The remaining parameters were not influenced (P>0.05) by dietary Ca and avP levels. The diet containing 4.5% calcium improved feed conversion ratio per dozen eggs and eggshell quality. The lowest avP level fed (0.25%) is sufficient to maintain the performance and the egg quality of semi-heavy commercial layers after molting

RESUMO -Objetivou-se, nesta pesquisa, estudar o efeito dos níveis de energia metabolizável (EM) da dieta sobre o desempenho e o metabolismo energético de frangos de corte machos na fase de crescimento (22 a 43 dias de idade) em condições de temperatura ambiente. Foram utilizadas 288 aves distribuídas aleatoriamente por três níveis de energia da dieta (3.050, 3.200 e 3.350 kcal/kg) e três níveis de alimentação (ad libitum, 75 e 50% do ad libitum), com quatro repetições de oito aves, para determinação das exigências de mantença e das eficiências energéticas. Foi utilizado o método do abate comparativo, sendo que 12 aves foram abatidas no início do ensaio experimental, para determinação da composição corporal inicial, e 144 aves foram usadas para determinação da energia metabolizável das dietas experimentais. Os níveis de energia influenciaram na ingestão de energia metabolizável (IEM) e, conseqüentemente, a retenção de energia na carcaça (ER) e a produção de calor (PC). As exigências de energia metabolizável de mantença (EMm) determinadas foram 131,12; 140,96 e 131,78 kcal/kg 0,75 /dia para os níveis de energia alto, médio e baixo, respectivamente. O nível de energia mais alto (3.350 kcal/kg) na dieta dos frangos de corte proporcionou melhores resultados de desempenho, enquanto o médio (3.200 kcal/kg), melhor equilíbrio na eficiência de utilização de energia para deposição de proteína e gordura, conseqüentemente, melhor qualidade da carcaça, em decorrência da menor deposição de gordura.Palavras-chave: eficiências de utilização da energia, exigência de energia para mantença, metabolismo energético, níveis de energia na dieta Effect of Dietary Metabolizable Energy on Energy Metabolism and Performance in Broiler ChickensABSTRACT -The objective of this work was to study the effect of dietary ME levels on the performance and the energy metabolism of male broilers on growing phase, from 22 to 43 days old. Two hundred and eighty-eight broilers were ramdomly assigned to three energy levels (3,050; 3,200 and 3,350 kcal/kg) and three feeding levels (ad libitum, 75% and 50% ad libitum), with four replicates of eight birds, to determine the energy maintenance requirements and the energy efficiency utilization. The method used was the comparative slaughter. Twelve birds were sacrificed in the beginning of trial to determine the initial body composition and 144 birds were used to determine the AMEn of diets according to ME levels and feeding levels. The dietary ME levels affected the ME intake and consequently in retained body energy (RE) and heat production (HP). The maintenance metabolizable energy requirements were: 131, 141 and 132 kcal/kg of W 0.75 / day for 3,350; 3,200 and 3,050 ME/kg, respectively. The highest ME level promoted better performance of the birds, however, the medium ME level provide better values of efficiency for protein deposition and for fat deposition, consequently, lower body fat composition, showing better carcass quality. IntroduçãoAtualmente, pesquisas nas aréas de genética, nutrição e manejo busc...

Aiming at evaluating the influence of cyclic temperatures on the performance and egg quality of Japanese quails an experiment was carried out with 480 birds after egg production peak. Birds were housed in a bioclimatic chamber with automatic temperature control that contained two rooms, one maintained at thermoneutral temperature (21 ºC) and the other adjusted for the tested cyclic temperatures (24, 27, 30, 33 and 36 ºC at a time). Each room had a battery of five floors and ten cages, with a capacity of 24 birds per cage, totaling 240 birds per battery. Birds were fed iso-nutritious and iso-caloric diets. Data obtained under the tested cyclic temperatures were compared with those obtained under thermoneutral temperature. At the end of each experimental period (14 days) performance and egg quality parameters were evaluated. A completely randomized experimental design with two treatments (thermoneutral temperature and tested temperature) and ten replicates of 24 birds each. Cyclic increases of 27 ºC and higher in environmental temperature negatively affected bird performance, with reduced feed intake and consequent reductions in egg weight and mass. A cyclic increase of the environmental temperature to 36 ºC reduced the percentage of saleable eggs and egg production

RESUMOAvaliaram-se o desempenho e a qualidade da carne de frangos de corte alimentados com diferentes níveis de sorgo, do cultivar SAARA, com 0,49g/kg de tanino, em substituição ao milho. Os 2600 pintos sexados de um dia de idade, da linhagem Ross 308, foram distribuídos em delineamento inteiramente ao acaso, com esquema fatorial 5×2 (cinco níveis de sorgo -0, 25, 50, 75 e 100% e dois sexos), e quatro repetições de 65 aves por unidade experimental. Não houve efeito (P>0,05) da substituição do milho pelo sorgo sobre as características de desempenho, de rendimentos de carcaça, carne de peito e pernas, de composição química e sensoriais. O pH observado nas carnes de peito e pernas foi maior para os machos (P<0,05), e houve diminuição do pH à medida que se aumentaram os níveis de substituição. Os machos apresentaram os maiores valores nas medidas de comprimento, largura e espessura do filé. Na carne do peito dos machos, ocorreu maior perda de peso por cozimento e força de cisalhamento (P<0,05). Observou-se diminuição (P<0,05) dos valores de a (vermelho) e b (amarelo) e aumento de L (luminosidade) à medida que aumentaram os níveis de substituição.Palavras-chave: frango de corte, qualidade da carne, sorgo, tanino ABSTRACTThe effects of diets with graded levels of SAARA sorghum, a variety containing 0.49g/kg of tannin, on broiler performance and meat quality were evaluated. One-day-old, sexed Ross 308 chicks (n=2600) were randomly assigned within sex to one of five levels of sorghum (replacement of 0, 25, 50, 75 and 100% of

This study evaluated the effect of dietary calcium levels and limestone particle size distribution on first-cycle layer performance and egg quality. A completely randomized experimental design in 4x3 factorial arrangement (four Ca levels -3.0, 3.5, 4.0, 4.5%; and three limestone particle size distributions -100% fine, 50% fine and 50% coarse, 30% fine and 70% coarse) was applied, totaling 12 treatments with six replicates of eight birds each. The treatments did not influence the most of evaluated performance and internal and external egg quality parameters. However, limestone particle size distribution quadratically affected with percentage of defective eggs, with the lowest percentage obtained with the distribution 61.75% fine limestone and 38.25% coarse limestone. Increasing dietary Ca levels significantly increased eggshell weight per surface area and the percentage of Ca excreted in the feces. It was concluded that the combination of the highest dietary Ca level (4.5%) with 50% replacement of fine-particle limestone by coarse limestone results in better eggshell and increases the number of marketable eggs.

This study aimed to evaluate the effects of probiotics and prebiotics of bacterial and yeast origin on the performance, development of the digestive system, carcass yield and meat quality of free-range broiler chickens. Five hundred and sixty male chicks of the strain ISA S757-N were reared from one to 84 days old. The birds were distributed in four treatments according to a completely randomized block design: T1 = Control, T2 = Probiotics and Prebiotics of bacterial origin, T3 = Probiotics and prebiotics of yeast origin, T4 = Probiotics and prebiotics of bacterial origin + probiotics and prebiotics of yeast origin. There were four repetitions with 35 birds per repetition, and the birds had access to a pasture area after 35 days of age. Characteristics evaluated were performance, development of the digestive system, carcass and parts yield, abdominal fat, breast meat physical measurements (length, width and height) and meat quality parameters (pH from breast and leg meat, cooking loss and shearing force from breast meat). Lower mortality (p<0.05) and higher weight gain from 64 to 77 and 64 to 84 days of age were seen in birds supplemented with probiotics and prebiotics of bacterial origin compared to the non-supplemented birds (control). There were significant differences (p<0.05) among treatments for carcass yield. Birds supplemented with both probiotics and prebiotics of microbial and yeast origin (T4) showed higher carcass yield than control birds. Supplementation with probiotics and prebiotics of bacterial origin (T2) or the supplementation of these together with those of yeast origin (T4) reduced mortality and increased the carcass yield in free-range broiler chickens

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