O objetivo deste trabalho foi avaliar um aparelho desenvolvido para a determinação da gravidade específica (GE) do ovo em água, comparando-o ao método de imersão em solução salina. Foram coletados 200 ovos de duas linhagens de poedeiras comerciais, divididos ao acaso em dois grupos de 50 ovos por linhagem e submetidos a duas seqüências de determinação da GE. Não foram observadas diferenças significativas entre os métodos utilizados. A determinação da GE dos ovos utilizando o aparelho desenvolvido pode ser realizada com a mesma precisão da determinação em solução salina.

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A protective digestive microflora helps prevent and reduce broiler infection and colonization by enteropathogens. In the current experiment, broilers fed diets supplemented with probiotics and essential oil (EO) blends were infected with a standard mixed Eimeria spp. to determine effects of performance enhancers on ileal and cecal microbial communities (MCs). Eight treatment groups included four controls (uninfected-unmedicated [UU], unmedicated-infected, the antibiotic BMD plus the ionophore Coban as positive control, and the ionophore as negative control), and four treatments (probiotics BC-30 and Calsporin; and EO, Crina Poultry Plus, and Crina PoultryAF). Day-old broilers were raised to 14 days in floor pens on used litter and then were moved to Petersime batteries and inoculated at 15 days with mixed Eimeria spp. Ileal and cecal samples were collected at 14 days and 7 days postinfection. Digesta DNA was subjected to pyrosequencing for sequencing of individual cecal bacteria and denaturing gradient gel electrophoresis (DGGE) for determination of changes in ileal and cecal MC according to percentage similarity coefficient (%SC). Pyrosequencing is very sensitive detecting shifts in individual bacterial sequences, whereas DGGE is able to detect gross shifts in entire MC. These combined techniques offer versatility toward identifying feed additive and mild Eimeria infection modulation of broiler MC. Pyrosequencing detected 147 bacterial species sequences. Additionally, pyrosequencing revealed the presence of relatively low levels of the potential human enteropathogens Campylobacter sp. and four Shigella spp. as well as the potential poultry pathogen Clostridiun perfringens. Pre-and postinfection changes in ileal (56%SC) and cecal (78.5%SC) DGGE profiles resulted from the coccidia infection and with increased broiler age. Probiotics and EO changed MC from those seen in UU ilea and ceca. Results potentially reflect the performance enhancement above expectations in comparison to broilers not given the probiotics or the specific EO blends as feed supplements.

The objective of this study was to evaluate the effect of betaine in methionine-and choline-reduced diets fed to broilers submitted to heat stress. In total, 1,408 male broilers were randomly distributed into eight treatments, according to 2 x 4 (environment x diet) factorial arrangement, with eight replicates of 2 birds each. Birds were reared environmental chambers under controlled temperature (25-26 °C) or cyclic heat-stressing temperature (25-31 °C). The following diets were tested: positive control (PC), formulated to meet broiler nutritional requirements; negative control (NC), with reduced DL-methionine and choline chloride levels; and with two supplementation levels of natural betaine to the negative control diet (NC+NB1 and NC+NB2). Live performance, carcass traits, and intestinal morphometrics were evaluated when broilers were 45 days of age. The results showed that all evaluated parameters were influenced by the interaction between environment and diet, except for breast meat drip loss. The breakdown of the interactions showed that birds fed the PC diet and reared in the controlled environment had greater breast drip loss than those submitted to the cyclic heat-stress environment. Birds submitted to cyclic heat stress and fed the PC diet presented the lowest feed intake. Feed conversion ratio was influenced only by diet. The FCR of broilers fed the NC+NB2 diet was intermediate relative to those fed the PC and NC diets. The addition of betaine in the diet, with 11.18% digestible methionine and 24.73% total choline reductions, did not affect broiler live performance, carcass yield, or intestinal morphometrics.

RESUMO -Foram conduzidos três ensaios para avaliar os níveis de energia metabolizável (EM) e a melhor relação energia:proteína (E:P) para aves de corte machos de crescimento lento criadas em semiconfinamento nas fases inicial(1 a 21), de crescimento (22 a 49) e de terminação (50 a 70 dias de idade). Em cada ensaio, 400 machos da linhagem ISA Label na fase de criação foram alojados em instalação experimental constituída de 20 piquetes com área coberta de 3,13 m 2 para alimentação e recolhimento das aves e uma área de pastejo de 72,87 m 2 . O delineamento experimental foi o inteiramente casualizado com cinco tratamentos e quatro repetições de 20 aves. Os níveis de energia metabolizável fornecidos na ração na fase inicial variaram de 2.600 a 3.200 kcal/kg; na fase de crescimento de 2.700 a 3.300 kcal/kg; e na fase final de 2.800 a 3.400 kcal/kg. A proteína bruta e os demais nutrientes foram mantidos constantes em todas as rações, de acordo com recomendações do NRC (1994) para cada fase. A relação energia:proteína e o nível de energia metabolizável que melhoraram o desempenho e as características da carcaça de frangos de corte ISA Label machos criados em sistema semiconfinado em cada fase estudada foram 128 e 2.750; 147 e 2.850 e 172 e 3.100 kcal de EM/kg nas fases inicial, de crescimento e de terminação, respectivamente.Palavras-chave: exigência de energia, linhagem ISA Label, relação energia:proteína Metabolizable energy levels for slow growth male broilers raised in semi confined system ABSTRACT -Three trials were conducted to evaluate the metabolizable energy (ME) levels and the energy to protein ratio for slow growth male broilers raised in semi confined system in the starter (1 to 21), grower (22 to 49) and final phase (50 to 70 days old). In each experiment, 400 males ISA Label line in the raising phase were allotted to experimental installation constituted by 20 lots with cover area of 3.13 m 2 for feeding and gathering of the birds and a pasture area of 72.87m 2 . A completely randomized experimental design was used, with five levels of ME and four replications of 20 birds per experimental unit. The levels of metabolizable energy fed in the ration in the different phases varied in the starter from 2,600 to 3,200 kcal/kg, in the grower from 2,700 to 3,300 kcal/kg and in the final from 2,800 to 3,400 kcal/kg. The crude protein and other nutrients were maintained at the same level in all diets according to the NRC (1994) recommendations, for each phase. The energy to protein ratio and the metabolizable energy that provide the best performance and carcass traits of male broilers ISA Label raised in semi confined system in each phase were: 128 and 2,750, 147 and 2850 and 172 and 3,100 kcal ME/kg of diet in starter, grower and final phases, respectively.Key Words: energy requirement, energy to protein ratio, ISA Label strain IntroduçãoOs sistemas alternativos de produção avícola têm sido adotados por pequenos e médios produtores rurais com o objetivo de oferecer produtos diferenciados ao mercado consumidor, o que...

Resumo -O objetivo deste trabalho foi avaliar o efeito da combinação de fitase e do complexo amilase, protease e xilanase, em dietas de milho e soja, formuladas com redução e sem redução dos níveis de energia, cálcio e fósforo sobre o desempenho e a digestibilidade ileal de nutrientes, em frangos de corte. Foi utilizado o delineamento inteiramente casualizado, com esquema fatorial 2x2, com duas dietas-controle: com redução e sem redução dos nutrientes, e duas suplementações das enzimas (sem adição e com adição de fitase e complexo enzimático), com dez repetições de 40 aves. A digesta ileal foi coletada aos 43 dias de idade, para determinação da energia digestível e dos coeficientes de digestibilidade da proteína bruta, matéria seca, cálcio e fósforo. O desempenho apresentou interação em todos os parâmetros analisados. As aves do tratamento com redução dos nutrientes mostraram pior desempenho em relação às aves da dieta sem redução dos nutrientes. Não houve efeito da matéria seca na digestibilidade e na retenção de cálcio. A adição da combinação enzimática melhorou a digestibilidade da proteína e a retenção de fósforo. Houve interação quanto à energia digestível, com efeito apenas nas dietas sem redução dos nutrientes, com maiores valores nas dietas suplementadas.Termos para indexação: amilase, energia, fitase, fósforo, protease. Exogenous enzymes in the performance and nutrient ileal digestibility of broiler chickensAbstract -The objective of this work was to evaluate the effect on the performance and nutrient ileal digestibility of broiler chickens, of the phytase combination with the enzyme complex of amylase, protease and xylanase in corn-soybean meal diets, formulated with or without reduction in energy, calcium and phosphorus levels. The experimental design was completely randomized with factorial arrangement 2x2, with two control diets: with and without nutrient reduction, and two supplementations for each control (with and without addition of phytase and enzyme complex of amylase, protease and xylanase), with ten replicates of 40 chicks. The ileal digesta were collected in the 43 rd day of age, in order to determine digestible energy and digestibility coefficients of crude protein, dry matter, calcium and phosphorus. The performance showed interaction for all the parameters analyzed. The broilers fed with nutrient reduction showed inferior feed intake, body weight gain and feed conversion than those fed without nutrient reduction. There was no effect of enzymes and diet control on dry matter and calcium retention. The enzyme combination inclusion improved the protein digestibillity and phosphorus retention compared to control diet. There was interaction for digestible energy, with effects only in without nutrient reduction with best values in supplemented diets.

RESUMO O experimento foi conduzido para avaliar a eficiência de enzimas exógenas em dietas sobre o desempenho de frangos de corte. Um total de 1440 pintos de corte machos (Cobb

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