ABSTRACT This study evaluated the effects of two protein levels and types of formulation on performance, nutrient metabolization, and myopathies of 390 female broilers from 21 to 46 days old distributed in a completely randomized design, with five treatments and six replicates of 13 broilers each. Treatments were two levels of protein (19.0 and 21.0%) in diets using only commercially available ingredients and three experimental formulations designed to keep similar the main nutrients that could influence nutritional performance (starch, fiber, ether extract), using unusual ingredients, with 19.0% (19E) or 21.0% (21E) crude protein and the third with 19.0% crude protein with amino acid levels similar to treatment 21P (19E+Aa). We studied broiler performance, nutrient digestibility, macroscopic muscular evaluation, and histological muscular evaluation. The design for the performance and myopathy assessment was a 5 × 2 factorial scheme, five diets × two ages (38 or 46 days). The worst feed conversion ratio was observed for the 19P treatment. Neither diet nor age had an effect on myopathies, however, older slaughter age increased the intensity of microscopic lesions. The diet 19P should be avoided and increased inclusion of lipids in diets improves nutrient utilization and, consequently, performance.

ABSTRACT The objective of this study was to ascertain the influence of different dietary fiber sources and the usage of xylanase on diet of commercial layers and their influence on productive performance, egg quality, and digestive organ biometry. A total of 864 Lohmann® White hens was fed diets with three different fiber sources (wheat bran, soybean hull, or coffee husk) with or without xylanase inclusion (concentration of 160,000 BXU/g) in a 3×2 factorial arrangement, with six replicates of 24 birds each, from 25 to 44 weeks of age. There were no interactions between dietary fiber and xylanase inclusion. The enzyme supplementation did not influence any parameters evaluated. There were dietary fiber effects on body weight gain, viability, egg weight, eggshell quality, yolk pigmentation, and liver and gizzard relative weights. Wheat bran, soybean hull, and coffee husk can be used in laying hen diets without detrimental effect on productive performance. The enzyme used had no effect on the performance and eggshell quality of laying hens.

Resumo: O objetivo deste trabalho foi avaliar o efeito de diferentes procedimentos de desinfecção alternativos à fumigação com formaldeído sobre a redução da contagem microbiana e a qualidade de casca de ovos de matrizes Cobb de 42 semanas de idade. Um total de 10.080 ovos limpos coletados dos ninhos foi distribuído de maneira aleatória, em delineamento de blocos ao acaso, entre os seguintes tratamentos: fumigação com 13,33 g m-3 de paraformaldeído, fumigação com 5-10 ppm de ozônio, 6,36 mW cm-2 de irradiação de luz UV-C, pulverização com 1,56% de peróxido de hidrogênio, pulverização com 0,13% de ácido peracético, pulverização com água (controle úmido) e sem desinfecção (controle seco). Por tratamento, foram coletadas oito amostras de quatro ovos cada uma, momentos antes e após as desinfecções, para contagem de Enterobacteriaceae e bactérias mesófilas aeróbicas totais da casca. Somente os ovos submetidos aos tratamentos com formaldeído e UV apresentaram redução significativa nas contagens de bactérias mesófilas aeróbicas totais, quando comparados aos do grupo controle seco. Os tratamentos não influenciaram a espessura e a resistência da casca. A exposição de luz UV é eficaz em reduzir a contagem microbiana da casca de ovos de matrizes de 42 semanas de idade, sem afetar sua qualidade, e pode ser considerada alternativa ao uso de formaldeído para desinfecção.

Abstract: The objective of this work was to evaluate the effect of different disinfection procedures as alternatives to formaldehyde fumigation on eggshell microbial load and quality of eggs from a 42-week-old Cobb commercial breeder flock. A total of 10,080 clean eggs collected from the nests were randomly distributed in a randomized complete block design, among the following treatment groups: 13.33 g m-3 formaldehyde fumigation, 5-10 ppm ozone fumigation, 6.36 mW cm-2 UV-C light irradiation, spraying with 1.56% hydrogen peroxide, spraying with 0.13% peracetic acid, spraying with water (wet control), and no disinfection procedure (dry control). Per treatment, eight samples of four eggs each were collected before and after the disinfection procedure, in order to count the number of Enterobacteriaceae and total aerobic mesophilic bacteria on the eggshell. Only eggs subjected to the formaldehyde and UV treatments showed a significant reduction in total aerobic mesophilic bacterial count on the eggshell, when compared with those of the dry control group. Treatments did not affect eggshell thickness and resistance force. UV light exposure is effective in reducing microbial load on 42-week-old breeder flock eggshells, without affecting their quality, and can be considered an alternative to formaldehyde disinfection.

RESUMO Objetivou-se avaliar o conforto térmico, o desempenho e as variáveis fisiológicas de frangos de corte alojados em aviários com e sem pintura de telhados de fibrocimento, no período de 21 a 42 dias de idade. Foi utilizado o delineamento inteiramente casualizado, em arranjo com parcela subdividida, onde as parcelas foram compostas pelos galpões (com e sem pintura de telhado) e as subparcelas os horários de avaliação (6, 9, 12, 15 e 18h) ao longo de 22 dias de coleta de dados, considerados como repetição. Observou-se que a pintura externa do telhado na cor branca, proporcionou melhorias no interior do galpão para a temperatura ambiente (Ta), temperatura de telhado (Tt) e na carga térmica de radiação (CTR). A umidade relativa (UR) e o índice de temperatura de globo negro e umidade (ITGU) variaram apenas em função dos horários de coleta. Não houve efeito da pintura externa do telhado nas variáveis fisiológicas das aves. Os índices de desempenho produtivo e a remuneração financeira por lote foram melhores para o galpão com pintura de telhado. Assim, recomenda-se a pintura externa em telhados de fibrocimento, na cor branca, em aviários localizados em ambientes de clima quente, como a região em estudo.

SUMMARY The objective this study was to evaluate the thermal comfort, performance and the physiological variables of 21-42 day of age broiler chickens housed in aviaries with painted and not painted fiber cement roof. A completely randomized design was used in a split-plot design where the plots were composed of the sheds (painted and not painted roof) and the subplots were the evaluation hours (6h00, 9h00, 12h00, 15h00 and 18h00) for a 22-day data collection, considered as the replicates. It was observed that the external painting in white of the roof provided improvements inside the shed for airtemperature (Ta), roof temperature (Tr) and the thermal load of radiation (TLR). The relative humidity (RH) and the Globe-Temperature-Humidity-Index (GTHI) varied only according to the collection times. The exterior painting of the roof had no effect on the physiological variables of the broilers. Productivity performance indexes and financial compensation per lot were better for the roof painted shed. As a result, fiber cement roof painted in white is recommended in aviaries located in hot climates, such as the region in this study.

RESUMO O experimento foi realizado com o objetivo de avaliar o efeito da inclusão de diferentes níveis de um complexo enzimático composto por fitase, protease, xilanase, β – glucanase, celulase, amilase e pectinase, em dietas à base de milho e de farelo de soja, sobre os parâmetros de desempenho, de rendimento de carcaça e de qualidade da carne de frangos de corte. Foram utilizados 600 pintos de corte, de um dia de idade, fêmeas, da linhagem Cobb 500, distribuídos em delineamento inteiramente casualizado, com cinco níveis de inclusão do complexo enzimático (0; 100; 200; 300 e 400 g/ton), e seis repetições de 20 aves cada. Foram avaliados, nas fases de 01 a 21, de 01 a 35 e de 01 a 42 dias de idade, o ganho de peso, a conversão alimentar, o consumo de ração e a viabilidade criatória. O rendimento de carcaça e a qualidade da carne foram avaliados aos 35 e aos 42 dias de idade. Avaliou-se as características de perda de peso por cocção, a força de cisalhamento, a capacidade de retenção de água, o pH, a luminosidade e a cor. Os parâmetros de desempenho, de rendimento de carcaça e cortes e de qualidade da carne não foram afetados pela suplementação enzimática das dietas fornecidas aos frangos de corte (P>0,05), exceto para as características de rendimento de peito e de asas aos 42 dias de idade (P<0,05).

SUMMARY The aimed of the study was to evaluate the effect of the inclusion of different levels of an enzyme complex consisting of phytase, protease, xylanase, β-glucanase, cellulase, amylase, and pectinase on the parameters of performance, carcass yield and meat quality of broilers. Six hundred broiler chicks were used, and the animals were females with one day of age, from the Cobb 500 strain, and distributed in a completely randomized design, with five levels of inclusion of the enzyme complex (0, 100, 200, 300 and 400g/ton), and six repetitions, with twenty animals each. The weight gain, feed conversion ratio, feed intake and production viability were assessed in stages between 1 to 21, 1 to 35 and 1 to 42 days of age. The carcass yield and meat quality were evaluated at 35 and 42 days of age. We evaluated the characteristics of weight loss by cooking, shear force, water holding capacity, pH, lightness and color. The parameters of performance, carcass yield and carcass parts, and meat quality were not affected by the enzyme supplementation of diets fed to broiler chickens (P>0.05), except for the performance characteristics of the breast and the wings at 42 days of age (P<0.05).