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 main objective of this study was to evaluate the effect of placement time on the performance of broiler chickens and the development of their gastrointestinal tract. Two methodologies for measuring broiler performance were compared, one considering day of pulling as the first day, the other considering day of placement as the first day. A total of 1,056 one-day old male Cobb® 500 broiler chicks were subjected to treatments of different placement times after pulling from the hatchery: 3, 24, 48, and 72 h. The studied traits were: feed intake, body weight, feed conversion, viability, and gastrointestinal tract development. When day of pulling was considered the first day, feed intake and body weight at 39 days decreased as placement time increased. However, when day of placement was considered the first day, fasting up to 72 h did not have any negative effect on broiler performance at 39 days post-placement. Placement time did not affect yolk sac utilization or liver weight. At nine days post-placement, weights of gizzard + proventriculus, pancreas, and small intestine increased with increasing placement time. At seven days of age, there was no effect of placement time on villus height or crypt depth. It is possible to place broiler chicks up to 72 h post-hatching with no negative effects when day of placement is considered the first day for evaluating broiler 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.

ABSTRACT This study was conducted to evaluate the effect of two levels of vitamin D3 with or without 1,25- dihydroxycholecalciferol (1,25(OH)2D3) on live performance and bone quality of broiler chickens. For that, we used a completely randomized design in a 2 × 2 factorial arrangement, with eight replicates of 30 Cobb®500 male broiler chicks each (n = 960). The two levels of vitamin D3 and the addition or not of 0.5 μg 1,25(OH)2D3/kg were considered as main factors. The vitamin D3 levels were: 2500/2000 IU/kg and 1250/1000 IU/kg for the starter (1 to 21 days) and grower (22 to 40 days) phases, respectively, with the first representing the levels used in industry (100%) and the second, a reduction in 50% of those levels. The 1,25(OH)2D3 source was Solanum glaucophyllum. On days 21 and 40, one broiler per replicate was killed and long bones were removed for analyses of mineral percentage, bone mineral density, biomechanical properties, and morphology. No significant differences were found related to vitamin D3 levels and the addition or not of 1,25(OH)2D3 for live performance, mineral percentage, strength, stiffness, and morphology. Toughness was lower when 1,25(OH)2D3 was used at 21 days, but this effect was not observed at 40 days of age. Bone mineral density was greater when 100% of vitamin D3 was used at 40 days of age. The reduction of up to 50% of vitamin D3 levels is sufficient to ensure performance and bone development of broilers at 21 and 40 days of age. The inclusion of 0.5 μg 1,25(OH)2D3/kg in addition to diets with sufficient levels of vitamin D3 shows no effect on the improvement of those parameters at the same ages.