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.

ABSTRACT This study investigated the effects of Cymbopogon flexuosus and Lippia rotundifolia microencapsulated essential oils on broiler performance and carcass yield. One hundred and fifty mixed-sex Cobb broiler chicks were used, from one day up to 42 days of age, in a completely randomized design, with five treatments and three replicates of ten birds each. The treatments were: negative control (basal diet), positive control (diet with enramycin and salinomycin), and three diets with microencapsulated essential oils from lemongrass, L. rotundifolia, and combination with 50% of both. The performance and carcass yield were not affected by the treatments. The intestine absolute weight was lower in the combination treatment compared with the negative control treatment and the lemongrass essential oil. The intestine relative weight was higher in the treatments with lemongrass and L. rotundifolia essential oils in relation to the combination. The liver relative weight was lower with the lemongrass essential oil and the combination compared with the treatment with the L. rotundifolia essential oil. The trial could not find results enough to recommend the use of the lemongrass and L. rotundifolia essential oils as an additive in broiler diets.

Realizou-se um ensaio metabólico para avaliar a lignina purificada de eucalipto (LIPE®), como indicador na determinação da digestibilidade da proteína bruta e matéria seca de alimentos para frangos de corte. Os tratamentos corresponderam a uma dieta basal e outras oito dietas contendo os alimentos-teste. Os alimentos foram: milho, milho expandido, farelo de soja, farelo de soja expandido, glúten de milho 22%, glúten de milho 60%, farinha de carne e ossos e farinha de penas e vísceras. Os alimentos protéicos e os com menor teor de proteína substituíram 25 e 40% da dieta basal, respectivamente. Foram utilizados 270 pintos de corte, linhagem Ross, de ambos os sexos, dos 21 aos 31 dias de idade. Utilizou-se um delineamento experimental inteiramente ao acaso em esquema fatorial 9×3 (rações × métodos), com três repetições. Os coeficientes de digestibilidade (CD) da proteína e da matéria seca e os valores da proteína bruta digestível e da matéria seca digestível de sete das nove dietas, calculados pelos métodos da coleta total de excretas e dos indicadores óxido crômico e LIPE®, foram semelhantes. Com os alimentos-teste, farelo de soja expandido e farinha de penas e vísceras, o uso de óxido crômico resultou em CD e valores de proteína e matéria seca digestível mais altos, quando comparado com o uso da LIPE® e da coleta total de excretas que foram semelhantes entre si. Pode-se considerar que a proteína bruta digestível e matéria seca digestível dos alimentos, calculada pelos três métodos, foram equivalentes. A LIPE® pode ser validada como indicador de digestibilidade da proteína e matéria seca de alimentos para frangos de corte.

A metabolism experiment was carried out to evaluate the use of LIPE® as an external indicator of dry matter and protein digestibility in broilers. The treatments corresponded to a basal diet and eight other different diets. The foods used were: corn grain, expanded corn, soybean meal, expanded soybean meal, gluten meal 22% crude protein; gluten meal 60% crude protein, meat and bone meal and feather meal. The basal diet was replaced with 40% or 25% of the food containing more energy or protein, respectively. Two hundred and seventy broiler chickens were used from 21 to 31 days old. A completely randomized design in a 9x3 factorial arrangement (nine forms of rations x three methods) with three replicates was used. The digestible dry matter and protein and metabolizable energy of the food was calculated by the total fecal collection method and by the indicator methods of chromic oxide and LIPE®; the three methods were further compared. Chromic oxide use resulted in higher values of coefficient of digestibility for expanded soybean meal and feathers and viscera meal when compared to the use of LIPE® and total feces collection which were similar. The results validated the LIPE® as an external protein and dry matter digestibility index of the feed of broiler chicks evaluated.

O experimento foi conduzido em delineamento inteiramente ao acaso, para avaliar os efeitos da redução de proteína bruta (PB) com suplementação de aminoácidos essenciais sobre o desempenho e características de carcaça de frangos de corte machos da linhagem Ross, na fase de 21 a 42 dias de idade. Foram utilizados 720 frangos, distribuídos em 4 tratamentos e seis repetições com 30 aves cada. Os níveis de proteína bruta utilizados foram 21; 19 e 17 e 15% de PB. A redução de proteína levou a um aumento linear dos teores de gordura e matéria seca. Houve ainda efeito quadrático dos níveis de proteína bruta, sendo para máximo ganho de peso, peso aos 42 dias e consumo de dieta os níveis de 19,28; 19,35 e 16,75% de PB, respectivamente. Houve efeito quadrático sobre o rendimento de peito, estimando máximo rendimento para frangos alimentados com dietas contendo 18,28% de PB.

A completely randomized experimental design was carried out to evaluate the effects of crude protein (CP) reduction of diets with essential amino acids supplementation on performance and body composition of male broiler chickens from 21 to 42 days of age. A total of seven hundred twenty broiler chickens were used. The birds were allotted in four treatments and six replicates of thirty birds each. The diet CP levels were 21, 19, 17 and 15%. The reduction of protein led to a linear increase in fat and dry matter. There was also a quadratic effect of the CP levels; for maximum weight gain; weight at 42 days and final weight and feed intake. The maximum performance of these parameters were estimated for broilers fed 19.28; 19.35 and16.75% CP diet, respectively. There was a quadratic effect of CP level on breast yield, the maximum performance estimated for broiler fed 18.28% CP diet.

Avaliaram-se os efeitos dos níveis de energia, lisina, metionina + cistina na ração sobre o desempenho e os rendimentos de carcaça e cortes de frangos de corte. O delineamento experimental foi o inteiramente ao acaso, em esquema fatorial (3 × 2), composto de seis tratamentos e oito repetições (quatro para machos e quatro para fêmeas). Os tratamentos foram definidos pelos níveis de energia (baixo, médio e alto), lisina e metionina + cistina (padrão ou 10% superiores ao recomendado) e pelo período de criação (1 a 45 dias de idade). Em frangos machos, níveis médios de energia (3.000, 3.100 e 3.200 kcal/kg, respectivamente, nas rações inicial, de crescimento e final) e níveis normais de aminoácidos proporcionam maior ganho peso aos 45 dias de idade, no entanto, para obtenção de maior rendimento de peito, o nível mais alto de aminoácidos é mais recomendável. Em fêmeas, para maior ganho de peso até os 40 dias de idade, devem ser associados níveis médios de energia e níveis mais altos de aminoácidos.

The effects of dietary energy, lysine and methionine + cystine levels on performance, carcass and cuts yields of male and female broiler chickens were evaluated. The experiment was analyzed as a completely randomized experimental design in a 3 × 2 factorial arrangement composed by six diets and eight replications (four males and four females). The diets consisted of energy (low, middle and high) and lysine and methionine + cystine (standard and + 10%) levels and of raising period (1 to 45 days old). Male broilers fed diets with 3,000, 3,100 and 3,200 kcal/kg, respectively, in the initial, growing and standard levels of amino acids showed better weight gain at 45 days old, however, for the best breast yield, the highest amino acid level was the most indicated. Middle energy and high amino acids levels are indicated for greater weight up to 40 days old, in females.