Exigência de lisina digestível de frangos de corte machos de 22 a 42 dias de idade / Digestible lysine levels of male broilers from 22 to 42 days of age

O objetivo deste estudo foi determinar a exigência de lisina digestível para frangos de corte machos sob as características de desempenho, composição corporal e rendimento de carcaça dos animais, de 22 a 42 dias de idade. As dietas diferiram quanto aos níveis de lisina digestível, mantendo-se a relação dos demais aminoácidos com a lisina. Foram utilizados seis níveis de lisina digestível: 0,88%; 0,96%; 1,05%; 1,13%; 1,22%; e 1,30%. Distribuídos em 36 unidades experimentais de 36 aves cada, 1296 animais da linhagem Cobb - 500® tiveram as seguintes características de desempenho avaliadas: consumo de ração (CR), peso corporal (PC), ganho de peso (GP), conversão alimentar (CA), viabilidade criatória (VC) e índice de eficiência produtiva (IEP). Aos 42 dias de idade, foram selecionadas ao acaso cinco aves para avaliação do rendimento de carcaça, e duas para avaliação da composição corporal. A CA, o IEP e o rendimento de peito foram influenciados, sendo sua exigência de 1,30%, sugerindo que níveis maiores de lisina digestível que as recomendações utilizadas como base neste estudo (1,13%) trouxeram benefícios aos animais sobre essas características.(AU)

The objective of the present study was to evaluate the optimal levels of digestible lysine in the diet of male broilers, evaluating performance characteristics, body composition, and carcass yield of the animals in the final phase (22 to 42 days old). The diets differed in digestible lysine content, maintaining the relation among the other amino acids and lysine in accordance with the ideal protein concept. The six levels of digestible lysine in the diet were: 0.88%; 0.96%; 1.05%; 1.13%; 1.22%, and 1.30%. A total of 1296 animals were employed, distributed in 36 experimental units of 36 birds each. The determined performance characteristics corresponded to feed intake (FI), body weight (BW), weight gain (WG), feed conversion (FC), viability (VB), and productive efficiency index (PEI). At 42 days of age seven birds per experimental unit were selected at random, five for the estimation of yield and total carcass and commercial cut weight, and two for the evaluation of body composition. FC, animal breast yield and PEI weres influenced with requirements of 1.30%. With respect to nationally known recommendations regarding digestible lysine (1.13%), higher levels of the amino acid in the diet have brought benefits regarding the characteristics above.(AU)

Exigência de lisina digestível de frangos de corte machos de 22 a 42 dias de idade / Digestible lysine levels of male broilers from 22 to 42 days of age

O objetivo deste estudo foi determinar a exigência de lisina digestível para frangos de corte machos sob as características de desempenho, composição corporal e rendimento de carcaça dos animais, de 22 a 42 dias de idade. As dietas diferiram quanto aos níveis de lisina digestível, mantendo-se a relação dos demais aminoácidos com a lisina. Foram utilizados seis níveis de lisina digestível: 0,88%; 0,96%; 1,05%; 1,13%; 1,22%; e 1,30%. Distribuídos em 36 unidades experimentais de 36 aves cada, 1296 animais da linhagem Cobb - 500® tiveram as seguintes características de desempenho avaliadas: consumo de ração (CR), peso corporal (PC), ganho de peso (GP), conversão alimentar (CA), viabilidade criatória (VC) e índice de eficiência produtiva (IEP). Aos 42 dias de idade, foram selecionadas ao acaso cinco aves para avaliação do rendimento de carcaça, e duas para avaliação da composição corporal. A CA, o IEP e o rendimento de peito foram influenciados, sendo sua exigência de 1,30%, sugerindo que níveis maiores de lisina digestível que as recomendações utilizadas como base neste estudo (1,13%) trouxeram benefícios aos animais sobre essas características.(AU)

The objective of the present study was to evaluate the optimal levels of digestible lysine in the diet of male broilers, evaluating performance characteristics, body composition, and carcass yield of the animals in the final phase (22 to 42 days old). The diets differed in digestible lysine content, maintaining the relation among the other amino acids and lysine in accordance with the ideal protein concept. The six levels of digestible lysine in the diet were: 0.88%; 0.96%; 1.05%; 1.13%; 1.22%, and 1.30%. A total of 1296 animals were employed, distributed in 36 experimental units of 36 birds each. The determined performance characteristics corresponded to feed intake (FI), body weight (BW), weight gain (WG), feed conversion (FC), viability (VB), and productive efficiency index (PEI). At 42 days of age seven birds per experimental unit were selected at random, five for the estimation of yield and total carcass and commercial cut weight, and two for the evaluation of body composition. FC, animal breast yield and PEI weres influenced with requirements of 1.30%. With respect to nationally known recommendations regarding digestible lysine (1.13%), higher levels of the amino acid in the diet have brought benefits regarding the characteristics above.(AU)

Performance and Egg Quality of Commercial Laying Hens Fed Diets Formulated Using Non-Linear Programming

Feed formulation using linear programming consists of determining the mixture of feedstuffs required to meet pre-established animal nutritional requirements at the lowest cost. On the other hand, with the use of non-linear programming, it is possible to define nutritional requirements at the time of formulation, aiming at maximum profit. The objective of the present study was to compare feeds formulated using linear and non-linear programming in terms of live performance and internal and external egg quality of commercial laying hens. A total of 288 Hisex® White laying hens, 1.540 ± 0.128 g body weight, were evaluated from 33 to 45 weeks of age. Hens were distributed in a completely randomized block design, including six treatments with six replicates of eight birds each. Three treatments consisted of feeds formulated using linear programming and based on the nutritional requirements of Rostagno et al. (2011), of the genetic strain manual, or mathematical models to maximize performance. The other three treatments consisted of feeds formulated using non-linear programming considering typical, favorable, or unfavorable market scenarios. Data were submitted to analysis of variance, and in case of significance (p 0.05), means were grouped using the Scott-Knott test (5%).The treatments did not influence (p>0.05) Haugh unit, albumen height, or external egg quality parameters. Treatment effects (p 0.05) on yolk weight, albumen weight, yolk color, yolk percentage, albumen percentage, and performance parameters were described. In general, feeds formulated using linear programming and based on nutritional requirements obtained by mathematical models and the genetic strain manual promoted better performance results because the feeds were nutritionally denser. However, the treatments that maximized live performance did not result in higher profitability, which was obtained with the diet formulated for a favorable market scenario using non-linear programming.(AU)

Performance and Egg Quality of Commercial Laying Hens Fed Diets Formulated Using Non-Linear Programming

Feed formulation using linear programming consists of determining the mixture of feedstuffs required to meet pre-established animal nutritional requirements at the lowest cost. On the other hand, with the use of non-linear programming, it is possible to define nutritional requirements at the time of formulation, aiming at maximum profit. The objective of the present study was to compare feeds formulated using linear and non-linear programming in terms of live performance and internal and external egg quality of commercial laying hens. A total of 288 Hisex® White laying hens, 1.540 ± 0.128 g body weight, were evaluated from 33 to 45 weeks of age. Hens were distributed in a completely randomized block design, including six treatments with six replicates of eight birds each. Three treatments consisted of feeds formulated using linear programming and based on the nutritional requirements of Rostagno et al. (2011), of the genetic strain manual, or mathematical models to maximize performance. The other three treatments consisted of feeds formulated using non-linear programming considering typical, favorable, or unfavorable market scenarios. Data were submitted to analysis of variance, and in case of significance (p 0.05), means were grouped using the Scott-Knott test (5%).The treatments did not influence (p>0.05) Haugh unit, albumen height, or external egg quality parameters. Treatment effects (p 0.05) on yolk weight, albumen weight, yolk color, yolk percentage, albumen percentage, and performance parameters were described. In general, feeds formulated using linear programming and based on nutritional requirements obtained by mathematical models and the genetic strain manual promoted better performance results because the feeds were nutritionally denser. However, the treatments that maximized live performance did not result in higher profitability, which was obtained with the diet formulated for a favorable market scenario using non-linear programming.

Effects of nutritional levels on performance, carcass characteristics and nutrient digestibility of sexed broilers

The objective of this study was to evaluate the effects of dietary nutrient levels on performance, carcass yield, commercial cuts, digestibility and economical viability of broilers from 1 to 42 days of age. During the experiment, 180 COBB 500™ chicks were housed in metal batteries and subjected to a completely randomized design in a 2x3 factorial arrangement, of two sexes and three diets (male, female and mixed), totaling 6 treatments and 6 repetitions of 5 birds each. Data were subjected to statistical analysis and the means were compared using the Tukey test, at 5% probability. The results indicate the effect of sex on performance and commercial cuts, except for breast and thigh fillets, in which males and females showed similar results when given the mixed diet. The influence of the nutritional levels on performance, digestibility and commercial cuts was observed, in which the female diet showed the highest results for feed intake, body weight and weight gain, in addition to greater retention of protein and crude energy. For drumstick and abdominal fat yield, the highest values were obtained using the mixed diet and the female diet, and the lowest values were obtained using the male diet. Regarding economic viability, the female diet showed the highest return per unit of Real (R$) spent on feed. Therefore, these data prove that the female diet had a positive effect when provided to both sexes, and it may be a promising alternative for its application at the production level.(AU)

Effects of nutritional levels on performance, carcass characteristics and nutrient digestibility of sexed broilers

The objective of this study was to evaluate the effects of dietary nutrient levels on performance, carcass yield, commercial cuts, digestibility and economical viability of broilers from 1 to 42 days of age. During the experiment, 180 COBB 500™ chicks were housed in metal batteries and subjected to a completely randomized design in a 2x3 factorial arrangement, of two sexes and three diets (male, female and mixed), totaling 6 treatments and 6 repetitions of 5 birds each. Data were subjected to statistical analysis and the means were compared using the Tukey test, at 5% probability. The results indicate the effect of sex on performance and commercial cuts, except for breast and thigh fillets, in which males and females showed similar results when given the mixed diet. The influence of the nutritional levels on performance, digestibility and commercial cuts was observed, in which the female diet showed the highest results for feed intake, body weight and weight gain, in addition to greater retention of protein and crude energy. For drumstick and abdominal fat yield, the highest values were obtained using the mixed diet and the female diet, and the lowest values were obtained using the male diet. Regarding economic viability, the female diet showed the highest return per unit of Real (R$) spent on feed. Therefore, these data prove that the female diet had a positive effect when provided to both sexes, and it may be a promising alternative for its application at the production level.

Dietary Levels of Zinc and Manganese on the Performance of Broilers Between 1 to 42 Days of Age

The objective of this study was to determine the optimal dietary concentration of zinc and manganese on the performance characteristic and the requirement of these trace minerals derived from organic sources for broilers from 1 to 42 days of age. In experiment 1, zinc was evaluated, whereas manganese was evaluated in experiment 2. In each experiment, 320 males chicks were distributed in iron mesh metabolic cages (0.9m x 0.7m x 0.5m), according to a completely randomized experimental design in eight treatments with five replicates of eight birds each. In experiment 1, zinc sulfate was included at 0,60 and 100mg/kg and zinc methionine at 20, 40, 60, 80 and 100mg/kg. In experiment 2, manganese sulfate was added at 0, 65 and 105mg/kg and manganese methionine at 25, 45, 65, 85 and 105 mg/kg. Trace mineral requirements were determined comparing only organic trace mineral levels. The evaluated trace minerals (zinc and manganese) did not influence broiler performance, independently of source or level. It was concluded that the requirements of broilers from 1 to 42 days of age were supplied with no addition of zinc or manganese, under the conditions of the present experiments. However, under commercial rearing conditions, which are more challenging, the use of levels higher than 33.00 mg/kg and37.80 mg/kg of zinc and manganese, respectively, may be justified.(AU)

Dietary Levels of Zinc and Manganese on the Performance of Broilers Between 1 to 42 Days of Age

The objective of this study was to determine the optimal dietary concentration of zinc and manganese on the performance characteristic and the requirement of these trace minerals derived from organic sources for broilers from 1 to 42 days of age. In experiment 1, zinc was evaluated, whereas manganese was evaluated in experiment 2. In each experiment, 320 males chicks were distributed in iron mesh metabolic cages (0.9m x 0.7m x 0.5m), according to a completely randomized experimental design in eight treatments with five replicates of eight birds each. In experiment 1, zinc sulfate was included at 0,60 and 100mg/kg and zinc methionine at 20, 40, 60, 80 and 100mg/kg. In experiment 2, manganese sulfate was added at 0, 65 and 105mg/kg and manganese methionine at 25, 45, 65, 85 and 105 mg/kg. Trace mineral requirements were determined comparing only organic trace mineral levels. The evaluated trace minerals (zinc and manganese) did not influence broiler performance, independently of source or level. It was concluded that the requirements of broilers from 1 to 42 days of age were supplied with no addition of zinc or manganese, under the conditions of the present experiments. However, under commercial rearing conditions, which are more challenging, the use of levels higher than 33.00 mg/kg and37.80 mg/kg of zinc and manganese, respectively, may be justified.

Firewood ash as calcium source in the initial diet of broiler chickens

This experiment aimed to evaluate the utilization of firewood ash as calcium source in the initial diet of broiler chickens. One hundred and twenty eight broiler chickens of Cobb-500® strain, from 1 to 21 days of age, were randomly distributed in four treatments with four repetitions of eight birds each, been four female and four male. The experimental diets were corn-soybean based, been isoenergetic and isonutrients, and had 0, 0.32, 0.98 and 1.27% of firewood ash as calcium source. The firewood ash utilized had 23.8% of calcium, 0.39% of total phosphorus, and 0.11% of sodium. The experimental treatments did not influence the feed intake, body weight, body weight gain, and food conversion from 1 to 7, 1 to 14, and 1 to 21 days of age. The tibia and femur thickness and length at 21 days of age were not altered by treatments. It was concluded that the firewood ash can be used as calcium sourcereplacing limestone in the initial diet of broiler chickens, without change the performance and the bone development.

Firewood ash as calcium source in the initial diet of broiler chickens

This experiment aimed to evaluate the utilization of firewood ash as calcium source in the initial diet of broiler chickens. One hundred and twenty eight broiler chickens of Cobb-500® strain, from 1 to 21 days of age, were randomly distributed in four treatments with four repetitions of eight birds each, been four female and four male. The experimental diets were corn-soybean based, been isoenergetic and isonutrients, and had 0, 0.32, 0.98 and 1.27% of firewood ash as calcium source. The firewood ash utilized had 23.8% of calcium, 0.39% of total phosphorus, and 0.11% of sodium. The experimental treatments did not influence the feed intake, body weight, body weight gain, and food conversion from 1 to 7, 1 to 14, and 1 to 21 days of age. The tibia and femur thickness and length at 21 days of age were not altered by treatments. It was concluded that the firewood ash can be used as calcium sourcereplacing limestone in the initial diet of broiler chickens, without change the performance and the bone development.(AU)

Levels and sources of vitamin D on performance and bone development of strains in broilers / Níveis de vitamina D sobre o desempenho e desenvolvimento ósseo de linhagens de frangos de corte

The availability and appropriate level of vitamin D to promote physiological demand, bone formation and reduce the occurrence of locomotors problems in broilers. The aim of this study was to evaluate three levels of vitamin D on performance breaking strength and mineral content of tibia of three strains of broilers, it was used 1,440 chicken of one day of age. The complete random design used was in factorial 3X3, with three strains (Ross 308, Cobb 500 and Hybro) and three inclusion levels of vitamin D3 (1250 IU vitamin D3; 3000 IU vitamin D3 and 2760 UI of 25- hydroxycholecalciferol (OH) D3), provided in the diet until 21 day of life, with eight replicates of 30 birds per group, a total of 160 birds per treatment. There was no difference (P> 0.05) between the levels of vitamin D, in the strains for the perfomance and breaking strength, except for feed intake for the strain factor (P> 0.05), with higher feed intake of Cobb, probably due to its higher growth potential. The levels of vitamin D had no influence significant (P>0.05) the quantities of calcium and phosphorus in the tibia bones. However, for strains was significant difference (P 0.05) at 14 days of age, with higher amounts of calcium to Ross 308 and higher amount of phosphorus to Hybro. This can be explained because of the genetic variation in metabolism of calcium and phosphorus in broilers. In conclusion the addition of 1250 IU vitamin D/kg of feed is sufficient to ensure performance and bone development of broilers independent of the strain to be used by proper adjustment of the levels of Ca and P

A disponibilidade e o nível adequado de vitamina D deve atender à demanda fisiológica para formação óssea, e reduzem a ocorrência de problemas locomotores em frangos de corte. Com o objetivo de avaliar três níveis de vitamina D sobre o desempenho, força de ruptura e conteúdo mineral das tíbias de três linhagens de frangos de corte, foram utilizado 1.440 pintos de um dia, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 3x3, com três linhagens (Ross 308, Cobb 500 e Hybro) e três níveis de inclusão de vitamina D3 (1250 UI vitamina D3; 3000 UI vitamina D3 e 2760 UI de hidroxicolecalciferol 25(OH) D3, fornecidos na ração até o 21º dia de vida, com oito repetições de 30 aves por parcela, totalizando 160 aves por tratamento. Não houve diferenças (P>0,05) entre os níveis de vitamina D, e as linhagens para o desempenho e força de ruptura, exceto para o consumo de ração para o fator linhagem (P 0,05), devido ao seu potencial de crescimento. Os níveis de vitamina D não influenciaram (P> 0,05) as quantidades de cálcio e fósforo nas tíbias. No entanto, para as linhagens houve diferença significativa (P 0,05) aos 14 dias de idade, com maior quantidade de cálcio para o Ross 308 e maior quantidade de fósforo para o Hybro, evidenciando diferenças no metabolismo do cálcio e do fósforo em frangos de corte. Em conclusão a adição de 1250 UI de vitamina D/kg de ração é suficiente para garantir o desempenho e o desenvolvimento ósseo de frangos de corte, independente da linhagem a ser utilizada, mediante ao ajuste correto dos níveis de Ca e P

Desempenho e rendimento de carcaça em frangos de corte de um a 46 dias alimentados com dietas contendo diferentes níveis de valina e reduzido teor proteico / Performance and carcass yield of broilers from 1 to 46 days fed diets containing different levels of valine and reduced protein content

Este estudo teve como objetivo avaliar as relações de valina:lisina digestíveis em dietas com teor reduzido de proteína bruta (PB) e os efeitos dessa redução sobre desempenho e rendimento de carcaça em frangos de corte. Foram utilizados 1200 pintos machos seguindo modelo inteiramente ao acaso, com seis tratamentos de seis repetições (exceto controle, com 10 repetições), compostos por 30 aves cada. O tratamento controle (T1) foi formulado conforme os níveis de proteína bruta e aminoácidos (AAs) recomendados por Rostagno et al . (2011), e os demais tratamentos (T2 a T6) tiveram seus níveis de PB reduzidos (4% em relação ao controle) e variaram em função da relação valina:lisina digestíveis, com cinco níveis equidistantes em intervalos de 0,07:1, variando de 0,63:1 e 0,91:1 (dietas até 21 dias) e de 0,64:1 e 0,92:1 (dietas após 21 dias). As seguintes características de desempenho foram avaliadas: ganho de peso, consumo de ração, conversão alimentar, viabilidade criatória e índice de eficiência produtiva. Aos 46 dias de idade, seis animais por repetição foram abatidos para determinação de rendimento de carcaça e de cortes comerciais. As diferentes relações valina:lisina digestíveis não influenciaram o desempenho dos animais (P>0,05) para nenhuma característica avaliada. A redução proteica piorou a conversão alimentar dos animais (P≤0,05) até os 21 dias. Os resultados sugerem que os níveis de valina utilizados não afetam o desempenho dos animais, apenas o rendimento de peito e que, portanto, a redução proteica não é recomendada durante as três primeiras semanas de criação(AU)

This study aimed to evaluate valine:lysine ratios in diets with reduced content of crude protein and the effects of this reduction on the performance of broiler chickens. 1200 male chicks were used following a complete randomized design with six replicates of six treatments (except control, with 10 replicates), each one with 30 chicks. The control treatment (T1) was formulated following levels of crude protein (CP) and the amino acids (AAs) recommended by Rostagno et al. (2011), and the other treatments (T2 to T6) had reduced levels of CP (4 % compared to control) and varied in proportion valine:lysine, with 5 levels at equidistant intervals 0.07:1 ranging from 0.63:1 to 0.91:1 (up to 21 days) and from 0.64:1 to 0.92:1 (after 21 days). The performance characteristics measured were: weight gain, feed intake, feed conversion, viability and productive efficiency index. At 46 days six animals per replicate were slaughtered for evaluation of carcass and commercial cuts. The different valine:lysine ratios did not affect animal performance (P>0.05). Reducing protein impaired feed conversion (P≤.05) up to 21 days. The results suggest that levels of valine used did not affect the broilers' performance, however, breast meat yield and reduced protein are not recommended during the first three weeks(AU)

Levels and sources of vitamin D on performance and bone development of strains in broilers / Níveis de vitamina D sobre o desempenho e desenvolvimento ósseo de linhagens de frangos de corte

The availability and appropriate level of vitamin D to promote physiological demand, bone formation and reduce the occurrence of locomotors problems in broilers. The aim of this study was to evaluate three levels of vitamin D on performance breaking strength and mineral content of tibia of three strains of broilers, it was used 1,440 chicken of one day of age. The complete random design used was in factorial 3X3, with three strains (Ross 308, Cobb 500 and Hybro) and three inclusion levels of vitamin D3 (1250 IU vitamin D3; 3000 IU vitamin D3 and 2760 UI of 25- hydroxycholecalciferol (OH) D3), provided in the diet until 21 day of life, with eight replicates of 30 birds per group, a total of 160 birds per treatment. There was no difference (P> 0.05) between the levels of vitamin D, in the strains for the perfomance and breaking strength, except for feed intake for the strain factor (P> 0.05), with higher feed intake of Cobb, probably due to its higher growth potential. The levels of vitamin D had no influence significant (P>0.05) the quantities of calcium and phosphorus in the tibia bones. However, for strains was significant difference (P 0.05) at 14 days of age, with higher amounts of calcium to Ross 308 and higher amount of phosphorus to Hybro. This can be explained because of the genetic variation in metabolism of calcium and phosphorus in broilers. In conclusion the addition of 1250 IU vitamin D/kg of feed is sufficient to ensure performance and bone development of broilers independent of the strain to be used by proper adjustment of the levels of Ca and P(AU)

A disponibilidade e o nível adequado de vitamina D deve atender à demanda fisiológica para formação óssea, e reduzem a ocorrência de problemas locomotores em frangos de corte. Com o objetivo de avaliar três níveis de vitamina D sobre o desempenho, força de ruptura e conteúdo mineral das tíbias de três linhagens de frangos de corte, foram utilizado 1.440 pintos de um dia, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 3x3, com três linhagens (Ross 308, Cobb 500 e Hybro) e três níveis de inclusão de vitamina D3 (1250 UI vitamina D3; 3000 UI vitamina D3 e 2760 UI de hidroxicolecalciferol 25(OH) D3, fornecidos na ração até o 21º dia de vida, com oito repetições de 30 aves por parcela, totalizando 160 aves por tratamento. Não houve diferenças (P>0,05) entre os níveis de vitamina D, e as linhagens para o desempenho e força de ruptura, exceto para o consumo de ração para o fator linhagem (P 0,05), devido ao seu potencial de crescimento. Os níveis de vitamina D não influenciaram (P> 0,05) as quantidades de cálcio e fósforo nas tíbias. No entanto, para as linhagens houve diferença significativa (P 0,05) aos 14 dias de idade, com maior quantidade de cálcio para o Ross 308 e maior quantidade de fósforo para o Hybro, evidenciando diferenças no metabolismo do cálcio e do fósforo em frangos de corte. Em conclusão a adição de 1250 UI de vitamina D/kg de ração é suficiente para garantir o desempenho e o desenvolvimento ósseo de frangos de corte, independente da linhagem a ser utilizada, mediante ao ajuste correto dos níveis de Ca e P(AU)

Sources of trophic action on performance and intestinal morphometry of broiler chickens vaccinated against coccidiosis

The aim of this experiment was to evaluate the effect of sources of trophic action (glutamine alone, glutamine associated with glutamic acid and yeast) associated with vaccination against coccidiosis on the performance and morphometry of the small intestine of broilers. In the trial, 1,200 broiler chicks were distributed according to a completely randomized design with a 3 x 2 + 2 (trophic action x vaccination or not + control - free trophic factor) factorial arrangement, with five replicates of 30 birds each. Vaccination negatively affected performance parameters and the morphometry of the intestinal mucosa, but at the end of the experimental period, among the broilers vaccinated against coccidiosis, the group fed glutamine presented better recovery from epithelial losses of the intestinal mucosa compared with the control groups. Therefore, the dietary supplementation with the evaluated sources of trophic action could be a strategy to enhance the development of broilers submitted to vaccine stress, also considering the economic viability of the productive segment.

Sources of trophic action on performance and intestinal morphometry of broiler chickens vaccinated against coccidiosis

The aim of this experiment was to evaluate the effect of sources of trophic action (glutamine alone, glutamine associated with glutamic acid and yeast) associated with vaccination against coccidiosis on the performance and morphometry of the small intestine of broilers. In the trial, 1,200 broiler chicks were distributed according to a completely randomized design with a 3 x 2 + 2 (trophic action x vaccination or not + control - free trophic factor) factorial arrangement, with five replicates of 30 birds each. Vaccination negatively affected performance parameters and the morphometry of the intestinal mucosa, but at the end of the experimental period, among the broilers vaccinated against coccidiosis, the group fed glutamine presented better recovery from epithelial losses of the intestinal mucosa compared with the control groups. Therefore, the dietary supplementation with the evaluated sources of trophic action could be a strategy to enhance the development of broilers submitted to vaccine stress, also considering the economic viability of the productive segment.(AU)

Palatabilizantes em dietas de leitões recém-desmamados / Flavors in diets for weanling pigs

Com o intuito de verificar a eficácia do açúcar e do edulcorante à base de sacarina sódica e neoesperidina nas dietas de leitões, foram realizados dois experimentos, ambos com 42 leitões recém-desmamados aos 21 dias de idade. Foram oferecidas três dietas: dieta controle (DC), dieta com açúcar (DA) e dieta com edulcorante (DE). Os experimentos foram em blocos ao acaso, sendo o primeiro com sete repetições e dois animais por unidade experimental e o segundo com seis repetições, um animal por unidade experimental, e arranjo fatorial 3 x 2 + 1 (três dietas, duas épocas de abate: aos 28 e 35 dias de idade e um abate no dia do desmame). No primeiro experimento, os animais permaneceram nas instalações de creche até 63 dias de idade para avaliação do desempenho e da viabilidade econômica das dietas. No segundo experimento, os animais foram abatidos para se proceder à pesagem de órgãos, medição do comprimento do intestino delgado e coleta dos segmentos do duodeno e jejuno para realização da morfometria intestinal. Não houve diferenças entre as dietas para consumo diário de ração (CDR), ganho diário de peso (GDP) e conversão alimentar (CA) nos períodos 1 (21 aos 28 dias), 3 (21 aos 50 dias) e 4 (21 aos 63 dias de idade). No período 2 (21 aos 35 dias), os animais que consumiram a DE apresentaram maior (P<0,05) CDR e GDP, se comparados aos que consumiram a DA. Nos períodos 1, 2 e 3, foi observado menor custo da dieta por kg de peso vivo ganho e melhores índices econômico e de custo para os animais que consumiram DE. Ao se avaliar a morfometria intestinal e o peso de órgãos, não se observou diferença entre as dietas, com exceção para o peso do estômago, que foi maior nos animais que consumiram DE. A inclusão de edulcorante é eficaz em melhorar o desempenho no período 2, além de ser viável sob o ponto de vista econômico.(AU)

In order to verify the effectiveness of sugar and sweeteners containing saccharin and neohesperidin in diets of piglets, two experiments were conducted, both with 42 newborn piglets weaned at 21 days old. Were offered three diets: control diet (DC), diet with sugar (DA) and diet with sweetener (DE). The experiments were done in randomized blocks, the first of which had seven replicates and two animals per experimental unit and the second, six replicates and one animal per experimental unit comprising a factorial 3 x 2 + 1 design (three diets, two slaughter ages: at 28 and 35 days of age and slaughter on the day of weaning). In the first experiment, the animals remained in the nursery facilities until 63 days of age to evaluate the performance and the economic viability of the diets. In the second experiment, the animals were slaughtered to weigh the organs, measure the length of the small intestine and collect segments of the duodenum and jejunum to determine intestinal morphology. There were no differences between diets for the average dairy feed intake (ADFI), average dairy gain (ADG) and gain:feed (G:F) in Periods 1 (21 to 28 days), 3 (21 to 50 days) and 4 (21 to 63 days old). In Period 2 (21 to 35 days), animals that consumed DE had higher (P<0.05) ADFI and ADG, compared to those fed the DA. In Periods 1, 2 and 3 a lower cost per kg of the diet of live weight gain and better economic indicators for the animals fed DE were observed. No differences were observed between the diets when evaluating intestinal morphology and organ weights, except for the weight of the stomach, which was higher in animals fed DE. The inclusion of sweetener is effective in improving performance in Period 2, and is viable under the economical point of view.(AU)

Performance and morphometry of the intestinal mucosa of laying hens fed diets containing xylanase

The objective of this study was to evaluate the effect of dietary energy level reduction and xylanase inclusion on the performance and on intestinal mucosa morphometry of two- to six-week-old laying hens. In total, 400 Hy-line W36 laying hens were distributed according to a completely randomized design in 2 x 2 factorial arrangement (energy level x inclusion of xylanase), totaling four treatments with 10 replicates of 10 birds per experimental unit. The following treatments were evaluated: positive control (balanced diet); positive control + xylanase; negative control (diet with of 100 kcal ME reduction /kg); negative control + xylanase. Body weight, weight gain, feed conversion ratio, uniformity and livability were not influenced by diets with metabolizable energy reduction and xylanase inclusion; however, the addition of xylanase to the diets resulted in shallower crypts depth and greater villus:crypt ratio in the ileum. The energy reduction of the diet associated with the supplementation of xylanase did not influence performance, but increased the feed intake of 2- to 6-week-old laying hens and increased villus height in the ileum of 6-wk-old hens. Xylanase reduces crypt depth in the ileum of 6-week-old hens.

Performance and morphometry of the intestinal mucosa of laying hens fed diets containing xylanase

The objective of this study was to evaluate the effect of dietary energy level reduction and xylanase inclusion on the performance and on intestinal mucosa morphometry of two- to six-week-old laying hens. In total, 400 Hy-line W36 laying hens were distributed according to a completely randomized design in 2 x 2 factorial arrangement (energy level x inclusion of xylanase), totaling four treatments with 10 replicates of 10 birds per experimental unit. The following treatments were evaluated: positive control (balanced diet); positive control + xylanase; negative control (diet with of 100 kcal ME reduction /kg); negative control + xylanase. Body weight, weight gain, feed conversion ratio, uniformity and livability were not influenced by diets with metabolizable energy reduction and xylanase inclusion; however, the addition of xylanase to the diets resulted in shallower crypts depth and greater villus:crypt ratio in the ileum. The energy reduction of the diet associated with the supplementation of xylanase did not influence performance, but increased the feed intake of 2- to 6-week-old laying hens and increased villus height in the ileum of 6-wk-old hens. Xylanase reduces crypt depth in the ileum of 6-week-old hens.(AU)

Utilização da glutamina, associada ao ácido glutâmico, sobre o desenvolvimento e a atividade enzimática em frangos de corte / Utilization of glutamine, associated with glutamic acid, on development and enzymatic activity in broiler chickens

Avaliou-se o efeito da glutamina, associada ao ácido glutâmico, proveniente de um produto comercial, sobre o desenvolvimento e a atividade enzimática em frangos de corte. Foram utilizados 800 pintos de corte, machos, de um a 42 dias de idade, distribuídos em cinco tratamentos, sendo quatro níveis de suplementação do Aminogut®: 0,5; 1,5; 3,0 e 5,0 por cento + uma dieta-controle, isenta do produto. Observou-se melhor índice de eficiência produtiva para os frangos alimentados com dietas suplementadas com 2,8 por cento de Aminogut®. Independentemente dos tratamentos, verificou-se aumento das atividades da maltase, sacarase e fosfatase alcalina intestinais com o avanço da idade das aves. Para as enzimas pancreáticas, observou-se maior atividade da amilase e lipase aos 14 dias de idade, coincidindo com a maior taxa de crescimento alométrico do pâncreas.(AU)

Evaluation of the effect of glutamine associated with glutamic acid in a commercial product, on the growth and enzyme activities in broiler chickens. 800 day-old male broiler chicks were used during the 42 days of trial, and were allotted to five treatments, four levels of Aminogut® supplementation - 0.5, 1.5, 3.0 and 5.0 percent + control-diet, free product. The best index of productive efficiency in broiler chickens was observed in those fed diets supplemented with 2.8 percent Aminogut®. Regardless of the treatment, there was increase in maltase, sucrase and alkaline phosphatase activities as the age of the chickens increased. For pancreatic enzymes, more activity of amylase and lipase can be observed at 14 days of age, coinciding with the highest rate of allometric growth of pancreas.(AU)

TEXTURE AND METABOLIZABLE ENERGY LEVELS OF THE DIET FOR BROILER CHICKENS FROM 1 TO 21 DAYS OF AGE. / FORMA FÍSICA E NÍVEIS DE ENERGIA METABOLIZÁVEL DA RAÇÃO PARA FRANGOS DE CORTE DE 1 A 21 DIAS DE IDADE.

This study aimed at evaluating the effects of feed form and diet metabolizable energy levels (ME) on broiler chickens performance from 1 to 21 days of age. Four hundred and eighty chickens were randomly assigned in a 2 x 3 factorial scheme: ME (2900 and 3050 kcal/kg) and feed form (mash, crumbled, and extrused), with four replicates of 20 birds each. No interaction was observed between the factors on performance characteristics from 1 to 7 and 1 to 14 days. The studied factors did not influence chickens performance from 1 to 7 days. At 14 days, chickens fed extrused diets showed lower feed intake without impairing other characteristics. Also, broilers fed diets containing 3050 kcal/kg ME had better weight gain and feed conversion without influencing feed intake. A significant interaction between factors was found for weight gain and feed conversion from 1 to 21 days, where broilers fed crumbled diets with 2900 kcal/kg ME showed better performance. Feed intake was not influenced by ME in any age. It is possible to conclude that the use of crumbled diet allows a reduction in ME and promote better performance in relation to extrused and mash diet. Broilers chickens at initial phase do not control the feed intake according to ME of the diet at the studied levels. KEY-WORDS: Crumbled diet. Extrused diet. Mash diet. Metabolizable energy. Pelleted diet. Performance.