Effect of phytase and protease combination on performance, metabolizable energy, and amino acid digestibility of broilers fed nutrient-restricted diets

Three experiments were carried out to evaluate the effect of dietary combination of different enzymes (phytase + protease) on performance, metabolizable energy, and amino acid digestibility of broiler chickens fed diets with nutritional reduction. A total of 1,400, 336, and 384 male chickens were distributed in a completely randomized design, in the experiments of performance, metabolism, and digestibility, respectively. Treatments were divided as follows: positive control (PC), negative control - NC1 (PC minus 0.16% Ca, 0.15% available P (aP), and 0.5% crude protein (CP)), NC2 (PC minus 0.16% Ca, 0.15% aP, and 1% CP), NC1 added with phytase deriving from citrobacter and protease deriving from Bacillus licheniformis (CBE), NC1 added with phytase deriving from E. coli and protease deriving from microbial fermentation (SE), NC2 added with CBE, and NC2 added with SE. A protein-free diet was included in the digestibility experiment. The nutritional restriction did not affect feed intake of birds in the first experiment; however, the restriction inhibited body weight gain and feed conversion ratio in all phases. In experiment 2, the nutritional restriction decreased AME and AMEn values, although the addition of phytase and protease in diets improved both parameters, mainly in NC2. Treatment NC2 impaired the standardized digestibility of total essential amino acids of animals subjected to experiment 3, although the addition of enzymes helped to recover the digestibility to levels similar to PC. Supplementation of phytase in association with protease is effective to improve performance, energy metabolism, and standardized amino acid digestibility of broilers fed diets with nutrient restriction.(AU)

Xylanase and B-glucanase in maize- and soybean meal-based diets for broilers / Xilanase e B-glucanase em dietas a base de milho e de farelo de soja para frangos de corte

The objective of this study was to evaluate the effect of adding different xylanase and β-glucanase enzyme blends to maize- and soybean meal-based diets on performance and energy metabolizability in broilers. Two experiments were carried out with broilers of the COBB 500 strain. In the first experiment, 1960 chicks were assigned to a completely randomized design with a 2 × 3 + 1 factorial arrangement, totaling seven treatments, namely, T1- Positive control (PC); T2 - Negative control 1 (NC1; PC minus 200 kcal kg-¹ ME); T3 - NC1 + Blend A; T4 - NC1 + Blend B; T5 - Negative control 2 (NC2; PC minus 167 kcal kg-¹ ME and 5% amino acids); T6 - NC2 + Blend A; and T7 - NC2 + Blend B. Fourteen replicates were used per treatment and 20 birds per experimental unit. The parameters evaluated at 21 and 42 days of age were weight gain (WG), feed intake (FI) and feed conversion (FC). At 42 days, production efficiency index (PEI), viability and the yields of cuts were also calculated. Birds that received diets with a reduced nutritional value showed a reduction in WG and PEI and worsened FC as compared those of PC treatment (p 0.05) from 1 to 21 days of life. For the yield of thigh + drumstick, the factors were statistically similar (p > 0.05) to those observed in the PC birds. In the second experiment, 432 fourteen-day-old chicks were distributed in a completely randomized design with seven treatments, with eight replicates per treatment and six birds per experimental unit. The apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) values were determined. Overall, the NC2 diet with Blend B provided the highest AME and AMEn values; however, NC1 with the same enzyme blend was the treatment which provided the lowest values. The addition of xylanase [...].

Objetivou-se avaliar o efeito da adição de diferentes blends enzimáticos de xilanase e β-glucanase em dietas a base de milho e de farelo de soja sobre o desempenho e metabolizabilidade da energia para frangos de corte. Foram realizados dois experimentos com frangos de corte da linhagem COBB500. No primeiro experimento, foram utilizados 1960 pintos distribuídos em delineamento inteiramente casualizado em arranjo fatorial 2 x 3 + 1, totalizando sete tratamentos: T1- Controle Positivo (CP); T2- Controle negativo 1 (CN1; CP menos 200 kcal Kg-¹ de EM); T3 - CN1 + Blend A; T4 - CN1 + Blend B; T5 - Controle negativo 2 (CN2; CP menos 167 kcal Kg-¹ de EM e 5% de aminoácidos); T6 - CN2 + Blend A e T7 - CN2 + Blend B. Foram utilizadas 14 repetições por tratamento e 20 aves por unidade experimental. Os parâmetros avaliados aos 21 e aos 42 dias de idade dos frangos foram o ganho de peso (GP), o consumo de ração (CR) e a conversão alimentar (CA). Aos 42 dias calculou-se o índice de eficiência produtiva (IEP), viabilidade (VIAB) e rendimento de cortes. Foi observado que as aves que receberam dietas com reduzido valor nutricionais apresentaram redução no GP e IEP e piora na CA comparadas ao CP (p 0,05) no período de um a 21 dias de vida. Para o rendimento de coxa mais sobrecoxa (RCS), foi possível observar que os fatores apresentaram estatisticamente (p >0,05) semelhantes ao CP. No segundo experimento foram utilizados 432 pintos com 14 dias de idade, distribuídas em um delineamento inteiramente casualizado com sete tratamentos com 8 repetições por tratamento e 6 aves por unidade experimental. Foram determinados os valores de energia metabolizável aparente (EMA) e aparente corrigida para balanço de nitrogênio (EMAn). Em geral, a dieta CN2 como Blend B apresentou o maior valor de EMA e EMAn, porém, [...].

Xylanase and B-glucanase in maize- and soybean meal-based diets for broilers / Xilanase e B-glucanase em dietas a base de milho e de farelo de soja para frangos de corte

The objective of this study was to evaluate the effect of adding different xylanase and β-glucanase enzyme blends to maize- and soybean meal-based diets on performance and energy metabolizability in broilers. Two experiments were carried out with broilers of the COBB 500 strain. In the first experiment, 1960 chicks were assigned to a completely randomized design with a 2 × 3 + 1 factorial arrangement, totaling seven treatments, namely, T1- Positive control (PC); T2 - Negative control 1 (NC1; PC minus 200 kcal kg-¹ ME); T3 - NC1 + Blend A; T4 - NC1 + Blend B; T5 - Negative control 2 (NC2; PC minus 167 kcal kg-¹ ME and 5% amino acids); T6 - NC2 + Blend A; and T7 - NC2 + Blend B. Fourteen replicates were used per treatment and 20 birds per experimental unit. The parameters evaluated at 21 and 42 days of age were weight gain (WG), feed intake (FI) and feed conversion (FC). At 42 days, production efficiency index (PEI), viability and the yields of cuts were also calculated. Birds that received diets with a reduced nutritional value showed a reduction in WG and PEI and worsened FC as compared those of PC treatment (p < 0.05). However, the birds that consumed the NC2 diet with Blend B exhibited a similar WG to those in PC group (p > 0.05) from 1 to 21 days of life. For the yield of thigh + drumstick, the factors were statistically similar (p > 0.05) to those observed in the PC birds. In the second experiment, 432 fourteen-day-old chicks were distributed in a completely randomized design with seven treatments, with eight replicates per treatment and six birds per experimental unit. The apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) values were determined. Overall, the NC2 diet with Blend B provided the highest AME and AMEn values; however, NC1 with the same enzyme blend was the treatment which provided the lowest values. The addition of xylanase [...].(AU)

Objetivou-se avaliar o efeito da adição de diferentes blends enzimáticos de xilanase e β-glucanase em dietas a base de milho e de farelo de soja sobre o desempenho e metabolizabilidade da energia para frangos de corte. Foram realizados dois experimentos com frangos de corte da linhagem COBB500. No primeiro experimento, foram utilizados 1960 pintos distribuídos em delineamento inteiramente casualizado em arranjo fatorial 2 x 3 + 1, totalizando sete tratamentos: T1- Controle Positivo (CP); T2- Controle negativo 1 (CN1; CP menos 200 kcal Kg-¹ de EM); T3 - CN1 + Blend A; T4 - CN1 + Blend B; T5 - Controle negativo 2 (CN2; CP menos 167 kcal Kg-¹ de EM e 5% de aminoácidos); T6 - CN2 + Blend A e T7 - CN2 + Blend B. Foram utilizadas 14 repetições por tratamento e 20 aves por unidade experimental. Os parâmetros avaliados aos 21 e aos 42 dias de idade dos frangos foram o ganho de peso (GP), o consumo de ração (CR) e a conversão alimentar (CA). Aos 42 dias calculou-se o índice de eficiência produtiva (IEP), viabilidade (VIAB) e rendimento de cortes. Foi observado que as aves que receberam dietas com reduzido valor nutricionais apresentaram redução no GP e IEP e piora na CA comparadas ao CP (p < 0,05), porém as aves que consumiram a dieta CN2 com o Blend B, que apresentaram GP semelhante ao CP (p > 0,05) no período de um a 21 dias de vida. Para o rendimento de coxa mais sobrecoxa (RCS), foi possível observar que os fatores apresentaram estatisticamente (p >0,05) semelhantes ao CP. No segundo experimento foram utilizados 432 pintos com 14 dias de idade, distribuídas em um delineamento inteiramente casualizado com sete tratamentos com 8 repetições por tratamento e 6 aves por unidade experimental. Foram determinados os valores de energia metabolizável aparente (EMA) e aparente corrigida para balanço de nitrogênio (EMAn). Em geral, a dieta CN2 como Blend B apresentou o maior valor de EMA e EMAn, porém, [...].(AU)