Effects of different proteases on commercial laying hens at peak production

We evaluated the effect of adding proteases in diets of laying hens at peak production on the performance, egg quality, relative weight of digestive organs, and intestinal morphometry. Hy-Line W36 layer hens (390; 28-39 weeks old) were distributed in five treatments, with 13 animals each, with six replicates. The treatments were: control (standard formulation without nutritional reduction or protease inclusion), negative control A - NCA (nutritional reduction according to protease A matrix, without protease), negative control B - NCB (nutritional reduction according to protease B matrix, without protease), NCA + protease A, and NCB + protease B. The experimental period lasted 12 weeks, divided into three cycles of 28 days. Hens subjected to treatments (NCA and NCB) showed a decrease in feed intake. However, the addition of proteases A and B promoted improvement in this trait. The diets NCA and NCB had a negative influence on the production rate of the hens, but the diet supplementation with protease B resulted in significant improvement on egg laying rate. Hens subjected to nutritional reduction presented the worst results regarding mass and conversion by egg mass. However, the addition of enzymes reversed these results. Although the diets did not affect the relative weights of yolk, albumen, eggshell, Haugh unit, and specific gravity of the eggs, a higher eggshell thickness was observed in hens that received NCA, NCB, and NCB + protease B diets. The diets did not influence the relative weights of digestive organs and the small intestine morphometry. Hens fed diets supplemented with A and B have performance recovered in relation to those that received diets with reduced levels of nutrients.(AU)

Phytase and protease supplementation for laying hens in peak egg production / Suplementação de fitase e protease para galinhas em pico de produção

The effects of enzyme combinations in diets for commercial laying hens need further clarification. The goal of this study was to determine if the type of protease used in diets supplemented with phytase affects performance, nutrient intake, egg quality or intestinal mucosa morphometry of laying hens during peak egg production. Seven hundred and eighty hens (25-week-old Hy-Line W36 hens) were assigned to a completely randomized design composed of five treatments/diets with 12 replicates of 13 birds each. The five treatments were: 1) positive control: diet formulated according to the Hy-Line nutritional recommendations, without proteases , 2) negative control A: positive control diet reduced in energy, protein and amino acids according to protease A matrix, without protease supplementation, 3) negative control B: positive control diet reduced in energy, protein and amino acids according to protease B matrix, without protease supplementation, 4) negative control A plus protease A, 5) negative control B plus protease B. There was no effect of the treatments (P > 0.05) on egg production, egg mass or feed conversion; however, the nutritional restriction imposed by the negative controls reduced egg weight (negative control A, P=0.02), albumen height (P < 0.01) and the Haugh unit (P < 0.01). Protease supplementation reduced the calculated intake of protein and amino acids compared to the positive control; nevertheless, protease A was able to maintain egg weight, albumen height and the Haugh unit at the same levels as that obtained with the positive control hens. The intestinal mucosa responded to treatment only at the jejunum (P < 0.01), but the negative controls did not modify villus height or crypt depth compared to the positive control. However, crypt depth of protease B hens was higher than that of the positive control hens.[...]

Os efeitos da utilização em conjunto de enzimas exógenas para aves de postura precisam ser mais explorados na literatura. No intuito de determinar se o tipo de protease, em dietas suplementadas com fitase, interfere no desempenho, qualidade do ovo, ingestão de nutrientes e morfometria da mucosa intestinal de galinhas em pico de postura, 780 galinhas Hy-Line W36 de 25 semanas foram distribuídas em um delineamento inteiramente casualizado composto por cinco tratamentos/dietas com 12 repetições de 13 aves cada. Os cinco tratamentos foram: 1) controle positivo: dieta formulada de acordo com as recomendações nutricionais da Hy-Line, sem proteases, 2) controle negativo A: dieta controle positivo reduzida em energia, proteína e aminoácidos conforme a matriz nutricional da protease A, sem proteases, 3) controle negativo B: dieta controle positivo reduzida em energia, proteína e aminoácidos conforme a matriz nutricional da protease B, sem proteases, 4) controle negativo A com inclusão da protease A, 5) controle negativo B com inclusão da protease B. Não houve efeito dos tratamentos (P > 0,05) sobre produção de ovos, massa de ovos e conversão alimentar; porém, a restrição nutricional imposta pelos controles negativos diminuiu o peso do ovo (controle negativo A, P = 0,02), a altura do albúmen (P < 0,01) e a unidade Haugh (P < 0,01). Embora a inclusão das proteases em seus respectivos controles negativos não tenha garantido o mesmo consumo de proteína e aminoácidos observado no grupo controle positivo, a adição da protease A reverteu os efeitos adversos da restrição nutricional sobre o peso do ovo, a altura do albúmen e a unidade Haugh. O efeito dos tratamentos sobre a morfometria da mucosa intestinal foi detectado somente no jejuno (P < 0,01), porém, o consumo dos controles negativos não alterou a altura de vilosidades e a profundidade de criptas em relação ao controle positivo.[...]

Phytase and protease supplementation for laying hens in peak egg production / Suplementação de fitase e protease para galinhas em pico de produção

The effects of enzyme combinations in diets for commercial laying hens need further clarification. The goal of this study was to determine if the type of protease used in diets supplemented with phytase affects performance, nutrient intake, egg quality or intestinal mucosa morphometry of laying hens during peak egg production. Seven hundred and eighty hens (25-week-old Hy-Line W36 hens) were assigned to a completely randomized design composed of five treatments/diets with 12 replicates of 13 birds each. The five treatments were: 1) positive control: diet formulated according to the Hy-Line nutritional recommendations, without proteases , 2) negative control A: positive control diet reduced in energy, protein and amino acids according to protease A matrix, without protease supplementation, 3) negative control B: positive control diet reduced in energy, protein and amino acids according to protease B matrix, without protease supplementation, 4) negative control A plus protease A, 5) negative control B plus protease B. There was no effect of the treatments (P > 0.05) on egg production, egg mass or feed conversion; however, the nutritional restriction imposed by the negative controls reduced egg weight (negative control A, P=0.02), albumen height (P < 0.01) and the Haugh unit (P < 0.01). Protease supplementation reduced the calculated intake of protein and amino acids compared to the positive control; nevertheless, protease A was able to maintain egg weight, albumen height and the Haugh unit at the same levels as that obtained with the positive control hens. The intestinal mucosa responded to treatment only at the jejunum (P < 0.01), but the negative controls did not modify villus height or crypt depth compared to the positive control. However, crypt depth of protease B hens was higher than that of the positive control hens.[...](AU)

Os efeitos da utilização em conjunto de enzimas exógenas para aves de postura precisam ser mais explorados na literatura. No intuito de determinar se o tipo de protease, em dietas suplementadas com fitase, interfere no desempenho, qualidade do ovo, ingestão de nutrientes e morfometria da mucosa intestinal de galinhas em pico de postura, 780 galinhas Hy-Line W36 de 25 semanas foram distribuídas em um delineamento inteiramente casualizado composto por cinco tratamentos/dietas com 12 repetições de 13 aves cada. Os cinco tratamentos foram: 1) controle positivo: dieta formulada de acordo com as recomendações nutricionais da Hy-Line, sem proteases, 2) controle negativo A: dieta controle positivo reduzida em energia, proteína e aminoácidos conforme a matriz nutricional da protease A, sem proteases, 3) controle negativo B: dieta controle positivo reduzida em energia, proteína e aminoácidos conforme a matriz nutricional da protease B, sem proteases, 4) controle negativo A com inclusão da protease A, 5) controle negativo B com inclusão da protease B. Não houve efeito dos tratamentos (P > 0,05) sobre produção de ovos, massa de ovos e conversão alimentar; porém, a restrição nutricional imposta pelos controles negativos diminuiu o peso do ovo (controle negativo A, P = 0,02), a altura do albúmen (P < 0,01) e a unidade Haugh (P < 0,01). Embora a inclusão das proteases em seus respectivos controles negativos não tenha garantido o mesmo consumo de proteína e aminoácidos observado no grupo controle positivo, a adição da protease A reverteu os efeitos adversos da restrição nutricional sobre o peso do ovo, a altura do albúmen e a unidade Haugh. O efeito dos tratamentos sobre a morfometria da mucosa intestinal foi detectado somente no jejuno (P < 0,01), porém, o consumo dos controles negativos não alterou a altura de vilosidades e a profundidade de criptas em relação ao controle positivo.[...](AU)