Phytase and protease supplementation for laying hens in peak egg production

Vieira, Bruno Serpa; Barbosa, Silvana Alves Pedrozo Vitalino; Tavares, João Marcos Novais; Beloli, Inês Gameiro Colvara; Silva, Guilherme Moreira de Mello; Lima Neto, Hélio Rezende; Caramori Júnior, João Garcia; Corrêa, Gerusa Silva Salles

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)

Biblioteca Virtual en Salud

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

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