Phytase and protease supplementation for laying hens in peak egg production

Abstract

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. In conclusion, when included in diets supplemented with phytase, the type of protease affects performance, nutrient intake, egg quality and intestinal mucosa morphometry of laying hens during peak egg production. Key words: Amino acid. Egg production. Egg quality. Enzyme. Nutritional restriction. ResumoOs 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 confor...

Effects of different proteases on commercial laying hens at peak production

“…However, the addition of protease B in the diet provided an increase in this variable. These results are similar to those presented by Vieira et al (2016), who also observed a reduction in egg weight values of light laying hens at peak production fed a diet with reduced energy, protein, and amino acids. The authors found that the addition of the enzyme (Streptomyces fradiae, 0.125 g kg −1 in the feed) to the hens' diet promoted an increase in egg weight.…”

“…However, Lima et al (2012) did not observe any significant treatment effect on the egg mass when providing diets with low levels of crude protein (0.0 and 4.0 g/kg) with or without supplementation of enzymatic complex for light laying hens at 30 weeks old. Similar results were also found by Vieira et al (2016), who did not observe any significant differences in egg production of light laying hens at peak production fed diets with reduced energy, proteins, and amino acids, with or without the inclusion of proteases (Streptomyces fradiae, 0.125 g kg −1 in the diet and Bacillus licheniformis, 0.250 g kg −1 in the diet) in their composition. Considering that the reduction in the crude protein level of the diet can cause reduction in egg mass values of light laying hens (Silva et al, 2010;Mousavi et al, 2013), it can be inferred that the nutritional reduction of diets negative control A and B promoted reduction in the egg mass values found in the present research, since they had lower levels of crude protein and amino acids in their compositions.…”

Effect of Dietary Supplementation of Different Multi-Enzymes on Production Performance and Egg Quality Characteristics in Laying Hens

“…It is seen that the literature on the effect of enzyme addition to laying hens diets on egg production is incompatible. In related studies [12,13,19,20] reported that the enzyme addition did not change egg production. On the other hand, Khan et al [21] reported that dietary enzymes increased egg production in laying hens.…”

“…Some researchers [15,16,17] reported that the addition of multi-enzyme improved the feed conversion rate in laying hens. In contrast, some researchers found the opposite results [18,19,20]. As it is known, 'FCR' is the ratio of feed intake to egg weight in laying hens.…”

The Effect of Bacterial Enzyme-Based Feed Additives on the Productivity, Digestibility and Assimilation of Nutrients in Young Laying Hens

“…Balancing the contents of protein, amino acids, minerals and vitamins is essential for high productivity in this category of birds. The feed mixture for laying hens is based on grain containing an increased amount of poorly digestible phytates, which accommodate up to 80% of the total phosphorus content in the grain (Vieira et al, 2016).…”