Phosphorus equivalency of three phytases of fungal and bacterial origin under different manufacturing processes for broilers

• Ano de defesa: 2020
• Autor(a) principal: Silva, Raully Lucas
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Zootecnia
• Palavras-chave em Português: Nutrição animal; Alimentos - Aditivo; Fitases; Fósforo; Nutrição e Alimentação Animal
• Link de acesso: https://locus.ufv.br//handle/123456789/29407

The aim of this study was to determine the efficacy and the phosphorus equivalency of three commercial phytases of fungal (Aspergillus niger) and bacterial (Hafnia sp., Yersinia mollaretii and Buttiauxella gaviniae) origin under different manufacturing processes in the diets of broiler chickens from 1 to 21 days of age. A total of 1750 male broiler chickens were randomly distributed in 7 treatments with 10 replicates of 25 birds each. A basal diet was formulated containing 1.8 g/kg of nPP and 4.05 g/kg of total calcium (T1). For treatments 2-4, the basal diet was supplemented with 0.7, 1.4, or 2.1 g per kg of inorganic phosphorus from dicalcium phosphate to create diets with 2.5, 3.2 or 3.9 g/kg of nPP, respectively. The treatments from 5 to 7 received 500 phytase units per kg of 3-fungal phytase powder (phytase A), 6-bacterial phytase powder (phytase B) and 6-bacterial phytase granular (phytase C) respectively. Increasing levels of inorganic phosphorus from dicalcium phosphate at 0.7, 1.4, or 2.1 g per kg improved (P<0.05) final body weight by 17, 21.7 and 22.4%; feed intake by 14, 18 and 16.4%; weight gain by 18, 23 and 24%; tibia ash by 27, 43 and 37.3% and tibia P content by 25.4, 36 and 32%. Supplementation with phytase A, phytase B and phytase C contributed to an improvement (P< 0.05) of 15.4, 20.8 and 21% in final body weight, 11, 16 and 15.5% in feed intake, 16.3, 22 and 22.2% in weight gain, 10.4, 24 and 41.7% in tibia ash weight and 7, 21.4 and 36% in tibia P, respectively in relation to the basal diet. Linear and quadratic regression equations (P<0.05) were used to estimate phosphorus equivalency values of the three phytases. Phytase A, phytase B and phytase C can be used in the diets of broiler chickens from 1 to 21 days of age to partially reduce the addition of dicalcium phosphate source. The supplementation of 500 FTU/kg with phytase A, B and C were determined to be equivalent on average of 0.097, 0.139 and 0.145% of inorganic phosphorus from dicalcium phosphate, respectively. Keywords: Animal nutrition. Feed additive. Phytase efficacy. Phosphorus equivalency.