Relative bioavailability of phosphorus in wheat midds, and in soybeans roasted or extruded with and without microbial phytase in the diet

Author(s)

Bianca Almeida Brandão Martins

• Document type: Master's Dissertation
• Press: Pirassununga. , gráficos, tabelas.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2003-12-18

Examining board members

Felix Ribeiro de Lima; Ricardo de Albuquerque; José Roberto Sartori

• Advisor: Felix Ribeiro de Lima
• Field of knowledge: Agronomical Sciences - Animal Husbandry
• Indexed in: Banco de Dados Bibliográficos da USP-DEDALUS; Biblioteca Digital de Teses e Dissertações - USP
• Location: Universidade de São Paulo. Biblioteca da Faculdade de Medicina Veterinária e Zootecnia; T1333

Abstract

Five hundred and four male Cobb chicks were used in a 21 day study to determine the relative bioavailability of phosphorus (RBP) in wheat midds, or soybean roasted or extruded with and without added microbial phytase (0 or 750 FYT/kg of diet).The reference standart was a purified grade calcium phosphate dibasics (DPS). The experimental ingredients, as well as the DPS, were added to the semi-purified starch-soybean meal control diet (22% protein; 0,32% P + 0,08% P from DPS) provinding 0,05 and 0,10% additional P, for a total of 9 experimental diets containing 0 FYT/kg, plus a second group of 9 diets containg 750 FYT/kg of diet. Slope ratio technique was used to calculate RBP, based on tibia bone ash weigt (TIAW) or toe bone ash weight (TOAW), regressed on added P intake within each P source. Coefficient of determination were higher to TIAW, so these values were used to express RBP. With no phytase added to the diet RBP values were 74,4 (wheat midds), 56,9 (soybean roasted) and 56,5% (soybean extruded), and the addition of 750 FYT/kg of diet increased these values to 79,4; 93,5 and 100%, respectively. (AU)