MICROBIAL PHYTASE ENZYME PRODUCTION AND ITS APPLICATION IN FEEDING LACTATING ANIMALS

Abstract

Enzyme production, chemical and microbiological analyses were carried out at the Laboratories of Applied Microbial Genetics Lab., Genetics and Cytology Department in collaboration with Animal Production Department, National Research Centre, Dokki, Giza, Egypt. Laboratory in-vitro trials were carried out at the Laboratories of Animal Production Department, Faculty of Agriculture, Ain Shams University, Egypt. The farm trials were carried out at the Animal Production Unit, Agricultural Experimental Station of the National Research Centre, Al-Noubareya, Egypt. This study was carried out to: 1- Screening various fungal genotypes for their ability to produce phytase and improve the produced enzyme by ethyl-methane sulfonate (EMS) mutagenesis. 2- Evaluate the potential use of different levels of laboratory produced phytase enzyme (PE) for improving in-vitro nutrients degradability of lactating animals' ration compared with different levels of commercial phytase enzyme (Axtra® PHY) to decide the most effective level of phytase supplementation from both sources. 3- Investigate the impact of adding Axtra® PHY and PE enzymes, at the best level that was obtained from the results of the in-vitro study, to the ration of lactating buffaloes on nutrients digestibility, some blood parameters, milk yield and composition. Three experiments were carried out in this study: 1. The first experiment [Laboratory microbial phytase production trials] Based on the previous studies in the literature, submerged fermentation (SmF) was used to evaluate the effect of different phytase