Abstract
Phosphorus (P) as phyiic acid accounts for about 50-80% of the total P present in cereals and legumes. Due to the lack of phytase, it is hard for non-ruminants to digest this phyiic acid, which is therefore excreted in the feces. Thus, inorganic P is added to the feed of non-ruminants to satisfy their requirements. However, most of this inorganic P is excreted in the feces and leads to environmental pollution. Recently, a new feeding technology which supplements phytase to the diets has been shown to effectively improve the availability of dietary phyiate P and reduces the requirement of inorganic P added to diets. If this technology becomes widespread, inorganic P in feces of non-ruminants will be markedly decreased and reduce its value an available P source for crops.HomePage
The present report deals with the liberation of phyiate-bound P in composts made with feces of cows, pigs, chickens and air-dried rice straw. It was found that with phytase of 1.25U/g and incubated under 55oC for 16 hours, increments of mineralized P were 14.3, 13.6, 9.15 and 46.2% in ratio over total inorganic P in composts from feces of cows, pigs, chickens and rice straw, respectively. This result suggests the possibility that phyiic acids in feces or rice straw may be decomposed into inorganic P in the composting process by phytase added to diets.Keywords: phyiic acid, phytase, compost, rice straw