عنوان مقاله [English]
Introduction Phytic acid is a main compound in all plant seeds and contains 60 to 70% of total phosphorus in plant. Monogastric animals cannot use phytatephosphorus because of low phytase activity in their digestive tract. Thus in addition to unabsorbed mineral phosphorus, phytate phosphorus in fecal ofmonogastric animals may affect water and environment pollution. It is suggested to use of phytase enzyme for resolving of this problem. Phytase activity was showed in some bacteria like pseudomonas, bacillus subtilis and amyloliquefaciens. Few strain of lactic acid bacteria order showed phytase activity or were different for this activity. On the other hand these bacteria order are important as probiotic strains. There are numerous studies to use probiotic bacteria with specific enzyme activity for increasing nutrient availability to animals. This experiment was aimed to study of a recombinant Lactococcuslactis performance to degrade of phytate phosphorus in broiler chicken diets.
Materials and methods Lactococcuslactis was supplemented to a phosphorus deficient diet (50% of available phosphorus recommended by NRC) lonely or with two other lactobacillus bacteria (lactobacillus crispatusand lactobacillus salivarus) in rate of 108 CFU/g diet. Diets were also formulated with recommended available phosphorus by NRC with or without probiotic supplementation. Two hundred eighty eight one day old male Ross broiler chicks were subjected to 6 experimental treatment in 4 replicates and 12 chicks in each replicate. Growth performance, bone characteristics, intestinalmicroflora, and blood metabolites were measured. Apparent phytate digestibility was estimated by chromic oxide marker method. The chromic oxide was added in rate of 0.3% ofthediets. Phytate phosphorus was measured by the method of wheeler et al (1971). On day37, level of calcium, phosphorus and cholesterol of serum were measurement by bleeding from wing vein. Left thigh bone was isolated on 42 days and its dimensions and strength were measurement by Caliper and Instron instruments respectively.
Results and Discussion Body weights of deficiency phosphorus treatments showed significant decrease even in presence of recombinant probiotic (P