Effects Of Phytase On Growth And Calcium Phosphorus Metabolism Of Gold Carp Carassius Auratus

The gold carp was selected as the research object,through the two test, to investigate the effects of adding different levels of phytase in the whole plant protein in feed on the calcium & phosphorus digestibility in vitro and on the growth,feed utilization of calcium and phosphorus metabolism and regulation. The main results are as follows:Experiment 1: Initial body mass(34.40 ± 3.14)g gold carp was selected as the research object. Six groups of test feed(the control group added calcium dihydrogen phosphate,the test group added 0U/kg,300U/kg,600U/kg,900U/kg,1200U/kg phytase),calcium and phosphorus of gold carp intestine and hepatopancreas of adding different level of the whole plant protein feed phytase in feed digestibility in vitro. The results show that, with the increase of feed phytase levels, each experimental group gold crucian carp calcium and phosphorus digestibility in vitro was significantly increased(P < 0.05),when the feed phytase levels increased to 900 U/kg(Group 4),calcium and phospho rus gold crucian carp in vitro digestibility and control group no significant difference. Show that the optimal level of phytase is 900 U/kg.Experiment 2: Initial body mass(10.71±0.14)g gold carp was selected as the research object. Six groups of test feed,which controls the test group added calcium dihydrogen phosphate,adding phytase(0U/kg,300U/kg,600U/kg,900U/kg,1200U/kg),were fed for 8 weeks,explore the effect of adding different levels in whole plant protein feed the golden crucian carp of phytase on the growth,feed utilization of calcium and phosphorus metabolism. The results show that the experimental group,the golden crucian carp specific growth rate increased with the increase of feed phytase levels significantly increased(P< 0.05),when the feed phytase levels increased to 900 U/kg(Group 4),the golden crucian carp specific growth rate, feed efficiency, protein efficiency ratio was significantly increased(P < 0.05),and compared with control group no significant. When phytase level reached 900U/kg,promoted the growth and feed utilization of gold carp. The test group, the apparent digestibility of calcium,calcium,bone phosphorus with increasing Feed Phytase increases,when the Feed Phytase increased to 600U/kg(Group 3),and the control group no significant difference;the test group of intestinal protease activity, phosphorus apparent digestibility of calcium and phosphorus,bone blood with the increase of feed phytase increases,when the Feed Phytase levels increased to 900U/kg(Group 4),and the control group no significant difference;calcium and phosphorus digestibility in vitro and in vivo calcium and phosphorus digestibility significantly positive correlation. Each experimental group of ammonia nitrogen and phosphate excretion decreased with increasing feed phytase level,when the Feed Phytase increased to 900U/kg(Group 4),ammonia nitrogen and phosphate excretion and the control group no significant difference. Showed that phytase promote calcium and phosphorus metabolism is the best addition is in the range of 600U/kg~900U/kg. Each experimental group of parathyroid hormone increased with the increase of Feed Phytase level,when the Feed Phytase increased to 600U/kg(Group 3),and the control group no significant difference;the test group of calcitonin and 1,25-dihydroxy Vitamin D3 increased with the increase of feed phytase level,when the Feed Phytase increased to 900U/kg(group 4),calcitonin and 1,25-dihydroxy Vitamin D3 and control group no significant difference. Regulating the metabolism of calcium & phosphorus in the best of phytase addition amount is indicated as 900 U /kg. Under the conditions of this experiment,from in vivo and in vitro,from the growth,feed utilization and metabolism of calcium & phosphorus,combining with economy and applicability to consider,in the whole plant protein feed the gold carp of phytase in the suitable content of 600U/kg ~900U/kg.