Safety Assessment Of The Phytase Transgenic Corn In The Broiler Diet

Five experiments were conducted to evaluate the safety of the phytase transgenic corn as afeed ingredient in the broiler diet.Experiment1. Effect of the phytase transgenic corn on growth performance, carcassperformance and meat quality of Broilers. Trials using the single-factor completely randomizeddesign,the160one-day-old AA cocks is divided into two treatment groups for each treatmentgroup of10repeats, each repeated eight chickens,housed in stainless steel-plated plastic cages,the control group was fed with non-genetically modified phytase corn diets, the test group was fedwith genetically modified phytase corn diets, two groups in two phases (0-21days and22-42daysold) to add available phosphorus and all other nutrient content are equal. The results showed： nosignificant differences broilers in weight gain, daily feed intake,feed gain ratio, carcassperformance and most of meat quality indicators were observed between the control group and thetest group in the0-21days and22-42days(P>0.05); Flesh (b*value) of pectoral muscle, pH ofleg muscle were more significant differences(P<0.05); pH of breast muscle and flesh (b*value),shear force, drip loss of leg muscle was extremely significant difference (P<0.01). It was clear thatgrowth performance and carcass performance of broiler had no adverse effects fedding the phytasetransgenic corn diet.,and although some of meat quality indicators significantly,but there are noharmful situations.Experiment2. Effect of the phytase transgenic corn on blood routine indicators, serumbiochemical parameters, organ development and pathological changes of Broilers. At the age of42days two broilers were bleed at Wing vein from each repeat cage, slaughter to weigh visceral andsmall intestine. And duodenums, livers, kidneys, spleens were made by tissue sections; The resultsshowed that no significant difference were observed (P>0.05) between control group and the testgroup in the blood routine indexes, serum biochemical indexes(apart from total bilirubin), organindex and duodenal villus height, crypt depth.No histopathological damages were detected withmicroscopic examination of tissues. the test group total bilirubin were significantly lower than the control group (P <0.01), showed that the experimental group of chicken liver may be morehealthy.From this trial, it was concluded that there were no observed adverse effects of thetransgenic brown rice on the broiler chicken's health.Experiment3. Effect of the phytase transgenic corn on immune organ development andimmune function of Broilers. At the21days and42days of age two broilers were bleed at Wingvein with each replicate cage. Immune organ indext anti-NDV antibody of the21day and42dayof age in broilers were determined, and Immune organ indext, serum globulin content, peripheralblood T lymphocyte cell proliferation of42day of age of broilers were measured. The resultsshowed that no statistically significant difference were observed (P>0.05) in the immune organindex and immune response between two groups. From results of this trial, it was concluded thatthere were no observed adverse effects of the the phytase transgenic corn on the broiler chicken'simmune organ development and immune response.Experiment4. Effect of the phytase transgenic corn on Intestinal Microbial Community anddiversity in Broilers. At the age of43days two broilers were killed from each repeat cage toretrieve the intestinal and cecal. its was studied on microbial number and advantages of floradiversity. by Plate culture and denaturing gradient gel electrophoresis (DGGE) analysis of16Sribosomal RNA. The Plate culture results showed that the microbial community of total aerobicbacteric, anaerobic bacteria, Lactobacillus, E. colibacillus and the number of dominant specieswere no significant difference in cecum and ileum (P>0.05), DGGE analysis showed there wereno abnormity of the microflora in the cecum and ileum. In conclusion, the phytase transgenic cornhad no observed adverse effect on the intestinal microbial community in broilers.Experiment5. Detection of Recombinant DNA Fragment and phyA Protein of the phytasetransgenic corn in Broilers.the Experiment4broiler intestinal digesta, feces,heart, liver, kidneyand muscle were collected under sterile condition. PCR and Western blot methods were used todetecte exogenous gene and exogenous protein of the the phytase transgenic corn. The resultsshowed that no678bp fragment of phAy gene and60KD phAy protein were detected in heart,liver, kidney, muscle. exogenous protein is detected in the duodenum and jejunum chym,but no detected in Ileum and feces,so exogenous gene and its protein may be gradually degraded in theintestinal tract of broilers. Therefore, there were no residual of transgenic composition in broilers.In conclusion, no adverse effect was found in growth performance, carcass performance,meat quality, blood routine indicators,serum parameters, immune function, intestinal microfloraand organ development of broilers when the the phytase transgenic corn was used in broiler duringthe trial period, and key organizations of broilers did not produce pathological damage. there wereno residual of transgenic composition in broilers. So the phytase transgenic corn as broiler feedingredients may be safe.