Study And Application Of Mycoplasma Antibody Monitoring Baselines In Yellow Feather Broiler Chicken Farms

With the effective control of Avian Influenza,Newcastle disease,Avian leukosis,Infectious Bronchitis and other diseases that seriously affect the production efficiency of yellow feather broiler chicken farms,the damage of Mycoplasma has been increasingly valued by chicken farms.Currently,there is a high infection rate of Mycoplasma in farms,the laying rate and hatching rate of breeder chickens will be greatly reduced,and more and more joint diseases will be caused.Farms can adopt purification,vaccine immunization,and drug control methods to prevent Mycoplasma,and all programs should base on detection,which can be used for antigen and specific antibodies.Pathogen culture is not used widely in farms because of the harsh conditions and the high requirements,and antibody test is more widely used worldwide.In this study,the concept and influencing factors of antibody baseline will be further clarified,according to the production characteristics of yellow feather broiler chicken farms,mycoplasma antibody baselines will be established to guide drugs and immunity,and to improve the level of disease prevention and control in breeding farms.In this study,MG and MS standard positive serum was tested by ELISA kits of I company and D company.For 8 times diluted MG serum,result of I kit was positive,meanwhile the result of D kit was suspect.For 16 times diluted MS serum,result of I kit was positive,meanwhile the result of D kit was suspect.Considering of simple operation,kits from I company were selected to establish Mycoplasma antibody baselines.Based on the production process of domestic yellow feather broiler chicken farms and the mycoplasma antibody monitoring plan of some domestic breeding farms,15 yellow feather breeding farms in Guangdong,Guangxi and Sichuan,and 3 white feather breeding farms in Shandong were selected as research subjects,which were classified according to different regions,seasons and varieties.7 production indexes were collected,including time of breeder introduction,birth weight,dead scouring rate in the breeding period,dead scouring rate in the egg producing period,number of eggs produced,number of qualified breeding eggs and number of healthy chicks.Heart blood was collected at 0 days age,and blood was collected at 35,84,126,168,245,315 and 385 days age from wing vein.The collected serum for 46 samples at each point,6624 samples totally were detected by MG and MS antibody test.Results of the titer value were calculated with x Chekplus software,and then the upper and lower limits of the mean titer values of 15 fields at each detection time point were calculated according to the 95% confidence interval with IBM SPSS STATISTICS software,and the MG and MS antibody baselines were obtained.It is clearly proposed that the animal antibody baseline refers to the range of titer values of a specific antibody in the same phase of the life cycle of an animal population.Animal antibody baseline is affected by many factors such as animal species,feeding mode and use of drug and vaccine.MG antibody baseline was used to detect the risk of MG infection in three groups of breeding chickens in farm P of yellow feather broiler fames.The results showed that the antibody of group 1 and group 2 stock changed in the scope of the baseline.The antibody value of group 3 of breeding chickens exceeded the upper limit of the baseline at the age of 85 days,and then the chickens were immediately treated with Tiamulin Fumarate and the disinfection frequency was increased.After 20 days,the antibody returned to the baseline range.There was no significant difference in laying rate between the three groups.MS antibody baseline was used to detect the risk of MS infection in two groups of breeding chickens in farm S of yellow feather broiler fames.The results showed that although the change trend of antibody in the control group was consistent with baseline,the antibody was negative only between the age of 35 days and 84 days,and the antibody was positive at all other test time points.In the application group,when the antibody was exceeded the upper limit of the baseline at the age of 35 days,Tiamulin Fumarate was immediately used for control for 5 days every 5 weeks.At the age of 95 days,the antibody returned to the baseline range.From the age of 126 days to 385 days,the MS antibody value was always lower than the lower limit of the baseline.The laying rate of this group was 5% higher than that of the control group,and the time of laying rate exceeding 80% was extended by 4 weeks.The peak laying rate reached 88%,5% higher than that of the control group,and no clinical joint disease was found.In summary,the definition of animal antibody baseline was clearly proposed,MG and MS antibody baselines of yellow feather broiler farm were established in this study and successfully applied in yellow feather broiler farms,which could be used to guide rational drug use and scientific immunity.