Submitted to: Southern Poultry Science Society Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2003
Publication Date: 1/25/2004
Citation: Vance, A.M., Collier, S.D., Branton, S.L., Peebles, E.D., Evans, J.D. 2004. Infection by the ts-11 strain of mycoplasma gallisepticum in commercial egg-laying hens persists in conjunction with a subsequent infection by the f-strain. Southern Poultry Science Society Meeting. Abstract 83. p. 21.
Technical Abstract: Possible competitive exclusion between two vaccine strains of Mycoplasma gallisepticum (MG) administered at different times to commercial egg-laying hens was investigated. This was accomplished by determining the effects of a TS-11-strain of MG (TS-11 MG) inoculation at 10 wk of age followed by secondary F-strain of MG (FMG) inoculations at either 22 or 45 wk of age. A trial was conducted using 160 commercial pullets separated into four replicate pens within each of four treatments. Each replicate pen contained 10 birds. Treatments and their corresponding times of MG inoculation were as follows: Non-inoculated controls; Inoculation of TS-11 MG at 10 wk; Inoculation of TS-11 MG at 10 wk and FMG at 22 wk; Inoculation of TS-11 MG at 10 wk and FMG at 45 wk. Tracheal and choanal cleft swabs were taken from two birds in each replicate pen and cultured in Frey's field media two weeks before and after the Week 45 FMG inoculation, and at necropsy (57 wk). RAPD PCR analyses were performed on each swab to determine which vaccine strains were present. Both TS-11 MG and FMG were present in all birds tested at all three times. These data suggest that TS-11 MG persists in commercial egg-laying hens throughout lay following a 10 wk in vivo inoculation, and that a competitive exclusion process does not occur between TS-11 MG and FMG when subsequent in vivo FMG inoculations are given at either 22 or 45 wk of age.