Eradication of Mycoplasma gallisepticum and M. synoviae from...

A chicken breeding flock of 3,464 hens, naturally infected withMvcoplasma gallisepticum (MG) and M. svnoviae (MS), was subjected to a mycoplasma eradication scheme, based on antimicrobial treatment of eggs and their hatched dayold chicks. The egg injection sites utilized were the air cell and the small end (albumen), and the antibiotics used were tylosin at two different doses (3 mg or 5 mg per egg) and gentamicin (0.6 mg/egg). For the chicks treatment, a combination of spectinomycin and lincomycin, diluted in dextrose-vitamin complex solution, was employed. The differences in hatchability for the egg air cell-embryo (17.2%), egg small end (albumen)-3mg tylosin (72.4%) and egg small end (albumen)-5mg tylosin (42.1%) injection procedures were significantly different by Chi-square analysis (