Effect of tylosin in the feed of broiler breeder birds on their serological reaction to Mycoplasma synoviae.

Serum plate (SP) reactions and geometric mean Mycoplasma synoviae (MS) hemagglutination-inhibition (HI) titers were determined on sera from broiler breeder hens fed either 50 g tylosin per ton of feed or 150 g tylosin per ton of feed for 4 weeks before and 4 weeks after MS exposure by aerosol. Then tylosin was increased to 150 g per ton of feed and 300 g per ton of feed, respectively, for 8 weeks. One group of birds, without tylosin in the feed, was exposed to MS by aerosol.

Comparison of Mycoplasma synoviae hemagglutinating antigens by the hemagglutination-inhibition test.

Mycoplasma synoviae (MS) strains were isolated from the trachea of hens from MS-positive broiler breeder flocks having progeny condemnations due to airsacculitis. Hemagglutinating (HA) antigens were made from several strains. The HA antigen made from the 95th medium passage of MS FMT strain was compared with that of the standard MS WVU 1853 strain by the hemagglutination-inhibition (HI) test.

Effect of sex and Mycoplasma synoviae infection on chicken red blood cells used for hemagglutination-inhibition test.

A total of 10 male and 10 female 9-week-old commercial Mycoplasma-free broiler chickens was used in this test. Five males and 5 females were artificially infected by aerosol with a broth culture of Mycoplasma synoviae (MS) F10-2AS. The other 5 males and 5 females were used as noninfected controls.

Studies on the effect of butylated hydroxytoluene on Mycoplasma synoviae.

Butylated hydroxytoluene (BHT) is one of the antioxidants added to human and animal feed products in concentrations ranging from 50 to 200 ppm to delay degradation of the labile lipid components. BHT is known to be an inactivator of mammalian and bacterial viruses that contain lipid. Results of in vitro studies showed that 10 ppm of BHT in Mycoplasma medium prevented growth of each of the six Mycoplasma synoviae (Ms) isolates.

Serological and cultural studies on broiler breeder multiplier flocks infected with Mycoplasma synoviae.

Nine broiler breeder flocks found infected with Mycoplasma synoviae (MS) at 17 to 42 weeks of age were used for serological tests and isolations of MS. Five live females and 20 to 30 serums were brought to the laboratory from each flock on three occasions. Serums from flocks naturally infected reacted to the serum plate agglutination and hemagglutination-inhibition tests throughout one laying season.