Effect of Mycoplasma Synoviae on Broiler Performance

Abstract

Two trials were conducted to determine the effect of Mycoplasma synoviae (Ms.) on broiler performance. A total of 1,200 males and 1,200 females was used in each trial. At 28 days of age, 75 birds per pen were placed, sexes separate, in 32 pens in a house equally divided by a solid partition. The temperature in the house was maintained at 21° C., and the ventilation rate varied from 28 to 56 liters per minute per bird. A combination vaccine for Newcastle disease and infectious bronchitis was given in the water at 28 days of age. All birds were weighed and feed records started 3 days after vaccination. At 32 days of age, all birds in the 16 pens in one section of the house were exposed to an aerosol of a Ms. broth culture. All birds were weighed and feed records terminated at 59 days of age. The four groups, Ms.-free males, Ms.-exposed males, Ms.-free females and Ms.-exposed females, were processed at a federally inspected processing plant at 60 days of age and post-mortem condemnation records obtained. The Ms.-exposed groups had significantly higher condemnations that were due to airsacculitis than the Ms.-free groups. There was a trend for decreased body weight and increased feed conversion ratio for the Ms.-exposed birds.