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A pilot project for a meat turkey National Animal Health Monitoring System was undertaken in California in 1988-89 to explore data gathering techniques and to estimate the frequency, magnitude, and variability of management, flock health (including administration of pharmaceuticals for prevention and treatment of disease), and production variables in order to facilitate planning for future food animal monitoring systems. Enteritis, which occurred in over one-third of the flocks, and colibacillosis, which occurred in nearly one-quarter of flocks, were the most common diseases reported. Mycoplasma synoviae was reported in two flocks and Mycoplasma gallisepticum and Mycoplasma meleagridis each were reported in one flock. Total mortality rate in the sample flocks was 9.0% (95% confidence interval [CI] 8.2%-9.8%). The tom-specific mortality rate was 10.9% (95% CI 9.8%-12.1%) and the hen-specific mortality rate was 6.6% (95% CI 5.7%-7.4%).

The virulence of three strains of Mycoplasma gallisepticum (S6 of low broth passage, S6 of high broth passage and A514) and of one strain of M gallinarum was investigated in specific pathogen free chicks, turkey poults, chick embryo tracheal organ cultures and embryonated fowl eggs. One strain of M gallisepticum, S6, of low passage, caused high mortality in newly hatched chicks, and turkey poults, high embryo mortality, and rapid suppression of ciliary activity in tracheal organ cultures. The other strains of M gallisepticum and M gallinarum had relatively less effect. In view of its greater sensitivity, chick embryo mortality is preferable to tracheal organ culture for assessing the virulence of experimental strains of M gallisepticum.

As a result of temperature differential dipping of turkey eggs in 715 p.p.m. of tylosin or 1000 p.p.m. spiramycin in tap water, air sac lesions caused by M. meleagridis were reduced 87% and 72%, and the M. meleagridis isolations were reduced 85% and 84% respectively. Mean weights at six weeks of age showed that poults hatched from eggs dipped in tylosin and spiramycin were 128 and 130 grams heavier than control birds. This difference in mean weights was apparent at two weeks of age. DIPPING OF EGGS IN SPIROMYCIN APPARENTLY PRODUCED A DETRIMENTAL EFFECT ON THE POULTS ONE TO SEVEN DAYS OF AGE, RESULTING IN: increased mortality of 62.4% vs. 12.5% for control and 14.7% for those dipped in tylosin, and a mean weight depression of -3.6 grams and -4.4 grams below those dipped in control or tylosin solutions, although no detrimental effect of the antibiotic introduction was apparent at hatching time.