Mortality Records:

The mortality records from transfer up to the day of the veterinary visit were examined and summarized in three graphs. Figure 1, the total cumulative mortality for the farm, demonstrates that the males were dying proportionately more than females. Mortality became noticeable at about 20 weeks of age, the problem slowed down during amoxycillin treatment, only to increase markedly on week 24. Half of the males had died by the time of the visit, suggesting that it would be necessary to obtain further males in order to maintain fertility.

Weekly % mortality for the females in each house is shown in Figure 2 and seems to indicate that the problem started in house 3 then progressively affected houses 2 and 1 in that order. Farm staff confirmed that this was also their impression from the appearance of the birds.

In Figure 3 there is a similar trend for the males, though the patterns for houses 2 and 3 are nearly identical. The reduction in mortality associated with the antibiotic treatment is evident in both this and the previous graph.