ABSTRACT
A summary of the causes of mortality, based on the records of 258 postmortems between 1987 and 1993, is presented in Fig. 8.1. Proportions of the various etiologies observed in 1989 were the same as in 1987. The increase in the number of deaths in 1989 compared to 1987 was mainly due to the increase in the total number of birds. This was followed by a decrease in mortality rate in 1990 and 1991. The large increase in the total number of birds in 1992 and 1993 explains the high number of deaths. Infectious diseases were the major cause, responsible for 50 per cent to 60 per cent of deaths.
