Demographic parameters of a cattle (Horro breed) herd in a rural highland
district of Ethiopia (Boji, West Wellega) are described. Data were collected in
the course of a herd-monitoring project on the spread of contagious bovine
pleuropneumonia (CBPP). The mean age at first calving and calving rate (for
females older than 4 years) in the monitored herds were estimated at 5.8 years
and 0.37 year-1, respectively. The annual natural mortalities were 17, 9 and
3% for calves (0 to 9 months old), subadults (> 9 months to 4 years) and
adults (> 4 years), respectively. No effect of the herd status (CBPP-free or
CBPP-infected) was observed on the mean mortality of weaned animals. A
main feature of cattle management in the area was the common practice of
animal lending between farmers (more than 35% of the adults in the
monitored herds were loaned during the year), mainly for agricultural
activities and manure. This practice may have had a major impact on the
observed age structure of the cattle population.