A longitudinal study of disease incidence and case-fatality risks on small-holder dairy farms in coastal Kenya. uri icon

abstract

  • A longitudinal study was carried out in the coastal lowlands coconut-cassava agro-ecological zone of Kaloleni Division, Coast Province, Kenya between June 1990 and December 1991 to estimate disease incidence and cause-specific case-fatality risk in an average of 120 cattle in 26 small-holder dairy herds kept in two grazing-management systems. East Coast fever (ECF) was the predominant disease diagnosed; the mean monthly incidence rate was 2.5 and 6.9% in animals less than or equal to 18 months of age under stall-fed and herded-grazing systems, respectively. In cattle > 18 months of age, the monthly incidence rate was <1%. The 6-month ECF incidence rate was 20 +/- 8% (S.E.) in the stall-feeding system compared with 39 +/- 7% in the herded-grazing systems. There was a gradual increase in antibody prevalence with age to over 90% in cattle over 18 months of age in herded-grazing systems, whilst less than a third of cattle in the stall-feeding systems were sero-positive at any age. Overall accumulated mortality to 18 months of age was estimated to be 56%. Annual mortality in cattle > 18 months averaged 9%. Cattle managed in the herded-grazing system had a 60% higher mortality, although not significantly so, than those fed in stalls. Deaths due to ECF accounted for over two-thirds of the deaths. ECF was then the major disease constraint to smallholder dairy production in the coconut zone of coastal Kenya. Clinical cases occur the whole year round (especially in young stock) - despite apparent tick control, and in both herded-grazing and stall-feeding system. (C) 2001 Elsevier Science B.V. All rights reserved.

publication date

  • 2001
  • 2001