Epidemiological Studies of Vector-Borne Diseases with Consequent Development of Preventive Medicine Programmes for Small-Holder Dairy Farmers in Coastal Kenya

Maloo, Seiffuddin Hatimali (1993) Epidemiological Studies of Vector-Borne Diseases with Consequent Development of Preventive Medicine Programmes for Small-Holder Dairy Farmers in Coastal Kenya. PhD thesis, University of Glasgow.

Abstract

This thesis describes a series of epidemiological investigations carried out between 1989 and 1991 in small-holder dairy cattle in coastal Kenya, with the aim of estimating prevalence, incidence and mortality rates of major diseases limiting dairy production. In addition, the studies assessed the on-going disease control measures and identified appropriate alternative interventions to reduce disease risk and minimise production losses. Chapter One comprises a background introduction with general objectives of a multidisciplinary approach to research on identifying and resolving biological and socio-economic constraints affecting small-holder dairy development in coastal Kenya carried out by the KARI/ILCA project. The disciplines involved were animal health, animal breeding, animal nutrition, forage agronomy, socio-economics and milk marketing. Chapters Two and Three reviews the literature on the subject of epidemiology of tick-borne diseases and tsetse-transmitted trypanosomiasis, the major diseases encountered in coastal Kenya, and specify the objectives of studies reported in the thesis. Chapter Four gives a comprehensive description of the three study areas: Kaloleni, Kwale and Mtwapa, together with the farming systems, animal husbandry and health practices carried out in small-holder and research cattle herds. In addition, the general sampling and diagnostic methods are included. In Chapter Five, two epidemiological investigations are described using on-farm small-holder cattle herds in Kaloleni Division, Kilifi District. The first investigation a stratified cross-sectional study of disease prevalence (Section 5.1) was designed based on cattle census data from the area. The next stage in the investigation was a 19 month longitudinal study (Section 5.2) involving 195 cross-bred dairy cattle in 30 herds, half of them zero-grazing herds and the remaining free-grazing, all located in CL3 AEZ. The study aimed at estimating disease incidence and mortality rates. In Chapter Six, experimental studies were carried out to identify target population and age-window for immunisation against ECF. This was followed by a pilot immunisation trial of small-holder dairy herds. Chapter 7 describes two studies, the first involving on-farm small-holder cross-bred dairy cattle in Kwale District, and the second with an on-station dairy herd of Jersey cattle at Regional Research Centre, Mtwapa. In the first study which lasted 7 months (Section 7.1), the chemoprophylactic drug isometamidium chloride (Samorin ) given at 0.5 mg kg-1 every 6 weeks to 75 dairy cattle, failed to protect against trypanosomiasis in areas of known high tsetse challenge, An overall prevalence of 17.5% in chemoprophylactically-treated cattle indicated the likelihood of drug-resistant trypanosome strains. On the other hand, curative treatments with diminazene aceturate (Berenil) at 7.0 mg kg-1 successfully cured parasitaemic cattle. The second 18 month study (Section 7.2), two drug treatment groups, one receiving isometamidium chloride at 0.5 mg kg-1 every 3 months, and the other treated with diminazene aceturate at 7.0 mg kg-1 only when detected parasitaemic, were monitored for occurrence of trypanosome parasitaemias and their effect on liveweight changes and daily milk yield. No significant differences were observed between the isometamidium prophylactic group and the non-prophylactic group in the occurrence of trypanosome parasitaemias, liveweight changes and daily milk yields. However, parasitaemic cattle showed a significant drop in mean PCV and in daily milk yield for 2 weeks after curative treatment. Both studies showed that isometamidium chloride failed to afford adequate protection and at the same time highlighted the importance of regular blood-testing and early curative intervention for the control of trypanosomiasis in these areas of coastal Kenya. Finally, Chapter Eight presents an overview of the epidemiological investigations undertaken and consequently describes preventive medicine programmes for small-holder dairy farmers with the emphasis on the role of private sector in providing cost-effective and sustainable animal health services. The thesis ends by highlighting the significance of the blueprint of epidemiological methods developed with the view to them being used in various countries of sub-Saharan Africa. These methods will support the intensification of livestock production by small-holder farmers, reckoned to be the main producers of meat and milk in the future. (Abstract shortened by ProQuest.).

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: William Thorpe
• Keywords: Veterinary science, Animal diseases
• Date of Award: 1993
• Depositing User: Enlighten Team
• Unique ID: glathesis:1993-74773
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 27 Sep 2019 16:33
• Last Modified: 27 Sep 2019 16:33
• URI: https://theses.gla.ac.uk/id/eprint/74773