Antigenic components of taenia saginata oncospheres and their use in immuno- diagnosis of bovine cysticercosis
This thesis describes a study on the major factors associated with morbidity, mortality and performance of camel calves, kids and lambs in Rendille and Samburu pastoral herds in Marsabit district, Kenya. The main objective of the study was to identify and assess the major factors in order to formulate guidelines for appropriate disease control strategies for improved performance. The study was conducted in three phases for a period of 27 months from March 2000 to May 2002. The first phase was to assess pastoral perceptions on the livestock production systems in the study area. A pastoralists’ appraisal was conducted through rapid rural appraisal (RRA) by community meetings in six sublocations namely Olturot, Ilaut, and Ngurunit in the arid agroecological zone (AEZ) V and in Kargi, Korr and Loglogo in the very arid AEZ VI from 20th March to May 2000. The meetings were held in six settlements know by the same names. These were purposively selected, as they were the only physical foci easily accessible and representing the six administrative sublocations. In all the sublocations, the major livestock reared were indigenous camels, cattle, sheep and goats. The camels reared were described as Rendille/Gabra; cattle as the Zebus; goats as the East African breed and sheep as Blackhead. The pastoralists reported that some exotic breeds of camels, cattle and goats had been introduced in the area and that a few households had also accepted chicken and bees. Donkeys and dogs were also important domestic animals among the pastoralists. Twenty-six household and six commercial needs were listed as fulfilled by the animals kept. Milk for household use from camels, cattle, goats and sheep was ranked as the most important utilization of livestock. The participants listed 15, 13, and 10 diseases and casual organisms affecting camel calves, kids and lambs respectively. In camel calves, ticks were ranked first followed by, diarrhoea, gulor (navel ill) and wounds in all areas. Lice and fleas followed by diarrhoea, worms, foot rot and ndis (yellow liver) were listed in kids and lambs in all areas while Contagious caprine pleuropneumonia (CCPP), orf, konkoro (central nervous disorder), Ikang (rabies like disease) were listed as common in kids. In all locations the pastoralists indicated that they would improve livestock by increased traditional mobility and quarantines, cleaning of bomas and wells, avoiding known poisonous plants and parasite-infested areas and also by use of veterinary medicine and disease control regimes. The second phase was a cross-sectional study to estimate the prevalence of morbidity and mortality in camel calves, kids and lambs. It was conducted between November 2000 and January 2001 among 60 households, 10 from each of the six sublocations randomly selected from a list frame. A descriptive analysis on disease epidemiology was carried out and prevalence of morbidity and mortality rates estimated. Significant similarities and differences in the prevalence were generated and association between them and AEZs, previous treatments, sex and sublocations determined using the generalized linear models (GLM). The results showed that mean morbidity prevalences were 36.8%, 33.0% and 39.9 % in camel calves, kids and lambs, respectively. Sublocations were associated with mean morbidity prevalence in the three species of livestock (p<0.05). There was an interaction of sex and sublocations in Ngurunit where mean morbidity prevalence in female camel calves was higher than in males (p<0.05). Also, there was an interaction of sex and sublocations in lambs in Ngurunit and Olturot where the mean morbidity prevalence in female lambs was higher than that in males (p<0.05). The highest infection prevalences were; mange (10.2%) in camel calves; worms in kids (2.3%) and lambs (4.5%). The prevalences of coccidiosis based on laboratory diagnosis were; 2.2%, 23.2% and 28.9% in camel calves, kids and lambs, respectively. Infection prevalence of T. evansi based on CATT/T. evansi test was 14.3 %. The mean mortality prevalences were; 22.9%, 50.3 % and 51.3 % in camel calves, kids and lambs, respectively. Sublocations and AEZ were associated with mean mortality prevalence in kids and lambs (p<0.05) but only the AEZs were associated with mortality prevalence in camel calves. In Ngurunit there was interaction of sex and sublocation in camel calves where more females than males died. The third phase of this study was a longitudinal observational study to estimate the incidence of morbidity and mortality as well as growth rates in camel calves, kids and lambs. It was carried out in 11 and 15 households in Olturot and Korr sublocations respectively. The households were randomly selected from a list frame in each sublocation. The results confirmed that grazing was communal and that most households kept home and fora herds. A descriptive analysis on disease epidemiology was carried out and incidences of morbidity and mortality rates estimated. Attack rates within age sets were also determined. Mean daily weight gains (MDWG) up to weaning age were calculated and variations determined. Significant similarities and differences in the incidences and MDGW were generated and associations between each one of them and AEZs, sublocations, seasons, breeds, birth order, sex and health status determined using the generalised linear models (GLM) and generalised estimating equations (GEE) procedures. Mean morbidity incidences were; 79.7%, 19.7% and 6.4% in camel calves, kids and lambs respectively. Morbidity was higher during the wet than the dry seasons. Sublocations were associated with mean morbidity incidence in kids and lambs (p<0.05). The highest infection incidences were; mange (16.5%) in camel calves and pneumonia in kids (6.1) and lambs (2.5%). The incidences of nematodosis based on laboratory diagnosis were; 38.3%, 15.8% and 33.0% in camel calves, kids and lambs, respectively. The incidences of coccidiosis based on laboratory diagnosis were; 12.5%, 56.8% and 45.4% in camel calves, kids and lambs, respectively. Incidence of T. evansi based on CATT/T. evansi test was 5.9%. Mean PCV of healthy camel calves (22.2%) was not significantly different from that of unhealthy ones (19. %) (p<0.05). The mean mortality incidences were; 12.1%, 10.5% and 3.8% in camel calves, kids and lambs, respectively. Sublocations were associated with mean mortality incidence in kids only (p<0.05). The most important cause of mortality in the three species of livestock was predation, followed by ticks in camel calves and abomasal obstructions (Lkang) in kids. The mean birthweights of Rendille and Rendille*Somali camel calves were 32.0kg and 28.8kg, respectively. The mean birthweight of East African Goat kids was 2.2kg and that of Blackhead Sheep lambs was 2.5kg. Overall MDWG at 540 days of age were 0.28kgd'* and 0.39kgd"' for Rendille and Rendille*Somali camel calves, respectively, while that of kids and lambs at 240 days of age were 52.9gd_1 and 66.7gd \ respectively. Sublocations were associated with mean growth rates of camel calves where those in Olturot were higher than in Korr herds (p<0.05). There was a significant interaction in sublocation and the first dry season (DSi) on growth rate of camel calves. Health status was not associated with growth of camel calves. The growth rate of healthy kids in Olturot was higher than that in Korr. Also, the growth rate of the unhealthy kids in Olturot was higher than that in Korr (p<0.05). There was an interaction in sublocation, and first dry season (DSi) in influencing the growth rate of kids. Also, there was an interaction in health status and WSi in the growth rate of kids. In lambs there was no association between growth rates with sublocation, health status or seasons. Olturot and Korr were in AEZ V and VI, respectively where there was more forage in former than in the latter sublocation. In both sublocations and AEZs the quantity and quality of available forage fluctuated with seasons. These natural phenomena influenced the animal husbandry practices described in the two sublocations. On the basis of these findings, recommendations for appropriate disease control strategies to reduce morbidity, mortality and improve performance were formulated under the following guidelines, that: 1) Introduction of veterinary interventions alone is recommended to directly improve performance of preweaned kids in Rendille and Samburu semi-nomadic pastoral livestock production systems. 2) Introduction of veterinary intervention integrated with nutritional and animal husbandry strategies are recommended to improved performance of preweaned camel calves and lambs in Rendille and Samburu semi-nomadic pastoral livestock production systems. 3) An integrated veterinary, nutritional and animal husbandry intervention is recommended for improved performance of preweaned camel calves, kids and lambs in Rendille and Samburu semi-nomadic pastoral livestock production systems. 4) Integration of control of predators in livestock improvement interventions is recommended to reduce mortality of preweaned camel calves, kids and lambs in Rendille and Samburu semi-nomadic pastoral livestock production systems.