Prevalence and seasonal patterns of coccidial infections in goats in two ecoclimatic areas in Morogoro, Tanzania

Abstract

A field study was conducted between November 1993 and December 1994 to determine monthly prevalences and oocyst outputs in tethered, stall-fed and herded goats in tropical highland (Mgeta) and semi-arid (Mlali) areas of Morogoro, Tanzania. The prevalences in the tropical highland area were 78.2 and 76.5% in tethered indigenous and stall-fed crossbred animals, respectively. In the semi-arid area, the prevalences were 76.5% in seasonally-tethered indigenous goats and 76.9% for herded indigenous animals. The prevalence (94.7%) in a herd of Toggenburg×Small East African crossbred animals in the semi-arid area was significantly higher than those of other herds ( P<0.05). Kids in the tropical highland area had a significantly higher prevalence of coccidiosis than adults ( P<0.001), whereas in the semi-arid zone there was no age-related differences in the prevalence of infection. There was no significant seasonal variation in the prevalence of infection in animals in all the management systems. Median oocyst counts were highest in crossbred goats in the semi-arid area, followed by stall-fed crossbred animals in the tropical highland area compared to indigenous ones in the two areas ( P<0.001). In all management systems, kids had significantly higher oocyst counts than adults ( P<0.05). Higher median oocyst counts were observed during the dry short rainy seasons compared to other seasons ( P<0.01). The predominant species of Eimeria were E. arloingi (91.7%), E. alijevi (80.3%), E. ninakohlyakimovae (71.4%), and E. christenseni (45.2%). Others were E. caprovina (27.6%), E. hirci (27.2%), E. pallida (8.8%), E. jolchijevi (6.9%) and E. aspheronica (5.2%).