Strongyle infections of small ruminants in Nigeria

A survey of strongyle infections was conducted in sheep and goats reared in a traditional e extensive husbandry system in two ecological zones if Nigeria. One zone had a seasonal pattern of infection. The majority of animals had faecal worm parasite egg counts of below 500 eggs per gram. Kids, and lambs younger than 3 months did not carry strongyle worm burdens, and the highest infection rate was found in the 7–12 month age group. A high proportion of small ruminants shed strongyle eggs during the postparturient period.The helminth species found by the use of larval culture techniques on the faeces were: Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostonum columbianum. Adults of the same species were found in the few animals necropsied. The significance of the findings is discussed.     

Prevalence of Anaplasma marginale, Babesia bigemina and B. bovis in Nigerian cattle using serological methods

Serum samples collected randomly from 500 cattle from the 10 northern states of Nigeria were tested for antibodies against Anaplasma marginale by indirect fluorescent antibody (IFA), card agglutination (CT) and capillary tube-agglutination (CA) tests. The serum samples were also examined for antibodies to Babesia bigemina and B. bovis by the IFA test only. Of the serum samples tested, 79.4% had antibodies against A. marginale by the IFA test, 40 and 25% in the CT and CA tests, respectively. The IFA test results for B. bigemina and B. bovis were 29.4 and 14.1%, respectively.     

The presence of kinetes of a Babesia species in the haemolymph smears of engorged hyalomma ticks in Nigeria

Kinetes of a Babesia species were found in the haemolymph smears of 5 species of Hyalomma which were detached from trade cattle after engorgement. Hyalomma rufipes had the highest percentage of infection; while this infection rate was significantly higher than those of H. trupcatum and H. impressum, it was statistically similar to those of H. marginatum and H. impeltatum. Studies on the morphology and dimensions of the kinetes show that they are larger than those of B. bigemina, smaller than those of B. major and B. bovis, but similar to those of B. occultans.     

Bacterial isolation from and transmission by Boophilus decoloratus and Boophilus geigyi

Bacteria were isolated from the haemolymph of Boophilus decoloratus and Boophilus geigyi which had engorged on trade cattle in Nigeria. All the genera of the bacteria were also isolated from the eggs which they laid although some of them were missing from the larvae which eventually hatched. When clean rabbits were inoculated with some genera of bacteria and clean, laboratory bred larvae of B. decoloratus and B. geigyi fed on them, the same genera of bacteria were subsequently isolated from the haemolymph of the engorged adults, the eggs they produced and the larvae which hatched from them. Staphylococcus pyogenes and Pseudomonas aeruginosa were consistently encountered in the haemolymph, eggs and larvae of both Boophilus species while Proteus mirabilis was additionally consistent in B. geigyi.     

Studies on ticks of veterinary importance in Nigeria. VIII. Differences observed in the biology of ticks which fed on different domestic animal hosts

Ticks of the species Amblyomma variegatum (Fabr.), Boophilus decoloratus (Koch), Boophilus geigyi Aeschl. et Morel, and Hyalomma rufipes Koch were detached from cattle, sheep and horses and the influence of these various hosts on the biology of ticks was investigated. No A. variegatum was found in horses. The parameters studied were preoviposition and oviposition periods, ovipositional capacity, eclosion period, hatching patterns, egg sizes and temperature effect. Although the preoviposition and eclosion periods were similar in each tick species irrespective of the host from which the adults were detached, the oviposition period was longest among ticks detached from cattle and least among those detached from horses. The ticks engorged on cattle also laid the highest number of eggs and those which engorged on horses laid the least number. The hatching pattern of the eggs in any tick species was not influenced by the host from which the female was detached. The lengths of eggs of the ticks whose adults were detached from horses were generally smaller than those detached from cattle and sheep. Temperature affected the adult females detached from cattle, sheep and horses equally and this was also true of the larvae they produced. The practical field applications of these results are discussed.     

Seasonal prevalence of flies feeding on cattle in northern Nigeria

Summary A survey over a year of flies feeding on a tethered bull was carried out on a ranch in the north of Nigeria. Flies were netted on one day in each month for two hours in both morning and afternoon. Flies caught included surface feeders, blood suckers and those causing myiasis. The commonest genus caught wasMusca which was present in relatively large numbers throughout the year.Stomoxys calcitrans was by far the most abundant of the blood-sucking fly species caught.

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Résumé L'auteur a observé durant toute une année les mouches se nourrissant sur un taureau au piquet, dans un ranch de la Nigéria du Nord. Les captures au filet, ont eu lieu à raison d'un jour par mois et à raison de deux heures le matin, et le soir. Les mouches capturées comprenaient des mouches lécheuses, piqueuses et celles causant des myiases. Le genre le plus communément capturé a été le genreMusca, qui a été de loin le plus abondant parmi les espèces hématophages capturées.

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Sumario Se efectuó un reconocimiento de un a?o, sobre la prevalencia estacional de moscas, en un rancho localizado en el norte de Nigeria. Las moscas se alimentaron en un toro centinela. La recolección se hizo un día cada mes, dos horas en la ma?ana y dos en la tarde. Se colectaron moscas que sen alimentan en la superficie, moscas hematófogas y las que causan miasis. De todas las capturas, el géneromusca fue el más común y estuvo presente en abundancia todo el a?o. La especie hematófaga más abudante, de todas las atrapadas fue laStomoxys calcitrans.

     

Seasonal abundance of adult ixodid ticks infesting cattle belonging to resource-limited farmers in the north-eastern Free State Province of South Africa

A study was undertaken to determine the seasonal abundance of the ticks infesting cattle owned by resource-limited farmers in the north-eastern Free State Province of South Africa. Infestations of Boophilus decoloratus Koch, 1844, Rhipicephalus evertsi evertsi Neumann, 1897, Rhipicephalus follis Donitz, 1910, Rhipicephalus gertrudae Feldman-Muhsam, 1960 and Rhipicephalus warburtoni Walker & Horak, 2000, were monitored on cattle of mixed breeds at monthly intervals from May 1998 to April 1999. High tick intensity on the cattle was observed between March and June, with a peak in May to June 1998 for B. decoloratus and R. evertsi evertsi. Few ticks from the other three species were recovered from the cattle. Small peaks in November to December 1998 for R. warburtoni, and in December 1998 for R. follis and R. gertrudae were observed. Following the winter (June to August), numbers of B. decoloratus declined markedly, while those of R. evertsi evertsi and other rhipicephalids increased. These results represent the first published information on ticks of veterinary importance infesting cattle in the north-eastern part of the Free State Province.     

Studies on ticks of veterinary importance in Nigeria XVII. Resistance of rabbits to infestation with Amblyomma variegatum and Boophilus decoloratus (Acari: Ixodidae)

Rabbits exposed to larvae, nymphs and adults of Amblyomma variegatum acquired resistance to the infestation with adults of this tick. The degree of acquired resistance was lowest in the rabbits exposed once previously to larvae and highest in those exposed twice previously to adults. Rabbits also acquired resistance after primary infestation with Boophilus decoloratus; their resistance became very high during the thrice-repeated feeding. New terms are introduced for the quantification of the degree of resistance of animals to tick infestation. Rabbits were protected against infestation with B. decoloratus by intravenous injection of serum from the rabbits on which the ticks had fed three times. The relevance of the results to integrated tick control strategies is discussed.