Carry-over of some Fusarium mycotoxins in tissues and eggs of chickens fed experimentally mycotoxin-contaminated diets.

Fusarium mycotoxins are fungal contaminants found in different crops intended for human and animal consumption. Due to the co-occurrence of several of mycotoxins, the present study aimed at examining the transfer of these toxins into tissues of broiler chickens and eggs of laying hens fed contaminated diets. After an adaptation period, the chickens were fed contaminated diets containing mg/kg levels of deoxynivalenol (DON), enniatins (ENN A, A, B, B) and beauvericin (BEA) and high μg/kg levels of HT-2 toxin (HT-2), T-2 toxin (T-2) and zearalenone (ZEN) during a repletion period of two weeks, followed by a depletion period of two weeks.

Feeding patterns of immature stages of Hyalomma truncatum and Hyalomma marginatum rufipes on different hosts.

In this study we examine the feeding patterns of immature stages of Hyalomma truncatum and Hyalomma marginatum rufipes ticks on different hosts. Larvae of H. truncatum developed through a three-host pattern on two species of field mice, Rhabdomys pumilio and Lemniscomys rosalia.

Resistance of indigenous African cattle to the tick Amblyomma hebraeum.

Field collections of Amblyomma hebraeum Koch adults from six breeds of cattle were conducted on two farms in the Northern Transvaal. The density of A. hebraeum adults was highest on Simmentaler cows, followed by Santa gertrudis, Africaner, Bonsmara, Brahman and Nguni.

Development of resistance in laboratory animals to adults of the tick Rhipicephalus evertsi evertsi.

Acquired resistance to adults of the two-host tick Rhipicephalus evertsi evertsi Neumann has been demonstrated in guinea-pigs and rabbits. Four infestations of both hosts with R.e.

Resistance of Brahman and Simmentaler cattle to southern African ticks.

Field collections of ticks from two breeds of cattle in the North Western Transvaal showed the common tick species to be Rhipicephalus appendiculatus, Amblyomma hebraeum, Rhipicephalus evertsi evertsi and Hyalomma marginatum rufipes. The number of these ticks was higher on Simmentaler than on Brahman cattle. Correlation was found between the number of ticks on the cattle and their serum gamma globulin levels indicating an increase in the production of antibodies.