EFFECT OF A SINGLE DRY SEASON ANTHELMINTIC TREATMENT OF NDAMA CATTLE ON COMMUNAL PASTURES IN THE GAMBIA

The effect of a single anthelmintic treatment of cattle during the ear ly dry season was studied. One hundred and sixty-six N'Dama cattle, 1- 3 years old, were selected from five herds. There were 65 males and 10 1 females divided into two groups of 83 animals each. One group was tr eated with fenbendazole at 7.5 mg/kg body weight by mouth in November 1992; the other group remained as the untreated control. At monthly in tervals from November 1992 to April 1993, each animal was weighed and the number of eggs/g of faeces (epg) was determined. The infective lar vae (L3) were examined following culture of pooled samples from each g roup of animals. In April 1993, 6 animals (3 treated and 3 controls) f rom the herds under study were necropsied. The difference in the weigh t gains (4.6 kg) of the two groups was highly significant (p<0.0001). The difference in the weight gains and the epg between the treated and control groups was influenced by the age of the animals. Of the treat ed animals, one contained no nematodes, one contained only 25 Oesophag ostomum radiatum: and the third contained 25 Cooperia LA. The three un treated animals were all infected. It was concluded that the treatment in early dry season, with an anthelmintic effective against both adul ts and larvae, led to a significant reduction in egg counts, to elimin ation of adults and hypobiotic larvae and, consequently, to an increas e in the body weight gain by the treated animals.