Impact of gastrointestinal helminths on production in goats in Kenya

The impact of gastrointestinal nematodes on health and production of goat w as investigated in a low potential area (Ecozone 3) of Kenya. The study inv olved 44 Small East African goat kids aged 4-5 months divided into two repl icate groups (treated and control) and set stocked on pasture for 7 months through a dry season and a short rainy season from May to December 1998. The treated group received fortnightly albendazole treatment while the cont rol group were untreated. Live weight, packed cell volume (PCV), faecal egg counts and pasture larval counts were measured every 2 weeks. Half of the animals from each group were randomly selected for slaughter, total worm co unts and identification at the end of December. The faecal egg counts, for the treated group remained low while those of th e control group rose gradually through the study period. The counts were hi gher during the short rainy season. The control group lost weight during th e dry season and underwent compensatory growth during the short rainy seaso n. The treated group maintained their weight during the dry season and also showed compensatory growth during the short rainy season. Comparing the we ight at the start and end of the study, the treated group gained an average of 3.1 +/- 0.3 kg while the control group gained 1.1 +/- 0.2 kg. Two goats in the control group died at the end of the dry season after showing clini cal signs of parasitic gastroenteritis. Two others in the same group were g iven salvage treatments during the same period. The PCV (%) values were red uced during the dry season in both groups. The values were higher in the tr eated group. At slaughter the mean group worm counts for the control group was 1133 +/- 387 while that for the treated group was 123 +/- 56. In all th e animals Haemonchus contortus was the main nematode recovered. Hypobiotic larvae were recovered in the abomasum. The pasture larval counts were significantly lower in the paddocks grazed b y the treated group in both the dry and short rainy season compared to that grazed by the control group. It was concluded that gastrointestinal helmin ths cause production losses, weight loss and mortalities in goats. H. conto rtus was the main nematode infecting the goats in this area. The albendazol e treatment prevented parasitic gastroenteritis, weight loss and mortalitie s. (C) 2001 Elsevier Science B.V. All rights reserved.