EFFECT OF MOLASSES-UREA-BLOCK (MUB) ON DRY-MATTER INTAKE, GROWTH, REPRODUCTIVE-PERFORMANCE AND CONTROL OF GASTROINTESTINAL NEMATODE INFECTION OF GRAZING MENZ RAM LAMBS

The effect of urea-molasses feed-supplement blocks (MUB) on feed utili sation and the inclusion of anthelmintic medication into the blocks at strategic times to control nematode parasites was studied in lambs gr azed on low quality tropical pasture. 120 Menz ram lambs of 5-7 months of age were divided into six groups for methods of treatment against internal parasites and urea molasses supplementation. The benzimidazol e anthelmintic fenbendazole was administered at the rate of 10 mg kg(- 1) liveweight as a drench or via medicated MUB. Animals grazed in two lots during the day and had access to grass hay in night pens ad libit um. Groups 1-3 comprised a non-supplemented (NOSUP) lot that only graz ed while groups 4-6 consumed, in addition, an average of 80g per head per day of molasses-urea-block (SUPP) supplement. The MUB supplement w as provided daily for nine months but medicated MUB was used only for strategic prophylactic treatment against nematodes. SUPP animals had h igher daily DM intakes (568 +/- 11 versus 532 +/- 11g DM per head per day, P < 0.05), the advantage being greatest in the wet season when th ere was also a concomitant increase in herbage digestibility (P < 0.00 1). SUPP animals were 4kg heavier (25.7 +/- 0.5 versus 21.7 +/- 0.5 kg , P < 0.05) and had deposited more body reserves as judged by conditio n score (3.2 +/- 0.1 versus 2.4 +/- 0.1) after 6 months. The level of infection with endoparasites was lower in the dry than in the wet seas on. Medicated MUB was as efficient in treating against endoparasites a s drenching. Similarly, the MUB supplement mitigated the effect of end oparasitism. Anthelmintic treatment did not improve testicular size or semen quality (P > 0.05). Testicular growth increased faster during t he first 3 months to highest Values of 26.9 +/- 0.3 and 25.3 +/- 0.3 c m, respectively in SUPP and NOSUP animals (P < 0.001) at 6 months. Sem en quality improved with age and was better in SUPP than NOSUP males ( P < 0.05-P < 0.001). It is concluded that MUB supplementation is a sui table method for supplementing the nutrition of grazing sheep in Ethio pia, and that MUB feeding can help alleviate the effect of endoparasit ism. (C) 1998 Published by Elsevier Science Ltd.