|Integrated Helminth Control - KARI technical note no. 2 (DFID - KARI, 1999, 54 p.)|
|PART FOUR - The Strategies|
Medicated feed blocks are high energy feed and mineral supplement blocks incorporating an anthelmintic. Animals can have access to these blocks at night in the boma and effectively worm themselves. The continued ingestion of low levels of anthelmintic can help to overcome anthelmintic resistance and the additional mineral, protein and energy supplement can be very beneficial to animals during times of nutritional stress. Problems may be encountered with particular animals that do not take to the blocks, but in most cases animals will learn very quickly by watching others. Blocks are not currently commercially available in Kenya, however the technology required to make them and the ingredients are all readily available:
2 volumes molasses
1 volume urea (fertiliser grade)
1 volume cement
½ volume common salt
½ volume mineral premix
2 volumes maize germ (or other suitable bulking product)
1 × 100 kg cow dose of a benzimidazole anthelmintic per kg of ingredients
1 volume water
The technique is essentially that of making concrete blocks. Thoroughly mix half the water with the urea until the urea granules dissolve. Mix in the anthelmintic then the cement and most of the remaining water. Add the molasses, the salt and mineral premix and the remaining water. Finally add the maize germ or other bulking agent. It is important that the ingredients are mixed well before the addition of each additional ingredient. After all the ingredients are well mixed, pour the mix into moulds (buckets, basins, pots or wooden frames). Stand the moulds in the sun for 3-4 hours then turn the blocks out of the moulds and allow them to dry for a further week before use.
Blocks should be placed in the boma protected from rainfall.
Caution: If animals (especially sheep) consume too much of the block at once they can suffer from urea poisoning. It is important that blocks are introduced gradually and that the consistency is not too soft otherwise an animal may eat too much. Since ingredient quality can vary greatly the above recipe can only act as a rough guideline.