摘要 |
An intraruminal device for administering an active agent in the rumen of an animal, comprises a metal weight (8) which gives the device sufficient density to be retained in the rumen which is made from compacted unsintered metal. The metal weight may be cylindrical and constructed of one (8, 20, 37 or 44) or several (31,32) pieces of compacted unsintered metal, of a tubular or annular (21,69) nature or incorporated as a discrete mass (66) within a drug matrix (67). When the weight is in an exposed position of the device (e.g. Fig.4), it is preferably enclosed with a material (38) that prevents damage to the weight from rough handling. |