BOLUS.

摘要

A bolus or pellet (10) for administration of trace elements and/or biologically active agents to ruminants is formed as compacted body (10) consisting of a particulate, non-uniform, weighting material held together by a binder, preferably wax, including a water soluble agent, such as a soap, and in which one or more biologically active agents are dispersed. Two such pellets are administered together so as to release the active agent by abrasion. A further embodiment encloses a compacted core (16) consisting of steel grit, wax, soaps and active agent in a plurality closely abutting P.V.C. rings (18) thus limiting erosion to the exposed ends only.