Abstract: A device for the sustained release of into the rumen of a ruminant animal has an elongate, tubular body for housing a therapeutic or nutrient composition. Wings are pivotably attached to one end of the body member and are resumably biased away from a storage position, in which they extend along body member, an operative position. In the operative position, the wings are at a pre-determined angle to the longitudinal extent of the body member and are constrained from pivoting beyond this angle.

Abstract: A controlled release composition for administering a therapeutic agent to a ruminant, using an intraruminal device, consists of a compressed tablet or bolus which comprises the therapeutic and a carrier material is formed from a non-tacky free flowing powder in which 90% of the particles are less than 100 .mu.

Abstract: A device for controllably delivering a solid, paste or liquid material in biological, environmental or industrial systems. The device is in the form of a tubular body, one end of which is open to allow egress of the material, and the other is closed. A gas-tight plunger slides within the body by virtue of spring driving means and gas from the external environment which enters the closed end of the tubular body by way of a gas permeable membrane and acts, together with the spring on the rear face of the plunger. The plunger controllably ejects the material from the open end of the device. The device has particular use in the delivery of therapeutic and/or prophylatic materials to animals.

Abstract: A capsule for administration to a ruminant, comprises two body portions of magnesium or an alloy thereof, pivotally connected for movement between a relatively small cross-sectional configuration in which the capsule can be administered per os into the rumen, and a relatively larger cross-sectional configuration adopted within the rumen to resist regurgitation. The pivotal connection between the body portions is provided by a resiliently flexible material such as rubber or silicone made electrically conductive by means of a matrix of conductive particles, for example carbon particles. The flexible material at least partially covers a surface of each body portion. When the capsule is in the rumen the conductive particles act as a cathode and the body portions as anodes.

Abstract: A controlled release composition for administering active agents to ruminants, which when mixed with said active agent has a melting point in excess of 39.degree. C. and when inserted as a solid into the rumen of a ruminent, is capable of slowly disintegrating at the interface between said composition and ruminal fluid present in the rumen of said ruminant.The composition may be administered by means of a variable geometry capsule.