Abstract: A dilution valve dilutes a liquid feed concentrate with water, to give a dilute feed for feeding to piglets. The valve has a plunger (20) which reciprocates within a mixing chamber (66), to which the water and liquid feed concentrate are admitted through separate valves (48,70). Water pressure drives the plunger (20) in a charging stroke, during which water and liquid feed concentrate are admitted to the mixing chamber (66). A change-over spring (60) causes the plunger (20) to change from a charging stroke to a delivery stroke, during which dilute feed is delivered, the plunger (20) undergoing alternate charging and delivery strokes driven by the pressure of the incoming water.

Abstract: Substances having biological activity in ruminants, e.g. nutrients, medicaments and diagnostics, are protected during passage through the rumen with a fatty acid having at least 14 carbon atoms. These acids, which preferably form a continuous outer coating around the biologically active substance, are resistant to rumen conditions but release the active substance lower down the digestive tract where the fatty acids can also be utilised nutritionally.