Silicone rumen cannula with a soft cylindrical part and a hard flange

A soft rumen cannula for sheep was made with two kinds of silicone rubber and a polyethylene plug. The design of molds is simple and the materials can easily be obtained. The elasticity of the cylindrical part of the cannula controlled leakage of rumen contents to a minimum, and the moderate hardness of the flange prevented loss of contents from the rumen. The cannula could be used repeatedly and functioned well for over 4 yr. The cannula was easily pushed into the rumen, and the collection of whole digesta was accomplished easily by hand. A small amount of sampling with pipette could be achieved through the punched opening without removing the inner polyethylene plug.