Inserting the gag
Draw the plastic hose of the Rumen-Fluid Collector all the way back through the gag, so that its steel tip lies against the free end of the gag. Ensure that the nose tong is open. Facing in the same direction as the cow, stand on the right-hand side of her head, holding the gag in the right hand. Pass the left hand over her nose and into her mouth through the left-hand corner, then press gently on the roof of the mouth with the fingers to make her open her mouth. Then insert the gag into the cow’s mouth, above and parallel to her tongue, as shown in Figure 1, until the nose tong reaches her nostrils.
Owing to the combined length of the gag and steel tip, the hose must be passed into the oesophagus before the nose tong can be closed on the nasal septum. Turn the cow’s head lightly to the right and push the plastic hose through the gag sufficiently gently to allow the cow to swallow the tip of the hose. When she has done so, close the nose tong on the nasal septum to secure the gag in the cow’s mouth. Pass the hose slowly through the gag into the rumen and through the mat of fibre which lies on the surface of the rumen contents. Do not use extra force if resistance is felt, since such resistance may indicate that the tip is not in the rumen.
Checking that the hose is in the rumen
At the open end of the plastic hose, smell the vapour inside it.
If the characteristic smell of the rumen contents is detected, it indicates that the tip of the plastic hose is indeed in the rumen, and it is safe to proceed to deliver fluid into it. If the characteristic smell of the rumen contents is not detected, draw the hose fully back through the gag and repeat the procedure from the point at which the cow’s head is turned gently to the right.
Fixing the hose and collecting rumen fluid
When it has been ascertained that the tip of the hose is in the rumen, fix the hose in position by turning the lever on the end of the gag until it tightens on the hose. Attach the open end of the hose to the tap at the bottom of the Selekt Cattle Pump. Collect fluid from the rumen, using steady, even, strokes of the Pump.
It is usually possible to collect up to 2 litres of fluid before the apertures on the steel tip become blocked by fibre.
Hygiene and biosecurity
The Selekt Rumen-Fluid Collector should be rinsed with warm water no hotter than 50oC and disinfected with a mild disinfectant after use.