Yeah .. I remember the tool .. ours was about a 1" dia SS tube .. about 4 or 5" long .. had a tight fitting spike inserted through it .. the sharpened end of the "spike" barely protruded to form the tip of the tool .. after the tool was inserted .. this cntr spike was withdrawn .. the air/gas escaped ..
Admittedly .. it's been 30 yrs since I've lived on a farm .. what a wonderful childhood environment (age 6~18) ..
I remember having to let the cows out easy on their first time off dry hay & on green grass .. if memory serves .. they'd bloat ..
Same if they got through a fence into an alfafa field .. they'd gorge on it & bloat .. again, if memory serves ..
Funny aside .. fall of the yr .. nasty windy rain storm .. apples all over the gnd under some apple trees on the ridge pasture land .. some days later .. apples soured .. cows found em .. one so drunk couldn't get up .. another, could not walk straight .. funny as all s#! !!