On
The Edge of Common Sense
When The Rumen Goes Awry
© Baxter
Black, DVM
published in The Draft Horse Journal, Summer 2005 I
am a student of the cow. I have come to conclude that cows
lead a fairly boring life. When I am giving cows their sporadic
weekly check, I think it’s probably the high point
of their day.
They graze their life away and if they are not grazing they
are chewing their cud. This cud is part of a magnificent
ruminant digestive process that allows them to digest foodstuffs
that are virtually inedible to simple-stomached animals like
people.
For instance, cows derive nutritional benefit from lettuce!
Who’d’a thunk it? Now, I’ll grant you that
people eat lettuce but they eat lettuce because it is the
next best thing to eating nothing. If you’re on a diet,
we all know that the best way to lose weight is to eat _?_.
No, not lettuce. Nothing! But nobody wants to eat nothing,
so they eat the next best thing, which is lettuce.
The cud is chewed, then swallowed into a vast fermentation
vat called the rumen. It can hold 300-400 pounds of water
and feed. It is nasty, green, and when you get rumen contents
on your hand you have to sleep with your arm hanging off
the bed for at least a week. The cud takes a soak in the
vat and is regurgitated, swallowed, then regurgitated, and
remember, it’s not always the same cud!
One of the by-products of the digestive process is that
cows give off enormous quantities of carbon dioxide and methane.
Horse people are aware that the horse’s exhaust is
in the rear. But cattle don’t do that! They belch off
the gas. But on occasion a wrench is thrown into the works
that prevents the gas from escaping; i.e., an occlusion of
the esophagus or a diminution in rumen motility. This gas
then collects and distends the rumen, creating a condition
we call bloat.
You may be driving by a field of cows and notice one is
football shaped. On closer examination, her feet may actually
be levitating slightly above the ground. As confirmation
of this phenomenon, recall those times you’ve been
checking cows, following their tracks, then suddenly…the
tracks disappear.
Since bloat is a life-threatening condition, good cattlemen
and vets often carry a delicate veterinary instrument called
a ‘bloat hose’ (imagine the stack on a Kenworth),
which is passed down the throat to relieve pressure. Or,
if you’re on your way to church and don’t have
your bloat hose in your purse, you might whip out your trocar
(a sharpened screwdriver with a sleeve) and puncture the
rumen through the left flank.
Finally, when treating a cow for bloat, there are some precautions:
- Regarding the bloat hose…blow, don’t
suck.
- Don’t attempt to peer into the inserted sleeve
after removing the trocar.
- Wear a protective moustache
cover when smoking around bloats, as methane will burn.
- If
you are tracking a suspected bloat and suddenly the tracks
stop, don’t
forget to look up.
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