Agriculture Reference
In-Depth Information
THE DANGERS OF BLOAT
Bloat is very serious in ruminants — it can be fatal in only a few
hours. Too much of almost any feed can cause bloat, but it most
commonly results from lush pasture. Legume pastures, such as
very leafy alfalfa and clover, are far more dangerous than grass
pastures, which is another good reason to develop mixed pastures
of grasses and legumes.
When changed from sparse to lush pasture, sheep may gorge
themselves unless they have been given a feeding of dry hay
prior to being turned out on the new pasture. Sheep seldom bloat
when they are getting dry hay with their pasture; the coarse feed
is thought to stimulate the belching mechanism while keeping
the green feed from forming a compact mass. Some sheep seem
more prone to bloat than others, possibly due to a faulty belching
mechanism. (See chapter 7 for more information on bloat and how
to treat it.)
The rumen of a mature sheep has a capacity of between 5 and 10 gallons
(18.9 and 37.8 L), and each gallon (3.8 L) has about 200 trillion bacteria,
4 billion protozoa, and millions of yeasts and fungi. Keeping this work crew
active and healthy so they can do their jobs well is an important function of
shepherds, even if they don't usually think in these terms. A key to rumen
health is making dietary changes slowly, so that the fl ora have a chance to
acclimatize to new feed regimens.
Some heavy items, like whole grain and stones, may bypass the rumen and
go directly into the second stomach, or reticulum. Grain that bypasses the
rumen won't be as thoroughly digested, which is why it's a good idea to feed
cracked grain or whole grains mixed with hay. That way, most of the feed will
get some time in the rumen.
The fermentation that occurs in the rumen produces a signifi cant amount
of gas, which an animal must pass by belching. Occasionally, an excessive
accumulation of gas or foamy material builds up in the rumen, causing bloat.
The Other Parts of the Stomach
From the rumen, a slurry of well-fermented feed passes on to the reticulum,
then to the third and fourth parts, or the omasum and the abomasum. The
