Low-Quality Forages Can Lead to Abomasal Impaction and Death of Ruminant

As winter approaches, many cattle producers are planning their winter feeding programs. The goal should be keeping our livestock grazing on pasture as long as possible according to Randy Wiedmeier, livestock specialist, University of Missouri Extension.

“This past couple of months have been very dry, so fall and winter grazing may be curtailed somewhat,” said Wiedmeier. “Consequently hay feeding may be of more importance this year.”

Some producers have an ample supply of good quality hay stored. Unfortunately, many have an abundant supply of lower quality forage according to Wiedmeier.

Low-quality hay or forage contains less than seven percent crude protein and less than 45 percent TDN (.36 mcal NEm/lb.).

Low-quality forages are high in fiber (> 70 percent). But the fiber of low-quality forages is digested/fermented relatively slowly, and only 40 to 50 percent of this fiber can be digested. That is why the intake and energy content of these forages is so low.

The anatomy of the rumen of ruminant livestock such as cattle, sheep, and goats is such that feed particle size must be reduced before passing to the remainder of the gastro-intestinal tract.

Usually, this is not a problem due to rumination (cud chewing) and the action of the microorganisms. However, if a supplement (protein source) is not fed with low-quality forages the activity of the ruminal microorganism is impeded, and the rate of feed particle size reduction is extremely slow.

This will result in larger than normal feed particles reaching the pyloric valve at the end of the abomasum (true stomach). Since many of these larger particles cannot pass through this value, feed particles will then accumulate in the abomasum, Abomasal Impaction. Once the abomasum is impacted, digesta flow ceases, and the situation is usually terminal for the animal.

Supplemental protein stimulates the activity of the “fibrolytic” microorganisms in the rumen, which in turn increases the rate and extent of hay utilization.

The available energy content of the hay can be increased by 10 to 20 percent, and hay intake can be increased by 20 to 30 percent. Energy intake can thus be increased by 40 to 60 percent.

“The amount of supplementation required depends on the quality of the hay. The lower the quality of the hay, the greater the amount of protein supplementation needed,” said Wiedmeier.

Consult your extension livestock specialist, feed company representative or veterinarian to custom balance supplementation programs for livestock consuming low-quality forages.