Manure holds key to herd health


SALEM, Ohio – Farmer Walter Burdette hasn’t paid much attention to cow manure. It’s simply cow excrement; it slops up the barn and smells bad.

But after attending a recent manure and nutrition workshop in Salem, Burdette will be taking a closer look at the manure at the Hiram dairy farm where he works.

To really investigate cow health, farmers need to look at the entire cow – including her manure – according to manure sleuth Mary Beth Hall of the University of Florida.

“You either make milk or you make manure, and the second isn’t probably high on your list,” Hall said at the workshop, which was also held in Wooster and Williamsfield.

It is no surprise that if digestion isn’t occurring, milk productivity suffers, Hall said. The nutrients aren’t entering the body and working to produce milk; instead, these nutrients are being excreted.

This means farmers should take a closer look at their cows’ manure to determine the health of their animals.

Tell-tale signs. Farmers may not realize that their feed is too coarsely ground, rations aren’t properly mixed or the cattle are sorting through their feed to eat only what they like best.

These situations may adversely affect cattle health and productivity and farmers need to know if these conditions exist.

The tell-tale signs are in the manure, said Hall, who is recognized for her work in fiber digestion and ruminant nutrition.

The manure will show what the cow ate and how well it was digested.

It will also show how the cow’s stomach is working and whether something in the feed needs to changed, Hall said. The clues from manure evaluation should be used with other observations to determine herd health.

A closer look. Hall told the approximately 15 producers at the workshop to go out in their pastures and get several manure samples. Then wash the manure through a strainer until the water runs clear, and see what’s left behind.

If there are coarse pieces of feed or whole kernels of corn, there’s a problem because it means the food isn’t being properly digested. This means the feed is not going toward making milk, it’s just making manure.

“Just because it’s eaten doesn’t mean it’s digested,” Hall said.

Generally, the smaller the particle size, the better chance of digestibility, Hall said.

Therefore, in the case of the kernels of corn, an option would be to steam flake the corn and roll it.

A kernel of corn has a smooth surface that makes it easier for it to slip through the digestive process of a cow and come out in manure. To counteract this smooth surface, the steam flake and rolling will break down the physical structure of the corn so it is more likely to stay in the rumen and be properly digested.

Hall said problems in the rumen part of the stomach can be traced to problems in feed management, misfeeding highly digestible carbohydrates, underfeeding effective fiber, or all the above.

Fermentation in the rumen reduces the size of the feed, so if the feed is excreted without being broken down, it shows that the rumen is not working as it should.

This is generally due to an inadequate intake of physically effective fiber, Hall said. This type of fiber enhances rumination.

In situations where larger particles of feed are in the manure, digestion isn’t occurring in the rumen. Instead it is happening in the hindgut. This results in bubbles in the manure.

It also signals a problem if the cow is excreting diarrhea. This means that the large intestine has been damaged due to digestion not occurring in the rumen, Hall said. Spoiled or moldy feed can also cause diarrhea.

Cow’s the boss. When the farmer rinses the various samples, it is not uncommon to find they are different. They may contain different feed and different size particles.

This should not be the case, Hall said. Ninety-five percent of the cows in the feeding group should have the same manure content, whether it is good or bad, she added. If this is not the case, it’s because the cows are sorting their food.

“[Cows] have few hobbies; they get really good at this one,” Hall said.

Cows pick through their feed, pushing away larger pieces of fiber and eating the grain or the other feed they prefer. If the feed is chopped and ground small enough, the cows can’t sort it.

“If you have cow sorting, they each become their own nutritionist, choosing what they want for their diet,” Hall said.

Watch for signs. These abnormalities in manure may signal ruminal acidosis, which is an upset in the digestive process.

Some signs of digestion problems are pieces of fiber longer than a half inch, whole cottonseed or hulls with lint still intact, sufficient amounts of ground grain and undigested citrus pulp.

Finding these types of feed in the manure means that it is not staying in the rumen long enough to be fermented and broken down into smaller particles.

When looking at manure, farmers also don’t want to find coarsely ground grain. This means the grain needs to be ground finer to ensure digestion or that the rumen isn’t working correctly, Hall said.

She points out that although finer grains may be better utilized, the amount fed, fiber feeding and feeding management must also be good so there are not other digestion problems.

Staying in check. In a workshop handout, Hall writes, “If everything else looks fine but the manure does not seem quite right, keep observing the cows to make certain that they continue to do well, and further question what you haven’t checked.”

For more information about manure evaluation, e-mail Hall at, or contact your local extension agent.

Related article:

Looking beyond manure…

By Kristy Hebert

SALEM, Ohio – Looking at manure is only part of evaluating dairy cows, according to ruminant nutritionist Mary Beth Hall. To properly evaluate herd health, farmers need to look at the entire package, starting with the cow itself.

In a cow’s ‘shoes.’ When a farmer starts to evaluate cattle, Hall said he or she should start by walking “the cow’s walk.” Go everywhere where the cow would go on a normal day: the barn, the stalls, the feed bunk, the pasture, the watering trough, the parlor.

* To begin with, farmers need to observe the cows, Hall said. Look at the body condition score, watch for lameness and judge the cow’s overall mood.

Check the cows to see if they are ruminating or chewing their cud. They should be doing this 40 percent of the time that they aren’t eating or sleeping.

* Next, look at the feed. First of all, make sure there is feed available for the cattle.

Is there mold or dust present, or is the feed spoiled? Make sure the food is mixed well and that it is consistent.

* Also, look in the bunk. Be sure there isn’t mold growing along the edges and that there isn’t old feed left over.

The bunk should be clean and there should be fresh feed that is mixed well.

Elbow room. Check, also, to make sure there is enough room for the entire feeding group to eat so none of them are pushed out of the way by more aggressive cows.

* After looking at the feed, examine the water. It should clean, fresh and readily available for the cows after milking.

Also look at the water availability in the pasture, making sure that the cows do not have to walk long distances to drink.

* Take a look at the facilities. They should be clean, ventilated and comfortable.

Listen to cows. “Watch your cows to see what they’re telling you,” said Maurice Eastridge, Ohio State dairy nutritionist. If they are not lying down, the stall may be uncomfortable, he said.

“You have got to let cows be lazy to produce milk,” Hall said. “Have a place for them to be comfortable.”

When looking at how comfortable the cows seem in the facility, check on them at different times during the day, Hall said. The sun may be shining in one end at some point during the day, which may make it hot and uncomfortable for animals lying on that side.

* Another important aspect of the operation is the employees. Make sure they are handling the animals well.

Walk into a pen of cattle and see if they run to the other end. If so, they may be worrying about what the employees are going to do next, and this is not good for the cattle.

Clearing the way. By moving those obstacles that make the cow uncomfortable or make the food unpalatable, she will be able to better produce, Hall said.

“You can’t push a cow to produce, but you can get the obstacles out of her way so she can,” Hall said.

(You can contact Kristy Hebert at 1-800-837-3419, ext. 23, or by e-mail at


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