The Stockman Grass Farmer


October 27, 2011

Staff report

DENVER: Green pasture growing in mineral-balanced soils is the key to “organic” animal health, Arkansas-based consulting veterinarian, Dr. Ann Wells told attendees of SGF’s Organic Pasture School.

Wells, now in private practice, was previously with ATTRA, the USDA’s extension service for sustainable and organic agriculture.

Her definition of health is “Mind and body together in harmony with the environment.”

The role of the grazier, she said, was to manage both the animal and the environment so as to keep everything in harmony.

“A healthy pasture that produces healthy animals is one that is made up of grasses, legumes and forbs,” she said.

“Forbs are frequently called weeds but have unique medicinal properties that can greatly benefit grazing animals.”

Some of these naturally occurring compounds help prevent legume bloat and others help control internal parasites.

Others contain by-pass proteins that enhance animal performance.

She said some organic graziers were now planting hedgerows of herbs in their pastures.

“In most cases, grazing animals actually prefer immature weeds to grasses. However, the beneficial weeds all require long rest periods and so are seldom found in continuously grazed pastures.”

Birdsfoot trefoil, Chicory, Sericea lespedeza, dock and sanfroin have all been found to have both nutritional and medicinal benefits.



She said most graziers considering going to Certified Organic production first seek out organic alternative products rather than learning preventative medicine.

“Keep in mind all wormers, drugs and chemical fly control are just band-aids as are all their organic replacements.

“None of them work if you don’t treat the whole system.

“We’ve been taught how to treat diseases. Now, we have to learn how to manage the whole system so as to keep animals healthy.”

She said preventative animal health practices include such things as:

Good animal husbandry practices such as calving during surplus grass periods; culling rather than treating sick animals; using mixed species grazing; and always providing good nutrition and plentiful clean water.

Good sanitation practices such as avoiding confinement, mud, and keeping pastures earthworm and dung beetle friendly so as to rapidly recycle manure.

Learning to observe your animals’ physical manifestations of health such as bright eyes and a shiny hair coat.

Using vaccinations. These are allowed under Certified Organic protocols.

And the quarantining of all new arrivals until you are sure they are not carrying foot-rot or other infectious diseases onto your pastures.

“A closed herd is a huge benefit in organic production. Most of your problems come from buying other people’s animals.”

She said culling was a major tool that most Certified Organic producers were slow to use due to the high prices they pay for their animals but was absolutely essential in creating a low labor and input herd.



“Eighty percent of your problems will come from 20% of your animals. The long-lasting solution is to get rid of that 20%.”

She said that within your herd there were a few carriers of internal parasites and lice. Eliminate this handful of animals and you eliminate most of your problems.

“Learning how to body condition score your animals will help you identify those poor-doers that should be eliminated from your herd or flock.”

She said most health problems come from poor nutrition.

She said graziers often unintentionally nutritionally stress their animals by not understanding their forage preferences.

“You can easily starve a goat to death in a lush, green bermudagrass pasture.

“Similarly, Eastern gammagrass is ice cream to cattle but sheep refuse to eat it.”

After lack of nutrition, she said stress was the top cause of disease in animals.

She defined stress as any situation over which the animal has no control.

She said a wet, cold wind situation is high stress.

Similarly a hot, humid environment is also high stress.

She said that all cattle need shade above 90 degrees F but black cattle stress the worst in hot weather.

“Black colored cattle have a very difficult time dealing with hot, humid weather.”

However, cattle of any color that go to shade at 80 degrees F should be culled.

“Apparently, some cattle go to shade whether it is hot or not. If they aren’t grazing they aren’t making you any money.

“In hot weather if you have paddocks with no shade, shift them to a shady paddock for the hottest part of the day and then back to the shadeless ones after four in the afternoon.”

She said that cattle would graze at night when it was hot but wouldn’t when the temperatures were below 50 degrees F.

Fenceline weaning whereby the dam and her calf can see each other prevents stress, weight loss and sickness in the calf.

“The cow has largely weaned the calf by eight months of age. They just like each other’s company.”

She said the best nutrition for a weaned calf was green grass.

She said occasionally putting animals through the chute and releasing them without doing anything would make roundup times much less stressful on the animals and you.

Transport stress can be eliminated by loading cattle in a trailer or truck and taking them to fresh pasture.

She said after doing this a few times, the cattle will readily load themselves.

“The best reward for any animal that does something slightly stressful for you is to get to go to a fresh paddock of grass.”



She said internal parasite problems are a sign that something has gone wrong with your farm system.

“Remember, the major part of the internal parasite’s lifecycle is outside the animal.

“This means you actually have much more control over internal parasites by what you do to the pasture than what you do to the animal.”

She said that cattle older than a year of age become naturally resistant to the internal parasites they grow up with.

However, this natural resistance is only present if the cattle are allowed to maintain a low level of parasitism.

In other words, worming cattle can actually make internal parasitism worse.

“You should never worm mature cattle and calves normally don’t need to be wormed either.”

She said diatomaceous earth is totally ineffective against internal parasites but is somewhat effective against external parasites and flies.

Garlic, epazote, African basil, Holy basil and Gentian herbs have proven to be effective against internal parasites.

Some graziers have found a water diluted organic herbicide called Garlic Barrier used as a drench is effective.

Wormwood is also effective but should never be used with pregnant animals.

A good source for herbal dewormers is Molly’s Herbals at

The primary pasture cleanser of internal parasites is hot dry weather.

She said internal parasites are never a problem in arid climates, only in humid ones or under irrigation.

In the humid Deep South, pastures can be effectively cleansed of parasites by taking the pastures short enough that hot summer sunlight can reach the ground.

She said to remember that the infective larvae of the parasites seldom are found more than two inches from the ground on the grass or more than 10 inches from the manure.

Young susceptible animals such as weaned calves and lambs can avoid parasitism by shifting them from the paddock before they graze the grass to the infective level.

Low stock densities of any one species is also an effective tool.

Cattle and sheep are dead end hosts for each other’s internal parasites as are cattle and goats. Therefore, mixed species grazing help’s reduce internal parasites except for goats and sheep, which share the same internal parasites.

She said at low stock densities, co-grazing was as effective as a leader-follower sequence whereby cattle lead sheep.

Goats are the most susceptible species to internal parasites.

They naturally prevent parasitism by grazing only tall forages with their heads up.

“A goat is primarily a browser and not a grazer. They don’t want to eat with their heads down.”

She said that rotational grazing naturally dilutes parasite intake as not all larvae mature at the same time.

As a result, the animals will only consume the infective larvae that happen to be mature the day they are in the paddock.

“Continuous grazing results in continuous re-infestation.”


Wells said manure that is broken down and recycled fast helps eliminate both internal parasites and flies.

The three best tools for this were dung beetles, earthworms, soil fungi and free-ranging poultry.

Earthworms cannot live in highly acid soil so liming acid soil pastures helps prevent flies and parasites.

While Ivermectin is cleared for emergency use on Certified Organic brood stock, it should never be used as it will have a detrimental effect in the larvae of the dung beetles.

Non-organic graziers should use Cydectin as it as effective as Ivermectin but does not have this negative effect.

“For fly control, free-ranging poultry is actually your best tool.”

She said that animals with short hair and greasy hides were naturally resistant to flies.

For some reason, flies naturally gravitate to poor-doing animals and this can be a good warning of an animal that needs culling.

She said walk-through fly traps are very effective. However, with Brahman cattle you have to build them a piece at a time over several days and let them get used to it gradually.

Organic graziers have learned that attaching stiff brushes to poles and thereby encouraging cattle to scratch have totally eliminated lice.

“There is now some research that indicates that lice by initiating this skin stimulation may actually benefit the cattle.

“Anyway lice are just a seasonal problem. Usually, once you see them they are nearing the end of their annual lifecycle.”

Coccidia are completely a management problem and are seldom a problem in pastured operations as they live in wet mud and manure such as normally found in confinement operations.

She said cattle gain immunity to coccidia really fast.



She said soils that were high in molybdenum and iron tend to be very low in copper.

Copper is effective against internal parasites but wooled sheep are susceptible to copper poisoning and should never be allowed to eat a high copper, cattle mineral.

In contrast, goats need a lot of copper and can eat cattle mineral. In research trials, feeding goats tiny pieces of copper wire appeared to be an effective dewormer.


Hair sheep are much more tolerant of copper than wooled sheep. Wells said “natural” worm preventatives are now in vogue even in Land Grant research as internal parasites have largely become resistant to all FDA cleared sheep and goat chemical wormers.

The cost of getting a new wormer cleared through the FDA is more than the small market for a sheep and goat wormer can justify so sheep and goat producers will be forced to learn “organic” methods in the future.

A good web site to keep up on USDA sponsored research on natural dewormers is

Wells said to keep in mind that the OMRI logo on a product means that it meets the organic standards, not that it is actually does what its ads say it does.

There is a lot of “buyer beware” when it comes to organic animal health products and a good preventative health program is always best.

She said the best test of soil mineral balance was to do a liver analysis of harvested animals.

Second would be a forage leaf analysis and last a soil analysis.

“There are no cookbook formulas. You must be willing to accept that any sick animal is your fault.

“Going Certified Organic is primarily a mindset change. You have to realize that animals don’t have to get sick.”

© by The Stockman Grass Farmer

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