Scold the mold and ventilate

Written by Dr. Jim White on .



Challenging hay conditions will affect feeding efficacy and safety

We had some interesting hay-making conditions this year. There was plenty of hay down during summer pop-up thunderstorms or more prolonged rain events, and, as always, there was plenty of humidity regardless if it rained or not. Fall cuttings weren't much different. Such conditions are the beginning of many undesirable things: reduced subsequent forage growth, loss of nutrients, mold growth, increased harvesting loss, increased harvesting costs, hay being put up at a higher moisture, heat damaged protein, brown spots, barn fires, etc. 

Given high humidity, expected forage drying in storage may not occur and the hay may have high enough moisture to permit mold growth.  On untreated hay (hay that is untreated with mold killers such as propionic acid, ammonia, sorbic acid/salts, etc.) mold will grow at moisture levels above 14 percent to 15 percent. The PhD forage geeks will wring their hands and remind us that the measurement should really be water activity rather than moisture. But measuring "water activity" is a tedious and hard-to-arrive-at-in-the-real-world formula. Moisture is easier to measure and is close enough to let you make management decisions. 

Mold growth produces heat and can result in large amounts of organic matter loss. Under some conditions mineral can be lost-leaching out potassium is common.

In some situations heating can be great enough to cause auto-oxidation, "charring" or spontaneous combustion leading to full-fledged hay fires. By rights, hay burns somewhere around 350F. But if you see what looks like steam, which is water vapor coming off the center of bales, you need to take immediate action. If you have a thermocouple or thermometer that pegs a temperature of no greater than 130F, the temperature will drop. If it hits 150F, the hay temperature may go down, which is good, or it may go up, which will be troublesome. If the temperature is greater than 175F, take immediate action. Here, immediate action means call the fire department. Then you call me and ask about carrying cows through winter on a low hay inventory.

Drying of stored hay is increased by: 

1. Ventilation: Having air space between bales increases air movement.

2. Adequate head space: Providing enough gap between the top of the stack and the roof allows moisture to move up and out the top of the stack.

3. Avoiding other wet products in the same area: In areas of low air circulation, additional wet material raises the humidity of the storage area.

4. Having smaller stacks.

5. Using alternating direction of stacked bales.

6. Avoiding use of tarps: Tarps on the top of a hay stack trap moisture via condensation and supports the growth of mold. 

Molds commonly found in hay include Alternaria, Aspergillus, Cladosporum, Fusarium, Mucor, Penicillium, and Rhizopus. In hay, mold growth-structures are comprised of two components: mycelium and spores. Mycelium is the stringy growth structure of fungi. It looks sort of like the strands of a cotton ball. Spores are the reproductive, seed-like structure. A principal concern for cattle is the total amount of mycelium and spores combined or the total "fungal biomass." In hay, the white mold in the bale is the mycelium and dustiness is from the tiny spores. These mold-produced spores are the "dust." They can cause respiratory problems, especially in horses or other animals fed in poorly ventilated areas. The physical dust problem associated with moldy forage can be reduced by ensiling, mixing with a high moisture feed or wetting the hay. 

Most molds are harmless; they don't produce known mycotoxins. But the fungi did use some forage energy-it is lost for livestock purposes. Under some conditions, Aspergillus, Fusarium and Penicillium will produce mycotoxins. Many of the commonly diagnosed mycotoxins are produced in the field prior to harvest. Here in the humid Midwest, we are well-acquainted with infected fescue. In harvested or stockpiled infected fescue, the toxic alkaloid concentration will decline over time. There is substantial discussion about mycotoxins in forages because several species and or mycotoxins may be present. Try as we might, control methods are not consistent nor are the diagnostic methods. Same goes for treatment recommendations. More research is needed. 

Livestock sensitivity

Feeding moldy hay to livestock is a frustration. The effect of mold on livestock health can vary depending on the type of livestock and fungi. Horses seem to be most sensitive to mold. Mold spores exacerbate respiratory conditions such as heaves and digestive problems like colic. Cattle can generally tolerate and eat a mold on hay without problems. Canadian work on molded hay showed limited reductions in digestibility and intake of molded hay, even up to as high as 10 percent fungal biomass in the hay. Hay harvested and stored under ideal conditions often contains 1 to 2 percent total fungal biomass while severely molded hay may contain up to 10 to 12 percent total fungal biomass. 

The researchers concluded, "Presence of fungal biomass in alfalfa hay does not affect the rate and extent of DM, CP, and NDF degradation of feedstuffs commonly used in ruminant rations but may affect rate and extent of DM degradation of highly lignified feedstuffs such as barley straw." To avoid livestock problems, the conservative approach is to minimize feeding hay to more sensitive livestock.

The interpretation of spore counts which have been suggested are:

< 500,000 per gram: low risk 

500,000 to 1 million: relatively safe

1 million to 3 million: feed with


3-5 million, dilute: feed with caution

> 5 million: do not feed

(Richard et al 1993)

Dr. Jim White is ruminant nutritionist for MFA Incorporated.

Grazing rice as a small grain

on .

Will it work? I'm trying to find out

I have been known to do egregious things. One I did recently was to mention Sericea lespedeza and not follow with how much Remedy to use to kill it. So let me clarify. Good Sericea lespedeza is dead Sericea Lespedeza.
Now that I have offended nearly everyone, except perhaps the Missouri highway department that introduced Sericea, I am pursuing another agronomic adventure.

I am trying to find information on grazing rice as a late-summer annual pasture. I was speaking with a Missouri cattle raiser who is looking at using rice as a pasture crop, seeding it down like any other small grain crop and grazing it as we would rye or wheat. The interest in rice is acute in that it has a growth habit that covers a part of the year when we tend to be forage short-the mid- to late-summer time of year.

When I look through the literature, I find data on feeding rice straw. Usually the reports are from Asia, and draft animals are fed the rice straw (people eat the grain). To the American ruminant nutritionist, this can be an emotional hurdle. I overcame it some years ago in Central America. I was looking at some skinny lop-eared milk cows. The farm manager solicited my opinion. I was the wise guy from the States. Trying to make a point, I said, "Hey! Do you know what corn is?"

The farm manager said, "Of course, we eat corn, all the tortillas on this morning's table were from slaked corn, and your point is?"

So, I said, "I, uh... I guess we won't be feeding corn to the cows; they get the stalks, cobs and husks, right?"
Rice straw is tough stuff, notorious for silica, it dulls knives about like chopping sand. It has fiber levels as high as cottonseed hulls.

Years ago I scrounged around looking for rice forage, because some high end Waggie recip cows were supposed to be fed rice straw and barley. I wanted to feed the cows Iowa brand corn silage, but the honorable Japanese owners wanted to feed the cattle rice forage, and since the honorable Japanese were paying the bills, we went to Arkansas for rice forage.

This was a tremendous experience. Most of the rice straw was plowed under, and the rest, which was baled, was most frequently used for erosion control. We did find some unheaded material that was baled, and it did not feed too bad-much better than straw would have.

For rice straw, figure these averages: about 60 to 65 percent neutral detergent fiber (of which 30 percent is digestible); 40 to 45 percent acid detergent fiber and 5 percent crude protein-roughly similar to corn stalks, although corn stover NDF will tend to be of higher digestibility than 30 percent. Given that whole-plant corn silage can have substantially more energy and protein than the subsequent corn stover, I would expect that younger rice plants have substantially higher nutrient content than rice straw. A research team from Korea, lead by Ki et al, in the April 2009 issue of Asian-Australasian Journal of Animal Sciences, reported that whole-plant rice silage could be used to replace corn silage in milking cow diets without reducing milk production. Ishida and the Korean Rural Development Administration have also done work on using whole-plant rice silage for dairy feed. I would suspect if a forage can be used as dairy feed, it would certainly be a beef feed alternative.
I would expect that higher protein content would tend to improve digestibility, as would lower silica contents. UC Davis did work across a wide variety of rice cultivars and the California work did not show a correlation between silica concentration and digestibility. This is encouraging in that the silica might not be directly reducing the digestibility.

When I went and asked colleagues about grazing rice, the most common response was, "I have no idea." Other common responses told me that rice is a grain crop-and one of the most costly crops to establish. It is too costly for cow feed with the exception of the by-products: bran, mill feed and hulls.

Agronomists I talked to were particularly concerned with the amount of silica. Rice may have a silica requirement, but cows do not. A clever emeritus professor said that it should work, but doubted the likelihood of getting funding for such a project.

So, at this juncture, I am soliciting the experience or advice of anyone who has tried grazing ruminants on rice as we would graze other small grains such as wheat, rye, barley, oats or triticale.
I'd be grateful for any insight or suggestions. Write to me at This email address is being protected from spambots. You need JavaScript enabled to view it..

Dr. Jim White is ruminant nutritionist for MFA Incorporated.

Modernizing feed mills

Written by stevefairchild on .

robot stacker

Feed and Grain, a business-to-business magazine that covers the feed market has a nice feature on the updates and upgrades MFA has installed in the Mexico, Mo. feed mill. The story explains how a new bagging system and robot bag stacker has increased throughput for the facility and helped to reduce working injury.

MFA’s new bagging system delivered on the promise of a 33% reduction in the overall plant labor/labor efficiency gains; the 50% reduction in overall shrink, the loss related to packaging; and a 20% increased throughput rate.

“Technology enhances your competitiveness. As other costs tend to go up, you need to find ways to minimize expenses where you can and improve efficiencies,” says Alan Wessler, vice president of MFA’s feed division.


Read the whole thing here.

Herdsman is on the way

Written by stevefairchild on .

Here is a behind-the-scenes look at a new offering that's on the way at your local MFA location. A couple times per year, MFA retail managers bring agricultrual vendors into a trade-show setting. Managers from across MFA's territory gather to work with the vendors to attain volume pricing and other forms of buyer savings. Those products then work through the cooperative to your farm. herdsman booth

At the August Buyers' Market, the Herdsman brand made its debut to MFA. Herdsman is a joint venture among several cooperatives who pool their buying power to get high-quality farm supply products at a reasonable price. Herdsman fencing products are first to hit the MFA system.

The Herdsman brand was conceived by farm product buyers at Tennessee Farmers. Participating cooperatives include: Tennessee Farmers, Alabama Farmers, MFA Incorporated, Heritage Trading and Intermountain Farmers Association. As buyers from these cooperatives negotiate deals with manufacturers, more Herdsman products will be available.

Time to test your hay

Written by Dr. Jim White on .

[Photo:Krystle Fleming via CC/Flicker]

In any number of producer meeting that I have been to, I have held up a feed sample and a $20 bill. I tell the audience what the feed sample is and the expected range of TDN. Then I tell them that the first correct guess gets the $20.  Everyone only gets one guess though—otherwise someone would guess 0-100 and claim the bill, similar to buying out a lottery. 

I have never had anyone win the $20.


A better deal would be to say that a player pays a dollar for a guess. I’d potentially make more money. The point of the exercise is that if we do not test our feeds and forages, we are, in effect, guessing at the nutrient concentration.

We would be happy to guess for the $20 when guessing doesn’t have a cost. But not knowing the feed value of hays, grains or silage has a huge cost—we will either over feed or under feed the animals.


What could be better than free hay? That might sound like a rhetorical question, such as, "What could be better than watching  a monster truck jumping a row of motorcycles?" Well, it would be cooler to see it done whilst the motorcycles were ablaze, or if the driver was blindfolded.


No such drama in the barn lot, but not dropping animal performance would be better than free hay.  Consider the data of Kawas et al out of WI. They compared different hays as to the amount of the hay a milk cow ate and her milk production.

While the milk-cow comparison might not be aples to apples with your beef herd, the results show that cows—and your feed costs—respond to hay qaulity.

The Wisconsin study  fed cows from high to low levels of concentrate and from high to low hay quality.  Using dairy quality hay, (RFV >150) at $120/ton gives better income over feed cost than does using free ($0.00/ton) beef cow quality hay (RFV <100).  Using the production data of Kawas, given typical feed situations, low quality hay can’t be cheap enough to feed; it can't be so cheap as to not be worth evaluating. Knowing the hay quality allows for appropriate usage and supplementation.


I've pasted the contrasts using the numbers from the University of WI.  The entire abstract is found in the papers presented at the 1983 American Dairy Sci Association meeting.


  • Subscriptions
  • Advertising
  • This email address is being protected from spambots. You need JavaScript enabled to view it.


  • This email address is being protected from spambots. You need JavaScript enabled to view it.
  • FAQ
  • Copyright Notice