Livestock

Feed laminitis-prone horses soaked hay

Written by Dr. Jim White on .

Hay soaking is one defense against laminitis, but don’t forget supplement nutrition

Soaking hay for the delicately constituted horse works, but you need to understand the practice to get it right.
Most candidates are horses that are prone to laminitis. Onset symptoms often include overconsumption of water-soluble carbohydrates or fructans. Likewise, we have seen older, obese and sedentary horses that seem to be intolerant of water-soluble carbohydrates at greater than about 10 percent of their feed. Whichever the case, these problem horses require some kind of feed modification when it comes to hay.

Although it sounds confusingly technical, it’s worth understanding how laminitis works. In a horse’s gut, starch is rapidly broken down to glucose by amylase in the horse’s system, but fructans aren’t. Some fructans will escape the small intestine and it’s possible they will ferment in the large intestine. When that happens, the bacteria turns to lactic acid.
When large amounts of sugar, starch or fructans show up in the large intestine, fermentation is rapid. This extensive fermentation in the large intestine produces substantial lactic acid, which drops the pH. If the decline in pH is drastic enough, bacteria in the intestine will disintegrate, releasing toxins that are stored in the bacteria cell walls.

These toxins enter the bloodstream and are thought to be the principal cause of equine laminitis.
The idea behind soaking hay prior to feeding is knock out some of the water-soluble carbohydrates. Cool-season grasses such as fescue, bromegrass and timothy accumulate fructan as their growth-storage carbohydrate. Clovers and alfalfa accumulate starch rather than fructans. Warm season grasses such as crabgrass, switchgrass, and sudangrass do not accumulate fructans.
Feeding is an important factor in the onset of laminitis. Typically laminitis occurs during periods of increased or rapid intake of non-fiber carbohydrates. While we can reduce the amount of water-soluble carbohydrates by soaking hay in water prior to feeding it, some horses are much more tolerant of water-soluble carbs than others. In other words, there is substantial variation between horses and establishing minimum/maximum specs for water-soluble carbohydrates/fructans is tenuous at best.

So how effective is hay soaking, and if what works the best? Usually, removal is greater with warm water than cold. Chopped hays loses more water-soluble carbs than long-stem hay, and removal increases with length of soaking. In addition to fructans and water-soluble carbohydrates, soaking hay also reduces potassium and protein, especially during long soaks.

Research at the University of Minnesota compared soaking long-stem bud alfalfa, full flower alfalfa, mixed orchardgrass/alfalfa, vegetative orchardgrass and mature orchardgrass. Researchers there compared soaking in 70 degree water and 100 degrees at 15, 30 or 60 minutes. The hay flakes were put in mesh bags and crammed into a bucket with 6 to 7 gallons of water.

Results showed the following: Soaking reduced water-soluble, ethanol-soluble carbs and fructan content in all hays.
Generally, the 15-minute cold water soak resulted in the least reduction carbs and fructans, but it usually would cut the water soluble carbohydrates by a third or so. The 12-hour cool soak had the greatest reductions.
As expected, water temperate influenced carbohydrate removal, with warm water being more effective. But, the researchers did note a significant problem with the 12-hour soak—25 to 30 percent loss in dry matter.

Results from other researchers have also shown highly variable removal of water-soluble carbohydrates. Ryegrass probably has the highest levels of fructans for any grass, and very few ryegrass samples reached below 10 percent of water-soluble carbohydrates regardless of length of soaking.

While soaking hay certainly provides some improved safety, it is a practice that cannot be used with complete confidence.
In other words ,there is concern that soaking may not be sufficient to guarantee that hay is safe to feed to laminitis-prone equids. And soaking effects vary widely among hay types and soaking methods.
The conservative approach would be to have your hay tested for water-soluble carbs, and devise a feeding program based on the test levels of water-soluble carbs.

Complimentary MFA horse feed would be EasyKeeper Golden Years or Legends CarbControl.
As an expedient field practice, soak hay in warm water for 30 minutes, or in cold water for an hour. The Brits are over the moon about soaking hay and have a number of cute hay soakers and steamers, but they are expensive.

Check out www.horseit.com to learn more. But if you’re pricing from that site, remember to convert from British pound to U.S. dollars.

Of course, you could hillbilly engineer one yourself for under $100 with a plastic truck box, a garment steamer, $5 of CPVC pipe and some window screen.


Dr. Jim White is ruminant nutritionist for MFA Incorporated.

Lunchtable hay talk

Written by Dr. Jim White on .

The other day, I was having lunch with some buddies who happened to all have cow herds. We got to talking about feeding cows. I will refer to them as A, B, and C to protect the guilty and to allow me to steal their good ideas. There is no such thing as a free lunch, comrades.
Here is how I remember it.


Me: Say, when do you determine your winter feed and forage inventory supply compared to your cows’ winter feed needs?
A: Usually about when I start to feed hay.
B: I look at cow BCS at weaning, determine if the cows are thin or not, and count bales between football games on Thanksgiving day. It gets me out of the house, which is full of in-laws.
C: I am constantly monitoring both, I try to maintain cow BCS at a 5 to 6.

Me: So, when do you cull cows?
A: When they do not raise a calf.
B: If they are open, aged and unsound. Or, if they have a bad disposition—these get culled at weaning.
C: Cows are culled when they are found to be below average in production, or if they are unsound or wild. If they are candidates for feeding, they are fed high-energy diets for 90 days and sold as white-fat cows. I have wondered about if I should establish an “old-cow rest home” for older thin cows to go to, get fed hard and pushed toward white-fat cows. It doesn’t make any economic sense to sell a thin cow.

Me: I suppose that you do stockpile winter forages. So, briefly, how do you manage the stockpiled forage?
A: Let the cows run—they will eat the leaves and better forage and leave the stems.
B: They get a field at a time, depending on where the water is.
C: I strip graze the swards. Electric fence is a wonderful thing.

Me: When do you determine what you are going to feed and how much you are going to feed?
A: They eat all they want, or all they can. They’ll be alright; they are cows.
B: Around Thanksgiving I estimate about what they are going to need, then feed them to that level.
C: I compare all available forages and feeds. I am not going to feed them more than they need, but I am going to make certain that they get what they need. They will not get 5 pounds of Super Cubes a day if forage quality and availability is such that their requirements are met with feeding 2 pounds of Breeder cubes.

Me: How do you decide which hay to feed when?
A: They get the hay I can get to.
B: We feed the lowest quality to animals in mid-gestation and save the best material for feeding when they start to calve. There are discussions that we might be better served by feeding hay before grazing stockpiled fescue. The fescue holds its nutrient value fairly well, and as it ages the alkaloid level drops off. It is a hurdle for me to get over to decide to feed hay when there is adequate forage standing available.
C: We test all the lots and allocate according to the animal’s nutrient needs. If the hay is dairy quality, we will sell it or use it to pull up the energy and protein in growing rations.

Me: What are ways to limit waste of the hay that is fed?
A: Don’t feed more than they will eat in an hour, and unroll the round bales.
B: Use a bale feeder, especially one that reduces waste, such as an inverted cone.
C: The same thing our buddies mentioned, plus grind the hay and feed in bunks or as a TMR. It cuts waste percentages.

Me: How do you store your hay?
A: Out at the fencerow.
B: Net wrapped, in rows four feet apart; I try to tarp them when I can.
C: In a shed, and the base is rock, not dirt.

Me: Do you test your forages?
A: No, they are going to eat it anyway. I have yet to have a cow ask me “has this hay been tested?”
B: Sometimes I get a forage analysis, but certainly “yes” if my friendly nutritionist is going to pay for it.
C: Yes, my friendly nutritionist can make better recommendations with the feeds having been tested. I’m not real good at guessing, and if I thought the hay was 10 percent protein, but it was really 13 percent, the extra 3 percent is not free. I’d be wasting it by not adjusting for it.

Me: Do you separate your cows?
A: No.
B: I split the young cows from the older cows.
C: We separate them into groups based on age, stage of production and BCS.

It would have been bad table manners to inquire about profits and loss. But you can see which of my buddies spends the most time on his herd. And you can guess, I bet, the one who is best paid for his time and labor. That’s something to think about as the winter finishes out and you look at next year’s hay crop.

Dr. Jim White is ruminant nutritionist for MFA Incorporated.

Profit loss from foot problems is so lame

Written by Dr. Jim White on .

Dairy herds can feed toward foot health


After mastitis, lameness is the most costly disorder of dairy cows. There are several factors that have an influence on hoof health, a few of which I'll explain below.

Producers tend to underestimate hoof health problems via lack of accurate records. Do you track loses on cows with hoof issues? Do your records show the extent of the problem? And, how you identify and define a lame cow? A too-strict definition won't make these losses go away. So for our purposes, is a 1-to-5 scale that comes in handy for finding where the herd stands.

For a score 1: The cow's top line remains flat or level while standing and walking; 3 out of 4 cows should be scored as 1.

A score 2: The cow's top line remains flat while standing and hunches up when walking. There should be less than one out of every six cows that are scored as 2. Score 2 cows will have slightly less dry matter intake than score one cows—say 99 percent as much as score 1
cows.

A score 3 cow has a hunched back when standing still and more pronounced hump when moving. A herd should have under 10 percent cows as score 3. Cows with a 3 score will have lower feed intake, and about 5 percent lower milk production than cows scoring as 1 or 2.

Cows that distinctly favor a foot are score 4, these cows will be 15 to 20 percent down on milk, and close to 10 percent down on feed
intake.

A score 5 cow is a severely limping cow, a cow that has limited interest in moving to the feed bunk or the parlor. These cows are often off a third of their milk, and 20 percent down on feed intake. Milk cows usually find a lameness score 5 to be lethal.

A leading cause of hoof problems is infectious agents or bacteria that can cause foot rot, hairy heel warts, etc.

Wisconsin researchers reported that 6 out of 10 cases of lameness were associated with infectious agents, 4 out of 10 cases are associated with laminitis—which is an inflammation of the foot. Laminitis changes blood flow to the hoof. One of the principal causes of laminitis is acidosis, where heavy grain feeding results in substantial production of lactic acid. This shifts rumen pH lower, which results in histamine increased after the death of gram-negative bacteria release endotoxin-causing blood pooling in the hoof claw.

Rumen protein degradation adds to the histamine load. Acidosis will result in breakdown in the bond between the epidermis of the hoof wall and soft tissue in the corium. It gives an increased incidence of sole ulcers and white line abscesses.

Of course, we can protect our herds from hoof problems through improving cow comfort, walking distances, walking surfaces, concrete exposure, heat stress, and exposure to frozen, slick surfaces, small rocks and yard wetness. And we can select genetics that boost sound foot and leg confirmation.
Feeding options to promote hoof health are as complicated as most "beneficial" rations.

Nutrients that seem to have little influence on hoof health are: salt, potassium, calcium, phosphorous, cobalt and magnesium. Rations do affect hoof health. Starch and sugar, the rapidly fermentable carbohydrates, are key factors leading to lower rumen pH and acidosis.

These carbohydrates can shift fermentation away from fiber digestion and increase levels of propionic and lactic acids. Finely ground, high-moisture grains or rapidly available sugars affect the rate of fermentation.

Sugars have the fastest rates of rumen fermentation. If you have a ration with a very fast fermentation rate of the fast-digesting feed, and a slow rate of the slow-digesting feed (which is common when we try to make up for low forage quality by bringing in a lot of grain), you're setting up the cows for acidosis. Expect Christmas presents from the hoof trimmer.

As a guideline, it is good to keep starch around 24 percent of the diet. Of course, it might move up or down from there by a couple of points. Sugar will usually be 2 to 4 percent of the diet DM.
Protein quality, protein solubility and protein degradability can influence lameness. As mentioned earlier, protein breakdown can lead to histamines.

Adequate effective fiber maintains a rumen forage mat, reduces the likelihood of laminitis, helps maintain butterfat percent and encourages cud chewing or rumination. There are a couple of general rules for effective fiber: maintain NDF and have at least 5 pounds a day of fiber over an inch of length. If butterfat is fine, the cows are getting bred and feet are good, effective fiber is adequate.

Fat does not ferment, it will not produce lactic acid. Overfeeding occurs sooner with oils than with animal fat, reducing fiber digestion. This reduction in fiber digestion tends to swing rumen pH lower. Not feeding more than a pound of additional fat is a good place to stop
with feeding fat.

Copper has some effect. We tend to get greedy on feeding copper, except to Jerseys, and especially when we are feeding fescue. Copper-short animals are more susceptible to heel cracks, foot rot and sole abscesses. Zinc, especially protected-chelated zinc, such as that used in MFA dairy feeds has been shown to improve hoof integrity, wound healing, epithelium maintenance and keratin synthesis.

Additionally it has been shown to be associated with lower somatic cell counts.

Classically it was argued that adult ruminants did not need, require, nor like water-soluble vitamins added to their feed. Research and field work has shown instances where ruminants have responded to niacin, biotin and B12. Biotin is requisite for keratin formation and claw horn development. University work on lame cows has reported that cows fed biotin will improve their lameness score by about one when fed 20 mg of biotin a day. The response to feeding biotin is not immediate, plan on doing it at least six weeks before seeing a response. Seeing a response in 6 months is more likely. Likewise, if you are feeding biotin, and pull it, the milk nor hoof health response is immediate.

Dr. Jim White is ruminant nutritionist for MFA Incorporated.

Scold the mold and ventilate

Written by Dr. Jim White on .

 

MFA TECHNICAL BRIEF

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

circumspection

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.

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