Potentials for Plant and Other Toxicities in Cattle

While Johnsongrass is a good quality forage, it can be challenging to control in pastures where the perennial, warm-season grass is not desired. Prussic acid production under stress can pose a risk to livestock when grazing Johnsongrass, especially during prolonged droughts or after a frost.
( Dirk Philipp, University of Arkansas )

Fortunately, there has been plenty of rain this year. However, heading into late summer and fall are times of the year to watch out for plant toxicity in cattle.  In some cases, plants can become more toxic during drought and heat stress.  In addition, there is the increased potential for cattle to ingest toxic plants due to lack of other feedstuffs.  There may also be more access to toxic plants.  With droughts come increased weed infestation of pastures, hay and crop fields.   Penned cattle may also be in corrals or drawn to low lying areas that are still green, both of which are where toxic plants are likely to grow.  Differentiating “good” vs. “bad” plants is a learned behavior, so toxicity is more likely in young animals and animals moved to a new location.  A grazing management and supplemental feeding plan is essential to minimize problems.  Veterinarians and producers should be familiar with which plants can cause problems in their area, and try to avoid them.  The following discussion covers some of the plants and situations to watch for during drought situations.  There may be plants that grow some regions that are not covered.

Stressed plants more readily accumulate nitrates and prussic acid (cyanide).  Drought stress can cause both pasture forages and weeds to accumulate toxic amounts of nitrates.  Recently fertilized pastures are also at higher risk.  Plants that have accumulated nitrates remain toxic after baling or ensiling.  Test forages for nitrates to prevent poisoning.  Prussic acid accumulates most often in sorghums, sudans and Johnsongrasses, but these plants can accumulate nitrates also.  There is no test for prussic acid, but it dissipates when plants are baled or ensiled, so harvested forages are safe.  Cattle poisoned by nitrates or prussic acid are usually found dead, so prevention of these toxicities is critical.   Cattle with nitrate toxicity have methemoglobinemia (brown blood) and cattle with prussic acid toxicity have cyanohemoglobinemia (bright, cherry red blood).  Nitrate and prussic acid both interfere with oxygen carrying capacity in the blood, so pregnant cattle surviving these poisonings often abort.

Two of the most toxic plants found in croplands and pastures are coffeeweed and sickle pod.  Cattle will generally not graze the green plant unless other forages are scarce.  However, they will readily eat the seedpods that are dry after a frost.  The plant remains toxic when harvested in hay/balage/silage.   Coffeeweed and sicklepod are toxic to muscles and cause weakness, diarrhea, dark urine, and inability to rise.  There is no specific treatment or antidote, and once animals are down, they rarely recover.

Pigweed or carelessweed is very common in areas where cattle congregate.  Cattle will readily eat the young plants, but avoid the older plants unless forced to eat them.  A common pigweed poisoning is when cattle are penned where pigweed is the predominant plant and no alternative hay or feed is provided.  Red root pigweed is more toxic than spiny root pigweed, but is less common.  Pigweed can accumulate nitrates, so sudden death is the most common outcome.  It also contains oxalates, so renal failure can also occur.

Black nightshade is common in croplands, and like pigweed, in often in high traffic areas.   The green fruit is most toxic, so cattle should not have access to nightshade during this stage, and nightshade remains toxic in harvested forages.  Nightshade is toxic to the nervous and gastrointestinal systems, and causes weakness, depression, diarrhea, and muscle trembling among other signs.  Bullnettle and horsenettle are in the same plant family as nightshade.  They are also toxic, although less so, and are usually avoided by livestock unless other forages are not available.

Blue-green algae blooms in ponds can also occur in hot weather.  They are most common in ponds with high organic matter, such as ponds where cattle are allowed to wade, or where fertilizer runoff occurs.  The blue-green algae accumulates along pond edges, especially in windy conditions, and exposes cattle when they drink.  Both the live and dead algae are toxic.  The toxins can affect the neurologic system causing convulsions and death, sometimes right next to the source.  They can also affect the liver, causing a delayed syndrome of weight loss, and photosensitization (skin peeling in sparsely haired or white haired areas).

Perilla mint causes acute bovine pulmonary edema and emphysema (ABPE), usually in late summer.  It grows in most of the central and eastern United States and is common in partial shade in sparsely wooded areas, and around barns and corrals.   There is no treatment, so prevention is critical.

Cattle with access to wooded areas may eat bracken fern.  Cattle must eat roughly their body weight over time before toxicity occurs, but may do this in situations where other forage is not available. Braken fern toxicosis causes aplastic anemia.  Fever, anemia, hematuria, and secondary infections are some of the most common signs.

As summer moves into fall, the potential for acorn toxicosis increases.  Cattle have to eat large amounts usually to become sick, but those that are in poor body condition and hungry are more likely to do so.  Clinical signs include constipation or dark, foul-smelling diarrhea, dark nasal discharge, depression, weakness and weight loss.

The lack of summer forages and the need for supplemental feeding during a drought can increase the likelihood of feeding “accidents” and toxicities.  Producers may be tempted to feed cattle pruning’s of ornamental plants, many of which are highly toxic.  Grain overload is also a potential problem if access to concentrate feeds are not controlled.  Salt toxicity can occur if hungry cattle are allowed free access to high salt containing “hotmixes”.  Even though these are meant to limit intake, initial intake can be high enough to cause toxicity in starved or salt deprived cattle.  Feeding byproduct feeds, candy, bread, screenings, etc. may also be more common, all of which have the potential to cause problems.  Producers may also be tempted to feed moldy hay or feed, which can lead to toxicity problems.

With careful planning, plant toxicities can be avoided. If you have questions on toxic plants and how to identify/avoid them, please contact your local veterinarian or Extension agent. If you have further questions please feel free to contact me at, lstrick5@utk.edu, or 865-974-3538.

Moisture the Critical Component to Good Silage

One of the most important steps to make good silage is to cut it at the proper moisture level. The optimum moisture range for cutting corn and making silage is between 60-70% moisture (30-40% dry matter). Given the genetics of today’s corn varieties, utilization of the old relationship between the milk line and plant moisture content may not always be accurate.

An easy, quick and relatively inexpensive method to determine the actual moisture content of the whole corn plant is using a microwave oven. One additional advantage is that it takes typically less than 20 minutes to run the test.

So what equipment will you need to facilitate the moisture test?

  • Microwave, with a turntable (preferably). Your wife or significant other will appreciate you NOT using the kitchen microwave or doing this in the house kitchen, as it does produce an unpleasant odor. It is thus recommend to have a microwave in the shop or barn to run the moisture test.
  • Scale, one that weighs in grams is best.
  • Container, something that is microwave safe such as paper plate, paper boat, or a glass or plastic dish.
  • Water – 8 oz glass to protect the microwave oven
  • Paper & Pencil to record weights
  • Calculator

Next you need to collect a sample. Collect at random 10-20 plants throughout the field. You will need to chop these plants and this can be done by either shredding them in a brush chopper/branch shredder or by running them through your chopper. Please keep in mind that this can be a very dangerous process and care should be taken when doing this. The other option is to chop test areas in your field. Then take random grab samples from the green chopped silage. You should have about 2 gallons worth of product to mix and collect your test sample from. Once you have collected a representative sample you can start the process to run the moisture test.

Follow these steps to determine the moisture content of your corn silage or forage. Please note that this method can also be used to determine moisture content in any other forage.

Microwave Moisture Testing of Forages

  1. Take your gram scale and weigh the container you will use to hold the sample. This weight is known as Value A.
  2. Mix your sample and place about 100 grams in the container. Collect the total weight of the container and wet sample, record the weight as Value B.
  3. Put an 8oz. glass of water in the corner of the oven.
  4. Put the container with the sample in the microwave oven. Using a medium to high heat setting start drying the sample, starting with approximately 3-4 minutes if you suspect the sample is above 35% moisture.
  5. Remove the container and sample, weigh them, and record the weight. It should weigh less than the Value B that you initially recorded.
  6. Gently stir the sample and place back in the microwave.
  7. Reheat the sample again for another 30 seconds. Remove, reweight, and record the weight. You should continue this process, recording the weight every time. (You will need to be careful not to char or burn the sample. If you do, then either start over or take the previous recorded weight prior to charring the sample. You do not want your sample to be charred, so a hint is to go in time increments of less than 30 seconds once you feel your sample is getting close to dry.)
  8. Once you have two continuous weights that are equal, the sample is considered dry. Record this final weight as Value C.

Lastly you will need to calculate the percent moisture using the following formula:

  • Value A = weight of container
  • Value B = weight of container + initial wet sample weight
  • Value C = weight of container + dry sample weight

%Moisture = B - C divided by B - A times 100

Producers need to remember that if the silage is too wet there is a risk of butyric acid forming and nutrients being lost due to seepage. Silage that is over 70% moisture should not be harvested and should stand in the field for a few more days. On the other hand if it is too dry it will not ferment or pack adequately resulting in mold development. You may then need to add water to get an adequate pack and fermentation process. Therefore, having an accurate determination of what your corn silage moisture is running is critical in putting up good silage in a timely manner.

Corn Silage Maturing Fast

Corn plants can lose more than two points of moisture on hot, windy days. ( Farm Journal, Inc. )

With plenty of moisture and lots of sunshine in much of the upper Midwest, corn silage is rapidly maturing.

Now is the time to aggressively monitor crop maturity and plant dry matter, says John Goeser, animal nutrition, research and innovation director for Rock River Laboratory in Watertown, Wis. Although ideal dry matter will vary with silage storage type, the general guideline is to shoot for 35% dry matter (65% moisture.

“The opportunity for failure, or for challenges to arise, is far greater when we aim for dryer and more mature thresholds,” says Goeser. “[Corn silage] will be harder to pack at those dryer levels. If we experience a dry spell with 80° F days and wind for a week, corn can go from drying out a point a day to losing several points of dry matter per day.”

That can lead to a “fluffier” crop with kernels harder to process, he says. “Realizing that chopping can take some time, it’s best to begin harvest just before you reach the dry-matter target,” he says. “Continue chopping beyond the target and realize an average dry matter this is right around the ideal level.”

Goeser also recommends:

Consider high cutting. “Many areas experienced plenty of heat and moisture early in the growing season this year, so I’m forecasting fiber digestibility and stover characteristics to be more ‘woody’ this years,” says Goeser. “These characteristics can be varied with cutting height.”

He recommends a simple on-farm experiment when kernels reach the half-milk line. Cut three or four stalks at normal height, another set of stalks at 12 to 14” and a third set at 18 to 20”. Chop these stalks and then submit the samples for neutral detergent fiber digestibility analysis. The results should tell you which cutting height will provide optimal feed.

Utilize kernel processing scores (KPS) throughout harvest. “It’s one thing to have your equipment ready for the season, but changes happen in equipment and crop status which affects KPS,” he says. So monitor KPS daily or every couple of days.

“Understand that the KPS benchmark is lower for unfermented, fresh chop whole plant corn relative to what it will be six months into fermentation,” he says. The fresh chopped corn KPS goal is 60 to 65, while fermented corn silage should be 75 or better, he says.

Use free app to monitor crop conditions in your area. Rock River Lab is providing a free, crowd-sourced phone app called InField Updates that reports dry matter, NDF and starch statistics on a map. This data can be used to track crop progress in your area. Download the FeedScan app and click on “InField Updates” to try out this tool.

Time to Plan for Corn Silage Harvest

( Sponsored Content )

Now is the time to start thinking about and planning for corn silage harvest. Preparations taken now and close attention to details like moisture content can mean higher-quality silage when you peel back the plastic months from now.

One of the most important factors influencing corn silage quality is moisture content at time of harvest. Ideally, corn silage should be harvested at the moisture content appropriate for the type of silo used. Recommended moisture contents are 65-70 percent for horizontal silos, 63-68 percent for conventional tower silos, 55-60 percent for limited-oxygen silos and 65 percent for silo bags, writes Jud Heinrichs, professor of dairy science and Gregory W. Roth, Ph.D., professor of agronomy, both with Penn State.

Crop dry matter yields are maximized near 65 percent moisture (Table 3) and losses during feeding, storage and harvesting are minimized. Delaying harvest can reduce both the fiber and starch digestibility as the stover gets more lignified and the overmature kernels become harder and less digestible if left unbroken after ensiling.

Table 3. Corn silage yield and quality as influenced by growth stage.

Corn Silage

Silage moisture at harvest is not difficult to determine and should be monitored, if possible, to prevent harvesting of the crop outside of the desired moisture range. A commercial forage moisture tester or a microwave oven can be used to determine the moisture content fairly rapidly. If silage moisture is above ideal levels, then harvest should be delayed if possible.

Corn that is ensiled extremely wet will ferment poorly and lose nutrients by seepage, which also has potential to damage the silo and if not contained, contaminate local water supplies. Silage that is too dry may result in poorly packed material, causing more mold and spoilage due to air trapped in the silage. In dry, overmature corn silage, the stover portion of the plant is less digestible and contains lower amounts of sugars and vitamin A.

Moisture content cannot be determined accurately using the kernel milkline, because of variations due to weather and hybrids. Moisture content should be measured rather than estimated.

One strategy for timing corn silage harvest is to chop a sample at the full dent stage, just as the milkline appears, and determine the moisture content. Then estimate the harvest date by using a typical drydown rate of 0.50 to 0.75 percentage units per day.

Harvest considerations should also focus on obtaining the correct particle size distribution and the need to process the crop. Processing silage refers to putting the chopped material between two rollers that are installed in the harvester to crush the harvested material as it passes through. Kernel processing units are becoming more popular on corn silage harvesters in Pennsylvania. Kernel processing has the advantage of crushing cob slices and kernels and can increase the starch availability by about 10 percent in the silage. The current data shows no clear nutritional advantage to processing silage unless it is overly mature with hard kernels. In some cases, this has resulted in increased milk production compared to unprocessed silage. A good general recommendation for the theoretical length of cut for processed silage is 3/4 inch with a 1-2 mm roller clearance.

Kennel Processing

Figure 1. The Penn State Particle Size Separator can be used to monitor silage particle size.

Corn DistributionFor unprocessed silage, an average theoretical length of cut should range from 3/8 to 3/4 of an inch. Particle size of corn silage should be monitored during harvesting because it can change as crop moisture content varies. The Penn State Particle Size Separator can be used to estimate the particle size distributions for harvested corn silage.

Table 4. General recommendations for corn silage particle size distributions on the three sieves and bottom pan in the Penn State Particle Size Separator.

Once harvesting has begun, fill the silo as rapidly as possible and continue until it is filled. Continue to evaluate processed corn throughout the harvest season. Kernels should be broken into multiple pieces and cobs should be broken into thumbnail-sized pieces or less. As the crop matures after half milkline, it may be desirable to have more kernel breakage so that much of the grain is in the bottom pan of the particle size separator.

The most desirable method of packing bunker silos is the progressive wedge method, where silage is continually packed on a 30-40 percent grade. This minimizes the surface area exposed to the air that can result in DM and forage quality losses. If this is not possible, the silos should be packed by spreading relatively thin layers of silage (6 inches deep) and packing it well. If packed well, the density of the silage should be about 14 pounds of dry matter per cubic foot.

Bunker Silos

Figure 2. Technique for ensiling forage in bunker silos.

For the full story, click here.

 

Sponsored by Lallemand Animal Nutrition

First Cutting in Alfalfa: Why Cutting Management is Important?

First cutting is the most important and critical of the alfalfa growing season. A late start of this growing season will determine multiple things during this year’s production. It is important to know that the success of the entire production will be based in determining a proper date to cut for highest yield and quality. As rule of thumb, forage quality varies with the environment and cutting management. If you are forced to delay the first cutting due to environmental conditions (rain or even drought), keep in mind that this could have negative consequences with a slower regrowth and perhaps a reduction in future yield production.

First cutting tends to have low quality if it is cut late during the growing season. Generally, during pre-bloom or bud stage the stems are highly digestible with high quality forage. Second and third cuttings still very important for production, however if there is a need to wait to harvest beyond the bud stage then the more the quality would suffer because of lower proportion of leaf and stem ratio. Below are some guidelines in plant height and harvest maturity in alfalfa. Producers should take this into consideration for future management and cutting strategies.

Table 1. Plant height and harvest maturity in alfalfa.

Cutting Schedule Plant Height (inches) Maturity Stage
First Cutting 32 Late vegetative to early bud
Second Cutting 23 Late bud to early flower
Third Cutting 19 Early to late flower
Fourth Cutting 16 Late flower

Source: Professor Marisol Berti; North Dakota State University for Midwest Forage Association (Forage Focus; May 2018).

Summary

Each growing season brings new challenges. It is important to plan ahead and be ready to make the best decisions. Oftentimes, compromising forage quality to avoid plant stress is one way to harvest a little later than expected. It all varies depending on climate and other factors such as: stand health, age of the stand, history of winter injury and winter kill, previous cutting management, soil tests, insect and disease problems.

Hay Moisture Levels

With the limited opportunities and short windows many have had to make hay so far this year, some hay may have been made at higher moisture levels than we would like. Moisture levels have a direct effect on hay quality. What we have found to be a consistent number in the literature is 20% moisture maximum. To be more specific:

    1. Small squares to be 20% or less,
    2. Large round, 18% or less and
    3. Large squares, 16%

Hay baled at 20% moisture or higher has a high probability of developing mold, which will decrease the quality of hay by decreasing both protein and total nonstructural carbohydrates (TNC) AKA energy! The mold will also make the hay less palatable to livestock and could potentially be toxic, especially for horses. Even hay baled between 15%-20% moisture will experience what is known as “sweating.” Sweating, in regard to hay bales, refers to microbial respiration, which will create heat and result in dry matter (DM) loss. A good rule of thumb is that you should expect a 1% DM loss per 1% decrease of moisture after baling. As an example, hay baled at 20% moisture that is stored and dried down to 12%; will result in 8% DM loss.

What happens if we bale hay and the moisture content is too high? Bad things. If lucky, maybe the hay will only mold, but if it is too moist and starts heating, it could catch fire. If the hay heats to 100-120 degrees F, it will be fine; if it goes above that, monitor daily. Once it gets to 140 degrees F, consider tearing down the stack. At 150-160 degrees F, call the fire department, and once it gets to 160 degrees F, there will be smoldering pockets and hot spots, and gases will ignite hay when exposed to air (source: Washington State University Extension, Steve Fransen and Ned Zaugg).

It can be a double edged sword in regards to losing quality by not baling, or losing quality by baling with moisture levels that are too high. Therefore, our recommendation to ensure adequate livestock nutrition this winter is to have a forage analysis done on the hay baled this year. Once you have those results, develop a corresponding supplemental feed program, if necessary, based on the nutritional requirements of your livestock.

The two short videos below by Clif Little and Rory Lewandowski will answer questions regarding forage testing, and subsequently interpreting the results of the test(s).

To bloom or not to bloom?

By Kassidy Buse

A common recommendation of agronomists is to let one alfalfa cutting reach bloom each year.

Ev Thomas, retired agronomist from the Miner Research Institute in Chazy, N.Y., says otherwise in The William H Miner Agricultural Research Institute Farm Report.

“For many years, I’ve said that in managing alfalfa for dairy cows, you should never see an alfalfa blossom, from seeding to plowdown,” says Thomas.

Thomas also notes there’s room for difference of opinion due to no research supporting either opinion.

But, if one cutting is to bloom, which cutting should it be?

The first cut of alfalfa-grass typically contains the most grass. Grass, even the late-maturing species, is close to heading when alfalfa is in the late bud stage.

The second cut is exposed to long, hot June days that result in highly lignified, fine stems. A Miner Institute trial found that the stem quality of bud-stage second-cut alfalfa was no better than full-bloom first-cut alfalfa.

The third cut can be influenced by prior harvest management. If it was a late second cutting, the third cut was growing during midsummer heat. This cut would also have highly lignified stems.

The fourth cut often takes a long time to bloom, if it makes it there. A killing frost might arrive first.

For any cutting, the more grass in the stand, the lower the forage quality if alfalfa is left to bloom.

“The objective of letting alfalfa bloom is to improve root reserves, and therefore extend stand life,” says Thomas. “We need to balance the impact of delayed harvest on plant health with the economics of feeding alfalfa of lower quality that is needed by today’s high-producing dairy cows,” Thomas adds.

How alfalfa and alfalfa-grass is managed depends on if the goal in mind is long stand life or high milk production potential.

Avoid Barn Fires, Let Hay Dry All The Way

Not only can wet hay catch fire, but it can mold. Hartschuh says bale temperatures of 120° to 130° F often results in mold growth and makes the protein less available to animals. ( Farm Journal )

Farmers across the country have either finished putting up their first cutting of hay, or they are in the process of doing just that. While it can be easy to get in a rush, avoid barn fires by ensuring your hay is dry enough before you bale it.

“When [hay] is baled at moistures over 20% mesophilic bacteria release heat causing temperatures to rise between 130°F and 140°F. If bacteria die and bales cool, you are in the clear, but if thermophilic bacteria take over temperatures can raise to over 175°F,” according to Jason Hartschuh a guest contributor to Ohio State University Extension’s Ag Safety Program.

Most wet bales catch fire within six weeks of baling, Hartschuh says. Here are some things to consider when determining if your hay is at risk of fire. Did the field dry evenly? Were moisture levels kept at or below 20%? If moisture was higher than that, was a hay preservative used?

If you are concerned that your hay is a fire risk, monitor it twice a day for the first six weeks or until low temperatures stabilize, he says. Temperatures should be taken from the center of the stack or “down about 8 feet in large stacks.”

Not only can wet hay catch fire, but it can mold. Hartschuh says bale temperatures of 120° to 130° F often results in mold growth and makes the protein less available to animals.

“While those temperatures are not high enough to cause hay fires, the concern is if the mold growth continues and pushes temperatures upward into the danger zone,” he says.

According to research from OSU, if the temperature in the hay continues to rise, reaching temperatures of 160° to 170° F, then there is cause for alarm.

“At those elevated temperatures, other chemical reactions begin to occur that elevate the temperature much higher, resulting in spontaneous combustion of the hay in a relatively short period of time,” Hartschuh says. “If the hay temperature is 175° F or higher, call the fire department immediately, because fire is imminent or present in the stack.”

 

Critical Temperatures and Actions to Take

The team from OSU extension recommends monitoring the following temperatures and taking appropriate action.

125° – No Action Needed

150° – Hay is entering the danger zone. Check twice daily. Disassemble stacked hay bales to promote air circulation to cool the hay outside.

160° – Hay has reached the danger zone. Check hay temperature every couple of hours.  Disassemble stacked hay to promote air circulation to cool hay have fire department present while unstacking from here on.

175° – Hot pockets are likely. Alert fire service to possible hay fire incident. Close barns tightly to eliminate oxygen.

190° – With the assistance of the fire service, remove hot hay. Be aware the bales may burst into flames.

200°+ – With the assistance of the fire service, remove hot hay. Most likely, a fire will occur. Keep tractors wet and fire hose lines charged in the barn and along the route of where bales are to be stacked.

 

Cutting Height in Hay Fields: How Low Can You Go?

The second consequence for mowing too close to the ground is increased ash content of the forage. All forage has a natural ash content of approximately 6%. However, mowing too closely with disk mowers can add soil to the crop, and increase the ash content by as much as 10-12% (18% ash content in total analysis). If we all had table-top smooth fields, it would also be much easier to make a closer cut across all fields. However, things such as groundhog holes and the unevenness of fields can add to increased ash content of our harvested forage.

So, the million dollar question is how low can you go? The best answer is…it depends! The first question I always ask is – is it a solid stand or a mixed stand? If you have grasses involved, you must keep cutting height higher than a pure stand of legume, if you want to keep the grass in the stand. Keep in mind these are minimum recommendations; it’s okay to mow higher than the numbers below. Here are my minimum cutting height recommendations:

Alfalfa or Clover

  • 2” minimum. Some literature shows a cutting height of 1” will not reduce stand longevity, but remember the increased ash content issue. Also, keep in mind that frequent cutting at early maturity will continue to deplete carbohydrate reserves. One cutting of alfalfa should be allowed to reach the bloom stage each year.

Cool Season Grasses (Orchardgrass, Timothy)

  • 4”during the establishment year
  • 3” minimum during production years. This is where we see most of our stand longevity issues. Frequent cutting of cool season grasses at a low height will continue to deplete energy reserves.

Mixed stands

  • You must manage for the predominant species. Do you have a grass stand with some alfalfa, or an alfalfa stand with some grass?
  • Alfalfa with some grass: 2.5” minimum
  • Grass with some alfalfa: 3” minimum (if you want to keep the grass sta

Hay Cost Calculator

Hay season is around the corner and many producers are likely greasing the wheels, sharpening blades, checking belt tension, and settling in for a long hay season. However, it may be wise to do some calculating and revisit some management decisions to determine hay needs and to see if there is a way to reduce hay needs. This could be important considering the tremendous cost of feeding cattle 365 days per year and knowing hay tends to be one of the most expensive feeds available.

In order to achieve the task of determining how much hay is needed and what the potential cost will be, Mr. Kevin Ferguson, Ms. Rebekah Norman, and Ms. Tammy McKinley developed an Excel based “Hay Calculator” to help with the calculations. That file can be found at https://ag.tennessee.edu/arec/Pages/decisionaidtools.aspx. The tool takes into account storage losses, feeding losses, bale size and weight, cattle weight, consumption, number of days fed, and hay price to determine hay needs and total cost. The calculator can also assist with hay quality analysis.

Based on several pieces of research, the method of storing and feeding hay significantly increase costs. Average storage losses for hay stored six months or longer range from 5 percent for hay in a barn to 30 percent for hay stored outside and uncovered. Hay stacked and covered with a tarp on a rock pad or pallets results in 12 and 14 percent loss respectively. Additional storage methods include a plastic sleeve and net wrap which result in average losses of 19 and 23 percent respectively.

Similar to storage, the method of feeding hay can influence hay loss. Feeding losses from feeding hay in a cone ring range from 2 to 5 percent while feeding hay in a conventional ring results in 4 to 7 percent hay loss. The use of a hay trailer generally results in 10 to 13 percent hay feeding losses while the use of a cradle will result in 15 to 20 percent losses. Unrolling hay on the ground has the most variability with losses ranging from 5 percent to 45 percent. Hay feeding losses are likely more a function of how much hay is fed at a time as opposed to the method. For instance, feeding a week’s worth of hay in a cone ring will result in more feeding loss than feeding one day of hay in a cone ring.

For illustration purposes, consider a producer with 30 cows averaging 1,200 pounds and feeding 2.5 percent of the cows body weight for 150 days. This would result in each cow needing 30 pounds of hay each day on a dry matter basis. Assuming 11 percent moisture would result in the herd needing 76 tons of hay or 152, 1,000 pound bales. If the bales cost $35 per bale then the total cost to the herd would be $5,320. However, storage and feeding loss have not been considered.

Now consider two management options with this herd: storing hay in a barn and feeding in a cone ring or storing net wrapped hay outside and feeding in a conventional ring. The first system of storing hay in a barn and feeding in a cone ring results in a total loss of 6.4 tons of hay or 13 bales of hay for an additional hay cost of $451 for the herd. The second system of storing net wrapped hay outside and feeding in a conventional hay ring results in a total loss of 21.6 tons of hay resulting in the need of 43 additional bales of hay and adding $1,513 to herd hay cost.

This basic illustration demonstrates changes in feed costs from differing hay storage and feeding management. Producers should consider methods of reducing hay storage and feeding losses to reduce total costs. Producers should also consider grazing management practices that reduce hay needs which have a potential of reducing feed costs.