April Snow Showers Bring Stress and Scours

This spring we have had some very untimely snow storms.  Some have even been historical, such as the blizzard that hit most of the midwest including Minneapolis as I was traveling to the Montana Nutrition Conference and Livestock Forum.  Unfortunately, I was not able to attend the conference as my airplane was diverted and the rebooked flights canceled, TWICE! So now here I am some how stuck over a thousand miles from my destination (Bozeman, MT) in the upper penensula of Michigan.  However, this was a minor inconvenience for me compared with the obstacles cattle producers face this season.  Through social media I have read countless stories about ranchers doing all they could to save calves and help cows in these snowy, windy, unseasonably cold conditions.  I have read about ranchers who were out rounding up newborn calves that were struggling as the storm began to roll in.  Some of those producers wrote of feelings of sadness and failure as they lost visibility and it became unsafe for them to be out in their pastures attending to their livestock. Other farmers, were able to get their calves in a hoop house shelter or barn to ride out the storm.

calvesinbarn2
Joeseph Skroch’s calves in a barn riding out the blizzard in central Minnesota.

While the storm has past, producers are not in the clear just yet.  Weather events such as this blizzard put extra stress on cattle.  The increased levels of cortisol in the animal’s system suppresses the immune system leaving them more susceptible to other infectious agents.

In mature cattle, the suppressed immune system is often taken advantage of by infectious agents resulting in a respiratory disease.  Bovine Respiratory Disease Complex (BRDC) can be caused by viral infectious agents (Bovine Respiratory Syncytial Virus (BRSV), Parainfluenza 3 (PI3), Infectious Bovine Rhinotracheitis (IBR)), bacterial agents (Pasteurella multocida, Mannheimia haemolytica, Histophilus somni, Mycoplasma bovis) or a combination of any of the above.  

In calves, this increased level of stress and suppressed immune system culminates as diarrhea, or calf scours.  With the storm, chances of calf scours increases if the dam is shortchanged nutritionally resulting in poor quality milk for the calf.   If the dam is low on protien and energy, she cannot produce milk containing the nessicary antibodies to protect the calf.  Therefore, especially after this storm event it is important to ensure a well formulated diet for the cow.  Opportunistic infectious agents can also play a role in calf scours and can be bacterial (Escherichia coli, Salmonella, Clostridia perfringens), viral (Rotavirus, Coronavirus, Bovine Viral Diarrhea (BVD), IBR) or parasitic (Cryptosporidium, Coccidia).

When cattle are already under extra stress due to the weather, it is important to not add any additional stress through poor nutrition.  Be sure to formulate precise and accurate diets for both the cow and calf through feed testing and consulting at Ward Laboratories Inc.  A good ration to avoid nutritional stress will provide ample protein, and energy to meet physiological requirements of the animal.  It is also important to provide minerals in the diet to support the immune system. When the immune system is supressed from stress due to the changing weather, absorption of minerals vital to immune function such as magnesium, selenium, copper and zinc are supressed.  A combination of stress and imporper nutirition can render a good vaccine schedule useless.  In addition to providing a high quality diet, avoid feeding questionable feeds containing mold or aflatoxin as these agents may not directly cause illness or death, they can contribute to the suppression of the immune system resulting in respiratory symptoms and reduced reproductive productivity.  While no one can truly be prepared for all adverse weather events.  Producers can always utilize all their knowledge and resources to move forward after an event such as this spring’s blizzard and snowstorms.  Now hopefully I will have made it back to Kearney, NE by the time you are reading this post and we are done with all of this cold weather and on to summer forage production!

 

Forage Creativity: Soy-Corn Silage

Here at Ward Laboratories Inc., we often encourage producers to be creative and try newapproaches to agricultural production.  A couple of weeks ago at the American Society of Animal Science Midwest meeting in Omaha, I listened to a talk about getting more creative with corn silage: “Production of High-Quality Forage through Unique Forage Blends” presented by Dr. Ishwary Acharya.  Ward Laboratories Inc. tested 1,451 corn silage samples and 2,197 total silage samples of all types in 2016.  So, I have seen the range and variation in the nutrient quality of silages used in the area.  Dr. Acharya’s research focused on making the best possible silage for a dairy operation, as he stated in his talk, “the ultimate measure of forage quality is milk production”.  Being in central Nebraska, I think his research could not only increase the nutritional content of the silages produced, but also the value of grazing the cornstalks by a beef enterprise after harvest.

The idea behind Dr. Acharya’s presentation was to double crop corn and vining soybeans to produce high protein low fiber silage without sacrificing yield.  First, to produce the best possible corn silage, the crop was chopped higher than producers typically chop corn silage.  This resulted in less stock and more leaves, husks, and cob in the silage.  Therefore, yield was compromised for higher protein and lower fiber concentrations.  The second part of the presentation explained that to overcome the sacrifice of yield, vining soybeans could be intercropped with the corn.  Therefore, when chopping for silage at a higher level, the soybean plant material made up for the loss of stocks in the yield.  In this study, the resulting silage had increase yield, forage quality, and protein compared with typical corn silage.  Dr. Acharya interseeded the vining soybean at various rates and determined that the optimal rate was somewhere between 67% corn 33% soybeans and a 50:50 mix.  The study also looked at the optimal time for fermentation based on pH and presence of volatile compounds that have affect on rumen function and animal performance.  At 60 days of fermentation Dr. Acharya determined that fermentation had not gone to completion and the silage should be ensiled for at least a 90-day period.  This finding agrees with other literature I have read on the topic.

Dr. Acharya’s idea of double cropping to create a high-quality forage source for dairy cattle could also be of benefit to beef cow calf pairs grazing the remaining corn stalks.  If soybeans were intercropped, I would predict that there would be some beans and vining materials left in the field which would be higher in protein and lower in fiber than the corn stalks alone.  Of course, I would advocate that producers test both their silage and try to get a representative idea of what has been left on their field to provide necessary supplementation.  For the silage, I would recommend testing crude protein, acid detergent fiber to predict energy values and neutral detergent fiber to predict dry matter intakes at a minimum noting that the sample would need to be ran as a wet chemistry feed test and that the addition of soybean to the silage would not allow for a reliable and accurate NIR scan.  For the grazing stocks and soybeans, I would run the same test to get an idea if protein or energy supplementation are necessary.  I would also caution that soybeans do contain urease and we typically do not graze cattle on soybeans fields as they risk urease toxicity if they have recently consumed non-protein nitrogen (NPN), therefore when considering supplementation strategies for cattle grazing a field of cornstalks intercropped with vining soybeans, lick tubs or mineral mixes with urea could not be utilized.

As, with any novel feed, always monitor animal body condition, production and health to ensure it is providing the nutrients required.  Don’t be afraid to try something new.  It might be of benefit to your operation weather it is vining soybean corn silage or grazing cover crops or feeding from the waste stream, feed testing and good ration and diet formulation can lead to success of a livestock operation.

Integrated Systems Agriculture: 4 Benefits of Grazing Cover Crops to Beef Producers

Intensive, specialized crop production has several widely agreed upon downfalls.  These specialized systems tend to have stationary yields with expensive pesticide and herbicide inputs all while profitability is widely dependent on a global market over which we have little control.  Dependence on these practices  leads to higher resistance among  insects  and weeds, reliance on fertilizers due to nutrient depletion  in the soil,  soil erosion and contamination of waterways due to run off, and improper soil management practices. Soil scientists and agronomists agree that the addition of cover crops to a cropping rotation can improve soil quality and health through decreased erosion, increased microbial activity, increased carbon sequestration, more soil aggregates, and increased conservation of moisture in the soil, all due to a more extensive rooting system and ground residue protecting the soil for more months out of the year.  The addition of livestock, most commonly beef cattle, to this rotational cropping system decreases the need for herbicides and fertilizers, as they help deplete the weed seed bank and their manure contains many nutrients vital to plant nutrition and soil health. Guest author, Emily Shafto, covered the benefits to the soil extensively in her blog Cattle and Crops: Completing the Nutrient Cycle.  Here are four benefits of grazing cover crops to cattle producers:

 

  1. Grazing cover crops extends the grazing season, leading to decreased costs of stored feeds.  Supplementation needs are also lessened due to the animal’s ability to preferentially graze to meet their nutritional needs. According to a study by Practical Farmers of Iowa, grazing cover crops can offset winter feed storage costs by up to $40,000. Of course, it is important to mention that labor costs increase, and grazing cover crops requires more intensive management of the land and cattle.  The cost may be offset by the reduced need to cut and bale excessive amounts of hay or corn silage. Feed should still be stored for emergency use, such as a failed cover crop or a stressed crop that has accumulated too much nitrate to graze.

 

  1. Grazing cover crops can improve cattle’s nutritional plane through preferential grazing.  Animals consuming a cover crop mix can choose plant parts such as leaves over stems which are higher in protein and non-fiber carbohydrates and lower in fiber.  Cattle can also choose less mature plants for the same nutritional reasons.  Therefore, by grazing a mix of annual crops, cattle can consume more protein and carbohydrates for performance than a balanced ration of roughages and grain supplements. Therefore, grazing cover crops can improve nutrition and eliminate the cost of ration balancing and mixing.

 

  1. By improving their nutritional plane, animal performance can increase when grazing cover crops.  Growing steers typically have increased feed intake when consuming cover crops as opposed to a mixed ration, which results in increased weight gains.  Heifers and cows on the higher plane of nutrition provided by cover crops can have increased reproductive performance.

 

  1. Grazing cover crops rotationally can have an added benefit of forage regrowth.  When animals graze a paddock for the first time, they open the top canopy and allow sunlight to reach shorter plants.  When the cattle are removed from that section, plant growth is stimulated and if allowed enough time, may recover sufficiently enough to allow the area to be grazed again.   Grazing regrowth is like bonus forage and can also contribute to decreased feed production and storage costs.

 

Integrating cropping systems with forage production and grazing benefits soil health, grazing livestock, and your pocketbook.  Grazing cover crops specifically benefits beef production by extending the grazing season, thereby saving on winter stored feed costs, improving the animals nutritional plane resulting in improved animal performance through increased intake and gains, and bonus regrowth can also be grazed, again saving on winter feed costs.  Don’t forget to take proper precautions before allowing cattle to graze cover crops. See my blog post: 6 Cautions When Grazing Cover Crops. 

What to Do with Down Corn?

Here in Nebraska, down corn has been an issue for cattle producers who want to graze corn stalks.  Due to a late harvest and weather patterns creating high winds, many corn fields have ears of corn just lying on the ground.  Cattle are selective grazers and will pick the high energy, high starch grain over the high fiber, low energy corn stalks if given the chance to be turned out onto those fields.  This can cause issues such as acidosis, bloat and eventually death among cattle.  The available starch in corn grain is rapidly fermented by rumen microbes, this can result in acidosis where the pH of the rumen decreases rapidly damaging the epithelial lining of the rumen.  If cattle are dealing with bouts of acidosis after eating they will likely go off feed for a short period, but then they will go right back out and consume the high grain diet that made them sick in the first place, thus resulting in another bout of acidosis.   The readily available energy in the corn grain can also result in a feedlot type frothy bloat.  If untreated and not taken off the high grain diet the cow will continue to eat and eventually death will occur.

Due to those risks in down corn fields, different management is necessary to graze those fields.  Unfortunately, varied management also means more labor-intensive strategies.  For example, the first step is to determine about how much corn is down in your field.  For this I would reference UNL extension Mary Drewnoski’s calculator and article regarding down corn https://beef.unl.edu/down-corn-problem-or-opportunity-cattle-producers.  After determining how much corn grain is available in the field, you can utilize a feedlot type / mob grazing strategy where you utilize electric fencing to reduce the amount of corn grain they consume daily and provide extra roughage in addition to the cornstalks already available.  In this way you can gradually allow them to have more access to the field and provide less roughage to acclimate the rumen microbes to the high starch diet without the pitfalls and production losses of associated acidosis and bloat.

Another strategy some producers have looked toward is to rake and bale the cornstalks corn grain and all to mix into a total mixed ration (TMR).  One issue that this strategy might run into is the ash content of the baled corn stalks may be high and may cause an impaction.   Ash is defined as the total mineral content of a feed and has two sources.  Endogenous ash is from the plant and is bioavailable providing micronutrients to the animal. Exogenous ash is from soil contamination of the feed.  This soil is not available as micronutrients and usually just passes through the animal’s digestive tract.  The problem with soil contaminated feeds is that the soil could cause a compaction within the omasum, abomasum or beginning of the small intestine.  An impaction would not allow other nutrients to pass through and could cause cattle to go off feed if it is serious enough.  Not enough research has been done in this area to determine how much ash or soil contamination would result in an impaction.  The more likely issue however would be a decrease in performance due to the dry matter intake the ash is taking up.  Roughages and forages generally range between 8-10% ash with 4-6% being endogenous.  Extremely soil contaminated roughages could contain as much as 18% ash.  Because cattle typically consume 2% of their body weight in dry matter, consumption of a soil contaminated feed can result in a considerable amount of the ash as dry matter intake with no nutritional value. Thereby, resulting in decreased performance for the animal.  Therefore, it would be my recommendation when raking and baling down corn for a TMR to test the ash content and if it is high, mix with feeds that have a low ash content to minimize impaction risk and performance losses. It is also important to remember to test the nutritional value of the baled corn stalks before mixing them into the TMR as it has more energy value than typical cornstalks due to the high grain content and should be treated as such. In addition, soil contamination of any feed can introduce mold spores heightening animal health risks and decreasing production performance. Therefore, it would be my recommendation when raking and baling down corn for a TMR to test the ash content and if it is high, mix with feeds that have a low ash content to minimize impaction risk and performance losses.

6 Cautions When Grazing Cover Crops

Grazing cover crops can be a cost-effective way to achieve multiple productions goals.  Cover crops can provide ground cover to prevent erosion, improve soil health over time, and provide nutrition to beef cattle.  However, cover crops are not a fool proof feed.  Turning cattle out onto cover crops to graze without proper feed tests can lead to a wreak due to improper management.  Recently, I had a producer lose 12 head of growing cattle to polioencephalomalacia, a neurological disease in cattle consuming too much sulfur.  After the incident, that producer wanted to test his cover crops to ensure he did not experience another tragic loss.  My advice, is to test cover crops before grazing for protein, energy value, minerals, nitrates, and under some circumstances, prussic acid to ensure proper management and prevent undue losses. These are the 6 cautions to consider when grazing cover crops:

  1. Nitrates

Cover crop mixes include several plant species known to accumulate nitrates for example: brassicas, such as turnips and radishes, or small grain plants, such as oats, millet, or grain sorghums. When cattle consume high nitrate feeds, the microbes in the rumen convert that nitrate to nitrite.  The nitrite is then in the gas, which the cattle belch and then inhale.  The nitrite then binds to the blood hemoglobin preventing oxygen from binding.  At levels between 1,400 – 2100 ppm NO3-N this can cause spontaneous abortions with no warning signs or symptoms.  At levels between 2,100 – 4,000 ppm NO3-N sudden death may occur and therefore, animals grazing cover crops should be slowly acclimated to consumption of nitrates and offered a low nitrate roughage to fill up on first.  Never allow hungry cattle onto a high nitrate field.  Nitrate levels above 4,000 ppm NO3-N should not be grazed as sudden death will likely occur.

  1. High sulfur

The toxic level of sulfur in a cattle diet is 0.40 ppm on a dry basis.  Brassicas are sulfur accumulators, that occasionally test above the maximum tolerable level, and are often included in cover crop grazing mixes.  When sulfur intake is above the tolerable level, thiamin metabolism is impaired in a condition known as polioencephalomalacia (PEM). Head pressing, blindness, and muscle tremors are all clinical symptoms of PEM which, untreated, results in death.

  1. Low magnesium

Grass tetany is a condition commonly associated with lush spring pastures.  These pastures are known for having low magnesium due to rapid growth conditions. Cover crops also tend to have low magnesium.   The magnesium requirement for a beef cow is 0.2% of the diet at peak lactation and 0.1% of the diet for growing cattle.  When cover crops contain less magnesium than is required, a magnesium deficiency can develop resulting in grass tetany.  The signs of grass tetany are cattle stop grazing, become overly alert, and appear uncomfortable, they will then begin to stagger until they finally lie down with their head pulled back into a “star gazing position”.  Untreated, this condition will result in death.  To prevent the development of a magnesium deficiency, many producers grazing cover crops feed a mineral between 8-12% magnesium to be consumed at a rate of 2.5-4oz per head per day.

  1. Prussic acid

In cover crop mixes there are species of plants which accumulate hydrogen cyanide, a poisonous gas commonly known as prussic acid, in their leaves under stressful growing conditions.  These plants include sorghum grasses, sudan grasses, and flax.  Stressful growing conditions includes drought or frost.  Plants grown in drought conditions should be tested for prussic acid prior to grazing because consumption of high levels of the gas is sudden death.  Contrarily, frost typically breaks cell walls allowing the release of the gas and therefore should be safe to graze after 4 days.  Regrowth after a frost however, should be tested prior to grazing because the plant is stressed from the previous frost, but the cell walls have not been broken to allow the gas to escape.

  1. Bloat

A frothy bloat is often attributed to legumes or high protein grasses.  Cover crop mixes high in legumes such as clover, beans, or cowpeas may result in some animals over indulging in the legumes resulting in frothy bloat issues.  These legume plants are high in soluble protein and sugars which allows the microbes to ferment and grow at a rapid rate resulting in a high rate of gaseous by-product accumulation.

  1. Choke

Brassicas such as radishes and turnips may be pulled from the ground to be consumed by cattle grazing cover crops.  If they are swallowed without proper mastication the animal may choke on the large root.  This is typically more of a problem for young cattle who are inexperienced in grazing brassicas.

Overall, grazing cover crops can be a great way to provide nutrients to cattle, prevent soil erosion and improve soil health.  However, the producer should be aware of the risks they are assuming feeding these diverse forages.  Testing for nitrates, minerals, and potentially prussic acid is highly recommended to avoid unnecessary losses due to grazing cover crops.

 

4 Considerations For Feeding Hail Damaged Forage And Crop Residues

 

Here in Central Nebraska we have experienced several mid-summer thunderstorms. These hail producing storms have wreaked havoc on crops and forage productivity, particularly in the Broken Bow and Ansley areas. As producers move forward with crop insurance, they will also be scrambling to utilize what is left of their standing row crops and forages. There are three laboratory tests I would recommend to make an informed decision about the remaining forage. Then depending on the results of your laboratory tests, you can determine what your most economical option is.

1. Nitrates

Defoliation due to the pounding hail results in decreased photosynthesis within the plant. This means that the plant can not convert nitrates to protein. The root system of the plant still continues nitrogen uptake, although the plant cannot utilize these nutrients, resulting in the potential accumulation of nitrates in the plant. Nitrate (NO3 – N) levels between 1400 – 2000 ppm can result in abortions while levels higher than 2000 ppm can result in sudden death if not diluted with other sources of roughage. Therefore, nitrate testing of hail damaged forages is highly recommended before making a decision to graze, hay or ensile the forage.

2. Mold and Mycotoxin Potential

Hail damages the outer cell wall of the plant. The cell wall is an immune defense similar to skin on animals. It prevents infectious agents from penetrating, proliferating and using the plant as a food source. When the cell wall is damaged, opportunistic molds may infiltrate and grow. Consequently, when haying or ensiling forage, testing for mold counts is important. Mold counts above 1 million cfu/g impact animal health and lower production potential.
If the forage is a grain producing forage such as corn or milo, a producer may want to inspect the crop to determine if grain has been produced. If there is grain and it is damaged by the hail, mycotoxins become a potential risk when feeding to livestock. Mycotoxins presence may be present even in the absence of a high mold count. If you suspect mycotoxins may be an issue, remember mycotoxins and molds are often produced together however, the absence of one mycotoxin does not mean conditions were not ideal for another mycotoxin to emerge. If haying the hail damaged forage, proper drying can cut down on mold and mycotoxin presence. If ensiling, proper fermentation and additives may reduce the risk of having these agents in the feed.

 

 

3. Relative Feed Value

The relative feed value (RFV) will be less in a hail damaged forage or crop than its intact counterpart. Defoliation caused by the hail results in the removal or the leafy mass of the plant and what remains is the stocks and stems. These parts of the plant are lower in protein and higher in fiber, which results in a lower relative feed value. Additionally, this also means lower total digestible nutrients (TDN), and net energy of gain (NEg), lactation (NEl), and maintenance (NEm). Therefore, when feeding hail damaged forage, testing the protein and energy of the feed is important to determine how much energy and protein supplementation will be needed to meet production goals.

4. Economics

The last thing to consider, and the most important to your bottom line, when determining how to feed a hail damaged forage is what is the most cost effective delivery system based on the results of feed reports. If the nitrate reports came back low and you have the means to supplement cattle in the field to meet energy and protein needs, grazing may be the most cost effective option. Haying may also be an option under that scenario, however, if selling the hay profit margins may be small do to the lowered feed value and potential mold risks associated. Additionally, when haying you must input equipment and fuel costs associated with cutting, windrowing, and baling. If the nitrates levels have been reported between 2000ppm and 3000 ppm ensiling the damaged forage may be a good option as the nitrates can decrease by up to 50% and then be fed back to the animal. Equipment, fuel and storage costs must also be taken into account for ensiling the feed. In the case of moderate nitrates, haying and mixing with a high quality forage, such as alfalfa, to both dilute the nitrates to the appropriate level and meet the difference in protein and energy provided by the damaged forage and the animals requirements, may also be a viable option. Finally, if the nitrates report is high, utilizing the forage as a fertilizer for next years crop may be the only option.

When determining how to best utilize hail damaged forage, always take nitrates, mold and mycotoxin risks into account as well as the lowered feeding value. Consider the man power, equipment, fuel and supplementation costs associated with each option. This will allow you to make the most informed and cost effective decision possible.