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Use Science to Increase Forage Yield

By: Gary Bates, Professor and Director, University of Tennessee Beef and Forage Center

Everyone wants to increase yield.  Usually it means providing more of some type of input.  Maybe more fertilizer, or irrigation, or some other thing that will make plants grow at a faster rate.  But there is a simple way to make our pastures grow faster and produce greater yield.  It involves simply understanding and manipulating a simple principle of plant physiology.  That principle is that plants grow at the fastest rate when they have plenty of leaves to capture sunlight, and the leaves are relatively young so they are very efficient at the photosynthetic process.

Figure 1 illustrates the three phases of plant growth.  In phase 1, the plant doesn’t have much leaf area to capture sunlight.  In order to grow leaves, it has to take stored energy from the roots and crown of the plant for the growth.  It then moves into phase 2, when the plant has plenty of young, efficient leaves.  During this phase, the plant produces plenty of energy for growth, as well as replace the stored energy used during phase 1.  As the plant continues to grow, the leaves get older and less efficient at photosynthesis.  The plant also produces a seedhead, which means it is trying to produce seed instead of leaves.  This results in a decrease in the growth rate of the plant.


Figure 1. Three phases of plant growth

A simple way to increase the yield of a pasture is to concentrate on keeping your grasses in the phase 2 of plant growth.  That means to make sure you leave enough leaf area so the plants can capture plenty of sunlight.  But don’t let the plants go to a reproductive state, meaning they are producing seedheads.  Staying in phase 2 will improve yield, because that is the phase where the growth rate is the highest.

How do you accomplish that?  You have to have some type of rotational grazing program, where you control where the animals graze and how long they stay in the paddock.  If you find that the forage growth is getting ahead of you in the spring, then cut hay from some of the fields.  If you find forage growth is getting slow during the summer, you can do a better job preventing overgrazing.

There is no need to make rotational grazing extremely complicated.  The principle is controlling plant growth through where the animals graze.  This will ultimately improve yield, plant persistence, and the production of forage and beef on your farm.

Researching varieties pays dividends

While it may still be winter, the time to start thinking about spring planting is now. A part of that thinking and planning process is choosing adapted and high-performance forage varieties.

In The Ohio State University (OSU) Ohio Beef Cattle Letter, OSU Agriculture and Natural Resources Educator Christine Gelley discusses what to keep in mind when selecting future forage genetics for your farm or ranch.

Know the difference

Let’s begin with a quick review about the differences between species, varieties, and cultivars.

In plant terms, a species is a plant that is distinctly different from other plants in features and characteristics, meaning that other plants of the same species will share similar characteristics. For example, think red clover versus ladino clover; both are clovers, but two distinctly different species.

A variety is a variation of a plant characteristic that still falls within the range of characteristics of a species. “Think of varieties as species variations that occur in nature without human interaction,” Gelley explains.

While varieties are naturally occurring, humans select for cultivars. These cultivars often bear a trade name that is marketed by the seed company. In spite of the difference between a variety and a cultivar, it remains a common practice for a cultivar to be referred to as a variety.

“By the time you are ready to shop for seed, have your species selected and a few potential cultivars on your list of acceptable choices,” Gelley advises.

Regional requirements

To narrow down your choices even further, look at results of regionally conducted forage variety tests. “If you are farming in Ohio and shopping based on variety performance trials conducted in Tennessee, you may end up unsatisfied with your results,” Gelley explains.

Pay attention to variables in the trial, including total rainfall, soil and air temperatures, soil type, fertilizer and pesticide applications, and the number of years evaluated. Trials that were conducted over the span of several years are typically more trustworthy.

Also consider who is conducting the trials. Many land-grant universities conduct forage trials and are unbiased. Performance trials by seed companies can be reliable, but keep in mind that they are trying to get you to buy their product instead of a competitor’s.

Know the supplier

Once you have a short list of varieties that will fit your farm and needs, shop with a reputable supplier. They should have clean facilities, knowledgeable staff, and good customer service.

“Contact the seed dealer with your cultivar list and have a conversation about what you are looking for and what they can offer,” Gelley recommends. She also advises looking at the seed tags and comparing production dates, germination rates, and the percentage of pure live seed.

“For your best chance at success, do your research before you shop, rather than settling for whatever is in stock at the local co-op,” Gelley says.

Keep records

After selecting, purchasing, and planting your cultivar, keep note of observations you make throughout the year. This includes seeding date, planting rate and depth, weather conditions, germination success or failure, weed pressure, and animal preference.

Perform your own experiment

“If you can’t decide between one cultivar and another, get more than one and start your own on-farm research project,” Gelley suggests.

Plant the cultivars in the same location under similar conditions. As you go through their production cycle, apply the same inputs and harvest the same way all while taking notes and making observations. The results may surprise you.


Foot-and-Mouth Disease Found on South Korean Dairy Forces Quarantine

A health officer checks a cattle in a farm in Gimje as a preventive measure against foot-and-mouth disease after South Korea on Monday confirmed a case of food-and-mouth at a dairy farm elsewhere in the country, South Korea, February 6, 2017.

Areas of South Korea are on quarantine after a dairy farm was found to have foot-and-mouth disease (FMD) in its cow herd.

The outbreak was identified on a 120 cow dairy near the city of Anseong, which is 67.6 km (42 miles) from the capitol city of Seoul. According to a statement from the South Korean Ministry of Agriculture, Food and Rural Affairs released on Jan. 28, this is first FMD outbreak identified in the country since March of last year.

Cows from the farm are being culled and to help decrease the likelihood of the disease spreading movement of livestock, including cattle and pigs, is prohibited in certain areas of the country. These regions include Gyeonggi, Chungnam, Chungbuk, Daejeon and Sejong. The halt on movement of livestock will be conducted for at least a 24 hour period ending on Jan. 29 at 8:30 pm in South Korea.

The prohibition also limits movement for livestock-related workers and vehicles. Workers and vehicles are to remain at the farm or facility.

Access and movement from the following livestock-related workplaces is limited during that time, according to the Ministry:

  • Slaughterhouses
  • Feed mills
  • Collecting yards
  • Feed dumps
  • Feed dealers
  • Manure disposal yards
  • Communal composting yards
  • Livestock manure public treatment facilities
  • Joint recycling facilities
  • Livestock transportation companies
  • Livestock related service companies
  • Livestock consulting companies
  • Compost manufacturers
  • Veterinary drugs and livestock equipment suppliers

If livestock, workers vehicles or goods are moving during the time of the announcement they are to be moved to a safe place approved by the Director of the Livestock and Livestock Bureau of the city or province.

Violations are subject to a fine of 10 million won ($8,937 USD) or less, or could result in a punishment of one year in prison.

Other Recent Outbreaks and U.S. Status

South Korea has had other outbreaks in the past few years, including a FMD outbreak on a hog farm in March of 2018. A similar case on two dairies in 2017 resulted in South Korea vaccinating all cattle in the country for FMD.

FMD is classified as a “severe, highly contagious viral disease” by the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS). The disease causes fever and blisters on the tongue and lips, in and around the mouth, on the mammary glands, and around the hooves. FMD is seen as being a major economic hindrance to livestock production because of its ability to spread quickly. The disease was eradicated from the U.S. in 1929.

In the U.S., programs have been put in place to help secure various segments of the livestock industry. The Secure Milk Supply Plan (SMS) for Continuity of Business has been implemented by some dairy farmers to bio-secure their farms.

Also, the 2018 Farm Bill contained funding for the National Animal Disease Preparedness Program and National Animal Vaccine Bank. The bill funds $300 million for programs like a FMD vaccine bank.

Winter Care Tips for Horse Owners

Winter weather has definitely arrived and along with it come additional challenges when caring for horses.  Horses are surprisingly adaptable to cold weather but paying attention to the small details is especially important to ensure good horse health in the winter months.  Here are a few specific things horse owners should focus on when caring for horses in the winter.

  • Forage/hay– After a tough year of weather conditions for local hay growers, finding good local hay may prove to be a challenging task but providing quality forage or hay in the appropriate quantity is especially critical in the winter. The microbial digestion of hay by the horse actually creates body heat, helping to keep them warm in cold temperatures. Remember the average horse should be consuming about 2.0% of its body weight daily between hay and grain but a minimum of 1.5% of that should be in hay.  That’s a simple math problem. For example, if your horse weighs 1000 lbs:

1000 x 0.015(1.5% converted to decimal form) = minimum of 15 lbs of hay per day

Also consider adding soaked beet pulp or a hay stretcher to your horses’ diet if hay is at a premium. The use of these types of products can possibly help you slightly reduce the amount of hay you have to feed. Beet pulp is also a great way to help get more water into the horse and helps keep the hind gut functioning well.

  • Water-Water is always one of the most important nutrients for horses but it becomes especially critical in the winter when horses are consuming larger quantities of dry feed. Fresh pasture can consist of nearly 60-80% water but grain rations and hay are generally less than 15% moisture. Always make any changes to your horses’ diet gradually.  The risk of impaction colic in horses becomes greater in the winter. By providing your horse with warmed water (45-65º F), you can help to decrease this risk by increasing water consumption. Research has demonstrated that by providing horses with only warmed water, they will consume a greater quantity then if they have cold water or both warmed water and cold water offered simultaneously (they will usually chose cold and drink less). Make sure that the water is always clean and pay close attention to tank heaters and other devices used to warm water. Always check that cords are not worn or damaged and there is no stray voltage that could potentially shock the horse.

 

  • Teeth– During a time of the year when we typically need to increase feed to maintain body condition, make sure that your horses are able to extract as much nutrition out of what they are consuming as possible. This is especially critical in young and senior horses. Have your horses teeth checked and floated by a professional a minimum of once a year. Some seniors and those with dental issues will need more frequent attention.

 

  • Hoof Care – Good hoof care is always important but the conditions we experience here on Delmarva make winter hoof care even more critical and more challenging. The freeze thaw cycles and the slippery mud that come along with it, can create problems.  Combining these environmental issues with slower rates of hoof growth and hoof health issues such as thrush, white line disease and bruised soles can come along with winter weather.  Keeping horses hooves as dry as possible and picking them regularly to remove mud or even snow/ice along with good routine farrier care is very helpful in preventing these conditions that can develop and potentially nag us into the summer months. Discuss with your farrier if your horse should remain shod or barefoot in the winter. In general horses that are barefoot have better traction and will have fewer issues with the development of snowballs or snow packing in hooves. Keep up with routine farrier appointments even though you may not be riding as much.

 

  • Mud– Controlling mud in a horse’s winter environment is easier said than done this year especially but providing the horse with an area to escape the muddy areas that typically develop around gates, feeders and waterers is necessary. This does not need to be a stall but could be a well-drained sacrifice lot or dry run in shed. Appropriate stocking rates, good footing and good sanitation/regular manure removal is critical in maintaining these areas. Besides affecting hooves, excess mud that is not removed regularly from the horse can lead to the development of bacterial infections such as greasy heel, mud fever or scratches on the lower legs.

 

  • Shelter/Ventilation– Horses do not require a fancy barn to provide adequate shelter in the winter but being able to escape the wind and wet/storms is important. Be sure that you are providing enough space that all horses can shelter at once, including the lowest in the packing order of the herd. Horses that have a winter coat and are not blanketed do not begin to expend additional energy to keep warm until the temperature reaches about 18degrees, provided there is no rain or wind. If you choose to keep your horse stalled in the winter, make sure that ventilation is adequate and that the bedding material you use is not too dusty. Confinement in a dusty stall with too little ventilation can actually cause more health problems then if horses were left outside with good footing and adequate protection from the weather.

 

  • Blanketing– Blanketing has been widely discussed among horse owners for years and could be an entire additional article. It comes down to a personal choice and how much work the horse will do in the winter. Age and body condition can also play a role in this decision. If you decide to blanket your horse with a winter appropriate turnout, then be sure to check under that blanket very regularly. Make sure the blanket stays dry, look for rubbing and chafing, inspect for the development of skin conditions such as rain rot and routinely monitor body condition scores on blanketed horses.

Horses don’t need to be doted on in the winter but by paying attention to some of these daily details of winter horse care and being well prepared, your horse will survive the winter months happy, healthy and ready to return to the arena, show ring or trail come spring.

Susan Garey, Extension Agent Animal Science, University of Delaware truehart@udel.edu

Be a Good Hay Shopper

When shopping for a new truck, you don’t buy just because the salesman says it’s a good deal. Most shoppers do their research, looking at body style, fuel mileage, towing capabilities, included options and a vehicle history. Shopping for hay should also be carefully researched because making the correct purchase can drastically affect your bottom line. Have you ever met a person that can tell you the value of a truck just by looking at the exterior? Or someone that can tell the quality of hay based on a physical evaluation alone? While a physical evaluation can help us determine several characteristics about the hay, it cannot tell us nutrient content or other potential problems, like nitrates. The only way to know the quality of the hay is by having a forage test done. Knowing the nutritional value of the hay not only helps determine if supplementation is needed, but also will save you money and hopefully avoid any headaches.

Nutrient/Energy Requirement

Knowing what quality of hay you need to purchase all begins with understanding the nutrient requirements for your livestock. Nutrient requirement is the amount of nutrient an animal needs to perform a specific task, or their energy requirement. This is determined by weight, sex, age, growth rate and stage of production. From this we can break down that animal into four nutrient priorities:

  1. Maintenance
  2. Growth
  3. Lactation
  4. Reproduction

The largest shift in nutritional requirement is the transition from pregnant to lactation. Animals fed differently from their nutritional requirements will either lose or gain excess weight. Something else to remember is that the energy requirement for livestock increases during the winter, 1% for every degree under 32°F. Your county extension agent can help you determine your livestock’s nutrient needs.

Forage Testing

A forage analysis is the only way to assess the quality of the hay. The quality of the forage is focused on the value of each pound versus the total of pounds consumed. There is a physical limit to how much livestock can consume. Digestibility is the ability of the livestock to extract the nutrients from the hay. The primary nutrient found in hay are protein, carbs, sugars, pectins and fiber. When purchasing hay, ask for the forage test results. If a forage test has not been performed on the hay, it something you can do yourself through your extension office. For more details on how to take a good hay sample refer to Ray Hicks’s article in this edition of the newsletter.

Reading the Results

After you receive your forage report, there are some numbers that you want to focus on. Always look at the dry matter levels, not as sampled. The dry matter level is best for comparing forages, ration balance and economic value. Most producers go straight for the protein content, but this is Crude Protein and based on nitrogen levels in the sample. So a sample that is high in nitrates can have a high Crude Protein. Protein is important, but many times is overemphasized. The Total Digestible Nutrients (TDN) is a measurement of digestible energy. This allows you to compare
forages of the same species and compare them to the needs of the livestock. The Relative Forage Quality (RFQ) predicts the energy base based on fiber quality and intake. RFQ allows for comparisons across forage species. We have also been able to link ranges of RFQ to meet the energy requirements for livestock at different stages. This does not mean that a RFQ at that range will automatically provide all the nutrients needed, but provides us with an approximation if the forage will provide a cost-efficient base.

Nitrates are also important to look at. Nitrates over 4,500 ppm need to be fed at restricted rates. As the nitrate levels increase, so does the restrictions on feed until 18,000 ppm when it is considered lethal.

Storage

Another factor that effects forage quality is storage. Hay bales should be stored to protect from rainfall and weathering. Loss from storage can range from 20%-45%. Before hay is stored it should be properly cured. Round bales should be allowed to dry to 15% moisture and square to 18%. Improper curing of hay can result in fires. The best way for hay to be stored is in a hay shed, but if bales have to be stored outside its best they are orientated north/south, the bales are dense and they are elevated. Net wrapping also distributes moisture better than bales wrapped in twine.

Buy by Weight

Finally yet importantly, consider the weight of a hay bale. Whether you are buying square bales or round, consider buying by weight instead of by bale. Humans are not good at estimating the weight of a bale and usually overestimate the weight. So if you can put some bales on a scale and get a good estimate of the lot weight, see if the producer will sale by weight. It will save you some money in the long run.

Summary

  1. Consider your livestock nutrient requirements
  2. Forage Test
  3. Read and understand results
  4. Compare your forage options
  5. How was the hay stored
  6. Buy by weight (if possible)

Prevent and Prepare For Barn Fires

Although you cannot completely eliminate the risk that there could be a fire in your barn, there are some steps you can take to reduce the risk and be more prepared. ( PORK )

Have you ever considered what you would do if you had a barn fire? How would you protect your animals and all the other assets you have in your barn? What could you have done to prevent it? The thought of a fire is very scary. Although you cannot completely eliminate the risk that there could be a fire in your barn, there are some steps you can take to reduce the risk and be more prepared.

Tips for reducing the risk of a barn fire

Contact your local fire department to have them do a “checkup” of your barn and offer more recommendations for your individual situation. The University of Kentucky’s “Preventing Barn Fire: Tips for Horse Owners” recommends the following steps in reducing your chances of having a barn fire.

  • No smoking! Bedding and hay can easily be ignited by a person smoking in or around the barn. Enforce a strict no smoking policy in your barn. Post signs inside and outside your barn.
  • Place a fire extinguisher next to each exit, utility box and at roughly 30-40-foot intervals in your barn. Inspect and recharge each extinguisher every year, and use a ABC (general purpose) extinguisher.
  • Clean off cobwebs and pick up loose bailer twine. By making sure your barn is clutter-free, you are helping eliminate ways for fire to spread.
  • Electrical devices need to be professionally installed and encased in conduit. Pay attention during winter months to water tank heaters and heated buckets—they continue to generate heat even if there is no water present, which can cause the plastic to melt and a fire to ignite bedding and hay. If you are using electrical cords, make sure that they are professional grade, inspected often and are not overloaded. Keep lights caged and only use lights that are designed for barn use.
  • If possible, keep hay and bedding stored away from a barn housing animals. If you only have one barn, like many of us, make sure hay has properly cured before storing it in the barn. Check the internal temperature of curing hay by poking a thermometer into the middle of the bale. If the temperature reaches 150 degrees, the hay should be monitored. If it reaches 175 degrees, contact the fire department.
  • Keep tractors, fuel, other petroleum products and machinery away from the barn. Clear any grass, hay, leaves or other combustible materials from equipment before storage.

Tips for being prepared in case there is a barn fire

Mentally prepare yourself so that you can act calmly and safely in the case of a fire. Remember that human safety is the top priority—ensure your own safety and the safety of others before taking care of animals. The University of Kentucky’s “Preventing Barn Fire: Tips for Horse Owners” recommends the following steps for preparing yourself and being ready if a fire does occur in your barn.

  • Identify and designate a safe place for your animals to go if you can get them out of the barn safely. This location should be away from the fire and allows fire crews enough room to do their jobs.
  • Handling equipment such as halters, leads, etc. should be quickly accessible. Consider the materials these items are made of. Remember that plastic and nylon will melt in heat.
  • Talk about the plan with members of your family and any employees you might have so they can also be prepared in an emergency.
  • Mark gates, pens or stalls with reflective tape or glow-in-the dark paint. This will make it easier to see where you are going in the dark.
  • If you are removing animals, start closest to the exit first and handle animals one at a time or by groups if they are herd animals. Always maintain control of the animals to help reduce their stress, which can prevent other injury risks.

If there is a fire, call 911 and get people out of the barn. Only get animals out if you can do so without risking human safety. Follow the directions from the fire department or 911 dispatcher.

No one ever wants to think about the risk of a fire, but it is best to be fully prepared so that you can react fast and appropriately.

Tips to Keeping Livestock Healthy During Winter Months

Most animals need some shelter during the winter months, however their natural winter coats allow them to endure cold temperatures. ( Drovers )

Winter has arrived in full force in Michigan. Cold temperatures can cause some challenges in our barns, but utilizing some easy techniques on your farm will help you manage your herd successfully during the winter months.

Water

Ensuring your herd has access to fresh, clean water is essential to their health. In the winter, battling frozen water buckets and tanks can be a challenge. By utilizing tank heaters, heated buckets or automatic waterers, water is kept ice-free and at a temperature the animal is comfortable drinking.

Products that utilize electricity, such as tank heaters and heated buckets, should be checked with a voltmeter to ensure there is no current running through the water. Any electrical current will deter animals from drinking from the water tank or bucket. By inserting one end of the voltmeter in the water tank and the other into the ground, you will get a reading that will indicate if there is a problem. Make sure to check this often.

The University of Wisconsin Extension has published a water consumption chart that outlines the amounts of water certain species will consume per day. Ensuring that your animal is consuming enough water each day is critical to their overall health and well-being.

Amount of water livestock will consumer per day
Species Water needs, gallons per day
Cattle 7-12
Goats 1-4
Hogs 6-8
Horses 8-12
Llamas 2-5
Poultry Up to 1
Rabbits Up to 1
Sheep 1-4

Housing

Most animals need some shelter during the winter months, however their natural winter coats allow them to endure cold temperatures. Providing shelter or wind breaks that can be easily accessed by animals is key. Humans oftentimes are prone to making the winter environment for their animals too warm, which is unhealthy for animals.

Michigan State University Extension recommends the following factors to consider when evaluating the housing of your animals:

  • Air quality. Is there adequate ventilation to help dispel respiration gasses and manure odor? Depending on the type of barn you have, there are various ways the barn can be ventilated. Ridge vents are more prevalent in newer barns and are based on the premise that heat rises. Older barns may require opening doors or windows to allow for air circulation. Poorly ventilated spaces can cause irritation in the animals’ lungs and lead to respiratory infections such as pneumonia. If you notice condensation on walls or ceilings, that is a good indication your air isn’t ventilating enough for the number of animals occupying the space. You will need to adjust accordingly.
  • Dry bedding areas. Dry bedding provides insulation from the cold ground and helps decrease the amount of energy animals use to keep them warm. There are many options for bedding you can use; straw, wood shavings and with cattle in particular you can use corn stover or similar crop residues for cows and bulls.

Feed

Animals must maintain their energy reserves in order to endure cold temperatures. Before the weather gets cold, asses the body condition of each animal and adjust the nutrition they are receiving to adequately prepare them to thrive in winter conditions. It is critical to continue to assess body condition scores throughout the winter, as it may be necessary to increase the amounts of good quality feed and forages. Supplying adequate amounts of feed is essential in your herds well-being through the winter months.

This article was published by Michigan State University Extension. For more information, visit http://www.msue.msu.edu.

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.

Tall Fescue

With its drought, low soil pH, and high stocking density tolerance, tall fescue is the forage of choice in many pastures. While it may come off as a “super grass,” tall fescue can cause major health and reproductive issues in some animals.

Danielle Smarsh, equine extension specialist at Pennsylvania State University, addressed tall fescue toxicity in pregnant broodmares in a recent article published in Penn State’s Field Crop News.

“Certain varieties of tall fescue are infected with the fungus Neotyphodium coenophialum,” explains Smarsh. While this fungus is great for the plant since it protects against drought and some insects, it isn’t so great for grazing animals.

The fungus produces ergot alkaloids, which have harmful physiological effects in grazing animals, including pregnant broodmares.

Fescue toxicosis is a major risk if pregnant broodmares consume infected tall-fescue. Some of the many symptoms of fescue toxicosis include abortions, stillbirths, and weak foals.

Late-pregnancy broodmares are the only horses that have ill effects from grazing infected tall fescue. Research demonstrates that stallions grazing infected tall fescue show no signs of declining reproductive performance.

The exact amount of ergot on a given pasture varies depending on the time of year, the amount of fertilizer present, and plant variation.

The real kicker is that you can’t tell if tall fescue is infected or not just by looking at it; the grass has to be tested.

Take tall fescue samples in early summer and fall when grass is growing rapidly. The exact time to sample is highly dependent upon weather and region.

What can be done to mitigate the issue with pregnant broodmares?

If pastures test positive for endophyte-infected tall fescue, remove pregnant broodmares 60 to 90 days before foaling. Another option is to treat mares with domperidone to relieve most toxicosis symptoms. Consult with your veterinarian before taking this approach.

If enough space, time, and money is available, renovating pastures to remove the infected tall fescue is a possible option. Tall fescue can be removed with an herbicide and replaced with other cool-season grasses or endophyte-free tall fescue.

“This process can be costly and take several years, so it might not be the best solution for everyone,” Smarsh warns. She also notes that it is difficult to remove all infected tall fescue.

If a mix of cool-season grasses is used, identify the percentage of tall fescue in the stand. If the percent of tall fescue is small, there is less risk for broodmares to contract toxicosis. Even so, the best management option is to remove them 60 to 90 days before foaling.


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.