Nutrition is the first defense

Written by Marc Epp on .

A healthy immune system is led by a balanced ration and planning for stress

Most beef herds are exposed to multiple health challenges. Viruses, bacteria, parasites and toxins can come from air, water, herd mates and wildlife. Stress factors such as weaning, co-mingling, handling, transportation and extreme temperatures exacerbate these challenges and can further suppress the immune system. Optimal nutrition is the first defensive measure. Optimal nutrition supports health functions and sends the animal toward its top genetic growth potential.

The immune system is composed of three general defense systems. The first two are called non-specific, in that typically the “defense” cells are indiscriminate against most foreign substances. First are skin and mucous secretions within the body. The second involves white blood cells from the blood stream and lymphoid tissues. These cells and sub-cells are released when there is injury to the body or by parasites and byproducts from allergic reactions. The cells seek and destroy harmful bacteria to prevent/fight against infection.

The third defense system is yet another set of white blood cells called T and B cells, but these are specific in nature. The primary function of these cells is to build specific ‘memory’ for the body against a particular invading virus. For example, giving a vaccine for BVD (Bovine Viral Diarrhea) is immunizing the body against invading BVD viruses. The T and B cells will act by producing specific antibodies that will bind to BVD only and will continue protecting against the organism.

It is a proficient and complex system. For it to work correctly the right nutrient profile for the animal is critical. All the basic nutrients have been shown to impact immune competence, including protein, energy, vitamins and minerals. For ruminants, by far the most important are protein and energy. Energy is the power source for the synthesis and function of immune cells, while protein regulates and provides structural element for cells and antibodies. During times of stress protein and energy are particularly important because stress can reduce intake, thus furthering the suppression of immunity functions through low intake of feedstuffs. When stress situations are impending, for example at weaning, supply a protein- and energy-dense feedstuff designed to compensate for low intake.

The roles of vitamins and minerals overlap for proper immune function. While there are several vitamins that are needed to support immune function, vitamins A and E need to be supplemented in the diet, whereas vitamins B6, B12 and C are supplied by rumen bugs and body tissues in sufficient levels. Multiple studies have demonstrated that vitamin E will increase the function of neutrophils (white blood cells), which are important scavengers of non-specific immunity.

Although several minerals are important for overall body function, zinc, copper and selenium are specifically important for the immune system and should always be offered to cattle in amounts that supply their requirements. Zinc is a well-studied trace mineral on immunity, particularly in stocker and feeder cattle. Zinc is essential in the formation of enzymes that work within cells thus making it vital for cell production, growth and function. A solid immune system is dependent on rapidly dividing cells and cell movement, therefore, a deficiency of zinc can have negative implications on animal health.
Negative interaction between trace minerals can also tie up availability of these nutrients.

University research recently found diets high in sulfur reduced retention of trace minerals copper, zinc and manganese in steers after only 20 days. Corn byproduct commodities, such as distillers grains and gluten feed, are high in sulfur. Thus, with diet high in these ingredients, consideration should be taken to insure there is adequate supplementation of the negatively affected elements.

Severe copper deficiency is generally due more to antagonistic effects of other minerals and/or organisms that make copper less bioavailable to the animal. Dietary molybdenum, sulfur and iron in excess can inhibit uptake of copper digestively, in tissues and bloodstream of ruminants. Consumption of heavy endophyte-
infected pasture starting mid-summer causes a reduction in overall intake, thus causing a deficiency of copper through simple lack of feed consumption.

During times of increased metabolic or immunological strain, overproduction of free radicals called reactive oxygen species (ROS) are formed as a normal end product. The over-accumulation of ROS can result in substantial damage to the animal’s tissues. Vitamin E and selenium are both highly effective antioxidants that will counter the effects of excessive ROS by preventing cellular dysfunction or premature protein degradation.

You should determination risk levels for your herd and plan for nutritional compensation during the most stressful periods. It will help you build an effective barrier against health challenges. The cash value of beef animals is at all-time highs. Along with those record prices, the return on supplementing the right nutrition to support your investment is at its peak.

Mark Epp is Ruminant nutritionist for MFA incorporated. Questions? Contact This email address is being protected from spambots. You need JavaScript enabled to view it..

Standing winter forage

Written by Dr. Jim White on .

A few thoughts on stockpiling fescue

In the love/hate relationship you have with fescue, one characteristic that should be tallied on the “love” side of things is that fescue is well adapted for fall stockpiling. It allows you to graze longer into the winter.

In a stockpiling system, fertilizer is applied in late summer and forage is allowed to accumulate until it goes dormant. Grazing the pastures usually starts in early winter. For stockpiling fescue, MFA forage specialist David Moore recommends application of fertilizer between Aug. 20 and Sept. 15. The application consists of a third of the year’s nitrogen, all the year’s phosphorus and half of the year’s potassium plus 5 pounds of sulfur.

If you don’t have a soil test for reference, in general terms, the application would be 40 pounds N, 50 pounds P and 75 pounds K with 5 pounds of sulfur.

Moore told me, “This should promote good fall pasture and stockpiling as well as support an early wakeup of healthy grass that is poised to grow well the following spring.” His mantra, which you can read more about on page 14, is “Don’t feed the weeds. More grass equals more beef.”

For the most appropriate fertility recommendations on your pasture, you should get a soil test. And, going forward, consider grid sampling and using some level of variable-rate application to get the right fertility to the places in your forage program that most need it.

Putting nitrogen on grass pastures is a bet that you cannot lose. Let me explain: the typical response is that 1 pound of nitrogen gives an additional 20 pounds of forage dry matter. There are some trade-offs: the earlier you start stockpiling, the higher the yield response, but stockpile forage will be more mature and lower in nutrients. And, rain is required.

When talking about stockpiled forage, I like to think of cows as self-propelled forage harvesters, keeping my labor down to moving fences. The way to achieve the highest utilization of the stockpiled fescue is to manage the pasture by frontal strip grazing. With this method, you will be managing cattle grazing behavior. By restricting grazing to strips, you’ll get a more complete forage harvest. In most cases, a new strip is offered every other day. Using this method, harvest efficiency can be better than 70 percent (a similar use efficiency to hay systems).

What makes fescue a high candidate for stockpiling is the fact it retains its nutrient value better than other forages and manages to stay standing. The feed value of stockpiled fescue is usually close to or greater than the nutrient requirements for dry beef cows, and with luck and good management, it comes close to covering energy and protein needs for wet cows of moderate milking ability.

If you are trying to put weight on calves, results might differ. When you test the stockpiled forage, results might indicate you ought to be getting a higher average daily gain than what you actually get. The traditional nutritionist excuse for slow calf gain on stockpiled fescue is to blame endophyte infection. Fescue infected with endophyte will slow intake and performance. If you need to push calves on stockpile, they will respond well to Cadence, Cattle Charge or Full Throttle.

University of Missouri agronomists Rob Kallenbach and Craig Roberts reported that stockpiled fescue typically will have a nutritive quality high enough to support wintering beef cows. Their research show average values of 12 percent crude protein at greater than 36 percent acid detergent fiber and 56 percent neutral detergent fiber. That would be a relative feed value of at least 100 with in vitro digestibilities in the 70s. Of course, there is a tremendous year-by-year variability to nutrient values of stockpiled forages. Snow cover will set you back, and ice is a plan wrecker.

Supplementing the stockpiled forage comes down to an art. You want to balance available stockpile with hay supplies and the cost of supplements along with the body condition or rate of gain you have targeted. The response to supplementation will depend on the availability and quality of the forage.

As a general rule, increasing the degradable protein and energy on stockpiled fescue will improve daily dry matter intake. Using ionophores such as Rumensin and Bovatec will significantly improve animal performance and help cows hold their body condition. Feeding a vitamin and trace mineral source will ensure the herd’s nutrient requirements are covered. You can piecemeal a supplementation or feed something like Cattle Charge as a single-product solution. If you have endophyte-infected fescue, the supplementation helps dilute or reduce the ergot alkaloid load in your animals’ bloodstream.

Dr. Jim White is the Director of Nutrition at MFA Incorporated. Questions? Contact This email address is being protected from spambots. You need JavaScript enabled to view it..

Making hay when the sun doesn’t shine

Written by Dr. Jim White on .

Fire isn’t the only worry–hot hay damages nutritional value

Depending on the operation, hay production can be a high priority or an afterthought shoved out of the way by spring planting. From a feed value perspective, though, it is crucial to minimize risks and losses in the field. It is essential to maintain forage quality and to protect the forage from storage losses.

It is spring. And, certainly, precipitation damage can reduce the quality and mass of harvested forage. Harvests of hay are frequently complicated by poor drying and the threat of unexpected rainfall. You often are forced to choose between baling hay before adequate drying has occurred or subjecting wilting hay to rain damage.

For hay that is not adequately dry, a potential problem is spontaneous heating. This process occurs when plant sugars are respired in CO2, water and heat up via microorganisms–principally fungi.

Traditionally, hay research has used small square bales to study how hay reacts to different conditions. However, due to cost and the limited labor available to handle conventional rectangular hay bales, many producers have been forced to consider larger bale sizes. Generally, larger bale sizes are more prone to heat spontaneously and require a reduced threshold moisture for acceptable storage. In addition, round bales show more measurable effects of spontaneous heating than are usually seen in a small rectangular hay bale. In other words, you’ll more often see brown spots in the middle of big bales.

Of course, brown spots aren’t good, but a hay fire is a total loss. A hay fire leaves you less worried about the nutritional value at stake and more concerned about the loss of a barn.
From personal experience, I can attest that it is really important to know the coverage and limits of an insurance product before a fire, rather than finding out the coverage after a fire. So, let’s concentrate on prevention.

It’s wet hay that causes fires. With adequate moisture to maintain the relative humidity of the air in the hay mass at 95 percent to 97 percent, heat generated by plant enzymatic activity and microbial growth may push temperatures to 160° F within a few days. This progression may take several weeks.

Above 160°F, oxidative chemical reactions are responsible for additional heat generation. This auto-oxidation greatly increases the potential for further rapid increase to combustion temperatures. In some research I’ve looked at, mixed hay at 44 percent moisture took a month to reach a temperature of 195° F, but then increased to 330° F in only three more days. Soluble carbohydrates were almost completely eliminated in the hay that reached 330° F.

Spontaneous combustion requires large quantities of oxygen. Thermal conductivity of dry hay is lower than moist hay, so heat transfer to the outside of the bale becomes progressively less effective as the hay dries. Thus, hay temperatures may increase rapidly after much of the moisture has been removed. Spontaneous combustion occurs near the outside of the bale because oxygen levels in the interior are reduced by microbial respiration.

To avoid hay fire damage
•    Adequate drying is the best solution; dry hay won’t produce heat-inducing fungi
•    Do not stack hay close to power lines, electric fences, trees or buildings
•    Do not park equipment close to hay stacks
•    Ensure adequate separation of stacks–use multiple stacks to reduce the chance of larger loss, especially with suspect hay
•    Exclusion of oxygen is an option: make silage
•    Use anti-mycotics (hay preservers) to allow more time for the hay to dry and knock down microbial growth

Fires are obvious. But bales that don’t get hot enough to burn can still deliver a non-visible loss, nutritionally speaking.

Hay that has gotten hot will test higher for crude protein than what the animal results indicate. It will look brown—and more brown if it was hot for a long time. You’ll also see this process in hay silage crops. They’ll come out looking and smelling like chewing tobacco. In corn silage, you’ll see heat-damaged kernels, which are usually associated with drier or poorly packed silages.

This is significant nutritionally because of what we call ADICP, the crude protein recovered within insoluble acid detergent fiber.

The browning reaction is important because ADICP has very low bioavailability to cattle. That’s what I mean by hay testing higher for crude protein than the livestock indicate.

If you are feeding heat-damaged hay or haylage, expect animals to digest the material at a higher rate (the rate of passage declines and digestibility increases). This often reduces energy intake on the animals, which is a big deal if you have cows that are on the feed to maintain their weight.
ADICP is commonly used as an indicator of heat damage; as hay heating increases, so does the ADICP. And while research is mixed, in general terms, you can count on crude protein in the hay plummeting if it has gotten hot.

Prevention is the best choice.

Dr. Jim White is a MFA's ruminant nutritionist. Contact us at This email address is being protected from spambots. You need JavaScript enabled to view it.

Biosecurity is everyday livestock management

Written by Dr. Tony Martin on .

PED in swine reminds us that prevention is the best defense against livestock disease

PED virus is a relative of the TGE virus that many of us know from previous years in the pork industry. This PED virus came from the Orient, impacts swine in ways very similar to the old TGE, and began creating havoc and massive losses in the U.S. swine industry last June. To date, through the Jan. 17, the disease has been diagnosed in 2,394 laboratory submissions across the USA and has been confirmed in 23 states.

The top five states in number of positive submissions are Iowa, North Carolina, Oklahoma, Minnesota and Kansas. These five states have 82 percent of the positive case submissions. Missouri is on the list with 18 positive submissions. Some of the studies looking at the spread of this virus have found it present on tires of vehicles, inside cleaned livestock trailers/trucks, and, believe it or not, on the floor of convenience stores frequented by producers and employees.

I won’t spend time on the details of the disease and I don’t want to create a “germophobic” state of mind, but this disease and its devastating effects on infected herds should serve as a reminder to every livestock producer of any species that preventing disease entry into their production operation should be one of the focal points of their management efforts. 


Biosecurity is most simply preventing the entry (external biosecurity) and spread (internal biosecurity) of disease in a livestock operation. It requires attention to items coming into the operation (animals, people, equipment, products and services) to make sure they aren’t carrying infectious agents that could be presented to the herd. It also requires attention to how things are done within the operation. It is important to think through exposure points when handling sick animals. Make biosecurity an integral part of logistics as you move feed, equipment and animals from one area of the operation to another. And remember, people moving from place to place should observe biosecurity protocols  to minimize spread of disease if it occurs. We’ve been reminding producers and our own MFA employees that products, people, equipment and animals can play a role in disease spread. 

The early season jackpot and regional shows have begun. As you go to shows, whether you take animals or not, think about biosecurity as you come back home to your own operation. Boots and coveralls can carry disease back home. 

If you take animals to shows, preventing disease may require equipment cleaning and quarantine of show animals returning to the home place. Much the same can be said about visits to livestock auctions and bringing new or replacement animals home.

This discussion is sure to evoke thoughts of extra work and inconvenience. But that is what it takes to do the job right and help prevent disease and the production loss it can create. I read a quote from a veterinarian from Ohio this week that stated, “If biosecurity doesn’t inconvenience you…  you aren’t doing it right.” Doing the extra work and dealing with the inconvenience takes perseverance and encouragement. Be that source of encouragement and remind your customers and coworkers in agriculture about the daily importance of biosecurity.

And the subject could be good discussion and education point for your non-agricultural friends and neighbors! 

Calf scours is a common setback

Written by Dr. Jim White on .

Good nutrition and vigilant care can limit loss

Calf scours is costly to your herd. Most veterinarians tell me the general causes of calf scours are infectious bacteria such as E. coli, salmonella or clostridia. Or the source can be viruses such as rotavirus, coronavirus or BVD. And finally, parasites such as coccidian or crypto can cause scours.

Livestock pass these disease agents through manure. As animals shed these infectious agents, their bacteria and virus numbers build up where animals spend the most time.

Overcrowding particularly exacerbates the problem—causing the infectious agents to drastically increase in the environment (additional stress leads to increased shedding).

Scours affect calves most often through dehydration and altering the animal’s acid/base balance. Additionally the lining of the intestine becomes inflamed. If the calf has enteritis, its ability to absorb nutrients is reduced and its growth rate is negatively affected. Some infectious agents, say clostridia, can release endotoxins that can kill the calf.

These infectious agents are very common, yet frequently they are seen in some places and not in others. This variability goes to show there are many factors in the incidence of infection and disease among livestock. Some variables include genetics (some lines are heartier than others), nutrition, underfeeding protein and available energy. Lack of vitamins or minerals can significantly influence calf performance as well.

The dam is another factor–calves from heifers tend to be at greater risk than the calves of mature cows.

Stocking rates affect the incidence of scours. Overcrowding barn lots increases the chance of scours, and the longer cows are in an area, the greater the buildup of infectious agents. Of course wet and cold weather, which makes the herd pack together, increases the load of infectious agents. In fact, wet conditions in general give scour-causing agents a better chance to infect hosts. You’ve all seen it: cows lay down in the slop; calves suck their dirty teats and the disease agents are introduced to the calf.

The herd and individual dam’s vaccination/immune status also has an affect on the incidence of scours. A healthy dam will produce antibodies to counter disease organisms and store them in her colostrum. One of the most important things in a calf’s life is to get adequate quality and quantity of colostrum.

What to look for
Usually when calves are scouring, they will look weak, depressed and have lost their desire to eat. They will develop a sunken-eyed appearance due to dehydration. They will appear listless, and might be too weak to stand. At this point it is likely their future is short.

Depending on the cause(s) and the severity of the infection, a case of scours in a calf can last anywhere from a day to two weeks. During this time, you’ll observe watery fecals. Fecals may be off-color or may contain blood or mucus. Fecals with significant blood are usually associated with infections by coccidian, salmonella or clostridium bacteria.

Prevention and cure
One of the best prevention paths for scours is to feed a high-quality supplemental feed like Cattle Charge. Even better, you can simply follow Health Track protocols for all growing animals. It builds immunity and provides needed nutrients.

Because many of the infectious agents that cause calf scours are shed by healthy cows and calves, it is not considered practical to expect to prevent scours from ever occurring on your farm. Instead, you should work toward a target to have no more than two or three percent of your calf crop develop scours.

Maintain a clean calving area. Do not calve on pastures where cows have been kept in large numbers for long periods of time. If possible, segregate calves by age to prevent passage of infectious agents from apparently healthy, older calves to newborns. This usually entails moving cows that have not calved into new pastures while keeping pairs in pastures where the calves were born. Pregnancy exams can be used to sort cows into early and late-calving groups.

Sloped or drained areas will tend to be drier and cleaner for cattle. If pastures cannot be rotated, consider dragging the pasture to increase the dispersion and drying of manure.

It is critical that all calves receive adequate colostrum as soon as possible after birth. If the birth was difficult, the dam may be tired and hurting. And, the calf might also be weakened. Under either circumstance, the calf might fail to nurse. In these cases, the calf should be fed colostrum. You can get colostrum replacers from your local MFA.

Vaccinating the cow herd against scours-causing diseases will help increase immunity to the disease. Work with your veterinarian to develop an effective program. When vaccinating cattle, ensure that they are getting adequate energy, protein, vitamins and minerals (supplemental feed will help ensure that they are in good enough condition to get the proper response from the vaccine).

Treating scours
Many of the bugs we’re talking about here also affect people, so when you’re working with infected animals, wear gloves. Thoroughly wash and disinfect clothing, equipment and anything in contact with the sick calves. From a practical perspective this means you should do chores among healthy calves first, then work on the sick ones (and then clean and disinfect).

The principle objective of treating scours is to get lost water and electrolytes back into the calf. This is “fluid therapy” and the intent is to relieve the dehydration, correct the animal’s acid/base balance, replace cations (sodium, potassium) lost in the scours. For rough figuring, expect calves to need a gallon of fluids each day. The faster they tighten up, the happier you’ll be. Letting them drink on their own is what you hope for, but if they won’t or can’t drink enough on their own, there a couple ways to introduce fluids.

Orally: if the calf can stand, grab it and dose with an esophageal feeder. Always follow label directions when making up the electrolyte solution, this will typically mean using plain, clean water to make the solution. I resist the temptation to make it better by adding some of the secret ingredients you hear about: vinegar, evaporated milk, corn syrup solids, etc.

Intravenous: obviously this is for very weak calves–ones that can’t stand and look like they might end up in the mortality column. You and your vet need to work out the path forward for treating such calves.

Scouring calves frequently do not want to nurse, they tend to lay about and shiver. Keeping them warm, hydrated and fed an energy source will do much to help them get over the incident. Scours may require a course of antibiotics. If that’s the case, your veterinarian will be of great help determining the appropriate antibiotic treatment.

Dr. Jim White is a Ruminant Nutritionist for MFA Incorporated. READ MORE OF DR. JIM WHITE'S ARTICLES HERE.


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