Skip to main content

Spring Manure Applications

Carefully Approach Spring Manure Applications

Appropriate timing is an important part of efficient manure application.

At this time of year you may be looking at a full manure storage and desire to get an early jump on application for the coming growing season. Patience can pay off in the form of manure nutrient conservation. After all, the goal of manure application is to place valuable nutrients on the soil where they are needed and to keep them there. A large part of this equation is timing. The closer the nutrient is applied to actual crop need the better.

The goal of manure application is to place valuable nutrients on the soil where they are needed and to keep them there.

Application of nutrients during times of snow-cover, frozen soil, or saturated conditions increases risk of nutrient loss. Once a nutrient passes the field edge it is lost to the environment – and lost from crop uptake. A fraction of both nitrogen and phosphorus in manure will be present in soluble forms. If the liquid solution of manure can infiltrate the soil then soluble nutrients will infiltrate with the liquid to a location that is safe from overland runoff. The ammonium nitrogen fraction will also be safe from volatilization after it is beneath the soil surface. Frozen, snow-covered, and saturated soil conditions hinder infiltration. Spring rain events can carry both the soluble and solid portions of manure from the field.

If you must apply manure before conditions are ideal, you should go to fields specifically listed in your nutrient or manure management plan to receive manure during the current season. Some things that limit risk of manure nutrient loss include fields with shallow slopes, fields with a perennial crop such as hay, fields with a cover crop, fields with lots of crop residue, and fields that are more distant to water. You should prioritize the order of manure application according to risk and go to the least risky fields first.

Because infiltration can be limited at this time of year, extreme runoff events can occur. For instance, snow melt or rain on frozen or snow-covered ground can cause runoff to occur from lands that rarely lose water. For this reason, it is wise to skip subtle swales in these fields where water can gather and flow. Nutrients placed here certainly won’t stick around. These shallow depressions can be covered with manure later in the spring when risk is lower. Pay attention to the weather forecast, and avoid situations where you expect upcoming weather may undo the nutrient placement work you have done.

What Makes a Cow Fertile?

Why do cows fail to get pregnant when you do everything right? Having a healthy cycling cow in heat, bred by an experienced technician is not enough to ensure a viable pregnancy. There are two crucial things that must occur prior to breeding for any real chance of producing an embryo that will survive to term.

High Progesterone

The first essential item for a lasting pregnancy is high progesterone. Not the progesterone needed to sustain the pregnancy once it has been created, but progesterone prior to fertilization. Numerous studies eshow for the developing oocyte to be able to fertilize and make an embryo that will survive to term, it must grow under high progesterone during its last days prior to ovulation.

The second critical factor to producing a viable pregnancy is to ovulate a follicle that is not too old and degenerate or too young and immature. To make an embryo that is the strongest and survives the best, we must breed a fresh, competent oocyte (the unfertilized egg, which is released from the follicle), and this is often a problem for lactating dairy cows. There are a high percentage of natural heats that ovulate aged dominant follicles. These cows often appear as strong heats, have great mucous and uterine tone, but the oocyte is aged. Most of these aged oocytes will fertilize, but they make small weak embryos that do not survive well.

Both follicle competency and adequate progesterone during its development are essential for maximizing fertility. It is the reason some dairies are attaining conception rates exceeding 60% using first-service synchronization programs such as the G6G or the Double Ovsynch. Interestingly, when you look at the last three injections in these two popular programs, it’s still the original Ovsynch program that finishes them.

Enhance Survival

The only difference in these programs is the shots that precede the Ovsynch. Those are meant to synchronize cows at around days five to eight of their cycle. At this time most lactating cows have a next follicular wave large enough to ovulate, and the first GnRH injection of the Ovsynch is meant to get rid of older, less fertile follicles/oocytes.

Starting cows around days five to eight of their cycle results in higher ovulation rates. By removing the dominant follicle and its hormones, we start a new follicular wave that will ovulate a fresh oocyte, making an embryo that has the best chance of surviving. Another benefit of starting cows in Ovsynch at that time is most cows will have an active corpus luteum (CL) producing enough progesterone to grow a fertile follicle/oocyte.

These first service programs attain amazing conception rates, but what about the cows that do not conceive? How do we resynchronize them if we fail to observe a standing heat or our conception rates are too low with natural heats?

In subsequent articles I will discuss the challenge in managing these cows reproductively and some strategies to apply to achieve higher conception rates.

Don’t Fall Behind with Coccidiosis

Among the “biggies” of pathogens that cause scours in both pre- and post-weaned calves is coccidia, a parasitic protozoa that sets up shop in the intestinal tract of cattle. Eggs are produced internally and pass into the environment via shedding in manure.

Shedding of coccidia “eggs” or oocysts by infected calves and heifers usually peaks about 3 weeks after initial exposure. In one study the peak numbers of oocysts shed per day by untreated infected calves was 50,000,000 on day 21! Older, immune animals continue to contaminate their environment at a much lower — but consistent — rate. These facts tell us that from the moment a calf is born, she is very likely to get some of these oocysts in her mouth.

Don’t fall behind – reduce exposure of newborn and older calves

Once a newborn calf stands up, she is in a perfect situation to begin getting coccidia eggs in her mouth. Licking the dam’s hair coat, searching for a teat to suck, and licking on anything in her environment, unfortunately, all are generous sources of coccidia eggs. Moving her to a cleaner space does work to cut exposure.

Among older calves, we should think about ways to reduce their shedding rates (that is, the rate that she passes coccidia eggs in her feces):

  • Create clean, well-bedded resting space for calves.
  • Optimize ventilation in the barn and calf or heifer pens.
  • Provide adequate feed space per animal.
  • Minimize weight and age variation between animals in the group.
  • Avoid feeding on the ground unless it is at a bunk.
  • Provide 12″ of linear water space per 10 animals.
  • Treat infected animals.
  • Maximize time between successive occupants of the same pen.

Managing infections – building immunity

On nearly all dairies, all animals will eventually be exposed to coccidia. Through natural exposure, they will build immunity that suppresses infection. If the exposure of young calves can be managed to maintain a low level of infection, they can build immunity without excessive damage to their gut and loss of normal growth.

So, what can we do if natural exposure rates are uncontrolled (and likely to be high)? Use one of the feed additives that act to control coccidia activity in the calf after exposure. The four additives approved for use in the United States include:

  • Deccox®-M [decoquinate] – available in milk replacer, or powder, mixed with milk to make suspension
  • Bovatec® [lasalocid] – available in milk replacer, liquid additive to mix with milk
  • Rumensin® [monensin] – added to dry feeds like calf starter grain
  • Corid® [amprolium] – liquid can be added to milk or milk replacer, or dry crumble

When used as prescribed, all of these additives limit the population of coccidia in the gut. Their effectiveness is shown in studies in which the shedding rates have been reduced about 96 to 98 percent.

Preclinical use of the additives is recommended. Damage in the gut due to uncontrolled growth of coccidia will occur as early as 5 days after coccidia exposure. Thus, don’t wait until clinical symptoms are present to begin using the additive that you and your veterinarian believe is best for your situation.

What You Can’t Do With a VFD

For some time now, livestock producers and veterinarians have been gaining an understanding of the new Veterinary Feed Directive (VFD) rules. These rules went into effect on January 1, 2017, and as the year progressed, livestock producers have been confronting what those rule changes mean for their own operations. Before January 1, feed-grade antibiotics such as chlortetracycline (CTC) for their animals could be purchased and used by livestock producers without any input from a veterinarian. Now, in order to use those medications, a VFD form from a veterinarian must be obtained.

Understanding the New Rules

As all parties have quickly discovered, the VFD process is more than just having a vet’s signature on a scrap of paper. Because there is no allowance for using feed-grade medications in an “off-label” manner, veterinarians completing the VFD’s have had to pay exquisite attention to every detail on the label, including the dose, duration of feeding, reasons (disease treatment vs. control) for feeding, and the diseases the medication could be used for.

For many cattle producers, the fall of 2017 has been the first time they’ve encountered this new way of doing business. Issues with pneumonia post-weaning, or following arrival of feeder cattle have always been challenges. In past years, uses of CTC in cattle feed have been subject to very little oversight, and some of those uses, although well-intended, were off-label. With the onset of the new rules, producers are having to square their previous treatment methods with what a VFD can – or can’t – allow them to do.

  • Refills
    A VFD can’t provide for refills, like a prescription one might get from a family doctor. This means a producer can’t use the same VFD form to come back and get another quantity of medicine if it’s determined to be needed later on.
  • Expiration Dates
    All VFD’s have expiration dates, and that’s a point of confusion as well. A VFD actually expires when the treatment is done (or the expiration date is reached – whatever comes first). Even though a VFD might not expire until February (authorizing a treatment any time until then), if a 5-day treatment is finished in November, the VFD is finished too.
  • Repeat Treatments
    A VFD can’t contain a statement authorizing a “retreatment as needed” or “repeat treatment in xx days.” An animal can’t show up on a VFD form more than once. If another round of treatment is necessary, a veterinarian will have to issue another VFD for the second treatment. That means that some groups of cattle might need 2 or 3 separate VFD’s written for them.
  • Animals Covered
    A VFD can’t be written for more animals than the veterinarian expects you’ll have on the farm. The veterinarian is responsible for indicating the number and location of the animals to be treated. This might get a little tricky for producers who buy several groups of feeder calves over time. Veterinarians might decide to only write the VFD for what is currently on the farm, or they could write it for the number eventually expected, if they are confident that number will be eventually procured.
  • Pneumonia 
    A VFD can’t be written to treat or control pneumonia when there isn’t any pneumonia in the cattle. In the past, it was not uncommon for treatment doses of CTC to be fed to cattle to “get ahead of” an outbreak, or to “clean up” the calves’ respiratory tract in anticipation of problems. When treatment doses are authorized by a VFD, this implies that active pneumonia is present in the group. It doesn’t mean producers have to wait until each and every calf is sick – but clearly, CTC labels don’t allow for using treatment doses in a group of completely healthy calves. This is the veterinarian’s call. If their clinical judgement tells them there’s pneumonia present in the group, they can write the VFD.

In Summary

It’s understandable that some livestock producers are feeling pinched by what a VFD can’t do. However, these new rules can do one very valuable thing: giving livestock producers an opportunity to interact with the one local professional who can best guide them through health-related decisions about their animals – their veterinarian. Since the VFD’s implementation, many of these interactions have resulted in more effective and efficient use of these tools and consideration of disease prevention methods that preclude the need for antibiotics. These conversations are definitely a positive by-product of these new regulations.

Forage Analysis: What Numbers Do I Need

One the more common questions I receive with regard to analytical testing of forages and other feedstuffs is, “I have the sample, now what do I test for or what analysis package should I select?”

The basic components that nutritionists need to evaluate a feedstuff or develop a ration are dry matter or moisture, crude protein, an estimate of the energy content of the feedstuff — Total Digestible Nutrients (TDN), Net Energy for Maintenance (NEm), Net Energy for gain (NEg), and the macro minerals, Calcium and Phosphorous. These are the most basic numbers that are required but including some additional analyses in the report can give us additional insight into the quality of the feedstuff or improve our ability to predict animal performance, which is the primary reason we analyze feedstuffs.

I recommend that the report include acid detergent fiber (ADF) and neutral detergent fiber (NDF).  The amount of NDF in forage reflects the amount of cell wall contents (hemicellulose, cellulose, and lignin) within the sample. The NDF fraction is often associated with the respective bulkiness of forage and is correlated with dry matter intake of the forage or feedstuff. Therefore, the amount of NDF may be used to estimate the expected dry matter intake associated with the forage.  The ADF number represents the amount cellulose and lignin within the forage and is correlated with the respective digestibility of the forage.  In general, a higher ADF value is associated with forage that has a greater proportion cellulose and lignin and would likely be a more mature. Additionally, the ADF fraction is used to calculate the energy estimates TDN, NEm, and NEg that appear on the report. There are a number of different mathematical equations that the testing laboratory may use to calculate these numbers, based on the type of sample (corn silage, alfalfa, grass hay, etc.). If the ADF is included in the report, the nutritionist can adjust or recalculate the energy estimates if necessary.

If the forage will be fed in combination with a byproduct feed such as wet distiller’s grain, including an analysis for sulfur can be beneficial if the forage will be used in a growing or feedlot ration.  Additionally, if the forage is a known nitrate accumulator (forage sorghums, sudangrass) or may have been stressed due to drought, including a nitrate analysis should always be considered, especially if the forage will be fed to pregnant cows.

Most analytical laboratories have a number of different analysis packages which encompass the most common procedures or numbers that a nutritionist or producer needs to know about their feeds. These packages will typically include the basic procedures (DM, CP, TDN) and then add on specific analyses such NDF, or the Macrominerals (Ca,P, Mg, K, Na, Cl, S). Some laboratories may group analysis packages by the type of sample (Forage, vs. mixed ration) or production purposes (dairy vs. beef).

The objective of analytical testing of forages and feedstuffs is to improve our ability to meet the animal’s nutrient requirements and ultimately predict animal performance. The unequivocal best method of evaluating the quality of a feedstuff is feeding the feedstuff to an animal and evaluating performance over a set period of time, under a specific set of conditions. Since that would not be cost effective or timely, analytically evaluating feedstuffs in a laboratory is the next best the thing and although it is not perfect, it is unequivocally better than the “this looks like really good stuff” method of evaluating feedstuffs.

Prussic Acid and Nitrate Poisoning are Concerns After a Light Frost

Although late October has been very warm and “summer-like”, the average first frost date for much of the Southern Plains is here.  Soon a cold front will bring near-freezing to sub-freezing nighttime temperatures

It was discovered in the early 1900s that under certain conditions sorghums are capable of releasing hydrocyanic acid or commonly called prussic acid.  Prussic acid when ingested by cattle, is quickly absorbed into the blood stream, and blocks the animal’s cells from utilizing oxygen.  Thus the animal dies from asphyxiation at the cellular level.  Animals affected by prussic acid poisoning exhibit a characteristic bright red blood just prior to and during death.  Lush young regrowth of sorghum-family plants are prone to accumulate prussic acid especially when the plants are stressed such as drought or freeze damage.  Light frosts, that stress the plant but do not kill it, are often associated with prussic acid poisonings.

Producers should avoid grazing fields with sorghum type plants following a light frost.  The risk of prussic acid poisoning will be reduced, if grazing is delayed until at least one week after a “killing freeze”.  As the plants die and the cell walls rupture, the hydrocyanic acid is released as a gas, and the amount is greatly reduced in the plants.  One can never be absolutely certain that a field of forage sorghum is 100% safe to graze.

Cattle that must be grazed on forage sorghum pastures during this time of year should be fed another type of hay before turning in on the field, and should be watched closely for the first few hours after turn in.  If signs of labored breathing, such as would be found in asphyxiation, are noted, cattle should be removed immediately.  Call your local veterinarian for immediate help for those animals that are affected.  Be certain to read OSU Fact Sheet PSS-2904 “Prussic Acid Poisoning” before turning cattle to potentially dangerous fields.

Frosts also stress the plant before a hard freeze kills it.  Plant stress from frosts will impair the normal metabolism of the plant.  Therefore the plant continues to take up nitrates from the soil but is inefficient at converting the nitrates to protein.  Therefore nitrate accumulations may reach dangerous levels.  Testing the forage before grazing or cutting for hay will provide important knowledge about the safety or danger in the forage.  Visit with an OSU County Extension office about testing procedures and read OSU Fact Sheet PSS-2903 “Nitrate Toxicity in Livestock”.

Five Colostrum Storage Tips

Maintaining colostrum quality should be a huge priority on the dairy. The quantity of colostrum a calf receives does not matter if the colostrum is junk. Here are five tips to ensure you’re storing and handling colostrum properly.

1. Don’t pool raw colostrum. Even if the colostrum is going straight into storage it should never be pooled, according to Kimberley Morrill, PhD regional dairy specialist Cornell Cooperative Extension.

2. Feed or refrigerate colostrum within one hour of collection. Colostrum can be stored in the fridge or the freezer. According to research from the National Animal Health Monitoring System of the dairy producers who store colostrum, 21% store it in the fridge and 73% of producers store colostrum in the freezer.

3. If storing in the fridge, only keep colostrum for one week. After that, Bethany Lovaas, DVM University of Minnesota, says quality declines. “If you refrigerate colostrum, be sure that the refrigerator is cold (33 – 35 degree F) to reduce the onset of bacterial growth,” she says.

4. Keep frozen colostrum for six months or less. While not everyone agrees on how long frozen colostrum can be stored without damage to the antibodies, Faith Cullens of Michigan State University Extension says most researchers agree the six month mark is safe.

5. Thaw frozen colostrum with warm water or a microwave. “The main concern regarding thawing frozen colostrum is to thaw the ice without degrading the immune proteins,” says Lovaas. She adds colostrum is best thawed with warm (not hot) water. Add more water to the bath as the frozen colostrum cools down the water. Alternately, Lovaas says colostrum can be thawed in a microwave oven with little damage to the Ig. “It is important to microwave the colostrum for short periods on low power,” she says.

 

Maintain Your TMR Mixer

Mixer Wagon Maintenance

Want to get the most life out of your mixer while maintaining a high quality mix? Maintenance is the answer. Mixer maintenance, beyond greasing, is often overlooked but Mike Everson, a field support representative with Kuhn North America says taking the time to do it is crucial.

“We like to take care of our cattle, mixers need to be maintained on a weekly and monthly basis also,” he says. “We look at the outside on a daily basis but very seldom do farmers look inside.”

Everson recommends farmers take a look inside their mixer at the knives, scrapers and shoes every 90 days. Knives should be sharp. If your mixer wagon’s knifes are beginning to look like butter knives, it’s time to replace them.

“Sometimes a small investment in new knives or scrapers can make a world of difference,” he says.

Also look at the “shoe” at the base of the auger. According to Everson, this is a very inexpensive part, but one that is worn is often the cause of poor mix quality.

“The shoe is the lifeblood of a vertical mixer,” he says.

Everson’s biggest advice? Dig your operating manual, see what the manufacturer recommended for maintenance intervals and then actually follow their guide.

“Maintaining your mixer will insure good mixing quality for the lifetime of the mixer,” he says.

Build silage piles correctly

By Jim Dickrell 

With large crops of forages coming off fields this fall in many areas, some farmers might be storing silage in piles for the first time.

Constructing these piles correctly spells the difference between having good quality forage or a spoiled mess, says Jerry Clark, an Extension soil and water educator in Chippewa County, Wis.

“Without proper packing, silage losses can easily exceed 30% of ensiled dry matter,” he says. “With proper management, silage piles serve as a short-term storage option with dry matter losses as low as 15%.”

The first step is to construct storage piles on a solid, well-drained surface. Concrete or asphalt slabs are preferred. Barring that, well packed surfaces underlain by geotextile fabric can work. The pads should be constructed above existing ground level to ensure rainfall and silage seepage runoff, Clark says.

“To ensure well safety and prevent water contamination, silage piles should be at least 100′ away and down slope from any existing well,” he adds. “On lighter soils, or with shallow well depths, this distance should be even greater.”

Piles should be constructed using the wedge method, with a 3:1 maximum side slope for safety. “Systems that have steep side slopes will [also] have inadequate sideslope packing and appreciably higher silage losses on the side,” Clark explains.

Forages should be added to the pile in thin layers no more than 6″ in depth. Forage moisture should be at least 65% to 70% at ensiling to improve packing.

“When constructing the pile, plan for at least 12″ of feed removal per day,” he says. Such a feed out rate is needed to minimize spoilage, though lower rates can be removed during cold weather.

“Therefore, when planning for a 270-day (nine month) feed storage period, the length of all piles should add up to 270′ long.”

Piles should also be covered as soon after the pile is completed as possible A 6-mil black plastic sheet should be used, weighted down with tires over the entire surface, and sealed along the sides of pile.

Protecting Your Animals This Summer

As it gets further into the summer months, livestock begin to show express a common discomfort as humans do: sunburn. Exposure to UV radiation can cause skin damage to dairy cows, light-colored beef cattle, sheep, pigs, and horses. Affected skin becomes red, painful and raised, which can lead to the skin becoming extremely dry and will eventually slough off leaving those areas exposed to secondary infections.

A cow losing patches of its coat due to sunburn
A cow losing patches of its coat due to sunburn

Sunburn not only makes the animal uncomfortable, it affects their overall productivity and performance. The body takes the nutrients that is needed for growth and uses them to repair the skin that is damaged. In dairy cows, this can lead to a decrease in milk production and in sheep, a decrease in wool quality. Sheep can be burned sheared or unsheared since the radiation is strong enough to penetrate through the wool. Pigs are one of the lucky animals that can protect itself form the suns rays. By wallowing in mud, the pig is forming a protective coating that shields the skin from the sun. Light coated animals are not as lucky. Cows and horses with predominantly white coats suffer more sunburn than those with dark coats. However, dark coats absorb more sun, which leads to more symptoms of heat stress.

UV radiation isn’t the only determinant of sunburn in animals. Animals that feed in wheat pastures with certain weeds are likely to develop photosensitivity. This is caused by a reaction within an animal’s body when the chlorophyll in some wheat plants release a toxin that increases sensitivity to the sun. Weeds such as barley, alsike clover, St. John’s Wort, nettles and others are some of the culprits in photosensitivity and can also be the causes of liver damage and neurological disorders that develop in the animal.

Preventing sunburn doesn’t just mean keeping them out of the sun, although providing a shady place for the animals can definitely help. If the sun is a concern, baby formula sunscreen can protect the areas that are more vulnerable to sunburn. Another way of decreasing sunburn is restricting the access of wheat pasture the animal is consuming to prevent photosensitivity. Adding grass hay in the morning when grazing intake is high helps in restraining the animal from consuming too much wheat during those times.