Potential for Nitrate Problems in Drought Stressed Corn

Source: Peter Thomison, Laura Lindsey, OSU

Have very dry soil conditions increase the potential for toxic levels of nitrates in corn harvested for silage? Nitrates absorbed from the soil by plant roots are normally incorporated into plant tissue as amino acids, proteins, and other nitrogenous compounds. Thus, the concentration of nitrate in the plant is usually low. The primary site for converting nitrates to these products is in the growing leaves. Under unfavorable growing conditions, especially drought, this conversion process is slowed, causing nitrate to accumulate in the stalks, stems, and other conductive tissue. The highest concentration of nitrates is in the lower part of the stalk or stem. For example, the bulk of the nitrate in a drought-stricken corn plant can be found in the bottom third of the stalk. If moisture conditions improve, the conversion process accelerates and within a few days, nitrate levels in the plant return to normal.

The highest levels of nitrate accumulate when drought occurs after a period of heavy nitrate uptake by the corn plant. Heavy nitrate uptake begins at the V6 growth stage and continues through the silking stage. Therefore, a drought during or immediately after pollination is often associated with the highest accumulation of nitrates. Extended drought prior to pollination is not necessarily a prelude to high accumulations of nitrate. The resumption of normal plant growth from heavy rainfall will reduce nitrate accumulation in corn plants, and harvest should be delayed for at least 1 to 2 weeks after the rainfall. Not all drought conditions cause high nitrate levels in plant. If the soil nitrate supply is low in the dry soil surface, plant roots will not absorb nitrates. Some soil moisture is necessary for absorption and accumulation of the nitrates.

If growers want to salvage part of their drought damaged corn crop as silage, it’s best to delay harvest to maximize grain filling, if ears have formed. Even though leaves may be dying, the stalk and ear often have enough extra water for good keep. Kernels will continue to fill and the increases in dry matter will more than compensate for leaf loss unless plants are actually dying or dead. Moreover, if nitrate levels are high or questionable, they will decrease as the plant gets older and nitrates are converted to proteins in the ear.

Making Corn Silage in Dry Conditions

Source: Bill Weiss, OSU

The primary goal of making corn silage is to preserve as many nutrients in the corn plant as possible, to produce a feed that is acceptable to cows, and to minimize any risks associated with feeding the silage.  The following are important considerations for making corn silage when growing conditions have been dry.

Chop at the correct dry matter concentration (Editor’s note: see accompanying article “Corn Silage Harvest Timing”). Drought-stressed corn plants are often much wetter than they appear, even if the lower plant leaves are brown and dried up.  Before starting chopping, sample some plants (cut at the same height as they will be with the harvester) and either analyze DM using a Koster tester or microwave or send to a commercial lab (turn-around time may be a few days if you send it to a lab).  If the plants are too wet, delay chopping until the desired plant DM is reached.  The plant may continue to accumulate DM (increase yield), and you will not suffer increased fermentation losses caused by ensiling corn that is too wet.

Use a proven inoculant.  When silage is worth upwards of $80/ton (35% DM) reducing shrink by 2 percentage units has a value of about $2/ton. Homolactic inoculants (these are the ‘standard silage inoculants’) produce lactic acid which reduces fermentation losses but sometimes can increase spoilage during feedout. The buchneri inoculants increase acetic acid which slightly increases fermentation losses but greatly reduce spoilage during feedout.  Severely drought-stressed corn can have a high concentration of sugars because the plant is not depositing starch into the kernels.  High sugar concentrations can increase spoilage at feed out because it is food source for yeasts and molds.  Use of a good (from a reputable company with research showing efficacy) buchneri inoculant may be especially cost-effective with drought-stressed corn.

Check for nitrates.  Drought-stressed corn plants can accumulate nitrates which are toxic (as in fatal) to ruminants.  Silage from drought-stressed fields should be tested before it is fed.  Ideally, corn plants should be sampled and assayed for nitrates prior to chopping (most labs offer very rapid turn-around times for a nitrate assay).  If values are high, raising the cutting height will reduce nitrate concentrations in the silage because the bottom of the stalk usually has the highest nitrate concentrations.  Because forage likely will be very limited this coming year, do not raise the cutting height unless necessary to reduce nitrate concentrations.  Nitrate concentrations are often reduced during silage fermentation so that high nitrates in fresh corn plants may end up as acceptable concentrations in the fermented corn silage.  Silage with more than 1.5% nitrate (0.35% nitrate-N) has a high risk of causing nitrate toxicity in cattle.  See the following University of Wisconsin-Extension fact sheet for more details on nitrate toxicity: https://fyi.extension.wisc.edu/forage/nitrate-poisoning-in-cattle-sheep-and-goats/

Chop at correct particle length.  Do not chop too finely so that the effective fiber concentration of corn silage is reduced.  If the corn plants have limited ear development, fine chopping is not needed for good starch digestibility.  Generally, a theoretical length of cut (TLC) of about ½ inch is acceptable (longer with kernel processing and BMR silage) but this varies greatly between choppers and crop moisture concentration.  If using a Penn State particle size sieve, aim for 5 to 10% on the top screen.

Use a kernel processor.  Kernel processed corn silage tends to pack more densely than unprocessed corn silage which may help increase aerobic stability.  Kernel processing will also increase starch digestibility by breaking the kernel.  Poor starch digestibility is a major problem with dry, mature corn silage.

Reduce Shrink. Fill quickly, pack adequately, cover, and seal the silo as soon as you are done filling.  Practicing good silage-making techniques can reduce shrink by more than 5 percentage units, which can be worth more than $4/ton of corn silage (35% DM).

Farm animals and COVID-19: Should you be worried?

With the rapid spread of the new coronavirus believed to have started in bats, some people might be genuinely concerned about their farm animals. Could the animals catch COVID-19?

The answer is murky.

While there have been no reported cases of pigs, horses, sheep, chickens, or cows getting COVID-19, their susceptibility to the respiratory disease has yet to be studied.

And though some pigs have been able to get COVID-19 in lab studies, it does not appear that they can catch or spread the virus very easily, said Scott Kenney, an assistant professor of veterinary preventive medicine at The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES).

“There are a lot of unknowns,” Kenney said.

What is known is that ferrets, minks, domestic cats, and some dogs have become infected with COVID-19. But neither pets nor farm animals are thought to play significant roles in transmitting COVID-19.

Kenney, whose research focuses on viruses that spread from animals to people, is pursuing grants with colleagues to study whether various farm animals are susceptible to COVID-19. He will address the risk of animals catching or spreading COVID-19 during “Ask the Expert” presentations Sept. 22–24 at this year’s Farm Science Review, an all-virtual show sponsored by CFAES.

Kenney’s talks will be from 11:40 a.m. to noon on Sept. 22 and from 1:20 to 1:40 p.m. on both Sept. 23 and Sept. 24 at fsr.osu.edu.

For the first time in its nearly 60-year history, FSR will be exclusively virtual with livestreaming and prerecorded talks and demonstrations about the latest in research and farm technology. The show is free, but “visitors” must register before they can access all of the presentations.

The novel coronavirus that causes COVID-19 is but one of many viruses in recent years that started in animals, then mutated and adapted so that it could spread to people. Viruses, in general, have been increasingly shifting from animals to people, particularly in the developing world, as people cultivate more and more acres that were once isolated forests and come into contact with wildlife.

While people are currently far more likely to catch COVID-19 from other people—rather than from their farm animals or pets—it’s still important for farm workers to wear masks at work, Kenney said.

And if they are sick, farmers would do best to avoid being around their animals and have someone else work with them instead, if at all possible, he said.

“Instead of thinking, ‘Oh, my animals can’t catch my cold,’ it’s important to consider that these animals could breathe in your virus. It only takes a couple of mutations for these viruses to switch to another species,” Kenney said.

As a farmer moves from one building to another on a farm, washing off boots and using a hand sanitizer before leaving each building would help cut the risk of spreading illnesses, Kenney said.

“More frequent washing means they are less likely to carry germs from one pen to the next or home with them.”

To register or find out more about the offerings at this year’s Farm Science Review, visit fsr.osu.edu.

Corn Silage Harvest Timing

Source: Mark Sulc, Peter Thomison, Bill Weiss, OSU

Silage harvest has begun in some parts of Ohio. Proper harvest timing is critical because it ensures the proper dry matter (DM) concentration required for high quality preservation, which in turn results in good animal performance and lower feed costs. The proper DM concentration is the same whether it is a beautiful, record breaking corn crop or a severely drought stressed field with short plants containing no ears.

The recommended ranges for silage DM are:

Bunker: 30 to 35%

Upright: 32 to 38%

Sealed upright 35 to 40%

Bag: 32 to 40%

Chopping corn silage at the wrong DM concentration will increase fermentation losses and reduce the nutrient value of the silage.  Harvesting corn too wet (low DM concentration) results in souring, seepage, and storage losses of the silage with reduced animal intake. Harvesting too dry (high DM concentration) promotes mold because the silage cannot be adequately packed to exclude oxygen. Harvesting too dry also results in lower energy concentrations and reduced protein digestibility.

Corn silage that is too dry is almost always worse than corn silage that is slightly too wet. So if you are uncertain about the DM content, it is usually better to err on chopping a little early rather than a little late. Follow the guidelines below to be more confident in your moisture assessment.

Kernel stage not a reliable guide for timing silage harvest

Dry matter content of whole plant corn varies with maturity.  Research has shown that the position of the kernel milk-line is NOT a reliable indicator alone for determining harvest timing. Geographic location, planting date, hybrid selection, and weather conditions affect the relationship between kernel milk-line position and whole plant DM content. In a Wisconsin study, 82% of the hybrids tested exhibited a poor relationship between kernel milk-line stage and whole-plant % DM. In Ohio we have seen considerable variation in plant DM content within a given kernel milk-line stage.

Appearance of the kernels should only be used as a guide of when to begin sampling for DM content, see section below When to Begin Field Sampling.

Determining silage moisture

Continue reading

Poultry Litter Application

Source: Glen Arnold, OSU Extension

Stockpiles of poultry litter can be seen in farm fields across Ohio. While common each year in wheat stubble fields, there also many stockpiles in soybean fields. Poultry litter is an excellent source of plant nutrients and readily available in most parts of the state.

Poultry litter can be from laying hens, pullets, broilers, finished turkeys, turkey hens, or poults. Most of the poultry litter in the state comes from laying hens and turkey finishers. Typical nutrient ranges in poultry litter can be from 45 to 57 pounds of nitrogen, 45 to 70 pounds of P2O5, and 45 to 55 pounds of K2O per ton. The typical application rate is two tons per acre which fits nicely with the P2O5 needs of a two-year corn/soybean rotation.

Like all manure sources, the moisture content of the poultry litter greatly influences the amount of nutrients per ton. Handlers of poultry litter have manure analysis sheets indicating the nutrient content. They are also required to inspect stockpiles and address any insect issues that may develop from the time stockpiles are created to the time the manure is field applied.

Poultry manure for permitted operations needs to follow the Natural Resource Conservation Service 590 standards when being stockpiled prior to spreading. These include:

– 500 feet from neighbors

– 300 feet from streams, grassed waterways, wells, ponds, or tile inlets

– not on occasionally or frequently flooded soils

– stored for not more than eight months

– not located on slopes greater than six percent

– located on soils that are deep to bedrock (greater than 40 inches to bedrock)

Farmers who want to apply the poultry litter delivered to their fields are required by Ohio law to have a fertilizer license, Certified Livestock Manager certificate, or be a Certified Crop Advisor. Check with your local Soil and Water Conservation District for proper setbacks from steams, ditches and wells when applying poultry litter.

Flushing Small Ruminants for a Higher Ovulation Rate

Michael Metzger, Michigan State University Extension Educator (Previously published on MSU Extension, Sheep & Goat: August 6, 2018)

(Image Source: Sheep 101.info)

Increasing the level of nutrition for does and ewes 2-3 weeks prior to and 3 weeks into the breeding season can improve kid/lamb crop in some instances.

When managing a goat/sheep herd farmers are always looking for ways to improve their herd, increase production and raise profitability. One way that a farmer can accomplish this is to implement flushing into their breeding practices. Flushing is a temporary but purposeful increase in the level of nutrition around breeding time. This is done to boost ovulation, conception and embryo implantation rates. Flushing may also increase the proportion of females that exhibit estrus. Flushing can increase lambing and kidding rates by 10-20 percent. This is important because a flock’s lambing/kidding rate is one of the primary factors influencing profitability. Flushing works best in mature females, at the beginning and end of the breeding season and in out-of-season breeding programs. After the first month of gestation, the level of nutrition fed to bred ewes and does can then return to maintenance levels until late gestation, when fetal development begins to place significant demands on the dam.

Continue reading

Asian Longhorned Tick; a new tick known to attack animals in large numbers!

– Tim McDermott DVM, OSU Extension Educator, Franklin County (originally published in Farm and Dairy)

My colleague Erika Lyon wrote a great article in the January 24th, 2019 All About Grazing column in Farm and Dairy (link) that discussed the invasive Asian longhorned Tick. I want to give an update on where that tick is now, where its new host range is located, and what potential disease problems to look out for.

Continue reading

ASIAN LONGHORNED TICK CONFIRMED IN GALLIA COUNTY

Livestock Owners Encouraged to Examine Livestock Regularly and Report Suspected Findings  

REYNOLDSBURG, OH (July 31, 2020) –Ohio Department of Agriculture (ODA) today announced the United States Department of Agriculture’s National Veterinary Services Laboratory in Ames, Iowa, has confirmed that an exotic tick, known as the Asian longhorned tick, has been found in Gallia County.

The tick was found on a stray dog originating from Gallia County, which was later transported to a shelter in Canal Winchester. The tick was identified on May 28 by The Ohio State University and sent to the federal lab for confirmation.

“Due to the nature of this pest, the female ticks can reproduce without a male, so it only takes one tick to create an established population in a new location,” said ODA State Veterinarian Dr. Tony Forshey. “This pest is especially fatal to livestock, so producers should practice preventative measures and be on the lookout for this new threat.”

The Asian longhorned tick is an exotic East Asian tick that is known as a serious pest to livestock. U.S. Department of Agriculture first confirmed the presence of this tick in the U.S. in New Jersey in 2017.

Asian longhorned ticks are light brown in color and are very small, often smaller than a sesame seed. They are difficult to detect due to their size and quick movement. They are known to carry pathogens, which can cause disease in humans and livestock, and may also cause distress to the host from their feeding in large numbers.

In the United States, the tick has been found in or near counties with large horse, cattle, and sheep populations. To protect against infestations, farmers should check their livestock for ticks regularly. If producers spot unusual looking ticks or large infestations, report this to your local veterinarian or ODA’s Division of Animal Health at 614-728-6220.

Preventative measures such as keeping grass and weeds trimmed, in addition to clearing away brush on feedlots and pastures, can also help.

ODA state veterinary officials will continue to work with the U.S. Department of Agriculture and other federal and industry partners to determine the extent and significance of this finding.

Livestock producers and owners should notify ODA’s Division of Animal Health immediately at 614-728-6220 if they notice unusual ticks that have not been seen before or that occur in large numbers on an animal.

 

Start Checking Your Livestock for the Asian Longhorned Tick

Erika Lyon, OSU Extension Educator ANR, Jefferson and Harrison Counties (Previously published online with Farm and Dairy: January 24, 2019)

(Image Source: Farm and Dairy)

You may have heard about a new(ish) tick to the U.S. The Centers for Disease Control recently published a news release on the spread of the Asian longhorned tick (Haemaphysalis longicornis), which is now found in eight states: Connecticut, New Jersey, Virginia, West Virginia, Maryland, North Carolina, New York, Pennsylvania, and Arkansas, and it is right next door to Ohio.

Continue reading