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Five Tips to Keeping Livestock Vaccines Viable on Farm

Brookings, S.D. – Vaccines are crucial to keeping livestock healthy and productive. While vaccines do not provide absolute protection, the “added insurance” helps stimulate the animal’s immune system and increases its ability to fight off an infection or lessen the impact of disease if it should occur.

However, with timing, labor constraints and the necessity for boosters, South Dakota State University (SDSU) Extension Veterinarian and State Public Health Veterinarian Russ Daly says there are several factors to consider before implementing a vaccination program.

“Herd history, vaccine type, method of administration and age of animal all come into play, so it is critical for producers to work with their local veterinarian in developing a vaccination program,” Daly says. “They have experience with and knowledge of the many different vaccines, as well as the disease issues in area herds.”

Most vaccines are either modified-live virus (MLV) or inactivated “killed.” MLV vaccines contain whole germs that have been altered such that, while they are able to multiply within the body, their ability to cause disease has been taken away. Inactivated vaccines contain bacteria or viruses that have been inactivated by heat or chemicals.

Whether the producer/veterinarian team chooses an inactivated or MLV vaccination program, Daly says it’s important that the vaccines don’t go past their prime.

“Proteins are the major components of the organisms that make up both killed and MLV vaccines, and they disintegrate according to two major factors: time and temperature. As time passes, the proteins that make up the vaccine organisms break up into smaller parts. Eventually, given enough time, there will no longer be enough intact organisms to effectively stimulate an immune response,” Daly says. “Also, storage temperatures higher than label recommendations will result in a quicker rate of disintegration and will reduce the effectiveness of any vaccine, whether inactivated or MLV. At the other extreme, freezing temperatures will also adversely affect vaccines.”

In addition to time and temperature, common disinfectants and ultraviolent light can reduce the viability of modified-live organisms. “Modified-live vaccines will only remain viable for an hour or two following their rehydration, even if they are kept cool,” Daly says.

Daly recommends the following tips for handling, storing and using vaccines:

* Purchasing vaccines and equipment: Observe expiration dates prior to purchase. Purchase the appropriate type and sufficient number of needles for the job. Plan on replacing needles when they become bent, dull or dirty, and before drawing up vaccine into the syringe.

* Transporting and storing vaccines: Keep boxes and bottles cool and out of sunlight while in transport. Use frozen ice packs in an insulated box in the summer and prevent vaccines from freezing in the winter. Prior to use, store vaccines in a properly working refrigerator.

* Equipment and work area: Use clean syringes, but not those that have had internal parts cleaned with soap or chemical disinfectants, including alcohol. Set up an area for syringes such that they are shaded and kept cool and dust-free while working.

* While working: Keep vaccine bottles in a closed cooler with ice packs (summer) or hot packs (winter) until they are needed. When using MLV vaccines, rehydrate the vials either one at a time as they are needed or as many as you will use within an hour. Always use a brand-new needle to draw vaccine into the syringe. Protect syringes from heat, light and freezing while working. When using needle-free injection systems, or syringes that draw doses from a tube attached to the vaccine bottle, care should be taken to assure the bottle and tubing stay cool and shaded from sunlight.

* After the job is complete: Discard any unused MLV vaccine that has been reconstituted. Discard any partial bottles of inactivated vaccine that have been contaminated by dirty needles. Return unmixed MLV and unused inactivated vaccines to a properly working refrigerator as soon as possible. Clean syringes, transfer needles and tubing. Follow the manufacturer’s directions on proper cleaning and maintenance of needle-free injection systems.

For more information on how vaccines work and proper storage and handling recommendations, visit the SDSU Extension website for this fact sheet (extension.sdstate.edu/livestock-vaccines-how-they-work-and-how-ensure-they-do-their-job) on vaccine basics and tips to maintain vaccine viability.

–SDSU Extension

Warming a Cold Calf with Fluid

When calves get severely chilled, with body temperature subnormal, there are multiple ways to warm them, but in severe cases it can be helpful to administer warm IV fluids and/or warm colostrum (to a newborn) or warm milk (to an older hypothermic calf).

How much fluid to give intravenously depends on whether the calf is dehydrated as well as cold. Dr. Robert Cope (veterinarian, Salmon, Idaho) says you should be careful not to run too much IV fluid into these calves. “They might end up with pulmonary edema (excess fluid in the lungs, making it difficult to breathe) if you overdo it,” he says.

“If they’re scouring and dehydrated, I start with 1 liter of lactated ringers, and put that bag in a microwave for about 3 minutes to warm up. You don’t want it hot, but it should be calf body temperature, about 102 degrees; it should feel warm to your touch,” he explains.

Some ranchers are good at giving IVs, while others have only watched it being done. “There’s a little trick to it, but the biggest thing is that you need to learn to feel the vein. If you can feel the vein, you can feel the needle pop into the vein. If you can’t feel it, you can’t hit it,” he says.

“Most people clip or shave the area over the vein, to make it easier to find, but the main thing is to rely more on touch than sight. You usually know when you hit it. There may be blood come back out your end of the needle, but not necessarily—if the calf is dehydrated and has low blood pressure. The main thing is to feel it and know it’s in the right place; that’s more accurate than seeing the blood,” he says.

How much fluid to give depends on degree of dehydration, so it’s important to be able to judge this. Photo courtesy Heather Smith Thomas

How much fluid to give depends on degree of dehydration, so it’s important to be able to judge this. Signs of dehydration include sunken eyes, several seconds for a pinched-up tent of skin to sink back into place, cold legs and feet, cold mouth, slow capillary refill (pressing the gum —pressing blood out of that area–takes several seconds for the white spot to go away), etc. If the calf is chilled, mouth will be cold and rectal temperature subnormal.

“Dehydration causes low blood pressure and poor circulation, cold mouth and skin turgor (lack of elasticity, slow to go back to its original shape),” explains Cope.

“Generally if the calf is pretty dehydrated, I give at least 2 liters of fluid, and if severely dehydrated I put in 3 liters. Then I usually back off because we don’t want to reach the point where it starts producing pulmonary edema,” he explains.

“If you are not really sure the calf need the IV, you are better off to just put him in a hot box and provide energy so he can start generating more body heat. You can give warm oral fluids by stomach tube or esophageal feeder probe, and I like to put a little honey in that warm fluid,” says Cope. It provides quick energy, and is better for the calf than sugar—and the warm fluid helps warm the calf internally as well as having external heat via heat lamps and hot box.

If the calf is a newborn, the fluid you provide should be warm colostrum. “It should be body temperature. If you’ve taken frozen colostrum from the freezer, don’t put it in a microwave. That will destroy the antibodies. Warm the frozen bag of colostrum in a pan of hot water. When it’s thawed and warm, it should feel warm to your touch but not hot. Check it like you would a baby bottle—put a little on your wrist,” he says.

A newborn with good suckle reflex can be fed warm colostrum with a bottle, but if he’s so cold he can’t suck, put it into him with a nasogastric tube or esophageal feeder.

There are two ways to “tube” a calf–with an esophageal feeding probe (down the throat and into the esophagus about 16 inches–attached to a container that holds fluid), or with a smaller-diameter flexible nasogastric tube that goes into the nostril and down into the stomach.

With an esophageal probe, the rounded bulb on the end protects the throat from being scraped and helps prevent backflow of fluid up the esophagus. It also helps the tube bypass the larynx and small opening into the windpipe.

If the calf is lying down, lift his head to insert the tube. If he struggles, lift his front end so he’s sitting on his haunches. If he’s standing, back him into a corner and hold his head/neck between your legs. Pull his head up with one hand under the lower jaw and insert the tube with your other hand.

Gently put the tube into the side of his mouth then aim it straight, slide it over the tongue to the back of the mouth and into the throat. The calf must swallow it as you move it a bit and apply gentle pressure. Don’t forced it or it may go into the windpipe; the calf must be given a chance to swallow it. Feel the outside of his neck to determine where the tube is going. You can feel or see the bulb slip down the throat.

If you can see or feel the bulb, it’s in the proper place and safe to continue pushing the tube down. If you can’t see or feel it, or the calf coughs, or puffs of air come out your end, it’s in his windpipe. Be sure it’s in the esophagus and fully inserted (bulb close to the stomach) before you administer fluid. Hold the calf so he can’t struggle—or the tube may come partway out and spill fluid into the windpipe.

According to Dr. Lora Bledsoe, a Hugo, Colorado rancher and DVM, it is important to clamp off the tube so no fluid is leaked into the calf prematurely. She says to feel the calf’s neck to feel the tube-like structure that is the trachea. The trachea has ridges of cartilage whereas the esophagus does not. If the tube is passed correctly, Bledsoe said the individual tubing the calf will feel the tube passed into the throat next to the trachea, leaving the throat feeling like there are two tubes. If only one “tube” can be felt, the tube is in the trachea and must be reinserted. Once the tube is in the correct place, the fluid can be allowed to flow at a rate that allows the calf time to swallow.

It is important to note that disposable tubes and bags may be a bit more awkward, but the cleanliness is far superior to traditional tubes and bottles, especially if they’re not sanitized between uses, she said.

“If there are any bacteria growing in the tube or bottle, the colostrum antibodies are going to bind to the bacteria and not be absorbed by the calf,” she said. “Cleanliness is paramount. Reusable drench bottles need to be cleaned and then either placed in boiling water or had boiling water run through them before they are stored in plastic bags.”

There are times a nasogastric tube is better to use than an esophageal probe, according to Dr. Cope. “Most feeder probes are stiff tubes about 16 inches long, which work best for small calves. Some esophageal feeders have a longer, flexible tube, but the typical stiff probe doesn’t work very well for larger, older calves because the probe is too short,” he says.

The nasogastric tube is also preferable to the short probe when you want to put something clear into the stomach, as when administering mineral oil or castor oil; it’s not as risky for possible backflow up the esophagus and into the windpipe. “You don’t want to inadvertently get any oil in the windpipe,” says Cope. Even a few drops in the wrong place can be lethal, since oil can’t be coughed up and worked up out of the airways like water can, and is more apt to cause aspiration pneumonia.

“If a calf’s throat is sore and swollen, which happens sometimes with diphtheria in a young calf, or if you’ve irritated the throat with multiple applications of fluid using a probe, the nasogastric tube is better,” he explains.

Adult cows can be given fluid and medications via nasogastric tube (with a longer and larger-diameter tube). “A tube into the rumen is also a way to get gas out of a bloated animal—which the short feeder probe cannot do,” says Cope. Knowing how and when to use this handy tool for calves or cows is very helpful.

To insert a nasogastric tube, tuck the calf’s nose down toward his chest before inserting the tube into a nostril. If his head is pointed up or stretched forward, it may go into the windpipe. Put the smoothed end of the tube into one nostril, pushing it quickly to the back of the throat, then gently and slowly so the calf can swallow it. If he fails to swallow, it will go into his windpipe instead of the esophagus.

Don’t administer fluid or colostrum until you’re sure it’s in the right place. If the calf coughs as you try to put the tube down, this usually means it’s in his windpipe. If it goes easily, with no resistance—and goes in at least 2 feet or more in a small calf—it’s in the stomach. Check by blowing on your end. If you hear burbling or smell stomach gas coming out, it’s in the stomach. If blowing makes the calf cough, it’s in the windpipe. Take it out and start over. Once you’re sure it’s in the stomach, attach a funnel and administer fluid or colostrum.

SDSU Extension offers on-site livestock water testing

BROOKINGS, S.D. – SDSU Extension offers on-site livestock water testing services at all SDSU Extension Regional Extension Centers and several SDSU Extension County Offices throughout the state.

“It is critical to monitor livestock water quality, because poor quality water can have a negative effect on growth, reproduction, and general productivity of the animal. In some cases, death could occur within days or hours after consumption of contaminated waters or water deprivation,” said Robin Salverson, SDSU Extension Cow/Calf Field Specialist.

Water samples can be taken to one of the SDSU Extension offices in a clean plastic or glass container including water or pop bottles, jelly jars etc.

A test is conducted free of charge with an electro-conductivity (EC) meter to determine total salts in the water. After consultation with an SDSU Extension field or state specialists, additional laboratory testing may be suggested.

“The appearance of water can be deceiving and the clearest of water can be the worst,” Salverson said. “Additionally, some water sources regardless if it has been dry or wet can be high in total salts. Therefore, continuous monitoring of water quality and quantity is important to maintain a productive livestock program.”

SDSU Extension locations where testing is available include: Aroura County Office, Bennett County Office, Butte/Lawrence County Office, Campbell County Office, Hamlin County Office, Hanson County Office, Harding County Office, Hutchinson County Office, Jones County Office, McCook County Office, McPherson County Office, Mellette County Office, Miner County Office, Potter County Office, Spink County Office, Walworth County Office, Ziebach County Office, Aberdeen Regional Center, Lemmon Regional Center, Mitchell Regional Center, Pierre Regional Center, Rapid City Regional Center, Sioux Falls Regional Center, Watertown Regional Center and Winner Regional Center.

Additional information on livestock water quality can be found at www.extension.sdstate.edu or by contacting Robin Salverson at 605-374-4177 or robin.salverson@sdstate.edu.

–SDSU Extension

Can livestock utilize moldy grain?

An ear of corn in a field with visible white mold on the tip of the ear.

The record-breaking wet conditions across South Dakota last year have resulted in a significant amount of corn still remaining in fields. Soggy fields this spring make removing that corn challenging but important, as outlined in Standing Corn Considerations.

Getting corn harvested from such fields is just the first challenge, however. The quality of the harvested grain may severely limit its marketability and usefulness. Moldy grain is the main consideration; moisture content is another.

While livestock producers know that moldy grain and forage are not ideal feedstuffs, they also know that stored feed occasionally contains a small amount of visible mold and that their animals consume it with no obvious adverse effects. The question arises, how much mold is too much for a feed to be unsuitable for animals? Also, which type of molds pose the most concern for aflatoxin and mycotoxin production?Labs that test feedstuffs for mold report their results in terms of cfus/gram (“spore count”). In general, feedstuffs with spore counts of 1 million or less per gram are safe to feed to livestock. Adjustments in rations should be made when feeds with higher spore counts are fed. Table 1 indicates safety levels and feeding risks and concerns.

Table 1. Mold count levels and feeding concerns.

Cfu/gram Feeding Risk and Concernsa

Under 500,000 Relatively low count

500,000 to 1 million Relatively safe

1 to 2 million Discount energy (x 0.95) feed with caution

2 to 3 million Closely observe animals and performance, discount energy (x 0.95)

3 to 5 million Dilute with other feeds, discount energy (x 0.95), observe closely

Over 5 million Discontinue feeding

a Risks refer primarily to effects of mold per se without regard to possible mycotoxin content. Depressed digestibility, feed intakes, and performance may occur from a high mold content without mycotoxins present. Harmful mycotoxins may be present, even when there is little or no obvious mold content.

As seen from Table 1, adjustments need to be made to rations due to mold counts in the feeds. Accumulation of mold can reduce the digestibility of the diet by up to 5% in ruminants, which is why Table 1 shows a 5% discount in energy levels once the mold counts reach 1 million. In addition to the reduced digestibility, palatability is another concern. Observing a reduction in feed intake of moldy feeds would not be unexpected, so diluting these feeds to reduce palatability concerns can result in more consistent intake. If mold counts reach 3 to 5 million, the feed should be diluted to 50% or less of the total ration and mixed with other feeds that contain few to no mold spores.

Grain tested for marketing purposes will sometimes have mold results reported as % mold damage. This is an estimate of the number of moldy kernels in a sample, it and is difficult to interpret regarding suitability for livestock feed.

For livestock feeding purposes, knowing whether mycotoxins are present in moldy feed is much more important than knowing mold spore counts. Mycotoxins are chemicals produced by certain molds; they adversely affect the health and production of animals exposed to them, and their presence may make their products (particularly milk) unsalable. Not all molds produce mycotoxins, and important levels of mycotoxins can be present when mold infestation appears mild.

Mycotoxins important in livestock feeding include vomitoxin (DON), fumonisin, zearalenone, T-2, and aflatoxin. Their effects on animals depend on the individual toxin and the amount consumed, and can include feed refusal, decreased growth and milk production, reproductive problems, and – in the case of aflatoxin – death losses. The effects of mycotoxins can appear vague, lag behind feeding substantially, and are difficult or impossible to detect in the body – making their detection in feedstuffs prior to their use very important.

Knowing the specific mycotoxins and their concentrations present in feed can help inform how the feed might be used for animal feed. Different animal species and production stages have different sensitivities to mycotoxins – examples of which are found in this Pennsylvania State University Extension (PSU Extension) article. In general, feedlot calves are less likely to experience adverse effects of mycotoxins compared to breeding-age cows, pigs, poultry, or dairy cows.

Moldy feeds should be sampled prior to use and screened for the presence of mycotoxins. The NDSU Veterinary Diagnostic Laboratory runs an extensive mycotoxin screening panel. Producers should remember that unless the sampled grain is dry (< 15% moisture), mold growth and mycotoxin production will likely increase as the grain is stored. As with any feed evaluation, representative sampling technique is critical. A sample analysis is only as good at the sample the screen was completed on. A representative sample of the feedstuff will ensure that the sample sent to the lab represents the total of the feed available to be fed. There are suggested sampling methods outlined depending on the moisture content of the sample. These methods will help insure a representative sample (PSU Extension). This website also provides valuable information on interpreting results.

–SDSU Extension

Scheduled Births? Does feeding time really affect when cows calve?

The Science and the Questions Behind Evening Feeding and Daytime Calving

Anyone up at all hours checking calving heifers and cows this time of year is ready for a break and a little bit more sleep. What if you could schedule 80 or even 90% of your cows to give birth during the daytime hours? Research says it is possible.

Marshall Ruble, Superintendent of the Ag Research Station at Iowa State University, has spent several decades calving out cows on the Iowa State teaching farm at Ames and swears by evening feeding to encourage daytime calving. Ruble participated in studies done some thirty-five years ago that proved the effectiveness of evening feeding.

“We heard reports from Manitoba that a cattle breeder named Gus Konefal had experienced this,” Ruble said, “And we decided to give it a try. We fed the cows at 4 pm and they had feed available to 6-6:30 am the next morning. We kept track of what time of day they calved; close to ninety percent calved between 6 am and 9:59 pm. This is a pattern we have been able to repeat for a long time, in fact we still use it as a management tool.

“The professor at the time of the original study decided to reverse the feeding times and see what happened. We put feed in front of the cows from 6 am to 4 pm, and 50-60% of them calved at night. We repeated this for two years, with both spring and fall calving herds, and it held true that the cows fed at nighttime calved during the day and the cows fed during the day calved at night.”

The cows spend their days on a three acre bluegrass pasture that has tough sod so it doesn’t get chewed up too badly from all the hoof action, but it doesn’t afford much daytime grazing for them. They are fed a ration of corn silage and haylage with a feed wagon along a fenceline bunk at 4 pm.

“This is about 60% of what I expect them to eat daily,” Ruble explained. “It’s pretty well gone by 9:30 when I’m doing my last check of the evening. I let them in to a pen next to the calving shed with a large round bale in it and they have access to that all night. At six o’clock the next morning I kick them back out into that little pasture. Once they’re on the schedule they’re waiting for you and moving them is pretty easy. They all follow in.”

Ken Olson, SDSU Beef Specialist in Rapid City, SD, said he knows many beef producers who swear by evening feeding to encourage daytime calving in their herds.

“I personally think it’s a good way to go,” Olson said. “We have plenty of anecdotal evidence that evening feeding causes more cows to calve during the day. There are producers who calve on the range and producers who calve in a more controlled environment and it works in both situations. Even with cows on pasture evening feeding still means the cows eat their major meal in the evening and less during the day. Most people who feed in the evening are convinced it works.”

Olson has also seen other interesting calving patterns documented in Kansas and Idaho that support the data from Iowa State.

“Early in my career I worked at a research station in Kansas,” he recalled. “Our herdsman fed in the evening for the same reason, to encourage the cows to calve during the day. When they calved he recorded the time of day the calf was born. Over several years he picked up on a pattern: the time of day a heifer gave birth to her first calf recurred with subsequent offspring! Whether she calved in the morning, or in the afternoon, or in the evening, she would calve close to the same time of day for the rest of her life! This was not officially part of a research project but it was well documented.

“Later the herdsman met a group from the University of Idaho who said they had observed the same thing. The cows in Idaho were in more of a controlled/small lot environment where they didn’t have access to grazing; the cattle in western Kansas were out on range and just had hay delivered to them in the evening. Both groups were fed in the evening, both calved predominately during the daytime hours, and both noticed that if they could get a cow into a pattern she would stay in that pattern for her lifetime. This was documented by two different universities in very different climates.”

Evening feeding to promote daytime calving was also tested by the USDA Agricultural Research Station at Miles City, Montana. While they did see an increase in daytime versus nighttime births, their percentages were not quite as high as those at Iowa State. The percentage of cows calving during the day increased from 66.9% to 78.1%. This was not as drastic of a change as Konefal’s increase from 38% daytime births when cows were fed earlier in the day to 80% daytime births when cows were fed later in the day, nor as significant as Iowa State’s daytime birth rate increase from 50% to 85% when evening feeding was implemented.

What makes evening feeding work? That is a theory that is still a theory and may always be somewhat of a theory due to the delicate nature of near-parturient mothers.

What we do know is that fetal stress and rising cortisol levels trigger the onset of labor. Fetal hormone levels, however, are impossible to test without causing greater stress to the unborn calf and the expectant mother; attempts to do a research project to document what hormones are changing and what is causing the levels to rise would probably cause more problems than they would give answers. Brent Bunderson, a retired Utah State extension agent speculates that the stress levels in the fetus are triggered by pressure of the near-term calf on the uterine artery when a cow is lying down to rest.

“This is a theory,” Ken Olson said. “When you’re close to calving you can’t mess with the cows so we can’t test it in a controlled fashion. However, there are other things that we know do cause restricted blood flow to the unborn calf, thus triggering labor, so I think it is a valid theory.

“Anyone running cows in Ponderosa Pine is aware that the Isocupressic acid present in pine needles can cause cattle to abort. This chemical causes restriction of blood flow to the uterus, thus triggering labor, and a birth way too early to get a live calf.

“Another thing we know is that the Brahman breed, known for calving ease and low birthweight, has genetics that dictate that when the calf gets to a certain size there is something in the cow’s physiology that restricts blood flow to the uterus, thereby triggering labor.

“We know that the stress hormones that trigger labor can come from genetics and they can come from certain poisons; it is entirely possible that something related to the rumen getting full could also be a trigger. Bunderson’s theory is just a theory but I think it is a good theory. I’m not sure we need to prove it; from the standpoint of research we’re curious, but from the producer’s standpoint if it works we don’t necessarily need to know why.”

For the producer wanting to try evening feeding, and those who may have tried and felt their results were not what they had hoped, here are a few things to consider.

Keep feeding time and time away from feed as consistent as possible.

“Time to feed initial ration was 3:59 pm-4:01 pm,” Ruble said. “If I was not around for the 4 o’clock feeding and the employee on the weekend changed the time by one hour my cows would calve early or late by 3 hours. They didn’t have to tell me their feeding time, the cows did!”

What are your expectations? Data suggests that 80% daytime calving using evening feedings is reasonable to expect, but things such as how much additional grazing or extra hay is available during the day or variations in the time feed is delivered can cause this to vary. Look at the whole picture and see what you might be able to tweak to make night feeding more effective.

Weather and other factors can definitely influence calving time so be aware that before and after major storms calving times may be less consistent than when the weather is stable.

“My working hours are best when I feed at night,” Ruble laughed! “Only ten percent of our calves are born when I’m not there. Night feeding is part of our calving protocol and has been for the last thirty-five years. We twin 3% of the time and we are averaging live calf numbers at 102%. That’s a pretty big deal.”

Don’t put all your eggs in one petri dish: IVF a viable option for quick genetic turnover

In dairy cattle, bull calves are generally an undesired outcome, but with innovations progressing in in vitro fertilization, males can become nearly obsolete, and, in both dairy and beef cattle, sought-after genetics can become more readily available. Several IVF companies, including Trans Ova and VyTelle, have been expanding with satellite sites across the nation for lab work and oocyte collection. 

IVF generally wins over embryo transfer in terms of prepping cattle. Typically, IVF requires one shot to embryo transfer’s eight to 10 shots prior to embryo retrieval. With Vytelle’s new technology, follicle stimulating hormones (FSH) are unnecessary. 

“We are able to utilize non-stimulation and able to grow those into healthier embryos in the lab,” said Taylor Grussing, special projects manager with VyTelle. “We like to say it’s low stress on cow as well as cattleman.” 

Even with practices that still require a shot, oocyte can be collected at any point in the cycle, from 15 days postpartum to 100 days pregnant, with two weeks in between collection, Grussing said. Most use IVF to increase genetic turnover, but it can also be a tool best applied to unique circumstances. 

Dave Winninger, an AI technician near Cody, Wyoming, has been working on a project with farmers in Massachusetts who wish to get offspring for very rare and old semen to enhance traits in their dairy cattle that they feel has been lost throughout the years. 

The bull calves yielded from the semen collected in the 1960s, ’70s, and ’80s would be unwarranted, Winninger said. The heifers, on the other hand, were highly desired, so with reverse sorting of the semen, of the 120 IVF embryos, all but one of the 50 calves yielded was heifers. 

“They got to avoid having all the male calves, which would have been a waste in this project,” Winninger said. “They got away with only one male calf. That’s the power of that technology.” 

IVF can be greater in cost than conventional ET, but more viable embryos can offset the initial expenses. Vytelle’s technology that eliminates the need for FSH minimizes the cost as well. 

“It’s more economical and on a per embryo basis,” Grussing said. “If you only get five embryos, you only have the cost of five. Before, there was a lot of expense setting up the cow.” 

This technology also leads to healthier embryos with less large-calf syndrome happening. 

IVF is also highly useful for cows that cannot get pregnant due to age or other circumstances or that underperform with embryo transfer practices. Such was the case of a particular cow of Dale and Nancy Venhuizen’s, of Churchill Cattle Company in Manhattan, Montana. 

“We had a couple of donors that were really good but wouldn’t fertilize any embryos when we did ET,” Dale said. “We changed one donor in particular to IVF in 2014, and she worked fantastic. We got six or eight calves out of the very first flush, when before, we had been getting nothing.” 

Dale spoke to varying experienced people in the industry with no reason for such a situation, but he gladly continued IVF with that donor to great success. 

In the summer of 2018, Trans Ova reached out to the Venhuizens regarding a satellite center in Montana, where they aspirate outside clients’ cows every other Wednesday. 

A typical aspiration generally yields about 20 oocytes from each egg, which are then transferred to labs by the next morning. The oocyte is fertilized and, if viable embryos are produced, will be implanted into a recipient cow on day eight of the cycle. An estimated 30 percent of oocytes will turn into embryos, Dale said. 

The pregnancy rates in IVF are about 10 to 15 percent lower than conventional embryos, but the opportunity for more calves from one animal is an obvious advantage.  

“One of the big advantages of IVF is that you can use several different sires and really spread out your risk,” Dale said. “We’re always trying to do that, and it allows you to do a little bit of an experiment.” 

IVF also allows a cow to stay within a regular calving cycle, if desired. Calving her versus keeping her open allows her to stay healthier and not become overweight, making her hard to breed and hard to donate. 

“If you want to flush a donor but want her to calve in February, you can flush her in late March, two times in April, then breed her in early May. Then you can wait maybe 40 days and do her while she’s pregnant,” Dale said. “That’s a wonderful tool because if you do conventional ET, you get one flush then breed the cow back.” 

Recipient cows can absorb or abort IVF embryos a bit later than recip cows generally will with ET embryos. 

“The recip cow has way more to do with what your preg rate is than if your embryo is conventional or IVF,” Dale said. “The industry rate is around 50 percent, and if we can bump that number up 10 percent by fine tuning some processes as we get more knowledge of the ideal implant times of recip cows and other protocols, IVF would be a simply amazing tool.” 

Protein for Pregnant Cows

Pregnant cows need different protein levels at different stages of gestation. Nutrient requirements in early gestation are similar to maintenance requirements, but as the fetus grows, the cow’s nutrient needs increase. A lactating cow needs a much higher level of protein and energy than when she’s pregnant.  

Mary Drewnoski, beef systems specialist, University of Nebraska-Lincoln, says there’s also a fetal programming factor; the amount of protein a cow gets during gestation affects fetal development. “Research data suggests that for cows on dormant range pastures (mature grass) we’ll see negative effects on their progeny if they don’t receive adequate protein; it has long-term consequence on those calves,” she says. 

These cows need supplemental protein. “This could be about 2 pounds daily of distillers or cake, which is usually about 25 to 30 percent crude protein. We can also feed it every other day, doubling the amount. Research indicates this can be a viable option for protein but it doesn’t work so well for energy (cows need an adequate energy level daily in their diet).” 

Increasing the protein helps ruminants digest mature forage, but it doesn’t need to be daily. “They can recycle some of that nitrogen back to the rumen, but they need at least 7 percent crude protein in the diet. If forage is lower than that in protein, cattle start decreasing intake.” Digestion slows and they can’t eat enough to maintain themselves and they start losing weight. Pregnant cows need adequate protein so they can eat enough and have enough energy.  

“What’s interesting is that we don’t see these same effects when grazing corn residue. Protein levels in those residues is below that 7 percent threshold yet cows maintain body condition, and we don’t see the fetal programming effects. My theory is that this is because digestibility of what they select when eating corn residue is higher, and they can continue eating an adequate amount. Corn husks can be up to 65 percent TDN.” The cows don’t decrease intake, since it’s so palatable and digestible. 

“As long as producers use recommended stocking rates, mature dry cows grazing cornstalks don’t need supplement. This doesn’t hold true for first-calf heifers, however. They are still growing and need higher protein level. On cornstalks they may need as much as 3.5 pounds per day of distillers to meet energy and protein requirements,” says Drewnoski. 

Jeremy Martin, PhD, ruminant nutritionist and reproduction manager, Great Plains Livestock Consulting says cows and heifers are very different in their needs. “Weather can be a significant factor, and was a major factor in most regions this past year, but stage of gestation and ability to consume feed is enough different that a heifer calf or pregnant heifer is a much different animal to feed than a mature cow.” 

Drewnoski says you can’t skimp on heifers; they may need to be fed separately. “Some people may not have enough room to do that, but could put them with their replacement heifers. This would be better than leaving them with the mature cows. The diet and amount of feed most people give replacement heifers would be closer to what those first-calf heifers need,” she says. 

“Here in Nebraska some people have replacement heifers on dormant range, with a fairly low rate of gain, and might only be feeding a couple pounds of distillers or cake. That’s appropriate for weaned heifers and a little light for pregnant first-calf heifers, but closer to what they need,” she says. 


“It’s important to provide protein to enable cattle to get full feed intake (and therefore adequate energy) but we also need to monitor body condition,” says Drewnoski. “If body condition is not maintaining, you may need to increase the protein, to increase feed intake. Body condition is a good gauge but some people don’t look at this until it’s too late and cows have already lost a lot of weight,” she says. It’s crucial to assess body condition at least three months before calving. That’s your last chance to do something to correct it because it’s hard to make a change after they calve. 

Weaning time is a good time to check body condition scores of cows, since as soon as lactation requirement is removed we can drop the protein requirements. “Those cows will be better able to regain lost body condition,” according to Janna Block, North Dakota State University livestock systems specialist.  

“We need to look at the thin cows or young cows because most people don’t think about using a supplement before winter. Many cows pick back up on green regrowth of cool season grasses and do well, but we need to pay attention to young cows and any cow that might be really thin. For those it might be worthwhile to separate them from the herd and feed them more, before they calve again. It’s cost-prohibitive and sometimes not possible from a physiological standpoint to try to get more condition on cows during late gestation or after they calve,” says Block. 

“Some producers get into calving and have a wreck because condition was not assessed earlier. The goal is to have mature cows calve in body condition score five, so we need to get them to that point prior to late gestation–then maintain body condition, rather than still trying to pick them up,” she says. 


Jeremy Martin recommends pricing protein supplements on a cost-per-unit-of-crude-protein basis, always looking at this on a dry-matter basis, particularly with liquid supplements. “This is the best comparison. Alfalfa hay is usually competitive in price, if available. In some areas distillers products and soybean meal are feasible options. Some years, and this may be one, whole soybeans may be very competitive in price, on a cost per pound of crude protein basis,” he says. 

It often comes down to availability and freight costs, or ability to handle and feed a certain type of supplement. “Soybeans are cheap in central Nebraska but there are not many grown in western cow country. Depending of freight and whether or not you are set up to feed them, they may or may not work,” Martin says. 

When comparing/selecting a protein supplement, it should be at least 18 to 20 percent protein. “Below that, it’s hard for that product to compete as a protein supplement because it requires so much volume that it won’t be cost-effective,” he says. 


Janna Block, North Dakota State University Livestock Systems Specialist, says protein requirements vary based on body weight, age, environment, temperature, how far the cows have to walk to water, etc. “Most mature cows in mid-gestation will need about 1.5 pounds of protein per day. In late gestation they probably require closer to 2 pounds per day. When lactating, their requirements are even higher and will vary depending on the level of milk production,” she says.  

Cow size also makes a difference. “A 1300-pound cow in early lactation producing 10 pounds of milk requires a little over 2.25 pounds of protein and this would increase to almost 3 pounds if you add another 10 pounds of milk. She’d also need more energy.” The amount of milk produced makes a big difference; it takes a lot more protein and energy to feed a lactating dairy cow than to feed most beef cows, and some beef cows give more milk than others, and must be fed accordingly. 

“It’s challenging today to find beef cows with moderate milk EPD. The production target has been moved a lot, in the past 20 years,” says Block. Thus today’s beef cows require more energy and protein—and more total feed—than their counterparts a few decades ago, and unfortunately producers don’t always have the environment/feed resources to support that much milk; ranchers often have cows that are drawn down in body condition, trying to crank out a lot of milk on a diet that is insufficient. Most of these cows have trouble breeding back again on schedule. 

PLASTIC DISEASE: The New Hardware Disease in Cattle

You’re out feeding your cows on a winter day when you notice a cow that just doesn’t look right. She’s big bellied, doesn’t seem to have much appetite, yet her nose is wet and eyes are clear. You can see by her tag that she’s a six-year-old, right in the prime of her life. There are no real symptoms that you can doctor her for, so you decide to just keep an eye on her. Days pass and she gets thinner and thinner, until finally you put her in the corral to give her a little extra help. In a few weeks, despite ample good feed, she dies. You have a couple more cows that are losing weight and acting similarly, so you call the vet out to do a necropsy, hoping to prevent any more losses if you can learn what you’re dealing with. 

 The vet opens the cow up and in the rumen is a sodden mass of what turns out to be netwrap or plastic twine, all mixed with the little bit of hay that she had eaten in her last days. The other cows with similar symptoms, plus that bull you spent so much on several years ago, are headed down the same road, and you can’t do anything about it. 

This is the new “hardware disease,” which should be called “plastic disease,” due to the volume of plastic twine and netwrap that are used in baling hay. Even the biodegradable twine that some have started using as an alternative will cause the same problem once it’s ingested. It only breaks down in ultraviolet light, so once it’s out of the sunshine, it stops dissolving. It will, however, break down and no longer be a threat if it is on the ground, unlike plastic twine and netwrap, which remain in the environment indefinitely. 

Pulling netwrap or twine off of round bales is time consuming and difficult, especially in country where it will become iced onto the bales. Sometimes yards of it will be frozen to the hay and is left on the ground under the hay when it is rolled out. The theory is that the cows will eat the hay off of it, but, if you can’t pull it loose with your fingers, they can’t pull the hay loose with their tongues. When that happens, they get large pieces of netwrap ingested due to the surface area and length. Once they get it in their mouth and swallow once, they can’t spit it out. 

Feeding in bale feeders is another place that twine and netwrap either are left on the bale to prevent waste, or not all of it is removed for various reasons. The bale feeder gets moved and the plastic is left on the ground in the lots, where cattle can try to pick hay out of it, eat weeds growing up through it, or baby calves just have to pick it up to taste it, and it’s in them. 

People who use bale processers often times don’t remove the netwrap or twine, believing that the beaters will peel it off as the hay is fed. That gets a lot of it, but certainly not all of it, as the netwrap is often shredded in the process. Walking the feedground after it’s fed will turn up pieces several feet long, even if only a few inches wide. It can go right into the cow when she takes a bite of hay and she’ll chew it and swallow it. 

Bale processing and feeding without the removal of the net wrap can lead to a high incidence of free-gas bloat caused from concretions of pieces of plastic wrap blocking the cow’s esophagus. It likely floats in the rumen until the cow belches and the wad of plastic becomes lodged in the esophagus, the cow can’t belch, and the gas buildup rapidly causes a fatal bloat. Even nursing calves will pick up a small piece of netwrap, and when mixed with the grass they graze, can have the same sudden onset bloat and death. 

 Veterinarian Dr. Jim Myers, Belle Fourche Veterinary Clinic, Belle Fourche, South Dakota, says “I’ve done necropsies of the second stomach and it looks like a piece of burned plastic. It stops the advancement of feed on through the digestive process. It’s not possible to remove anything from the second stomach, so there’s nothing we can do to save the animal.” 

Rumen microbes can’t break it down, so it stays in the rumen, unable to pass on through via the small intestine. Cattle that have “mysteriously” died on pasture, when the carcass breaks down and the rumen contents are revealed, can have a ball of plastic twine, some as big or bigger than basketballs, left within the ribcage. The netwrap will also be revealed in a similar mass. 

“Even grinding it can lead to impaction and isn’t safe,” says Dr. Myers. “It still can’t pass through to the small intestine.” 

Grinding hay has become a popular way to utilize lower quality forage by mixing with better feed for rations. Feedlot cattle receive a lot of ground feed, and even though there are incidents of impaction, they are usually slaughtered before the netwrap or twine becomes an issue. Mother cows and bulls, however, due to their longer lives, have the most incidents of blockage or impaction due to the years they are fed ground or processed hay. 

Midwest Ag and Veterinary Services, with locations in Watertown and Aberdeen, South Dakota, have had experience with the netwrap and plastic twine losses in customer cattle in that area, according to owner Chris Bartelt. “In 2018, Dr. Rink found an 18-pound piece of netwrap in an eight-year-old cow. In 2019, Dr. Whitlock did a post mortem on a bull and found a complete blockage. It’s a serious problem.” 

With the welfare of livestock being so important to producers, plus the sheer cost of losing cattle, it’s imperative that people review their methods of feeding and management of the twine and netwrap that are used. The extra time it takes to remove it will pay off in the long run with fewer problems of poor doing cattle or cattle that simply don’t make it. 

BRISKET DISEASE: Research Continues

It goes by several names, but the outcome is the same in every instance: it’s fatal. Bovine congestive heart failure, bovine pulmonary hypertension (right heart failure) and brisket disease are one and the same. It’s commonly called brisket disease because of the enlargement of the brisket area with fluid. Cattle will also develop fluid filled pouches under their jaw, abdominal swelling, jugular vein distension with visible pulsation, bugged eyes, and exhale “grunt” with some frothing at the mouth, depression, droopy ears, intermittent watery diarrhea, racing heart, and open-mouth breathing. All this leads to weight loss as the disease progresses. Not all cattle develop all symptoms, but they all die as a result of the disease. 

Upon necropsy, brisket disease cattle will have an enlarged heart that has remodeled until is often twice the size of a normal heart, and unable to pump blood and oxygen to the animal. Some cattle die very quickly of brisket disease, others linger for weeks. 

According to one study, as early as 1963 brisket disease was reported in cattle grazing at high altitude, with a prevalence of 2-10 percent. In 1976, a similar condition was being reported in yearling feedlot cattle at lower altitudes of 3,000 feet. 

Brisket disease is initially challenging to diagnose as it has so many similarities to respiratory problems. Due to the difficult diagnosis and usual treatment for respiratory disease, the animal is not salvageable when it’s determined that it has brisket disease. Even if they haven’t received antibiotics, handling the cattle so that they can be salvaged at all is nearly impossible due to stress/movement-induced heart failure. 

Some affected producers in the western plains states have experienced greater losses from brisket disease than bovine respiratory disease, so reducing the impact of brisket disease is a high priority in the industry. Research is currently underway at Great Plains Veterinary Education Center in Clay Center, Nebraska. Brian VanderLey, GPVEC researcher, says “We think that low-altitude and high-altitude cases are a little different. In the last half decade or so, one of the producers said that they’d always seen a few of them but in about 2007 it really came on with more cases. The effort to figure this out intensified and in 2017 we started collecting samples as part of a genetic investigation,” says VanderLey. “We made 21 trips to the Panhandle in about 11 months as we had a case control study going on in several feedlots. The feedlot would identify a case due to clinical signs and we would study the live animal before euthanasia. Then a control animal was chosen to compare it to. In some cases we were able to match half siblings due to the rancher’s sire tag numbers. The premise is to match them as close as possible except for the disease and we matched 102 cases in control.” 

“The study included 95 black, five reds, and two red-white faces. Of course, the population with the most cases was black cattle, but it’s important to point out that the feedlot population is predominately black Angus. With the dominance of the black cattle, there was just nothing there that was a standout conclusion,” according to VanderLey. 

“I think the black Angus has been hit hard by many for being responsible for this, but I’m not going to go that far. The fact is, the population is predominately black cattle. We have some very promising results that should be out in the near future that will really clarify the genetic factor in the disease,” says VanderLey. “Another thing that people have suggested is the speed at which we grow cattle may be part of the problem. I think that is true of cattle that are already at a genetic risk, but if they already are, maybe they develop the heart failure more quickly as well. There’s a relatively small percentage of cattle that are affected, so backing up the whole pen of cattle to protect the few puts the whole cost of production in jeopardy.” 

VanderLey explains “If those cattle at risk can be identified we have a host of options available. Maybe those cattle would be better off fed slower, fed in a different environment, or simply slaughtered off of grass. That’s why figuring out a diagnostic method is so important in our research.” 

High altitude producers have been utilizing a test that was developed in the 1960s to determine arterial pressure in the bovine heart. The PAP test used today was developed by Dr. Tim Holt, Colorado State University, Fort Collins, Colorado. It is Pulmonary Arterial Pressure testing and is generally done on yearling breeding bulls and heifers. Some high-altitude registered breeders have utilized the test for quite a few years and are able to more accurately predict which cattle can work at high altitude and which cannot, as it is a highly heritable trait. It’s important to note that PAP testing must be done on the cattle at the altitude they will be inhabiting after they have been at that elevation for at least three weeks. 

The research being done to find an earlier diagnosis, and more critically, a way to eliminate the disease from the population in general, is hopefully looming on the horizon for producers and feedlot operators alike. 

Dewormer Debunking: Not all cattle dewormers are created equal

Pour-on dewormers are a popular choice within the ranching industry as the ease of use is rather high, but does the effectiveness match the efficiency? Upon digging, it’s discovered that the answer is no. Pour-on dewormers often miss the mark when it comes to clearing the guts of parasites. 

While external parasites are a pest, naturally, internal worms are a far greater concern to producers for the effects they cause, such as poor feed efficiency, leading to poor breed-back rates and milk production in cows and minimal weight gain in calves. 

“Sometimes you don’t see the effects of that, the weight loss happening, because they could chalk it up to a bad year or drought year,” said Dr. Erica Koller with Cheyenne River Animal Hospital in Edgemont, South Dakota. 

There are four common methods of deworming cattle: the widely-used pour-on, an injectable format, an extended release bolus, and a drench. Three drug classes also exist: Imidazothiazoles, such as levamisole, Benzimidazoles, such as albendazole or fenbendazole, and Macrocyclic lactones or avermectins, such as ivermectin or moxidectin. By switching drugs for fear of resistance, but using a dewormer in the same drug class, true resistant parasites won’t be affected. 

“Any of your pour-ons that I know of on the market right now are all part of the same drug class,” Dr. Koller said. “So we’re worried about resistance because of the actual drugs being able to combat the parasite, then we’re using the same drugs over and over, even if we’re switching companies.” 

Often, misapplication is the greater concern with pour-on dewormer than actual resistance, whereas, other methods of application ensure that cattle are receiving the proper dosage. Upon applying pour-on, it is possible that the medicine isn’t seeping under the hair properly, the medicine isn’t applied along the entire backline, the temperature is too low for the medicine to be effective, or it could wash off in weather. Generic dewormers have been found to be as effective as saline, said Dr. Koller’s co-worker Dr. Stephanie Stephens, improper medicine application can cause a re-infestation. 

With all dewormers, the expensive portion of the drug isn’t the deworming agent itself, but rather the carrier that gets the medicine to the gut, Dr. Koller said. 

“The longer the product is on the shelf, even if it isn’t past the expiration date, the carrier availability diminishes,” she said. “Pour-ons that are past expiration dates, close to expiring, or have been exposed to the elements are going to be less effective than if you get it the day it was made.” 

There is no bad time to deworm, Dr. Koller said, but there are better times to deworm more effectively. She recommends deworming for internal parasites four to six weeks after putting cattle out on fresh grass in the spring, and treating external parasites in the fall, generally around Thanksgiving. 

Similarly Dr. Berit Bangoura, an assistant professor of Veterinary Parasitology with the University of Wyoming, recommends deworming cows before they calve, treating calves a couple weeks after birth, and deworming cows again after giving birth. 

“In this part of the country, people use pastures and don’t have cattle in all the time, so they can’t deworm monthly, or even every three months,” Dr. Koller said. “In confined areas, we would probably have to do that, but it would be more readily available.” 

Worms harbor in the ground over the winter, and in spring, larvae crawl to the top of grass blades where they can be picked up by cows and other livestock, where they remain all summer long, Dr. Koller said. 

She recommends deworming for internal parasites in the spring and fall for a few years, if cattle haven’t been dewormed regularly in some time, and switching what dewormer is used in the spring and fall, using an injectable one time then a “white dewormer,” or drench, the other time. 

Injectable dewormer must be kept warm, unlike vaccinations, while administering. 

One brand of drench dewormer, SafeGuard, can be given in high doses several days in a row to animals who have extensive worm issues, ensuring the cow gets what she needs and is still deemed safe. The downfall to drenching is that the animal must be caught by the head, but the upside of drenching is the appropriate amount of medicine is reaching the animal. 

Both drenching and injectable dewormers can be administered at the same time if an animal is exhibiting signs of a true resistance, Dr. Koller said. Some recommend keeping 10 percent of the worms in a cow’s gut to prevent resistance. 

“I am a little bit hesitant to promote doing that,” Dr. Koller said. “I don’t do enough fecal egg counts to prove we have a resistance problem around here. Usually when I go places, I see more of a misapplication than resistance. The theory behind saving 10 percent is you’re saving a small culture of the worms that are not resistant to reinfest for next year, so that instead of the big super bugs reinfesting, the non-resistant bugs are there.” 

There is no limitation on the amount of parasites that can be present, she said. No “no vacancy” sign, so to speak. Pasture rotation can help avoiding re-infestation and resistance as well. 

“Pasture rotation is always a very good thing if people have an opportunity to do so,” Dr. Bangoura said. “When animals are treated, I would move them to a new pasture one to two days later so they can excrete worm burden on the old pasture. It can provide the best effect to combine pasture rotation with deworming.”