2022 Beef MOOving Minutes

Nitrate Toxicity in Livestock

(PDF of Article)

Megan Van Emon, Extension Beef Cattle Specialist

Although many areas of Montana have received much needed rain this year, nitrates are still an issue that should be considered when harvesting forages. Oats are the number one nitrate accumulating crop, with wheat and barley being close seconds. In addition, weeds can also be nitrate accumulators. Oftentimes when a drought dissipates, stress on the plants is reduce. However, this may not correlate to a reduction in the plants.

In general, plants take up nitrogen from the soil in the form of nitrate, which is then converted into nitrite and then into ammonia and finally into amino acids. Amino acids are the building blocks to protein in the plants. Nitrates accumulate during the night when no photosynthesis is occuring and peaking during the early morning. Photosynthesis is active during the day, which converts the nigrate into the protein. Stressful conditions on the plant cause the roots to accumulate nitrate faster than it can be converted into protein.

Stressful conditions not only include drought, but also during time sof prolonged cool temperatures, hail, disease, mineral deficiency, and many others. Nitrates mainly accumulate in the bottom one-third of the plant, so one way to aid in reducing nitrates in the harvested forage is to raise the cutter bar on the swather. Another method to reduce nitrate concentrations in crops is to allow those plants to further mature before harvesting. Additionally, plants can be ensiled, which aids in reducing nitrate levels, but is not a reliable method because reduction in nitrates is variable.

Once nitrate containing plants are harvested, nitrates remain at the harvested level, they cannot be reduced by time because all photosynthesis has stopped. Therefore, it is extremely important to test for nitrates, not only in times of stress, but also on "average" years. There are two common tests available at your local Extension offices, the QuikTest and the Strip Test. THe QuikTest requires acid to determine if nitrates are present in the sample and can be conducted in a few minutes. However, this only gives a qualitative answer, yes, nitrates are present, or no, nitrates are not present. Therefore, samples should be submitted to a commercial laboratory for further analysis. The Strip Test provides a quantative answer using a colorimetric strip and takes about 45 minutes to complete. The Strip Test provides an estimated concentration of nitrates in the provided sample. However, we still recommend sending the sample to a commercial laboratory, especially if the concentration is high.

Toxic levels of nitrates in plants can cause nitrate toxicity in livestock. Similar to plants, nitrate is converted to nitrate and then to ammonia and then to microbial protein in the rumen. When excessive concentrations of nitrate are consumed, nitrite accumulates in the rumen faster than it can be converted to ammonia. The nitrate then enters the blood stream from the small intestine and causes the conversion of hemoglobin to methemoglobin, which cannot carry oxygyn efficiently. The main symptoms of nitrate toxicity include labored breathing, weakness, staggering gait, abortions and can cause death. In many instances, cattle are found near the nitrate containing feed. One of the main indicators of nitrate toxicity is after death, when the blood appears to be chocolate brown in color due to the lack of oxygen.

The main treatment plan for nitrate toxicity is prevention, However, if noticed quickly enough, a veterinarian may administer methylene blue, which can aid in allevaiting symptoms. However, prevetion and management are the best factors to reducing the potential for nitrate toxicity.

Montana is conservative in their recommendations when feeding nitrate containing forages. Lower risk forages should contain less than 1,500 ppm nitrate and above this level, forages should be fed with caution or or at all as levels approach 10,000 ppm. In addition, nitrate concentrations in the water should also be considered, as these can add to the potential of nitrate toxicity.

Overall, care should be taken each year when feeding livestock feeds or water sources that contain nitrates. When collecting feed and water samples for all analysis, not just nitrates, it is extremely important to collect a representative sample. The analysis is only as good as the sample collected, so care should be taken when collecting pre- and post-harvested feeds or water.

Body Condition Scoring Cattle and Why it's Important

(PDF of Article)

Megan Van Emon, Extension Beef Cattle Specialist, Montana State University

Body condition scoring prior to breeding is extremely important to maintaining conception rate and the yearly calving interval. Due to the drought is the past two years, producers have had a limited feed supply through pasture and harvested feeds. This had led to some cows being in poorer body condition than we would like them to be at breeding.

Body condition scoring is based on a 1 to 9 score with 1 being extremely thin and 9 being extremely obese. A body condition score of 5 to 6 is optimal. When looking at the cow herd, a body condition score 5 cow ill have the last two ribs visible, no fat in the brisket and the hooks and pins are visible. As body condition is increased the ribs will not be visible, the brisket will fill with fat and the hooks and pins will not be visible. As body condition is reduced more ribs will become visible, the brisket will tighten up and the hooks and pins will become more pronounced.

Fat cover and deposition is important for reproduction to provide additional energy for uterine involution after calving and for the estrous cycle. Cows with a body condition score of 5 or greater at breeding have a better chance to successfully rebreed and maintain the pregnancy. Maintaining a body condition score of 5 to 6 throughout the year helps provide cows with the extra needed energy during stressful events, such as calving and weaning. Maintaining good body condition also helps with colostrum and milk quality and the calf immune system.

Not only is body condition important for the cow herd but also for the bulls. Bulls should also be in a body condition score 5 to 6 during the breeding season. Bull body condition plays a large role in spermatogensis production and quality. The bull spermatogenesis cycle is 60-days long, so during a breeding soundess exam if the bulls were in poor condition most of the winter, this season due to the distance traveled to the cows for breeding, water source, and feed, so be prepared for them to lose body condition too.

The most difficult part of breeding season is increasing the body condition of thin cows. Over the past 2 years we have experienced limited feed availability, and this is continuing. Adding body condition to cows during early lactation is difficult and requires a nutrient dense diet. This can also be a challenge as this also coincides with pasture green-up.

Due to much needed precipitation in the area, we have lush, green grass, which can be between 60-70% water. These high moisture grasses are very palatable and digestible, and cattle must consume more of them to meet their nutritional needs. During the spring as the grass begins to grow, this can be a difficult time for cattle because if they are turned out, quantity may be limiting, depending on how many cows are within the pasture, which can lead to limited nutrients. Additionally, once cows are turned out onto green grass, many no longer will consume harvested forages unless access to the pasture is limited.

Body condition scoring your cows and bulls prior to the breeding season can help with management decisions. If cows are thin and need a better plane of nutrition, harvested feeds may need to be fed. Thin cows tend to struggle to rebreed and have poor reproductive performance. Therefore, an optimum body condition score of 5 to 6 will improve reproductive performance and produce healthier calves.

New Rules are Coming for Medically Important Antibiotics

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Many livestock producers were impacted in 2017 by FDA Guidance for the Industry #213, also known as the Veterinary Feed Directive. Guidance #213 impacted the antimicrobials are those that may be used in human medicine as well as animal medicine. Guidance #312 required a veterinary-client-patient-relationship and a prescription from the veterinarian to puchase and use feed and/or water antimicrobials in animals. The new FDA Guidance for the Industry #263, published on June 11, 2021, will now require purchase and use of current and future medically important antimicrobials to have a veterinary prescription and will no longer be available over-the-counter (OTC).

The FDA is allowing a two-year phase-in of the guidance, so by June 11, 2023, all current and future medically important antrimicrobials will require a veterinary prescription and must contain the prescription statement; "Caution: Federal law restricts this drug to use by or on the order of licensed veterinarian." The main restriction noted by most livestock producers will be the need for a veterinary prescription for injectable medically important antimicrobials. Some stores, just as with the feed and/or water antimicrobials, may stop selling the newly encompassed products, but they still may be purchased at other stores or your veterinarian.

Some examples of the drug classes that will be impacted are oxytetracyclines (Liquamycin LA-200, Noromycin 300 LA), penicillins, sulfa-based antimicrobials, and Tylosin. The new Guidance #263 not only impacts injectables but boluses as well. These products are not being removed from the market and will be readily available for purchase with a veterinary prescription.

Additionally, it is not recommended to stock up on these products prior to Guidance #263 implementation. Purchasing these products in large quantities also can lead to a large amount of product expiring prior to use. All of these products have expiration dates and are impacted by storage time and temperature. Utilizing any drug after the expiration date reduces its efficacy and may lead to additional treatments needed.

Guidance #263 only impacts medically important antimicorbials; it does not impact antimicrobials that are not considered medically important. Being prepared for Guidance #263 will help minimize complications as it comes into effect. If you don't currently have a veterinary-client-patient-relationship (VCPR), now is a great time to begin establishing it. This relationship will help both the veterinary and producer provide the best care for the livestock.

More information regarding Guidance for Industry #263

Drought Persistence and Cattle Decisions

(PDF of article)

Unfortunately, the drought continues to persist throughout Montana and relief is not forecasted. The current drought map has 92% of Montana in a drought, with almost half of the state designated as D3 and D4. The seasonal drought outlook map show that through May 31, 2022, the drought will persist for most of Montana and the Western United States. The persistent drought means tough decisions ahead for livestock producers.

Since the summer of 2021, many livestock producers have drastically reduced the number of cattle on their operations. Some producers even shipped cattle to the Midwest to graze corn stalks during the winter months due to the lack of pasture availability and price of harvested feeds. Cattle producers heavily rely on pasture for grazing and with the persistent drought, pastures will need extended time for recovery. If possible, delay cattle turnout to allow for additional pasture recovery. If adequate pasture is not available, additional feeds may need to be provided to ensure requirements are being met.

However, providing additional feed may not be an economical or viable option. Feed already accounts for upwards of 70% of input costs for producers and needing to provide additional feed during the grazing season can drastically increase feed costs. Additionally, many feeds have drastically risen in cost and may not be available in the area due to the on-going drought.

Due to the rising feed costs and the lack of pasture, strategic culling decisions may need to be made. Some culling decisions are easier to make than others, such as those cattle with production issues. Production issues can be varied, such as age, bad feet, bad teeth, bad udder, low-quality calf, thin cows, open cows, or late bred cows. Once these cattle have been culled, decisions become more difficult and are highly dependent on the goals of your operation. Other things to consider when making culling decisions include cattle efficiency and/or genetics. Efficiency can be defined in many ways depending on the operation, but a common method is pounds of calf weaned per cow body weight. Genetics is another area that is highly dependent on the goals of the operation. Old cows could be culled because their production has begun to decline, or the producer has moved on to different genetics. Young cows could be culled because they require additional labor and input costs, but they're the new genetic base for the operation. Another option is to reduce the number of heifers being kept for replacements.

Making these decisions is difficult are are highly dependent on the operation. Keeping accurate records of the cattle can help in making these grazing, feeding, and culling decisions are we continue with the drought. An additional consideration when selling/culling cattle would be to discuss the strategy with the banker to determine what tax implications may be occuring and the best financial strategies moving forward.

2021 MOOving Minutes

Feeding During Drought

This is a difficult year for all livestock producers, drought, grasshoppers, fire, etc. With these challenges comes the difficulty of feeding livestock not only throughout the summer/fall, but then into winter and the following spring. Feed costs already account for about 70% of annual input costs for livestock producers, and this year will be mor due to reduction in feed availability leading to increased cost.

There are options available for livestock producers, but these options are limited to location and availability. This year many producers are relying on grazing of cereal grains for additional feed and considering alternative feeds for fall and winter. The main concerns with feeding these alternatives are amount that can be fed and the potential for nitrates.

Nitrates accumulate in stressed plants, such as in drought, and can cause nitrate noxicity in cattle. Nitrates typically accumulate in the bottom 1/3 of the stem portion of the plant compared to the heads and leaves. However, when grazing ceral grains of feeding cereal grain hay, a nitrate test should be completed to determine how risky it will be to feed to cattle. Most local Extension Agents have the ability to test for nitrate using the Nitrate Strip Test, which is a quantitive measurement, meaning that an approximate concentration of nitrates in the sample can be provided. Nitrate concentrations will decrease as the plant matures, but once nitrate accumulating plants are cut, nitrates will not dissipate unless they are ensiled. If you are going to graze cereal grains that may contain nitrates, there are a few things to consider.

  1. Turn out cattle later in the day when they are full and not hungry.
  2. If there are high nitrate concentrations, less stocking density should be used so that the field can be grazed lightly and cattle will have the ability to select for the tops and leaves of the plants.
  3. If feeding high nitrates forages, make sure to test the water for nitrate levels as well. Water and forage nitrates are additive, meaning nitrate toxicity could occur even if water nitrate levels are relatively low.
  4. If higher nitrate feeds are fed, provide an additional energy source to the cattle to help with the conversion of nitrate to ammonia. Do NOT feed EPN (non-protein nitrogen) during times of high nitrates. Make sure the protein portion of the feed is all-natural protein.
  5. Monitor cattle closely when feeding nitrate containing feeds. If any adverse effects are observed, remove the cattle immediately from the field and provide non-nitrate containing feeds.
  6. If at all possible, when feeding high nitrate feeds, feed cattle with less risk, such as steers or non-pregnant heifers. High levels of nitrates can cause abortion.

Drought stricken pastures are of low-quality, menaing they have low protein, minerals, and energy and high fiber. Feeding a good-quality mineral during drought can help mitigate portential issues at a later date. Minerals are essential to maintaining cattle health and production. Montana pastures on an average have limited concentrations of copper, zinc, and maganese and require mineral supplements. During drought the concentrations of these three trace minerals may be extremely low, which may lead to mineral deficiency if not provided. Minerals are an expensive portion of feed inputs each year and should be sacrificed to save on these input costs.

Other alternative feeds that may be available are wheat midds, corn, barley, and wheat. All of these feeds are good sources of protein and energy, but care must be taken when feeding. Corn, barley, and wheat are highly digestible in the rumen and could potentially lead to acidosis or bloat if fed at too high level in the diet too quickly. Adapt cattle to grains over a period of time to allow the rumen to adapt to the new feedstuff. Wheat midds are a good source of energy and protein and provide these through digestible fiber and not starch.

Straw can be fed to cattle as long as a good-quality forage is fed with it, this will minimize compaction issues. Straw in mature cows can be fed up to 50% of the diet until the 3rd trimester and then straw should be limited to 25% of the diet. Straw should be limited during the 3rd trimester due to rumen capacity limitations and the increase in requirements. Straw should not be fed during lactation due to the large increase in nutrient requirements. Straw can also be fed to first-calf heifers at 25% of the diet until the 3rd trimester. Straw is not recommended during the 3rd trimester and lactation for first-calf heifers. Feeding straw can help stretch limited hay supplies. We can work together to create a good mix of straw and good-quality hay to prolong the use of higher quality hay.

This year is going to be a tough year when feeding livestock and many different feeding strategies will be employed. We can work together to develop feeding strategies that will work for your operation.

Mineral Nutrition for the Beef Cow Herd

  • Extension beef cattle specialists from South Dakota State University (SDSU), North Dakota State University (NDSU), Montana State University and the University of Wyoming are now accepting registrations for the educational series, Mineral Nutrition for the Beef Cow Herd. Started in South Dakota in 2017 and extended to North Dakota in 2018, the program was spurred by an increased interest in grazing mineral nutrition.
  • "I am so excited about the opportunity to expandd this program into Montana and Wyoming to reach a larger number of beef cattle producers and help them make positive changes to their mineral program, health of their cattle and the profibility of their operatiobns," says Adele Harty, SDSU Extension Cow/Calf Field Specialist. "This program has evolved, and improvements have been made every year to address the challenges and concerns brought forth by participants. As a result, this program provides hands-on, individualized assistance to ranchers that can make a meaningful difference to their operations."
  • "Mineral supplements may cost producers between $20 and $50 or more per cow per year. While minerals are a small component of beef cow diets, they are critical for a variety or functions in the body," says Janna Block, NDSU Area Extension Specialist. Livestock Systems. "This program gives producers more information about specific mineral challenges on their ranch and how to deal with them effectively to increase value and efficiency of mineral supplementation."
  • In 2020, the educational sessions were transitioned to a virtual format, which is being maintained this year - providing the opportunity to expand to a larger geographical region and reach a larger group of producers. The June sessions will provide basic knowledge about mineral nutrition along with tools to help producers successfully monitor mineral consumption and make adjustements to increase consumption.
  • The second part during the summer includes the submission of forage and water samples to Ward Laboratories, which has partnered with Extension to provide a discount for participants to get their samples analyzed. Once the Extension personnel recieve the results, they will work with the participants to interpret the results and determine what changes could be beneficial to the operation.
  • Harty says the third component that is critical to the success of the program in the ranch visits.
    • "This provides an opportunity for the particpants to share their specific situation and challenges with the Extension personnel one-on-one to find solutions or simply fine-tune what they have been doing," Harty says.
  • The series concludes with educational sessions in the fall, where all of the information that has been shared over the previous five months is brought together in an applied format.

Finish reading June MOOving Minutes

Determining Pregnancy Status in Your Beef Herd

  • The eyes can be deceiving at times, especially when you're hoping that high performing mother cow in your herd is pregnant. It is important to determine pregnancy status for a multitude of reasons, including to elevate herd reproductive efficiency and bull fertility, estimate calving dates to assist with strategic management of calving groups, and to improve flexiblity with marketing options of late calvers and non-pregnant females that conceived in the first cycle of the breeding season, and to identify females that conceived via artificial insemination from those bred by the clean-up bulls. Early detection can assist with selecting future replacement heifers and bulls, along with identifying future options for marketing of calves. It can also be beneficial for detecting issues that occured during the breeding season, such as individual bull fetility, poor estrus response, human error such as poor semen handling, synchronization protocol event timing, or insemination. Low pregnancy rates in one breeding group may indicate poor nutrition, or an individual bull fertiity issue, while whole herd rates may be due to an issue with the current breeding program, poor nutritional status at pre-breeding and throughout the breeding season, ingestion of poisonous plants, or infectious disease. In years of drought and limited resources, early detection of pregnancy status and strict culling can assist with flexible marketing and prevents the use of precious resources on overwintering open cows.
  • One misconception is that heat detection alone can be used to determine pregnancy status: however, some bred females can continue to express signs associated with estrus (such as riding herd mates) due to changes in hormonal changes that occur early in pregnancy or prior to calving heat. Therefore, more accurate pregnancy testing methods should be used to determine individual status.
  • Pregnancy status in beef cattle can be determined by several different methods including blood analysis, rectal palpation, and ultrasonography. Each method varies in cost and skill associated with accurately evaluating pregnancy status.
  • Blood collection can be a very convenient and cost-effective menas of pregnancy testing. The blood is drawn using a needle and syringe, or a needle, needle hub, and blood tube from the coccygeal vein in the tail or from the jugular vein in the neck. Care should be taken to use a new needle for each female as cross contamination can occur and lead to inaccurate results. There are several options in terms of companies, cost, and means of blood analysis for pregnancy testing. Bloose analysis will only be able to categorize a female as pregnant or open, and in the case of a recent abortion, the female may be deemed pregnant as the hormones of pregnancy and the fetus are still lingering.

Finish reading May MOOving Minutes

Alternative Feeds for Beef Cattle

  • The term alternative feeds can have several meanings for beef cattle production. I teind to think of alternative feeds and those feeds that are not traditionally fed, such as corn, barley, or grass/alfalfa hay. In a year where pasture or forage production may be limiting, alternative feeds should be considered as potential feed sources to make up for the energy and protein shortfall.
  • Producers need to consider the feeds available in their area, not all feeds are available in every area. When considering addititional feeds, prices should be considered on a per pound of nutrient basis, such as protein and energy. This allows for feeds to be directly compared to one another. Additionally, producers should consider the amount of feed needed to make up energy and protein shortfalls and/or if consumption should be limited for their cow herd. Moreover, nitrates may be an issue for some alternative feeds and care should be taken when feeding.
  • Several feeds can be considered for beef cattle during times of limited forage production. Corn residue, field peas and residue, beet pulp, and wheat middlings are just a few alternative-type feeds that can be fed to cattle. Several factors should be considered when considering alternative feeds. One of the largest factors is availability. Product availibility in your area is critical when considering alternative feeds.
  • Another large factor is cost. As mentioned previously, determining the cost of the product per pound of nutrient and cost per head per day based on needed consumption will aid in selecting a product. Nutrient analysis of the product is another factor to consider because it is needed to determine these costs. Alternative feeds may vary greatly in nutrient composition, so a current nutrient analysis should be conducted for the feed. When calculating these cost, the dry matter information should be used.
  • Additionally, transportation cost should be considered when determining which feeds are more economically viable. Transportation of a product such as beet pulp, which is high in moisture, reduces the amount of dry matter being transported, which increases the price of transportation. However, transporting beet pulp, which has moderate protein and high energy, may be ecnomically feasible over short distances.
  • Product storage is another factor that should be considered. Product can be stored in several ways, upright bins; silage bags, bunkers, or bins; open pits and bunkers; and baling. Storage of high moisture products, such as beet pulp, can be accomplished through ensiling. Grain residues may be grazed, but care should be taken for protein, where additional supplementation may be needed.
  • These several factors to consider when feeding alternative feeds in your beef cattle operation. Conducting a nutrient analysis is one of the best ways to mitigate feeding issues. Contact yor local Extension Agent of Extension Specialist with any further questions regarding feeding alternative feeds.

Preparing Your Operation for Drought

  • Much of the state have been experiencing Spring-like weather for the past few weeks, which has made for a pleasant calving season. However, based on snowfall and precipitation through the winter months, drought may be an issue to start considering.
  • The current U.S. Seasonal Drought Outlook was just released on March 18, 2021 and it appears drought is forecasted to continue for much of the Eastern side of Montana through June 2021.
  • One key aspects of your Drought Management Plan should be critical dates and thresholds for your operationh regard grass production, cattle production, and current inventory. Grass production in Montana relies heavily on spring and early summer precipition for forage quality and quantity. Without needed precipitation during those months, grass prodction is reduced, which reduces grazing time and capacity in those pastures.
  • Cattle production thresholds should be monitored through body condtion and calf growth during late spring and early summer. One method to aid in reducing forage demand from your cow-calf pairs is to early wean. Removing the suckling calf will reduce nutrient requirements of the cows and reduce forage consumption.
  • If the drought persists, a reduction in stocking rates may be an economical benefit to your operation. Reducing stocking rates on pasture may be done through selective culling or moving your herd to a drylot. These decisions and lists for culling priority should be included in your Drought Management Plan.
  • Read full MOOving minutes on Drought here

The iSperm: A Potential Alternative for On-Ranch Bull Semen Analysis

  • There have been reports that one in every 5 bulls are categorized as "unsatisfactory potential breeders" or subfertile, typically either due to poor semen quality, physical examinations concerns, or both.
  • It is estimated that use of subfertile bulls can cost a rancher 50 or more pounds of weaning weight per calf for every 21 days a cow fails to conceive in a given breeding season.
  • A breeding soundness exam (BSE) evaluates the phsyical health and structure of the bull, in addition to several key parameters of the semen collection, set by the American Society for Theriogenology.
  • In order to assess ability to successfully breed, bulls should be tested before the breeding season, whether the bull has been used in previous seasons or is a new purchase.
  • An annual BSE is critically important to the calf crop of the subsequent year.
  • Currently, the hemocytometer or visual evaluation of semen is common practice for veterinarians, seedstock producers, and even some bull testing centers when completing a BSE. This evaluation is dependent upon a trained individual that can accurately access the samples collected, and conclude with a simple pass or fail for the bull while considering the factors listed by the Society for Theriogenology.
  • There are certain semen quality factors that are evaluated during a BSE, including semen concentration, progressive motility, and abnormalities of the sperm.

Read full MOOving Minutes on the iSperm and bull reproduction

Lice Management for Cattle

  • Be on the lookout for lice this year. As our temperatures start to drop, lice may become an issue on your cows, bulls, and calves.
  • Lice infestations typically occur on beef cattle that are stressed from the cold weather, inadequate nutrition, have internal parasite infestations, or have lowered immune systems.
  • Heavy lice infestations can result in reduced feed efficiency, milk production, and weight gains.
    • Infestations can lead to anemia, skin infections, and other diseases.
  • Adult lce are between 1/16 and 1/8 inches long and spend their entire life on the host. The louse life cycle is approximately 3 -4 weeks.
  • In Montana we have four predominant species of lice on cattle, one chewing and three sucking.
  • The cattle biting louse is the most common species found on cattle in Montana and this louse feeds on skin, scurf, and hair. This louse is typically found along the back, withers, poll, and tail head areas.

Read the full article on Lice Managment for Beef Cattle


2020 MOOving Minutes

August 2020 - If Only We Had a Crystal Ball - Retained Ownership

2019 MOOving Minutes

2019 Steer of Merit Award Winners

 Montana State University Extension and the Montana Stockgrowers Association (MSGA) distinguished 126 "Steers of Merit" out of 1,089 entries for 2019. Out of 620 steers entered in the Carcass Division, 77 were deemed Steers of Merit. In the Ultrasound Division, 49 out of 469 entries recieved the distinction. The number of Steer of Merit certifications for 2019 decreased by 34 steers compared to 2018.

Click link above to view the results.

Pinkeye in Beef Cattle

Pinkeye is one of the most common disease in beef cattle. It is highly contagious and can spread easily throughout the herd if left untreated. Due to the regular moisture we have been receiving and the tall grass, pinkeye may be more prevalent this year.

Moraxella bovis is the primary bacteria species causing pinkeye. Typical symptoms are inflammation of the cornea and conjuctiva, casuing the eye to weep excessively. Affected cattle will keep their infected eye closed due to pain and to avoid bright sunlight. If left untreated, ulceration of the cornea can occur, which may lead to blindness in the infected eye. Pinkeye can also negatively impact calf growth and performance by reducing feed intake.

There are 3 stages of pinkeye:

  1. Stage 1: The eye will have increased light senstivity and weep excessively. As the pinkeye progresses in stage 1, an ulcer (white spot) will form in the middle of the cornea. The cornea will also appear gray due to the increased inflammation.
  2. Stage 2: the stage 1 signs will continue, and the ucler will begin to spread across the entire cornea. The cornea will appear cloudy as inflammation continues to increase. As stage 2 progresses, the blood vessels on the outer edge of the cornea will spread across the cornea to aid in healing. The outer edge of the cornea will appear pink, which provides the disease name sake.
  3. Stage 3: The ucler will encompass the majority of the cornea and inflammation will move into the inner eye. As this inflammation continues, the eye will fill with fibrin, giving the eye a yellow appearance, surround by the pink outer edge of the cornea.

Pinkeye is readily spread throughout the herd by face flies. Face flies can spread the disease to several animals throughout the day because they spend little time on the cattle. Therefore, best control of pinkeye is prevention. Having a good fly control program can help mitigate the spread of pinkeye throughout the herd.

If calves in the herd have pinkeye, the typical treatment plan is a long-lasting antibiotic and protecting the eye from sunlight. Consult your veterinarian to determine the best antibiotic to use for pinkeye. Applying an eyepatch to the infected calves is also crucial in the treatment plan because sunlight activates enzymes in the eye which can increase pinkeye damage to the cornea.

If pinkeye is prevalent in the herd year after year, consult your veterinarian to determine if a pinkeye vaccine may help. There have been mixed results on the use of pinkeye vaccines due to the multiple bacterial species that may be the cause. Bacterial cultures may need to be collected to determine if the vaccine will be effective in reducing the incidence of pinkeye.

Prevention, Treatment, and Control of Calf Scours

Another severe winter has led to instances of calf scours. Calf scours, or diarrhea, is typically associated with inflammation of the intestinal tract. Scours main occurs during the first few days and up to one month after birth. Young calves are most susceptible due to their naive immune system.

Scours can be caused in variety of ways. Rotavirus, coronavirus, BVD, coccidia or other parasites, E. coli, Salmonella, or Clostridium perfringens. Most cases of scores likely involve more than one cause. Overcrowding of pens is a main cause for calf scours, as it increases the number of infectious agents to increase dramatically. Other factors, such as consuming too much milk, which cannot digested by the calf, can also cause calf diarrhea.

The diarrhea is only one part of the issue, another major factor is severe dehydration by the impacted calves. The intestinal inflammation reduces the calf's ability to properly digest nutrients. If bacteria (Salmonella and Clostridium perfringens) are to blame for the scours, they will release toxins which can harm the vital oragns.

Baby calves can become infected when exposed to large colonies of the bacteria, parasites, or viruses. Shedding of the infectious agents is common by adult, pregnant cattle. Research has shown that as cows get closer to calving, shedding of the rotavirus and coronavirus increases. This increase in shedding was heaviest in heifers and may also increase after cold weather. Older calves that are exposed to the viruses may not develop scours, but also may shed these viruses. Therefore, moving cow-calf pairs soon after calving can help reduce in the incidence of scours.

One of the best ways to reduce the potential of scours is to maintain a healthy herd throughout the year. Maintaining a health herd through proper immunization, but also through nutritional means can help reduce the possibility of scours. If calving indoors, moving calves outside can also reduce the potential for calves to contract scours. Calving barns should be thoroughly cleaned after each calving season, which includes removal of all fecal material and putting lime on all surfaces that were potentially exposed to scours. 

Immediately upon observing scours symptoms, infected calves and their dams should be removed from the healthy herd. The main treatment for calf scours is providing water and electrolytes to the infected calves, this helps reduce dehydration and improves acid-based balance. There are two ways of administering the needed fluids, oral or intravenous administration. Your veterinarian can help determine the amount and how often calves should be treated. Make sure you are using proper biosafety protocols when dealing with scours, change boots when entering a clean area, wash your hands, and change clothes if needed.

Prevention of scours is difficult due to the number of agents that can cause the diarrhea. Therefore, the main way to prevent scours is to maintain clean calving facilities and to move cow-calf pairs to a fresh, clean area after calving. Ensuring all calves receive adequate quality and quantity of colostrum can also aid in preventing scours.

Weathering the Storm During Calving

The new year may have entered like a lamb, but February rolled in like a lion. For those that calve in January and February, the rapid changes in temperature may have played a role in calf sickness and growth. Maintaining a healthy calf is crucial to growth and a good immune system.

As the temperature drops, cow body heat needs to be maintained, which we can accomplish with extra feed. Utilizing forages, such as hay, will aid in maintaining body heat during cold temperatures through fermentation within the rumen. Dropping temperatures also increase nutrient requirements of cows, which may be increased by at least 50% as the temperature drops below zero.

The additional nutrients provided to cows during the winter also has an impact on calf birth weight. Birth weight of calves born in the winter and spring typically have great birth weights great than their fall born counterparts. The increase in birth weight of those winter and spring born calves is most likely due to the increase in nutrient influx through supplementation.

Bitter cold temperatures not only add stress to the cow, but also the calf. Calves need to nurse within 2-4 hours after calving to get the maximum benefit of the cow's colostrum. This becomes even more important during cold temperatures. Providing a sheltered, dry area for calving can drastically reduce the negative impacts of cold temperatures on calf health.

Research has indicated that the lower critical temperatures for calves is approximately 60oF. If the calf is not dried off quickly or if it's raining or snowing, that temperature is about 70oF. In Montana, we won't see 60oF temperatures again until March or April. Even with the bitter cold temperatures, calving can be managed to reduce the stress on the calf and the producer by monitoring the weather forecast, ensuring cows have a sheltered area to calve, and checking that calves are dried off quickly after calving.

A large drop in temperature can cause health issues for calves, but what occurs when there is an upward swing of temperatures or a large variation of temperatures. A wide swing in temperatures can also be detrimental to calf health. However, it difficult to adjust when the temperatures are highly variable. When it's cold, we can feed additional supplements to cows, which will provide additional nutrients to the calf through the milk.

If we see a rapid warming trend, the best way to ensure calf health is through your calf health program. The first step is to ensure your cows are on a good health and vaccination program that you have discussed with your veterinarian. The second step is to ensure your calves consume colostrum within 2-4 hours after birth, the colostrum provides maternal antibodies to calves and passive immunity. Having your calves on a good vaccination program beginning at birth will ensure good active immunity. Active and passive immunity will aid calves in maintaining a healthy immune system, especially if we see rapid changes in weather patterns.

Additionally, as temperatures warm, snow melts and the ground thaws, which can cause wet, muddy areas. Keeping cows and calves out of these areas can reduce the potential for illness. Keeping cows and calves dry, even if the temperature is not that low, is crucial to maintaining a healthy herd. Healthy calves have imroved growth and tend to be healthier throughout their life compared to calves with compromised immune systems.

2018 MOOving Minutes

Early Weaning Your Beef Calves

Megan Van Emon, Extension Beef Cattle Specialist

According to the United States Drought Monitor, approximately 57% of Montana is currently experiencing drought conditions. As the the dry conditions persist, some ranchers may consider early weaning their calves. Early weaning calves can relieve grazing pressure on pastures, which will become increasingly important if rain doesn't occur in the near future.

Early weaning can be used as a management tool when forage is limiting during drought. Early weaning can also impact cow and calf performance as well as pasture productivity and health. Early weaning may also require additional management, nutrition, health, and facilities.

Advantages to Early Weaning

  1. Improved cow body condition. Lactation increases the nutrient requirements of the cow, and cows can lose body condition due to the increased nutrient demand. During a drought, forage quality and quantity diminishes rapidly. Early weaning calves eliminates the nutrient demand for lactation, which allows cows to maintain or improve body condition prior to fall and winter.
  2. Improved forage availability. By eliminating the nutritional demand of lactation in the cows, cows will consume less dry matter. Early weaning in to a drylot also removes the forage demand by the calf and reduces the pressure of grazing on drought stricken pastures.
  3. Improved calf performance. As forage quality and quantity are reduced during drought, adequate forage may not be available for both the cow and calf. By early weaning in to a drylot, the calves may be fed a high quality diet, with calves reaching their growth potential. Calves may also be weaned early to a better quality pasture, which will better enable calves to reach their growth potential.

Disadvantages to Early Weaning

  1. Increased management needs. Greater attention to management, health, nutrition, and facilities is needed when early weaning. Improved facilities may be required, especially when weaning in to a drylot. Calf health is one of the most important considerations during weaning, both traditional and early, to maintain optimal growth. Due to the increased management demands, additional labor may be needed.
  2. Increased cash costs. By weaning calves early, additional costs may be accrued. Calves weaned in to a drylot require high quality feeds to reach their growth potential. Facility improvements to hold smaller calves may also be needed when early weaning.

Early weaning is a management tool that can be used during a drought when forage becomes limiting. If considering early weaning, determine the advantages and disadvantages associated to determine if this would be the best option available.

The Importance of Trace Minerals

Megan Van Emon, Extension Beef Cattle Specialist

It's the middle of June and Montana continues to receive precipitation. Although many of the pastures are green and lush, this is not the time to forget about trace minerals and their importance to beef production.


In Central and Eastern Montana, selenium concentrations in forages and grains are likely adequate to meet the requirements of the cow and calf. However, in some areas of Western Montana, forages and grains may not have adequate selenium to meet requirements. Selenium is required for decreasing oxidative stress and the production of thyroi hormones through the required enzymes. Oxidative stress can occur during weaning and if selenium requirements are not met, tissue damage can occur.


Most forages in Montana do not meet the copper requirements of cattle and needs to be supplemented. Copper is required for a number of enzymes that impact reproduction, bone development, hair growth, and iron transport. One of the tell-tale signs of copper deficiency is depigmentation of the hair coat, such as graying of black hair, and is especially seen around the eyes. When determining copper concentrations in supplement, antagonists need also be considered. Molybdemun and sulfur are both copper antagonists and can form thiomolybdates within the rumen, which renders copper insoluble. Forages in Montana are relatively high in molybdenum and water can contain high concentrations of sulfate.


In Montana, most forages are not adequate in zinc to meet requirements. Zinc is required for numerous processes, such as gene expression, fat absorption, antioxidant defense, and the control of appetite. Zinc is critical for DNA synthesis and plays a major role in fetal development. Zinc is also integral in the development of the immune system and its functioning. Adequate zinc concentrations will help maintain a healthy immune system during stressful situations, such as weaning, gestation, and calving.


Manganese is required for reproductin enzymatic activity to reduce oxidative stress and for energy metabolism. Manganese requirements vary based on production, either growth or reproduction. Cows have a much higher requirement for reproduction than growing and finishing cattle. Heifers have a large demand for manganese due to the combination of growth and pregnancy. Therefore, production goals must be considered when supplementing manganese.


Iodine has one major function as a part of thyriod hormones. Thyroid hormones are essential for immune function, thermoregulation, muscle function, and circulation. Each of these functions is important for growth and reproduction.


The main function of cobalt is the synthesis of B vitamins, which are formed in the rumen. Cobalt is also involved in energy metabolism. Regeneration of methionine, an essential amino acid, is also one of the main functions of cobalt.


Iron is a main structural component of hemoglobin, which transports oxygen in the blood to the tissues and carbon dioxide from the tissues back to the lungs. Iron requirements are most likely met by the forages and grains fed to cattle and do not need to be supplemented.

Providing trace minerals can be done in a number of ways, like free-choice loose mineral, injectable minerals, trace mineral-fortified salt blocks, and trace mineral fortified feed supplements. There are advantages and disadvantages to each of these trace mineral supplementation strategies. No matter how trace minerals are supplemented, ensure concentrations provided are adequate for cattle.

Having forages analyzed for trace mineral concentrations can help when determining which trace minerals are needed in a supplementation program. Analyzing forages for trace minerals can provide information to limit possible issues with trace mineral deficiencies.

Click link at top of article to view table.

Grass Tetany in Beef Cattle

Megan Van Emon, Extension Beef Cattle Specialist

With the abundance of snow this winter and the spring rains we have received, grass tetany may be an issue this spring. Grass tetany typically occurs when cattle are grazing rapidly growing, lush, green grass. The rapidly growing grass is low magnesium, resulting in a magnesium (Mg) deficiency in the cows.

Grass tetany is a metabolic disorder that results in low concentrations of magnesium in the blood. Older cows tend to be more susceptible because they may be unable to mobilize Mg from their bones as efficiently as younger cows. Cows in early lactation are most susceptible to grass tetany due to higher demand for Mg in the milk.

Grass tetany risk increases in lush, green grass that is also high in potassium and nitrogen. Both potassium and nitrogen can interfere with Mg absorption from the rumen. Calcium is also in high demand during early lactation, which could result in more severe cases of grass tetany when coupled with Mg deficiency. Additional stress or harsh weather can also lead to cattle going off feed for 1-2 days, which may result in low Mg concentrations in the blood, leading to grass tetany.

The early growing season results in grasses with a greater water content, which will dilute the minerals and nutrients in the grasses. Cows may not be able to consume enough grass on a dry matter basis to meet their requirements. For example, a 1300-lb cow eating 2.5% of her body weight on a dry matter basis needs about 33 lbs of dry feed each day. If the lush, green grass is 75% water, she would need to consume 132 lbs of that green grass to eat 33 lbs of dry matter.

It may be difficult to determine Mg deficient cows because symptoms may occur rapidly and your only evidence is a dead cow. Symptoms of Mg deficiency include disorientation, weakness, convulsions, or aggressive behavior. The cow may appear continuously nervous or alert, lie down and get up frequently, or staggering. These behavioral changes indicate additional Mg may be needed. If left untreated and additional Mg is not provided, cows will begin to lie down on one side and begin paddling. Immediate treatment is needed if Mg deficiency is encountered. During treatment, cows must be worked calmly and quietly, sudden excitement can lead to convulsions and/or sudden death. Blood concentrations of Mg will return to normal after death, but samples of eye fluid or cerebrospinal fluid do not change near death and are a good indicator of Mg deficiency.

Grass tetany can be prevented by providing a mineral or lick tubs with additional calcium and Mg. Maintaining adequate blood concentrations of Mg is essential to preventing grass tetany, which could occur within 48 hours if Mg concentrations are too low in the blood. Providing a "high-mag" supplement during the early growing season and during early lactation will help to prevent Mg deficiency.

Preparing for the Breeding Season

Megan Van Emon, Extension Beef Cattle Specialist

Breeding season success begins with management decisions made during calving. Here are a few tips for preparing for a successful breeding season.

  1. Nutrition - Ensuring all cattle are meeting their nutritional needs is an essential first step to having a successful breeding season. One way to determine if nutritional needs are being is met is to monitor body conditions score (BCS). Thin cows require additional time to reutn to estrous and may be delaying in rebreeding. Providing thin cows with additional nutrients and maintaining moderate body conditioned cattle may improve breeding success. This is especially important this year due to the lack of moisture in some areas, where additional supplementation may be needed prior to breeding. Don't forget about your bulls. Your bulls should be adequate condition to travel long distances to breed, feed, and water. Spermatozoa quality and quantity can be impacted by poor nutrition. Ensuring a good nutrition program for you bulls will aid in maintaining sperm production during breeding season.
  2. Vaccinations - Prebeeding vaccinations should be given 2 to 4 weeks prior to breeding. Heifers will need 2 doses of the vaccine given approximately 3 weeks apart, with the final dose given 2-4 weeks before breeding. A good vaccination protocol is essential to maintaining herd health and preparing for the breeding season. Contact your veterinarian to determine which vaccines will work best for you.
  3. Bull Breeding Soundness Exams (BSE) - The BSE is an exam conducted by veterinarians that includes a physical exam, semen evaluation, and an internal and external exam of the productive tract. Evaluating the feet, legs, teeth, eyes, flesh cover, and scrotal circumference and shape is included in the physical exam. The semen evaluation includes semen normality and motility. The BSE should be conducted 30 to 60 days prior to the beginning of breeding. It is important to note that the bull's sperm production cycle is approximately 60 days, and if illness, injury or other issue occurs, this could negatively impact the BSE and breeding capability of the bull and may need to be re-evaluated. An additional BSE can be conducted at the end of the breeding season to determine if bull fertility decreased throughout the breeding season.
  4. Inventory - Prior to the breeding season, take stock of your current inventory needed for the breeding season. This is especially important for those using AI. Inventory includes supplies needed, such as CIDRs, vaccinations, AI injectables (GnRH and PGF), and semen. Herd inventory is also crucial to a successful breeding season. Determining which cows you will cull and which you will keep, do you need to purchase another bull, or do you need to improve your herd genetically. Assessing inventory early will enable you to be better prepared for the breeding season.
  5. Prebreeding checklist - I like checklists because they allow me to be better prepared. Creating a prebreeding checklist and gathering the supplies in a central area will help keep things organized when the breeding season begins.

Rising Costs of Vitamins A and E

Megan Van Emon, Extension Beef Cattle Specialist

As many may have noticed, cost of vitamins A and E have increased over the past few months, and subsequently, mineral supplements that include vitamins A and E. The rising costs were mainly due to a fire on October 31, 2017 at the BASF plant in Germany, which produces citral, a precursor in manufacturing vitamin A and E products. The BASF vitamin A and E manufacturing plants were shut down for scheduled, routine maintenance at the time of the fire and will reopen once the citral plant beings production again and other production intermediates become available. Currently, the plant is working on repairs and information about those repairs can be found on the BASF website. The earliest the citral plant will be operation is the end of March, barring any delays in materials, inspections, and other issues. Downstream products, such as vitamin A and E, will become available 6 to 12 weeks after the citral plant resumes production. However, shipment and delivery of vitamin A and E may take up to several months.

Vitamins A and E are fat soluble vitamins and are required daily for beef cattle production. Vitamin A does not occur naturally  in plant material, but precursors, such as carotenes and carotenoids do occur in plants. The conversion of carotenes to vitamin A primarily occurs in the wall of the small intestine. Pregnant beef heifers and cows require 1,273 IU/lb of dry feed and lactating cows and breeding bulls require 1,773 IU/lb of dry feed to meet maintenance requirements. The majority of vitamin A is stored in the liver, with the remainder stored in fat and other organs. Vitamin A is stored in the liver, with the remainder stored in fat and other organs. Vitamin A deficiency symptoms include night blindness, lowered fertility, abortions, and lameness. Vitamin E is present in feeds a tocopherol, with alpha-tocopherol having the greatest biological value. Vitamin E requirements for reproducing beef cattle are not as clear as vitamin A. For young calves, the vitamin E requirements is between 7 and 27 IU/lb of dry feed and between 50 and 100 IU/head/day for older growing and finishing cattle. Vitamin E's main role is an antioxidant. Vitamin E deficiency symptoms include impaired reproduction and white muscle disease. Vitamins A and E are consumed in the diet and are also available as an injectable.

Tips for Calving Season

Megan Van Emon, Extension Beef Cattle Specialist

As the temperatures warm and winter moves in to spring, it's time to start preparing for calving season. Calving season is one of the most labor intensive and important times in the year for cattle producers.

Being prepared when the first calf hits the ground can reduce the stress on the cow and calf and improve health. Cleaning calving areas, calf chains, and the calf puller can reduce the health risks to the cow and calf. Gathering and organizing the supplies needed for calving can reduce the stress for your calving crew. Don't forget to include the name and phone number of a veterinarian with your supplies. Ensure all items needed are in good working order prior to calving.

Adequate cow nutrition can improve colostrum quality and quantity and has a large impact on calf health. A good way to determine if cows are receiving adequate nutrition is to assess body condition during gestation. Separating cows that may require additional feed to improve body condition from adequate conditioned cows is one way to ensure all cows are receiving proper nutrition. Severe temperatures may also require additional feed for all cows due to the increase in requirements.

Prior to calving, cows and heifers may be seperated in to different lots. Heifers may require additional management to ensure an easier calving experience. Additional groups may also be seperated between early and late calvers or AI and natural service.

Monitor cows and heifers closely during calving. Times may vary depending on the operation and the calving crew, but cattle should be monitored at least every four hours. This may be more intensive when the bulk of calving occurs.

After calving, different groups should be designated - neo-natal calves and cows and older calves and cows. Keeping newborn calves, up to 21 days old, seperated from the older calves reduces the risk of disease transfer between the two groups.

Keeping facilities clean is essential to minimizing health risks in newborn calves. Pens and calving areas should be cleaned regularly. Fresh bedding in calving areas should also be provided.

Calves should be monitored closely immediately after calving to ensure the calf has stood and nursed. If adequate colostrum quality and quantity is not consumed by the calf within the first two hours after birth, further assistance may be needed. Following a dystocia case, the cow may be milked to obtain fresh colostrum for the calf. Calves should consume sufficient quality and quantity of colostrum by six hours after birth. Keeping a colostrum replacement or frozen colostrum available will help when calves are unable to nurse.

Having a knowledgeable and reliable calving crew is essential to a great calving season. Providing training to a calving crew about your operation, the do and don'ts, and any additional information will make for a successful calving season.

2017 Cow Sense Chronicle Archives

Water Quality Concerns During Drought

Rachel Endecott

Water quality often decreases during drought. This special issue focuses on water quality concerns, testing, and interpretation. Many county Extension offices have a portable meter to measure total dissolved solids (TDS) which can be a first step in investigating water quality. If TDS measures in the 2500-3000 ppm range or higher, a sample should be sent in to a lab for further analysis to identify what salts make up the TDS. While each testing lab is a bit different, most water quality analyses will measure for sodium, calcium, magnesium, pH, nitrate, sulfate, and total dissolved solids.

Total dissolved solids (TDS) consist of the dissolved salts in the water, including sodium, chloride, carhonates, nitrates, sulfates, calcium, magnesium and potassium. It is generally expressed in parts per million (ppm). A guide to livestock and poulty response to saline water is summarized in the table below. Corresponding electrical conductivity values are listed in parentheses below TDS values.

View tables and more information here

Summer Pneumonia in Spring-Born Beef Calves

Rachel Endecott

The hot days and cool nights of mid-summer may bring summer pneumonia along with them. Sumer pneumonia in nursing beef calves is not uncommon, but occurs somewhat randomly and with low frequency. A wide variety of risk factors for summer pneumonia exist. These include relative success of colostral antibody transfer, commingling of groups, weather changes, nutrition changes or deficiencies, pathogen exposure, handling stress, and even operation-specific risk factors like lack of labor.

If you've been reading Cow Sense Chronicle for any length of time, hopefully I've convinced you of the critical importance of adequate and immediate intake of colostrum after a calf is born. Briefly, the immunity a calf receives through colostrum is called passive immunity, and is the major source of immune function in the newborn. If calves receive only limited amounts of colostrum, this is termed failure of passive immunity. Calves who experience failure of passive immunity are twice as likely to get sick before weaning, and 5 times more likely to die before weaning than calves that have adequate passive immunity. This means that incidence of summer pneumonia could be influenced by management at calving, by breeding decisions the previous summer that may have resulted in calving difficulty (limiting the calf's ability to get up and nurse quickly after birth), or by poor nutrition management or other stresses on the cow during gestation.

Commingling is a major and well-known risk factor for the development of bovine respiratory disease in calving after weaning. While mixing of sets of cattle is not normally a chief risk for nursing calves, commingling of groups from the same operation during the grazing season should not be ignored in regard to summer pneumonia risk. Moving pairs long distances to new pasture may also play a role.

Meanwhile, the weather can be a risk factor both early in the year and during the peak summer pneumonia season. Certainly, inclement weather can play a role in the success of passive transfer of antibodies from dam to calf. Heat stress, cold stress, and unexpected pre-weaning precipitation events like snow or freezing rain can all cause weather stress than can contribute to summer pneumonia.

Nutrition stress on cows during gestation can negatively impact calf health throughout the life of the offspring. Both energy and protein have been found to have impacts on fetal growth and development in utero and post-birth. Furthermore, poor nutrition can negatively impact colostrum quantity and quality. Nutritional impacts of a change in diet can also impact nursing calves directly. Examples might include change to a lush pasture, change to pasture quality during drought, or creep feeding.

Certainly, trace mineral deficiency, especially copper, selenium, and zinc, can negatively affect the immune system, which may result in increased susceptibility to summer pneumnia. In addition, toxicity from minerals, such as high-sulfate water, may impact calf health as well.

Exposure to pathogens such as IBR (infectious bovine rhinotracheitis), BVDV (bovine viral diarrhea virus), BRSV (bovine respiratory syncytial virus), BRCV (bovine respiratory coronaviruses), and Mycoplasma bovis, either within-herd or from other populations is also a risk factor in summer pneumonia.

Fortunately, summer pneumonia responds well to treatment if caught early. A variety of antibiotic and anti-inflammatory drugs have been used with success. Additionally, a well-managed herd health program including vaccination of cows and calves can greatly assist in herd immunity. Contact your veterinarian for summer pneumonia treatment advice and vaccination program recommendations.

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Selecting Culling and Early Weaning in Drought

Rachel Endecott

While forage and pasture conditions are in good shape on the western side of our state, the eastern half is suffering from a worsening drought. Reducing forage demand is an important part of a drought plan and selective culling early weaning are two strategies that can achieve that goal.

The first level of selective culling is to remove cows with obvious production issues, such as age, bad teeth, feet, or udders, as well as open cows or cows with poor quality calves. The second level of culling is where things get more difficult. There are a couple of approaches to consider, and I suspect most producers would use a combination of them. The first approach is to identify cattle with the most value per unit of forage consumed. These may be young cows and heifers that are products of the most advanced genetics in your herd. Retaining the young nucleus of the cowherd is important for future genetic improvement, so marketing older cows, some of whom may still be productive, may be the best option to retain a future genetic base.

On the other hand, young cows and heifers have higher nutrient requirements compared to mature cows and are more likely to not breed back. Additionally, young cows and heifers often command a higher premium, so a second approach may be to identify and retain cows who are done growing and will tend to breed back easier in tougher conditions while raising heavier calves.

Early weaning can reduce forage demand in a couple of ways. Lactating cows experience dramatically increased nutrient requirements compared to dry cows. Energy requirements decrease over 20% and protein requirements decrease over 30% as cows move from late lactation to mid-gestation.

This decreases the forage intake of the cow, as well as removing the forage demand the calf had been placing on the pasture. One rule of thumb indicates that for every day calves are early weaned compared to normal, about 0.6 grazing days' worth of forage are saved. This rule was calculated using a 1300-lb cow who weans a 600-lb calf at 7 months of age. Positive impacts from early weaning are generally observed for cow body condition and reproduction as well. Because of the decrease in nutrient requirements for lactation, more nutrients are available for the cow to partition to body weight gain. Reproductive responses and their timing depends on the timing of early weaning.

If the breeding season is already over, cow condition improvements may have an impact on breed back the following year if cows go into winter and calving in better body condition. If early weaning happens before the breeding season (calves around 80 days of age), reproductive performance can be positively impacted for the current year.

Hard decisions will have to be made if the dry conditions persist. In the meantime, pray for rain!

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Poisnous Plants: Larkspur and Death Camas

Rachel Endecott

The spring moisture much of Montana has received bodes well for a good poisonous plant year. This month, we'll focus on two common poisonous plants, larkspur and death camas.

Fatal poisonings from larkspur (Delphinium spp.) were reported in Montana as early as 189. There are at least 60 species of larkspur throughout North America. Poisoning has been attributed to nine of these species; however, it is probably a good idea to assume that all larkspur species are poisonous. It's common for larkspurs to be

Calfhood Vaccines or What Are All Those Clostridial Diseases?

As April is turning to May, some folks in Montana are already branding while some are still calving. This month, we'll focus on calfhood vaccination programs, which are most often based around the clostridial diseases. Producers may add other vaccines (pinkeye, H. somnus or other respiratory vaccines, etc.) depending on their situation and veterinarian recommendations.

Clostridial diseases in calfhood vaccines belong to the same genus as tentanus and botulism. Clostridial organisms are generally found in the animal's body, but with ideal conditions, grow very rapidly to cause a disease state. Because of this, affected animals are usually found dead, not sick. Thus, prevention of disease through vaccination is a better approach than treatment. Here is a brief overview of each strain:

Clostridium chauvoei causes blackleg, which presents as air-filled swelling in heavy muscle that will crackle when palpated. There is no history of wound with blackleg, unlike the next strain.

Clostridium septicum causes malignant edema, which results from contamination of wounds. Unlike, blackleg, malignant edema causes soft, fluid-filled swelling that pit on pressure. Large amounts of fluid are found in both subcutaneous and intramuscular connective tissues.

Clostridium haemolyticum causes redwater disease, also known as bacillary hemoglobinuria. Latent organisms lodge in the liver, waiting for localized cell death which is most often caused by liver flukes. C. haemolyticum produces beta-toxin, which ruptures red blood cells, leading to anemia and the presence of hemoglobin in the urine, hence the name redwater.

Clostridium novyi causes black disease, also known as infectious necrotic hepatitis. Like redwater, latent organisms wait in the liver for anaerobic cell death, again usually from liver flukes. Extensive rupture of subcutaneous capillaries can turn the skin black, giving this disease its common name.

Clostridium sordellii causes sudden death, primarily in feedlot cattle, and has no common name. It is characterized by massive black hemorrhage and smelly muscle necrosis in the brisket and throat area. Unlike blackleg, there is no gas formation from C. sordellii.

Clostridium perfringens type C and D cause enterotoxemia and overeating disease, respectively. Both lead to severe intestinal damage from necrotic and lethal toxins; type C produces beta toxin and type D produces epsilon toxin. Both are associated with the predisposing factor of the animal ingesting excessive amounts of nutrients. In calves, this may be after a period of dam and calf separation followed by a large intake of milk.

Successful vaccination needs an effective vaccine, a functioning immune system, and administration of vaccine before the animal is exposed to the disease. On branding day, do your part to make sure vaccines are effective; the temperature of your vaccine should be at least as important as the temperature of our branding beverages!

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Night Feeding for Daytime Calving

We've all experienced that middle-of-the-night calving incident that sure would have been easier to manage if it had happened in the daylight. Some ranchers use an evening feeding strategy to shift more cows to calve during the day.

A case study comparing two sets of calving data with different feedig times illustrates this phenomenon well (jaegar, et al. 2008 Professional Animal Scientist. 24:247). One group of cows was fed between 6 and 8 am (15 years of data, 1210 observations) and another group of cows was fed between.

4 and 6 pm (5 years of date, 537 observations). Researchers divided the day into six, 4-hour periods starting at 6 am and recorded the number of cows who calved during each 4-hour period.

Cows who were fed in the morning had nearly equal distribution of cows calving during each period of the day. This resulted in nearly equal proportions of cows calving between 6 am and 6 pm (52%) and those calving between 6 pm and 6 am (48%).

Cows who were fed in the evening did not have an equal distribution of cow calving during each period of the day. In fact, 85% of cows calved between 6 am and 6 pm and only 15% calved between 6 pm and 6 am.

There are many factors in addition to timing of feeding that can override the timing of calving. Research in cattle and other species suggests that physical activity, daily variation in hormonal secretion, ambient temperature, or day length may play a role.

Wintertime Herd Bull Blues

Happy New Year! As I write, we are finally experiencing some above-zero temperatures here in Montana for the year, which are very welcome. During my travels to Extension programs this month (fondly referred to as Asphalt Cowgirl January), I've seen a lot of herd bulls out to winter pasture, and I'll be very honest with you - I have concerns about the future fertility of many of the bulls I've driven past.

Protection from inclement weather is a critical factor in winter herd bull management because of the very real concern of frostbite of the scrotum. While mild frostbite generally has a good recovery rate, severe frostbite can leave a bull infertile. Scarring from frostbite can hinder a bull's ability to raise and lower the testicles for proper temperature regulation. This regulation depends on coordination of three structures: the tunica dartos muscle in the walls of the scrotum, which relaxes when hot and contracts when cold; the external cremaster muscle within the spermatic cord, which lengthens or shortens to lower or raise the testicles depending on temperature; and the pampini-form plexus, which is a coil of veins that provide an effective countercurrent temperature exchange by cooling arterial blood entering the testicle and transferring its heat to the venous blood leaving the testicle. Normal sperm formation only occurs as 4-5 degrees below body temperature, so any damage to any of these three structures could result in infertility.

Pull up that National Weather Service windchill chart and take a look at some of the effective temperatures we've experienced already this winter. The frostbite warning zones aren't going to be much different for that vital part of bull anatomy than they are for human skin. You've invested in those herd bulls for the future of your cow herd and sustainability fo your ranch. Shouldn't you put a little insurance policy on that investment? Ensure that bulls have the ability to get out of the wind and are not lying on unbedded, frozen ground. Putting testicles on ice is not conducive to fertility.

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