Cooler weather brings weaning calves, politician promises, hunting season and increased incidence of lice predation in cattle. Left uncontrolled, lice can cause problems in the herd. Protecting cattle from lice entails understanding the life cycle of lice, recognizing the potential damage and using effective methods of control.
In general, every herd has some level of lice infestation. Lice are carried from season to season by a small percentage of the herd that act as reservoir hosts. Clinical signs of lice-infected cattle generally begin with constant rubbing and scratching within the herd. Fences, posts, water troughs, trees and any other stationary object could be subject to damage from this rubbing. As the infection and irritation continue, large hairless patches will become evident on animals.
Beyond clinical signs, further diagnosis requires seeing adult lice on the skin. Parting the hair will reveal the lice. They are very small— roughly the size of a grain of sand— but can still be seen. The economic threshold for treatment is roughly 10 lice per square inch.
Louse life cycles are generally three to four weeks and spent entirely on animals. First, female lice lay eggs, which are glued to the host’s hair. Nymphs hatch from the eggs one to two weeks later and become fully developed adults in about two weeks. Adult females can lay approximately 30 to 40 eggs during their life. If not controlled, a single adult female in September can result in approximately 1 million lice by January.
Two types of lice live on cattle: sucking lice and biting lice. Sucking lice feed on the host’s blood and are most often found along the top line of an animal’s back. However, they can spread to the poll and tail head. Biting lice, which ingest skin, hair and scabs, are more widespread on the body. In the U.S., cattle can be infested by one species of biting louse, Bovicola bovis, and four species of sucking lice: the long-nosed cattle louse (Linognathus vituli), the little blue cattle louse (Solenopotes capillatus), the short-nosed cattle louse (Haematopinus eurysternus), and the cattle tail louse (Haematopinus quadripertusus).
Lice infestation can result in lameness, allergic responses, restlessness, agitation and skin damage from excessive rubbing or scratching. Open skin leaves cattle more inclined to illness and infections. If left uncontrolled, lice can cause anemia, lower milk production, decreased feed efficiency and reduced weight gain. Cattle with lice will recover from disease stress slower than non-infested cattle.
Both sucking and biting lice are equally harmful to cattle, and both respond to the same treatments. There are a variety of insecticides that can effectively control lice. Dusts, pour-on products and sprays provide easy-to-use and versatile treatment options. Traditional treatments involve a two-step process: First, treatment to kill adults and nymphs on the animal, followed by a second treatment three weeks later to kill adult lice and nymphs that hatched from eggs after the first treatment. Treated cattle should be re-examined about two weeks later.
One treatment option is avermectin endectocides. These products come in pour-on formulations and injectable formulations. Avermectins treat internal intestinal nematodes but also treat external parasites such as lice. It is important to note that the injectable formulations do not work on biting lice since they do not blood feed. Another option is a non-systemic topical treatment, typically pyrethroid products similar to what is used to control horn flies during the summer. These products are very effective against adult lice but do not affect the larvae or eggs. Retreatment is often needed 14 days after initial treatment.
Management practices should be undertaken to prevent re-infestation. Lice are spread primarily through animal-to-animal contact, including feeding, resting, breeding or shipping. Due to this threat, facilities used by infested cattle should either be treated with insecticide or remain empty for 10 days before allowing clean stock to enter. Any new animals should be isolated from the resident herd and treated before they are introduced to the herd.
Read the pesticide label and use only according to the directions. Know what personal protection equipment is required. Be sure that those making the application are trained in the proper use of each product and the appropriate equipment.
In fall and winter, most pastures are lower in protein than other times of year. Producers often like to continue grazing as long as possible. One of the most effective ways of improving the utilization of the forage is to feed additional protein to meet the animal’s requirement.
Adequate protein content is crucial for optimal microbial growth and animal performance. Rumen microbial growth is reduced in diets that are low in protein. With protein supplementation on dormant pasture, the rumen microbial population will have a higher growth rate, improving the energy available to the animal and increasing the intake of low-quality forages. In other words, protein provided through supplements such as liquid feed, cubes, blocks or tubs improves digestion of low-quality forages.
The key number is 9% crude protein. That’s the average protein requirement for cows, even for mid-gestation dry cows whose calves are weaned. The rumen microbes can make a living on a slightly lower protein content, so if we meet the cow’s requirement, we should cover the rumen needs.
If protein level in forage falls below 7%, it limits microbial fermentation in the rumen. The animal can’t grow a large enough population of microbes to get the job done. Digestion slows, forage moves more slowly through the tract and the cow can’t eat as much because fiber digestion is reduced.
To ensure adequate nutrition during fall and winter grazing, you need to know the protein level in the forage. Cattle are selective grazers. If you clip a sample of forage, it may be poorer in protein content than what they are actually eating. You’ll come closer to an accurate estimate by observing what they are eating and hand-plucking a sample of similar plants. Many native cool-season grasses can be good fall and winter pasture without a protein supplement. They have more nutrients in their mature, dormant state than many tame grasses do. Many stockpiled fescue samples are adequate, often with greater than 10% protein content.
Watch cow body condition and ensure they stay in good flesh. Evaluate the viscosity of manure. Beef cattle manure in the spring or on any lush green feed is very loose, almost liquid. This is a sign of excess protein. The material is digested quickly, traveling through the digestive tract too fast with waste of some nutrients. Often performance is good. On the other hand, if the manure is hard and makes a pile that stacks up, this can be a sign of protein deficiency. There’s not enough to digest forage efficiently and keep things moving through at a proper pace. Ideally, manure should be moist and loose but not liquid. It would stack maybe 1.5 inches high. This is how it would generally be when forage is green and protein level is in the low teens, about where it should be.
It is interesting to observe how well cattle do when you first put them into a new, ungrazed dormant pasture. They select a diet higher in protein and energy than in the average forage. The longer they stay in that pasture, the less protein they’re getting, because they are eating the higher-quality material first.
Young animals need more protein because they have a growth requirement, whereas the mature dry cow just needs maintenance. Replacements or stockers can’t hold as much feed as older animals, and they have less ability to ferment large enough amounts of low-quality forages. This can be partially addressed with grazing management. Forward graze the young animals. Let them graze a pasture first and get the best material to meet their higher requirements. Then let the cows clean up after them. The cows may need a protein supplement because the forage that would have allowed them to meet requirements of the rumen microbes has probably already been eaten.
There are many kinds of supplements and nitrogen sources. The question comes down to what is economical and available and how much needs to be fed. The next point is to determine what is going to be used and how it will be fed. The supplement might be 2 pounds per day of hand-fed Ricochet Breeder Cubes, a self-feeder full of Cadence or half a percent of bodyweight of MFA Trendsetter three times a week. How we provide the feed may depend on how far over the fence the truck can deliver or how many sacks we can get on the four-wheeler.
Some feed additives need to be fed very uniformly, such as melengestrol acetate—also known as MGA. Urea is better fed frequently, particularly when fed at higher rates. For ionophores or all-natural protein supplements, the reduction in utility is small if they’re fed every other day rather than every day. Feeding a supplement such as MFA Breeder Cubes can be done three times a week with acceptable results on mid-gestation beef cows in good flesh. Check with your livestock specialist about the right supplements for your operation.
Corn residue is an abundant, affordable feedstuff in the Corn Belt. Yet each year, acres upon acres go ungrazed, even on diversified farms. Grazing cornstalks is a significant source of feed for a cow-calf operation, but there are challenges: fencing, water, supplementation, compaction and the impact of grazing on the following grain crop, to name a few.
Over three years, University of Illinois researchers measured cow performance, residue quality and utilization as well as subsequent crop yield. Two grazing methods—strip grazing and continuous grazing— and an ungrazed control were used. Following corn harvest, cows were allowed to graze for six weeks.
In the continuous-grazed treatment, cows were allowed access to the full paddock the entire time. The stocking rate was 1.2 cows per acre.
In the strip-grazed treatment, the field was divided into three sections. Cows were allowed access to a new strip every two weeks. No back fencing was used. Thus, after 14 days, cows had access to the first strip and the new second strip. During the last two weeks, the cows had access to the entire paddock.
Residue grazing started in late September the first year, in early November the second year and in early October the third year. The acres were maintained in continuous corn during the trial period. Spring tillage occurred each year.
The research resulted in four main points:
Grazing residue for a six-week period following corn harvest did not impact subsequent crop yield. This was true for both continuous grazing and strip grazing.
Grazing helped remove and incorporate residue. Roughly 4 tons of dry matter per acre were available for grazing. Residue available after grazing in either treatment was close to half of what was initially in the field. In the ungrazed control paddock, 78% of residue remained, with losses likely due to wind and plant degradation.
Cattle consumed mainly husks and leaves. Cobs also declined.
Stalk percentage increased due to reduction of other components. After grazing, the actual weight of the stalk component was similar across all treatments, which illustrates the selectivity of cattle grazing cornstalks. Cattle look for more palatable feedstuffs. Cattle first eat the remaining corn grain, then husks, then leaves and finally the stalk.
Cows that strip grazed corn residue had increased bodyweight gains and weighed more than cows in the continuous-grazed trial. It’s likely that the strip-grazed treatment potentially partitioned nutrients more evenly over the period.
Measures of residue showed strip grazing had more nutritive quality toward the end of the grazing period. The strip-grazed cows were allowed less area to travel for the first two two-week periods. Continuous-grazed cows spent more time searching for palatable residue. This extra time spent traveling the area not only resulted in increased maintenance requirement, but also could have increased trampling of husks and leaves, thus reducing available residue for consumption.
Operations on heavy, deep, poorly drained soils can still benefit from cornstalk grazing, but management is needed to reduce traffic and avoid higher stocking rates during wet periods. But if the operation is not limited in corn acres, then stocking density is easily addressed by allowing more acres per paddock or by using a continuous-grazing system.
Because cattle eat the more-digestible and higher-protein portions first, a good mineral may be the only supplementation needed for the first month. The exception is a herd that includes fall-calving cows or stocker calves. For them, a supplement will be necessary to meet nutrient demands of lactation and growth, respectively
Health Track cattle, such as these on the farm of Jim Novinger in Kirksville, Mo., may be eligible to compete in the Missouri Cattlemen’s Association Profitability Challenge. MFA is among the contest’s supporters.There is a new game in town that promises genuine insight into the world of beef production. It is a “Profitability Challenge” that will use the latest beef industry technology to identify Missouri’s “Top 100 Steers.”
MFA Incorporated is dedicating considerable resources in support of this valuable project, also supported by the Missouri Cattlemen’s Association, the University of Missouri, GrowSafe, Idexx, Elanco and Valley Oaks Steak Company.
This is a great way to promote MFA’s commitment to young beef producers, highlight the value of Health Track preconditioning and promote Missouri beef in a way that hasn’t been done before. In the end, the winning steers will be the ones with the highest total profitability.
Renovations are being made at the MU South Farm in Columbia, Mo., to provide indoor housing for 100 steers that will be monitored using the latest GrowSafe technology. This equipment will measure individual feed intake and weight gain each time the cattle eat or drink from delivery to finish, which allows individual feed efficiency and overall performance to be determined. This system will also decide an optimum harvest date, and the steers will all be harvested at the Valley Oaks facility in Lone Jack, Mo., where carcass value will be determined on a standard grid.
The steers will be ranked in order of their overall profitability, which is a combination of performance and carcass value. There are cash prizes for the winners, but more importantly, producers earn bragging rights and the ability to measure genetics. All data will be shared with participating producers, although ownership of each steer will only be known by the participant during the contest.
As data is collected every day, a “Fantasy Football”-type contest will be available to local FFA chapters. The FFA members will be able to see each steer’s progress, build their “teams” and rank the steers. The final tally will occur after all of the steers have been harvested and carcass value is added to the profitability calculation.
Entry deadline is Sept. 13. All steers entered must have been preconditioned and approved through the MFA Health Track program. In addition, they must test persistently infected (PI) negative through IDEXX Laboratories prior to delivery. Delivery will be accepted only on Nov. 9 at the MU South Farm Beef Research Center. The weight after a settling-in period must be between 618 and 840 pounds. To get detailed data at the end of the contest, producers are required to donate half the value of the delivered steer to Missouri Cattlemen’s Association to help protect the viability of the beef industry.
Summer will soon officially arrive, bringing the challenge of managing horses during hot weather. Horses can acclimate to hot and humid environments. A 15-day to 21-day acclimation period is recommended for horses originating from cooler or drier climates that are traveling to compete or reside in hot, humid conditions. The acclimation period results in an increased tolerance to both heat and exercise. However, acclimation does not reduce the need for close monitoring of horses during training and competition in these environments.
To help reduce the effects of heat and keep horses comfortable, consider the following:
Provide turnout during cooler times of the day—early in the morning, late at night or overnight.
Provide relief from the sun through access to shade from trees or buildings. Remember that shade will change throughout the day, and constructed buildings may block natural air flow.
Watch for signs of sunburn, especially on white or light-colored areas. Use masks to protect the horses’ faces.
Fans help to improve airflow, but be sure to keep cords and plugs out of the horse’s reach to prevent electrocution.
Ensure access to clean, cool water at all times. “Cool” is defined as being 45 to 64 degrees. Depending on feed, an adult horse in a cool climate will normally drink 6 to 10 gallons of water each day while at rest and much more while working or in situations with high heat and humidity.
Water buckets and tanks may need to be cleaned more regularly in hot weather as algae and bacteria grow rapidly in warm water. Blue algae toxicity is more common in ponds or slow-running streams during hot, dry weather.
Free-choice access to salt will encourage drinking. The two electrolytes that most often need to be replaced from sweating are sodium and chloride, which make up salt. Loose salt is preferred to a salt block. Offering free-choice MFA 5% Horse Mineral with Shield also helps to mitigate heat stress. It contains salt as well as essential oils and a proprietary blend of botanical extracts and synbiotics, all of which help boost the horse’s health and immune system.
Consider providing electrolytes to horses that have been sweating heavily or are expected to do so. If electrolytes are added to drinking water, also offer plain water since some horses dislike the taste of electrolytes and will drink less. This situation is similar with people—some like to drink Gatorade. Others do not.
Reduce riding intensity and length. Heat stress can affect any horse but is especially common in older, obese and out-of-condition horses. Young foals also tend to be more prone to heat stress and dehydration.
Clip horses with long hair coats, such as horses with Cushing’s disease, to enhance cooling.
Transport horses during the coolest part of the day. Ensure that trailers are well ventilated. Offer water frequently. Do not park in direct sunlight with horses inside.
Horses that have little or no ability to produce sweat have a condition called “anhidrosis-hypohidrosis,” and are prime candidates for heat stress. Research shows 2% to 6% of horses can develop this issue. They may require additional management strategies to mitigate the effects of heat stress, such as electrolyte therapy.
Avoid riding a horse when the combined temperature in degrees Fahrenheit and percent relative humidity is greater than 150. For example, if it is 80 degrees out, a relative humidity of greater than 70% exceeds the 150 calculation.
If a horse must be worked during hot and humid weather, consider adjusting your schedule to ride early in the morning or late at night. Work the horse in shade when possible, and keep the work light. Include frequent breaks that allow the horse to cool down and regain a normal respiratory rate. Do not work the horse beyond its fitness level. Watch for normal sweating. Inside the stable, create airflow, use fans and exploit the “chimney effect,” in which rising warm air forces cooler air to infiltrate through doors, windows or other openings. Provide access to cool, clean water at all times and offer water frequently during work.
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