Livestock

Turning down the heat

Written by Dr. Jim White on .

Heat can be hard on the feet—of cattle, that is. It’s well known that heat stress can negatively affect milk production, calf growth and reproductive performance, but did you know it can also lead to lameness?

Hot cows stand more to try to cool off. When cows are standing, blood does not flow as effectively to the feet, and there is naturally more pressure and compaction on the hoof structure. The cow’s internal cooling mechanisms also cause blood to be redirected away from extremities, including feet and legs, and poor circulation can cause a host of hoof-related problems.

Needless to say, providing relief from the heat is important. Beef cattle are most productive in temperatures between 41 and 77 degrees. When temperatures exceed this range, cattle are less productive and at greater risk of heat stress. However, cattle can tolerate summer temperatures and remain productive when managed properly.

Available water and adequate shade can effectively reduce the effects of heat stress. Water is the most important nutrient and should be clean and abundant enough to meet summer demands. The amount of shade required is 30 to 40 square feet for mature cattle, 20 to 25 square feet for feeder cattle and 15 to 20 square feet for stockers. Heat stress is compounded by animals crowding, which happens when shade is limited. If natural shade is inadequate, construct permanent or portable structures.

Permanent structures are more suitable for feeding pens but are frequently placed in pastures, too. Portable structures are more expensive to construct but can be moved with the cattle. Advantages of portable structures include more uniform grazing, less pasture damage and better manure distribution. Locate shade structures in areas to take advantage of prevailing winds during the summer. Select areas with minimal slope to prevent erosion from animal traffic.

All shade structures should allow adequate airflow. Permanent structures will require manure removal in some situations. Inexpensive UV-resistant shade cloths that block at least 80 to 90 percent of light or two offset layers of snow fence provide adequate shade and allow for good airflow. Solid coverings are more expensive and last longer but are more susceptible to wind damage. If a solid covering is used, then the structure will need to be taller.

Summer nutrition also plays a role in helping cattle handle the heat. First, reduce forage to minimum effective fiber levels. Practically, this is a difficult task since many beef cattle primarily eat forage diets and dairy rations usually push the lower limit of fiber feeding. The best tactics are to feed the highest-quality forage available and use additives to alleviate heat stress.

We recommend MFA Ricochet FesQ Max products. Ricochet minerals have been tremendously successful, are easy to use and offer several significant benefits. Feeding a yeast culture helps with the heat as well. Feeding rate depends on the product. All MFA Gold Star Minerals and dairy feeds have yeast culture as do Trendsetter, Cattle Charge and Full Throttle feeds.

Proper amount of potassium in the diet is also a consideration. Usually beef animals on mostly forage diets are long on potassium, but when concentrate is fed, potassium content declines. Under heat stress, potassium is added to make up 1.5 percent of the entire diet. The potassium source that works best is potassium carbonate, but since this is an expensive mineral, many producers use potassium chloride.

Adding fat to the diet is another hot-weather strategy. Feeding fat increases energy while reducing fiber content and heat increment load but does not increase acidosis risk. Overfeeding fat, however, especially vegetable fat, will reduce fiber digestion and intake. That’s exactly what we don’t want for milk production in heat-stressed cows.

When heat stress is a possibility, avoid overfeeding urea or soluble protein. Evaluate the amount and degradability of the protein/nitrogen fed. Excess nitrogen-protein needs to be excreted; it is an energy drain, and tough on their kidneys.

Other nutrition strategies to beat the heat include altering feeding times to coolest parts of the day, pulling unpalatable feed from the ration and using higher-quality feedstuffs to encourage intake.

A proactive approach is best for dealing with heat stress in cattle. Once animals are severely affected, it may be too late. Before extreme temperatures arrive, be prepared to provide proper shade and water and adjust your feeding program according to your herd’s situation.

Cattle can suffer from too much sulfur

Written by Dr. Jim White on .

Thirty years ago, I routinely checked the nitrogen-to-sulfur ratio in feedlot diets to see if there was adequate sulfur. Cattle diets deficient in sulfur result in decreased microbial populations, microbial protein synthesis and lactate utilization. Severe deficiencies can cause lethargy, weight loss and potentially death. Nowadays, however, it is far more likely that there is too much sulfur rather than too little. Allegedly, famed actress Mae West once postulated, “Too much of a good thing is marvelous.” Too much sulfur is not. Excessive sulfur intake by cattle decreases dry matter intake and average daily gain and can lead to potentially lethal diseases.

An essential macro mineral, sulfur is a necessary component for many organic molecules. Beef cattle require 0.15 percent dietary sulfur for adequate growth. That percentage, for the most part, comes from sulfur amino acids in protein. Rumen bacteria, especially cellulolytic bacteria, also require sulfur for adequate growth.

While the appropriate amount of sulfur is vital to normal performance and productivity, excessive amounts can cause sulfur toxicity. In the rumen, bacteria reduce sulfur to sulfide or hydrogen sulfide. The balance in the rumen between sulfide and hydrogen sulfide is pH-dependent. As ruminal pH decreases, the proportion of hydrogen sulfide increases. Large amounts of hydrogen sulfide is believed to cause the negative effects of excess dietary sulfur, including decreased cattle growth, reduced copper, diarrhea, muscular twitching, and polioencephalomalacia, a potentially fatal neurologic disease of ruminants. In cases of sulfur-induced polio, the excess ruminal hydrogen sulfide—which is similar to weak battery acid—“chews” on nerve tissue.

The National Academy of Sciences suggests that 0.3 percent sulfur is the maximum tolerable level in beef cattle diets with less than 15 percent forage. For diets containing greater than 40 percent forage, the maximum tolerable level is 0.45 percent. Higher concentrations may result in sulfur toxicity. Therefore, the risk can be decreased by increasing the forage fraction of the diet.

A feedlot ration commonly has 8 percent of its dry matter as forage. That’s why sulfur toxicity problems are often found in finishing animals or in situations where an excessive amount of corn co-products, such as corn gluten or distillers grains, are used in the diet. When corn co-products are fed at more than 1 percent of body weight, they are being overfed. The feeding value decreases, with reduced average daily gain and gain-to-feed ratio. Excessive sulfates in the water source can also be a problem.

Not only does decreased ruminal pH increase the risk of sulfur toxicity, but it also negatively affects dry matter intake, fiber digestibility and increased risk of acidosis, a common nutritional disorder in beef cattle. Acidosis is caused by rapid rumen fermentation of carbohydrates, which results in an accumulation of rumen and blood lactate/lactic acid The lactic acid load is hurtful, not helpful.

There are three common approaches to address acidotic challenges that can lead to sulfur toxicity: feed a buffer, increase forage and manage feed intake.

Including dietary forage increases ruminal pH, but not all sources have an equal effect. The neutral detergent fiber of roughage does not account for physical characteristics such as particle size and shape, moisture and density that affect digestion. These combined measurements are defined as effective neutral detergent fiber.

Increasing forage intake adds to time spent chewing, which stimulates saliva secretion and increases the amount of buffers in the rumen. Thus, more forage in the ration will increase rumen pH, decrease the daily fluctuation in ruminal pH and lower hydrogen sulfide.

However, feeding greater amounts of roughage and other prevention practices are not always economical for cattle feeders. Increasing forage lowers the energy level in the diet, which tends to reduce average daily gain and efficiency. The opposing economics related to management practices known to decrease the risk of acidic pH and the goal to increase cattle performance pose a question of how to best optimize forage concentration to avoid sulfur toxicity and maintain cattle performance.

Changing the equation

Written by Allison Jenkins on .

Losing a calf means losing hundreds of dollars.

Potentially saving a calf by spending a few dollars just makes sense, said producer Tommy Summers, who raises red Angus cattle on his Green Hill Farms in Smithton, Mo. That’s why the cattleman has been giving newborns a healthy start with new MFA Shield Plus Technology, a nutritional supplement designed to support immune system development, improve feeding behavior and provide a quick source of energy.

“The first 48 hours are pretty rough on a little calf out here,” Summers said. “It’s important to give them a little bit of help to get them going.”

Launched in January, Shield Plus is the newest product in MFA’s feed lineup to contain Shield Technology, which was introduced in 2015 with a unique set of ingredients designed to enhance animal performance and health. Shield Technology employs an all-natural, research-tuned blend of essential oils and other additives and does not require a Veterinary Feed Directive.

“The science behind Shield is pretty incredible, and MFA is the only company in the U.S. that is going down this path,” said Mike Spidle, director of product sales and feed. “It’s not something we just woke up and decided to do. We’ve researched it, put many hours of trial work into it and studied it to know that it works and why it works.

“Shield Plus takes all the good things of Shield Technology and adds all the good things from colostrum that the babies need,” Spidle added. “We’re confident it will benefit our producers.”

Before Shield Plus became available, Summers had already seen the benefits of MFA Shield Technology on his farm. He creep-feeds MFA Cattle Charge to his young calves and finishes cattle with MFA Cadence pellets. Both of these products are formulated with Shield. In addition to his 200-cow beef herd, Summers raises 3,200 acres of row crops and runs a poultry operation with his brother, Timmy.

“I’m seeing the biggest difference in my weaned calves,” said Summers, who purchases feed and farm supplies from the MFA Agri Services Center in Sedalia. “They’re on Shield in the Cattle Charge when they’re on their mother, and they never seem to take a lull. They just keep right on going.”

Performance with Shield-enhanced feeds has been so impressive that Summers said it was a “no-brainer” to try Shield Plus when his spring calves began hitting the ground in early February. Even though the mostly mild winter made it hard to judge the full effect, he said the calves appeared to be more “aggressive” after a dose of Shield Plus.

“I’ve seen those little calves get stressed in the cold, wet ground, and this gives them an energy boost to get up and get milk from mama,” Summers said. “That’s the biggest thing—once they get some milk in their belly, they seem to be able to make it.”

At a cost of about $2 per dose, Shield Plus is administered orally in a pump bottle and contains a concentrated colostrum extract that helps ensure newborn calves get optimum levels of essential nutrients. It also contains probiotics, or “good bacteria,” to improve gut health and egg antibodies to combat scours, Spidle explained.

The supplement is also rich in Omega-3 and Omega-6 fatty acids as a quick source of energy and therapeutic levels of vitamins A, D and E to help prevent oxidative stress. It’s recommended for newborns as well as adult animals that are under stress.

“It’s vitally important that the baby gets colostrum within 24 hours—really within 12 hours—to get antibodies into the bloodstream,” Spidle said. “And you have to keep in mind that not all colostrum is the same. You can’t be sure that a cow’s colostrum is giving a calf what it needs. Shield Plus naturally stimulates the immune system, aids in improving survival and increases appetite and feeding behavior for weight gain.

“In other words, Shield Plus gives that baby the best start you can,” he continued.

Being able to reap the health benefits provided by Shield Technology and Shield Plus without needing a VFD is also an advantage, Summers added.

“Shield shows me what we can do without medicine,” he said. “I’ve only had one sick cow in two years. When they started talking about the VFD, we knew we already had a program in place that would let us avoid that unless we have some major outbreak.”

Although on the market for only a few months, Shield Plus is changing the equation at Green Hill Farms, where Summers is using the new product with his entire spring calf crop and says he plans to do the same when fall calves arrive.

“I’m not scared to try something new on the farm, especially when I can see the value,” Summers said. “You either stay on top of things, or you don’t stay in business. You’re talking about spending a minute amount of money to keep those calves healthy and gaining weight from Day 1. That’s worth a lot.”

In addition to cattle, Shield Plus can be used with other livestock species, including swine, equine, goats and sheep. For more information, visit with the livestock experts at your local MFA Agri Services or AGChoice location.

Feed your fly control needs

Written by Dr. Jim White on .

Willis Bruce—not to be confused with actor Bruce Willis—spent his career studying horn flies. Bruce was an USDA entomologist and professor at the University of Illinois who designed an ingenious walk-through horn fly trap in the 1930s and worked to develop other control methods for these pesky little insects.

Dr. Bruce was particularly interested in the horn fly because it is one of the most widespread and costly external cattle parasites. Current estimates are that horn flies cost the American cattle industry some $2 million every day. Adult flies bite the animal, causing irritation and often drawing blood. As calves spend less time grazing, weight gains will be reduced by an average of 20 pounds per year. But losses may also go much higher:

  • Cows produce less milk and may fall out of breeding condition.
  • Horn flies have been implicated in the spread of summer mastitis, which tends to be highest in fly season.
  • Eye problems may result.

Horn flies are small—adults are about 3⁄16 inch, half the length of a house fly. They are dark gray, blood-sucking flies that stay on cattle almost continuously.

Both male and female horn flies are blood feeders that spend most of their time on the shoulders and backs of cattle. During extremely hot weather or when it rains, they may move to the more protected underside of the animal. They are not strong fliers. When disturbed, horn flies will swarm but return to animals almost immediately. Females leave occasionally to lay eggs in fresh manure piles. If horn flies are not on manure, they are on the animal.

The close association between horn flies and host helps with control. The flies leave animals only to lay eggs or to change hosts, so many methods will expose flies to control practices such as ear tags, topical products, feed-through additives, etc. With some chemistries, insect resistance has been an issue. If a producer applies fly tags, and two weeks later there has been no decline in fly population, the insects are likely resistant to the product.

Resistance is not a problem when using the insect growth regulator (IGR) s-methoprene, brand name Altosid. It has been very effective in controlling biting adult insects that have specific larval environmental requirements, including horn flies and mosquitoes.

When using an IGR feed-through product, horn fly control is long-term and preventive, not reactive. The IGR is ingested as part of the animal’s feed. Cattle then excrete manure that contains the IGR. Horn flies must lay their eggs in fresh manure, and the IGR keeps the horn fly pupae from developing into breeding, biting adult horn flies.

New this spring, MFA has two additional options for fly control in our Gold Star Mineral lineup. Ricochet and Ricochet FESQ Max are now available with Altosid IGR, providing all the features and benefits of these trusted mineral products along with feed-through horn fly control. Given expected intakes, the 0.01 percent level of s-methoprene is adequate for nearly all cattle.

Both are convenient, ready-to-use minerals formulated to balance year-long pasture feeding programs for beef cattle, and they do not require a Veterinary Feed Directive.

Begin to use MFA Gold Star fly control minerals in the spring before horn flies appear on cattle. Flies emerge when 14-day mean temperatures are 65 degrees and above. Continue feeding until cold weather stops fly activity. Make sure to feed IGR mineral throughout the season for a successful fly control program next year. If IGR feeding ends too early, there is a late-season increase in the adult population to lay eggs. The eggs over-winter and are ready to establish fly populations next spring. All that can be avoided by extending the feeding period of fly control minerals for 30 days after a killing frost to minimize the adult population and keep egg populations as low as possible.

Horn fly control with feed-through IGR is the easiest, most effective and economical way of controlling horn flies for cattle producers. To achieve optimum fly control, MFA Ricochet products with Altosid should be used in conjunction with other good management and sanitation practices. A number of integrated pest management resources are available online.

Shrink happens

Written by Dr. Jim White on .

When humans are stressed, our bodies react with physical, mental and emotional responses. The same goes for beef calves that experience stressors such as hauling, handling or food and water deprivation. In cattle, these factors can lead to “shrink,” or weight loss that occurs from the time an animal leaves one location and is weighed at another.

The amount of shrink a calf experiences increases along with the number and duration of the stressors (see chart at right).

Managing shrink has implications on your calves’ health and profit potential, as demonstrated by a recent study by the University of Florida Institute of Food and Agricultural Sciences Extension. Shrink was measured in stocker calves after weaning in two separate years. The amount of shrink in one day amounted to 3.5 percent and 3.9 percent respectively, similar to the amount of shrink after eight hours of standing in a dry lot. In both years, calves did not regain their off-pasture weaning weight until day 14, even though they were offered high-quality hay and a pelleted supplement. The shrink was associated not only with a dietary change but also with handling, change in environment and tissue loss from stress.

In the second year of the study, the calves were also backgrounded for 50 days and transported 1,000 miles over 24 hours. These calves were unable to regain the lost body weight within 14 days, despite adequate access to hay, supplement and water. The amount of shrink increased because feed and water removal was coupled with the stress of transit.

How does shrink affect price? The appearance of calves at market can most certainly affect the bid. University of Arkansas data indicates that buyers adjust the price per pound based on an estimate of shrink to follow the purchase. Shrunk cattle received $3 to $8 greater sale prices compared to average fill calves. In contrast, calves that were full or very full were discounted $3 to $24 from the base selling price received by average fill calves.

Many different factors can affect shrink, but these have the most impact:

  • Transportation time: Studies show calves will shrink about 1 percent per hour for the first three to four hours, then 0.25 percent per hour for the next eight to 10 hours (e.g. 8 percent shrink in 16 hours).
  • Amount of fill: Diets low in dry matter and high in moisture result in a greater shrinkage, such as stockers on wheat pasture, whereas drier diets lead to slower weight loss and less shrink.
  • Body condition/weight: Typically, fatter cattle will not shrink as much as cattle with less body fat. Fat contains less water than lean muscle tissue, so lower amounts of metabolic- tissue water is lost to shrink.
  • Season: Higher temperatures induce a greater stress response in cattle and thus a greater shrink response. In hot weather, cattle lose more water through heavy breathing and greater maintenance energy expenditure than during cool temperatures.
  • Handling: Cattle shrink less when they are handled in a quiet manner using good Beef Quality Assurance practices.

Yes, shrink happens, but anything producers can do to minimize animal stress—and the resulting weight loss—protects the value of the calf when it is sold.

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