CATTLE HEALTH

Vaccination protocols and treatments for BRD, BVD, pink eye, trichomoniasis, vibrio, IBR, and scours

Think Zinc

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By: Gilda V. Bryant

Are you seeing some lame or poor-doing critters out there? It might be a good idea to give zinc some consideration.

Zinc works hand-in-hand with copper and selenium, but when it comes to supplementation this trace mineral is a work horse. It’s involved in some 300 enzyme systems including the metabolism of proteins and carbohydrates, which provide energy for growth and weight gain in cattle. Required for every phase of cell growth, zinc is necessary for tissue health and is essential for the proper function of reproductive and immune systems. Unfortunately, zinc is hard to come by in most American forages. Producers may not be aware of a zinc deficiency until animals develop problems such as footrot.

“It’s not uncommon to see cattle that are limping because of the problems they are having with hoof integrity,” says Steve Blezinger, PhD, PAS (Professional Animal Scientist), a ruminant nutrition and management consultant. “A lot of cases can be traced back to zinc deficiency that can lead to a breakdown of connective tissue that is so important in the makeup of the hoof. You have a situation where that hoof is a little more susceptible to infection when stepping on rough ground or sharp objects.”

Butch Whitman, PhD, PAS, Vice- President of Nutrition Programs at Westfeeds, says, “Moderate deficiency symptoms are fairly hard to observe, but are probably the more predominant one that producers experience. Moderate deficiencies retard growth rate, impair reproductive performance and the animal’s immune system, which is going to show itself as chronic health problems.” Whitman adds, “In extreme cases, you get severe restriction of growth and reproductive performance and have very poor health because of poor immune systems.”

For example, calves with low zinc levels aren’t able to mount a positive response to vaccines. And that means sick calves with reduced growth and weight gain. Stressful events, including calving, weaning, moving to a new location or environmental changes such as drought, tend to lower zinc levels in the animal. Eric Scholljegerdes, PhD, Assistant Professor in the Animal and Range Sciences Department at New Mexico State University, warns that cattlemen who work animals in a high stress manner potentially cancel all the good management practices done up to that point. He continues, “The animal is going to be exposed to pathogens no matter what, so if you do as much as you can to keep the stress level down so the body has the ability to mount a response, the better off the animal is going to be.”

Zinc is vital for bulls and a healthy calf crop. Although many producers tend to forget about their bulls until turnout, low levels of zinc can cause a reduction of spermatogenesis (sperm creation), testicular development and sperm volume. Zinc is also involved in the process that creates healthy, mobile sperm cells. Since the sperm that are produced today began developing some 90 days earlier, ranchers need to supplement with zinc well in advance of breeding season. How can cattlemen evaluate zinc availability to their herds?

“Start with an evaluation of the forages the cattle are grazing,” Whitman explains. “If you do that over time, you’re aware of unique problems in the area in which you’re raising cattle. You have to do that at different times of the year including harvested forages that are fed through the winter as well as grazed forages as cattle move to different pastures.”

Consider testing the water supply, which will not only give an indication of zinc levels, but also the level of other minerals that either enhance or prevent zinc absorption. If a producer doesn’t have a clear idea of zinc availability after forage and water testing, taking blood samples might be the next step, although these tests tend to provide an incomplete picture.

“Zinc is very transient in the body,” Blezinger explains. “You can get a reading of X milligrams of zinc per deciliter today, which might indicate an inadequate status when in actuality that cow may be deficient. She has just mobilized so much zinc that it’s in the blood stream, not in the liver. If she is under stress, it will mobilize more zinc and copper out of storage areas into the blood stream.” Most experts agree that free choice loose minerals work best for supplementation. Ranchers have more formulations to choose from and loose minerals provide more flexibility when feeding. Trace mineral injections may also be used with free choice minerals.

If the herd needs higher levels of zinc for optimal performance and health, consider adding chelated zinc to the mineral program. Also know as a complexed or organic mineral, micro minerals such as zinc are chemically bound to a protein or amino acid, making them more available for absorption in the small intestine. Chelated zinc may also need to be fed to overcome the effect of antagonists. Antagonists are natural compounds which can bind with zinc to make it unavailable to the animal. Occasionally, calcium and phytate, a form of phosphorus usually found in plants, bind zinc.

However, it’s much more likely that zinc will affect copper absorption. “At one time copper was The Thing,” Blezinger says. “For a while that was the only mineral anyone focused on. Over the last couple of years, I’ve seen more focus on zinc. We’re seeing some high zinc levels in some of these mineral supplements. In my opinion, we’ve gone overboard in some cases. We may be creating an antagonist situation between zinc and copper.”

He advises cattlemen to read the label, especially zinc to copper proportions.Look for a four to one (4:1) ratio, with zinc being four and copper, one. Blezinger has seen ratios as high as ten to one, which can reduce the absorption of copper.

Scholljegerdes adds, “If you have problems with zinc, there are going to be problems with other trace minerals as well. Feed a well-balanced mineral supplement especially if animals are facing times of high stress. These good mineral packages can be expensive. If you want to save as much money as you can, pick the times when you know your animals are going to have issues with stress and nutrient deficiencies during fall and winter. Splurge and take care of those girls a little better, then you can go to something a little less expensive when grass quality improves. You’ve got to have mineral year round.” Whitman offers this advice. “When producers are providing a mineral supplement package, make sure it’s balanced. Don’t get carried away with [one particular] nutrient.”

Zinc is essential for animal health, reproduction and the proper functioning of cellular processes throughout the body, including building DNA and proteins. Without a complete mineral package, cattle won’t perform at their genetic potential. Why not think zinc?

Who Me?

I’m Not Spreading BDV

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By: Merridee Wells

Calving season on the ranch is always an exciting time. The work of the past year, the offspring of that newly purchased bull, or the mating decisions you’ve made are about to be rewarded. So imagine, if you will, how it feels to find first one dead fetus, then another. Or to realize that one or more of those new bred heifers you purchased won’t be calving this year, ‘cause she’s open. Or maybe it’s worse. Maybe one or more of your cows will be giving birth to a true “fetal monster” of the worst kind… a BVDV-PI carrier. So what happened?

Perhaps the answer lies in understanding the disease; Bovine Viral Diarrhea Virus (BVDV) and its truly heinous cousin, the persistently infected version or PI. When a BVDV outbreak occurs in the cowherd the most common problems associated with the BVD virus infection are poor conceptionrates, abortions, stillbirths, and weak calves, and because this virus suppresses the immune system, animals become more readily susceptible to other infectious diseases. Thus cattlemen notice increased calfdeath due to scours and pneumonia and poor weaning weights. This is not a disease that should be taken lightly since it could have such a negative economic impact on your program.

The PI or persistently infected animal is a lifelong carrier and shedder of the BVD virus, and that’s pretty serious, too. This is an animal that was infected at 40-150 days of gestation (in uterine). The developing fetus recognizes the virus as part of itself, a condition called immunotolerance. Because the virus is recognized as part of the fetus, it is not attacked. Instead, the virus continues to replicate as long as the fetus is alive, or more importantly as long as the animal is alive once it’s born. And, interestingly enough, the dam of the PI calf is not always a carrier.

BAD NEWS AND REALLY BAD NEWS
The PI animal is the silent infector that, if left in the herd, continually infects and reinfects animals. It’s the one out of every 1,000 that typically is a PI among the general cowherd population. However, on individual operations prevalence can be much higher because of “bunching”. In this scenario, BVDV is actively circulating among a group of pregnant females that are at the correct stage of gestation for PIs to be created. The PI animal sheds huge amounts of BVD virus throughout their lifetime. The virus can be shed through feces, semen, nasal discharge, coughing, oral diffusion, blood transference on needles, colostrums, milk and placenta to the calf, with the most likely source being respiratory transmission. The bad news is that about 50% of BVDPI calves are poor-doers who generally die before they reach their first birthday. The really bad news: the other 50% appear as healthy calves that grow normally and enter the breeding herd or the feedlot. These are the really dangerous ones.

Dr. Brad White, with Kansas State University (KSU) Beef Production Medicine has extensive experience with the disease. In fact, through work with the Academy of Veterinary Consultants and the National Cattlemen’s Beef Association special focus committees, a team has developed a website, www.bvdinfo.org, which features a tool called BVD CONSULT. This tool allows ranchers and veterinarians to enter specific characteristics of their herds and generate a customized health management recommendation for that herd.

“Nationwide about 7% of cow herds are infected with BVDV,” says White. There are two broad genotype categories for BVD strains in the U.S.; Type 1 and Type 2. “Understanding whether or not your herd is one of those infected will impact the importance of instituting different control and preventative measures.”

“By using the BVD CONSULT tool on the bvdinfo website, producers can enter specific characteristics of their herd and generate a customized health management recommendation for their cowherd,” White continues. In other words, is your situation bad enough to warrant a complete herd test or not? Dr. White leans toward evaluation of production parameters such as pregnancy rates, calf deaths and illness to drive the need for testing.

“Several syndromes could cause reproductive losses in a cow/calf operation but BVD should be on the list of potential causes,” he explains. Washington State University’s Animal Disease Diagnostic Lab (WADDL) also has an excellent website which advises producers on when, where and how to test, with samples (ear notches) being sent to their facility
for diagnosis. The WADDL website recommends that herds should be examined on a case-by-case basis to determine the need for testing, because whole herd testing may not be warranted.

However, WADDL suggests testing of the following to identify and remove BVD-PI cattle if a problem is suspected.

CALVES
1. Test all calves born alive. Most conveniently this should be done at calving or before turnout to summer or winter range, but most definitely before any potential replacements enter the breeding herd.
2. All aborted calves (that can be found).
3. All purchased grafted calves.

COWS
1. Test all cows with a BVD-PI positive calf.
2. All open cows not sold.

3. Cows not calved at time of sampling.
4. All cows that lose a calf, and the calf wasn’t sampled.

NEW ENTRIES
1. Purchased open heifers.
2. Purchased pregnant heifers and
cows (also test calf when born).

3. Bulls.

Carl Lufkin, managing partner of KCK Leodore Angus Ranch, Leodore, Idaho, is concerned about the disease and feels it is his and other seedstock producer’s responsibility to provide customers with BVD-PI free bulls.

“A few years back we tested our entire cowherd for BVD. We didn’t have any positives,” Lufkin said. “We then started routinely testing our bulls for BVD-PI, just as we would Trich. About 60 days before our bull sale, when the vet is there doing the fertility test, they take an ear notch sample from each bull and test that. Again, we’ve never had a positive test returned on our bulls.”

The Leodore operation primarily runs cattle on public lands, therefore management is very conscious of keeping problems like BVD-PI, Trich and other reproductive diseases away from their cowherd. “We vaccinate pre-breeding with a modified live vaccine, which has been instrumental in keeping BVD out of our herd,” Lufkin concludes.

FIND THE CULPRIT
More and more, BVD-PI testing of bulls has become customary, like Trich or fertility testing; especially those being sold at public auction. In some cases, testing is mandatory, similar to the requirements for producers bringing bulls to sell, show or display at the National Western Stock Show in Denver. The National Western is very specific in their wording which states that no bulls will be allowed on the grounds without a negative test for BVD-PI.

So what to do if you have a PI?

Because BVDV is not a zoonotic pathogen and is no threat to human food, PI cattle can be immediately slaughtered (all slaughter cattle must be free of drug residue, of course – see withdrawal times on the package insert). If they have been treated for some reason, they must be set aside until the product withdrawal time expires before being sent to slaughter. The third option is humane euthanasia and proper disposal of the carcass. Everyone is in agreement that PI cattle should never be sold on the open market.

Annual vaccinations for the disease will usually suffice to keep the problem in check, but they will not “cure” a herd that has PIs present who continue to expose herdmates to the virus. Prevention is the best line of defense; however, if you suspect a problem, testing is an alternative that will determine the culprit. Talk to your veterinarian or go online to www.bvdinfo.org for more information.

Prep For The Cold

Make Sure Your Cows Are Nutritionally Ready 1

By: Gilda V. Bryant

Minerals are important for herd health, reproduction and efficiency during winter. However, that is only part of the picture.  Extra protein and energy are vital during cold, wet weather.  Producers should also be aware of forage and by-product supplementation quality, as well as body condition scores.

“The challenge with minerals is there’s just no single answer,” says Rick Rasby, PhD, PAS (Professional Animal Scientist), Beef Extension Specialist, University of Nebraska (Lincoln).  “Think about minerals as part of a total diet those animals are eating.”

Rasby encourages producers to sample baled forages for moisture content, protein, energy and mineral profiles.  Once a producer knows his forage quality, he can adjust the mineral package for his herd.  He says, “Use the mineral as a supplement to bridge the deficiency gap in those forages that are being consumed.”

He also recommends that producers analyze samples of supplemental feed such as gin trash, cotton seed, or distiller’s grains.

Many regions with ethanol plants have distiller’s grains available for the cow/calf sector.  Rasby says, “It’s an excellent feed, works well with forages, and is high in protein, energy and phosphorus as well.”

Typically low in winter forages, phosphorus is a mineral that’s vital for bone and teeth development, and metabolic, neurological and cellular functions in cattle.  It’s also one of the most expensive minerals to supplement.  According to Rasby, reducing or omitting phosphorus from the mineral package when feeding distillers grains can save money.  Get advice from a nutritionist or beef extension specialist about adjusting nutrient values when feeding these supplemental rations.

In addition to minerals, protein and energy, utilizing body condition scores (BCS) is a management practice that cow/calf operators can implement on a regular basis. Scores range between one and nine with one being a very poor specimen and nine being obese.

Rasby adds, “Having mature cows in condition score five at calving not only has an impact on what happens at calving, but also on how quickly those cows are ready to rebreed after calving.  Those first-calf heifers probably need to be in a little bit better condition, say conditioning score six.

“Cows that breed early in the breeding season are in the right nutritional status.  Their calves are older at weaning and generate more dollars,” explains Rasby.

Is it right?

How can a cattleman determine if his mineral supplement and diet are on target? “Measure how they perform at calving,” replies Rasby.  “Are they good mothers?  Do they give enough milk? Does the calf perform well while it’s on its mother?  How quickly does the cow get ready to rebreed?”

Providing minerals is crucial to the Thomas Angus Ranch outside of Baker City, Oregon.  Located in a valley between two mountain ranges, and flanked by sagebrush hills, owner Rob Thomas says, “We have long, fairly hard winters.”

He provides a custom mineral mix to his spring and fall calving herds, depending on forage analysis to fine-tune the supplement package.  Thomas says, “We increased levels of zinc, copper, and selenium, the three minerals we’re deficient in.”

Beginning in November when snow is on the ground, he’ll feed alfalfa and grass hay. He says, “We put up a lot of our own hay, so we feed what we put up.  We test our feed to see what minerals we need.”

As a result of their efforts he reports, “We have healthier cattle, better immune response, fewer treatments and a lower death loss.  We see increases in reproduction and gain and better feed utilization, which is important right now.  With extremely high feed prices, we want to utilize every bit of that feed, if possible.”

Across the country, Kevin Yon raises Angus cattle in the mild winters of west central South Carolina.  He provides three mineral mixes: summer, winter, and one for young growing livestock.  Yon says, “Our winter mineral program doesn’t differ drastically from our summer mineral program.  We include a higher level of magnesium to prevent grass tetany.  If all goes well we hope to have lush grazing on a limited basis, even in December and for sure in February and March.”

His winter diet includes stockpiled forages such as Fescue or Bermuda grass.  When possible, Yon likes to have rye grass or small-grain winter annuals on hand.  He explains, “It could be a combination of those and sometimes we’ll use a protein or energy supplement, which could be commodity by-products, such as whole cotton seed, dried distillers grains or corn gluten.”

He analyzes feed, grains and commodity by-products, seeking advice from a nutritionist to adjust his mineral program as needed.

“It’s important to have a year-round high-quality mineral program,” Yon advises. “That’s not always the cheapest bag of mineral, but it has the high levels that are needed for cattle in your area.  The cheapest bag is not always the best.”

Yon finds that his cattle have a more consistent consumption if he allows free choice at all times.  He says, “Know what the consumption rate should be and monitor that. In our part of the world, a covered mineral trough is important so the mineral doesn’t get wet, cake up and the cattle don’t eat it.

“As a producer, I see the benefit of minerals.” Yon explains, “The biggest for us is reproduction, cow herd efficiency, immune response, cattle health, and growth and development.  At our place we try to feed a cow as cheap as we can because 60-70 percent of our annual cost involves nutrition.  We don’t see that minerals are the place to skimp.”

Thomas also recommends feeding minerals, saying, “Do it based on science.  Go ahead and get a forage analysis based on what you’re feeding and do that every time you get a new batch of feed, so you know what you’re feeding and what minerals you need to add to the ration.”

Rasby says, “To be competitive, you’re really going to have to watch feed costs. How you put together feeding programs to meet your herd’s nutritional needs is going to be critical.”

To find a list of certified feed testing laboratories, check out: www.foragetesting.org.

 

PROTEIN AND ENERGY

“Minerals don’t do much if you’re not doing a good job of covering your water, energy, and protein needs for those cows,” advises Ken Bryan, PAS, and Ruminant Specialist with Cargill.  “A balanced diet is important because you have the added stress of environmental conditions like cold, wet weather, mud and wind, which are going to increase the cow’s nutritional requirements.”

Adequate amounts of energy and protein are critical during winter conditions. “If a cow will eat twenty-four pounds of dry matter in forage, she’s going to get all the energy she needs,” Bryan explains.  “If that rumen is functioning well, she’ll break down the fiber and utilize that feed.  That’s your energy source.”

Protein, a much-needed nutrient in cattle diets, is composed of true protein and nonprotein nitrogen.  Protein in forages will gradually decline, providing less protein as winter progresses, with a higher percentage of fiber.  “The nasty thing about fiber is a high fiber, low quality forage diet will restrict intake,” Bryan says. “Now we’re going to supplement with a protein source.  The nice thing is, there are options for protein supplementation.”

“There’s the old standby, cake or range cubes, protein tubs or blocks and leftovers from oil seed products such as sunflower, cotton seed, or soybean meal and distillers grains from corn.  Look at the most economical way to deliver protein to the cow.”

Bryan cautions, “We’ve got to keep a minimum amount of fiber in that diet as we feed energy supplements.  We’re going to cause some long- term changes in that cow’s rumen… we’ll ruin her if we feed her like a feedlot steer.”