The good news is, we can test for the usual cattle parasites — and if thresholds are passed, then those herds or pens are treated.

Work done a few years ago by a pharmaceutical company with which I was involved found that we could put most beef herds into low, medium and high categories for internal worms, and only the medium and high herds would need to be dewormed.

The best time to check is after cattle have been on grassy pasture later in the summer when burdens increase.

Cattle are generally pretty low shedders of eggs because of low infestation, but late summer is the best time to check. Yearlings generally have higher counts, followed by calves. The cows are most resistant.

Fresh manure is needed when doing a manure test. The modified Wisconsin test is the most accurate test for cattle.

It’s possible to pool samples instead of doing a group of 10. This should save time and money and be just as accurate if done properly. This should save the clinic time.

We all need to test more before treating the entire herd.

Managing ivermectin resistance

It has been found that ivermectin resistance is increasing, which reduces effectiveness. Resistance varies greatly from herd to herd.

Check to see if your herd veterinarian does parasite testing in-house, at their clinic, or sends them out.

The problem here is the number of tests that are needed as well as the cost and time.

Some producers complain about spending money on tests, only to have to deworm the herd anyway. Their response is that they might as well have just dewormed them in the first place.

This response is understandable, and quicker chute-side tests need to be developed to reduce this problem. I am sure some researcher will develop a quick, lower-cost method.

Another class of parasite treatment is the benzimidazoles, including products such as Safeguard and Valbazen. The problem is that only internal worms are treated, and the products don’t include treatment for lice.

Until the last decade or so, ivermectin products accomplished both parasite and lice control. They came on the market when my generation of veterinarians (baby boomers) were practicing, and everything was treated.

Lice were most visible, while internal worms rarely got bad enough in Canada to cause outward clinical disease.

However, this is changing.

Now, veterinarians must help producers fine-tune their entire parasite treatment program as well as their fly control program.

Internal parasites, such as liver flukes, and external ones, such as ticks, may also be showing up in slightly increasing frequency.

These parasite problems are in more specific geographic regions, and they can have complicated life cycles, so they may even show up in specific years under specific conditions.

Again, your herd veterinarian can help with specific treatments and monitoring if either liver flukes or ticks become prevalent in your area.

Fly control

For fly control, there are fewer and fewer products to use, and they are all similar chemically with no new ones on the horizon. Many have actually been taken away from us.

Treatments must be used only when fly numbers get high enough. If oilers are used, they can only be charged with product when necessary. This saves product and cost and slows down the development of resistance.

Canadian winter slows down the transmission of internal parasites, killing the eggs and reducing the survivability of larvae.

Rotational grazing, with a long time between pastures, allows more larvae to desiccate and die.

Producers should be able to keep parasites in check with selective and timely use of products, specific management changes and checking for eggs in the manure. It might also be a good idea to cull cows that are identified as lice carriers.

Parasites evolve and have been survivors, which means constant research is needed in this field so we are aware of new developments and products.

Most research is species-specific, but transmission can occur between similar species, such as bison and cattle or horses and donkeys.

Ticks, on the other hand, can involve several different species in their life cycle, as do liver flukes.

It’s a complicated world when it comes to parasite management, and herd management needs to be reviewed from time to time.

The post Test for parasites in cattle herd to avoid over-medication appeared first on Grainews.

Each cow or calf infected with untreated painful pinkeye (caused by the Moraxella bovis bacteria) has a good chance of going blind. It practically makes any semi-blind animal worth hundreds of dollars less than its herdmates; whether it’s a cow that cannot find a mineral feeder and becomes so mineral/ vitamin deficient that she fails to rebred or it’s a hungry calf that doesn’t come up to the creep feeder. As a result, it has a lower saleable weaning weight in the fall.

Prevention

Here are three important steps to minimize risk of disease spread:

• Know symptoms of pinkeye in cattle and the life cycle of the face fly, its transmitter.
• Put the cattle on a well-balanced mineral (and vitamin) feeding program.
• Make strategic use of insecticides on cattle grazing pasture.

Walk through the cow herd regularly, and look for signs of pinkeye. The initial source of eye irritation may come from abrasive pasture grass or dusty ground in pasture areas, but by far the main reason for cattle eyes to water excessively is the common face fly.

Like many other cattle fly pests, face flies go through a four-stage metamorphosis that encompasses about 21-25 days.

Understanding pinkeye and the face fly in the first protocol has little to do directly with the second protocol (mineral supplement) of pinkeye control, but there is a definite link. A good trace-mineral program should be provided in order to promote healthy eye tissue and surrounding areas as well as strengthen immunity against this disease. Producers in problematic pinkeye areas should feed a commercial beef “breeder” mineral at the rate of three to four ounces per head per day, year round. The fortified cattle mineral should contain at least four specific micronutrients that help combat pinkeye — Vitamin A and zinc as well as selenium and vitamin E .

Assuring mineral and vitamin status is optimized within the animal is a good idea to help control/recovery of pinkeye in cattle and should underscore the above third and final protocol — strategic use of pesticides. For instance, some producers apply one organophosphate- or pyrethroid-impregnated ear tag per head to one ear. They do this before letting cattle out on pasture.

I also understand that some producers forgo putting ear tags into their cattle because they feel that the efficacy of four-month ear tag control may not coincide with a major buildup of flies toward the end of the summer.

I have a friend that runs a 150 cow-calf operation on the eastern Prairies who doesn’t use ear tags in his cattle for this sole reason. As an alternative for face fly control, he applies a pour-on pyrethroid insecticide (one per cent cyfluthrin) to every animal just prior to releasing his cow herd onto pasture. About six weeks later, he and his brother walk the herd with backpack sprayers filled with malathion and they lightly spray the body of each animal.

I asked him, “How do you treat about 300 animals (calves included) on open pasture?” He laughed and said it’s amazing how fast all animals come around when you shake a bucket half-filled with corn! He realized a long time ago that you don’t fool around with pinkeye in cattle — employ a natural (he feeds a breeder mineral on pasture) and an insecticidal means to avoid the serious economic losses when even one animal loses sight from one eye.

The post Implement a good pinkeye control program appeared first on Grainews.

Last summer we began to notice not only were sprays not working as well as they used to, they are getting harder to find. This is due to tighter restrictions on chemicals. The flies are also becoming immune, making chemical control less effective.

Another option is biological control using fly parasites called parasitic wasps. This is not an eradication method, but a process of reducing the fly populations to a manageable level. These fly parasites already live in Canada. We are not introducing a new species by seeding our farms with inoculated fly eggs, we are just boosting their numbers.

Fly parasites, commonly referred to as fly predators, are one of nature’s control methods. Fly parasites are tiny wasps (the size of a fruit fly) that occur naturally, are mainly nocturnal, and do not harm humans, livestock or pets.

While there are other natural predators such as birds and spiders, the fly parasites are unique because they target the developing flies. Under circumstances normally observed in nature, these natural controls keep a balance in the fly population. When humans artificially increase the concentration of animals, we provide an ideal breeding environment for fly reproduction and the natural controls cannot keep up to the fly population explosion.

Parasite mode of action

The parasite females search for a fly pupa and can burrow up to six inches (15 cm) into manure or compost in order to reach the prey. They then deposit their eggs into the fly pupae and the young parasites will consume the fly pupae as nourishment while developing into adult fly parasites. Each female will lay between 50 to 150 eggs depending on the species. These adults emerge fully grown and ready to search out more fly pupae and start the reproductive cycle again. Normally, this cycle takes 18-21 days depending on the species of fly parasite and temperature. The adult fly parasites also consume some of the fly pupae, providing a secondary method of reducing the potential fly population.

Producers have been reporting very good results using predator insects for fly control in many settings. The largest sheep producer in Manitoba has successfully adopted their use. There are also feedlots, dairies and egg producers coming on board and are having a massive reduction in flies. That is not only making their neighbours happy — the less annoyed the livestock is, the higher their production.

A point to remember: a biological program should be started early in the year because it is easier to prevent an increase than to control a well-established fly population. Flies lay more eggs and have shorter life cycles than the fly parasites. If the problem is attacked early, the fly parasites have fewer pupae to attack, therefore they do a better job and fewer pest adults hatch out, resulting in fewer eggs laid.

Reducing fly numbers helps

Some things to keep in mind to help reduce fly reproduction and help out the fly parasites:

• Flies require a moisture range of 35-70 per cent for successful larval development so keep manure piles as dry or as aerated as possible.
• Stir lagoons or seed the top crust with fly parasites.
• Repair all leaking water lines and try to reduce any wet areas, as these are natural fly-breeding grounds.
• The fly larval developmental cycle is about seven days so the manure should be dried out before that time. In a humid region, it is best to wait until cooler temperatures in the fall before spreading the manure.

The idea is that once released, the predators will keep breeding and eventually keep up with the flies. We would get a shipment monthly during fly season to keep our population high. If we can cut back on the ideal conditions that have been provided for the flies to overtake the natural predators here already that would be very helpful also. The people at www.goodbugs.ca have been very helpful at formulating a customized program.

The post Nature’s fly control program appeared first on Grainews.

I saw that two of these steers had each something wrong with one eye; one animal had an inflamed dripping eye that was closed shut, while the other steer had a visibly cloudy eye. The manager took their ear-tag numbers and treated them that afternoon for pinkeye.

By now, I understand that the patches used to protect their infected eyes have fallen off and both animals are up to the bunk with the rest of the cattle, like nothing happened.

This story is a good reminder that early detection, rapid treatment and a good prevention program should halt the advancement of pinkeye in most cattle herds. We should also be reminded that untreated cattle that go blind in one diseased eye consume less feed and don’t gain as well compared to cattle with acceptable two-eye vision. For example, mid-American research (SDSU, 2013) states spring calves diagnosed with pinkeye weigh about 20 pounds less than normal, which translated in hard cash is about $30 of lost revenue at weaning time.

Even with a pinkeye program in place, some people are shocked when a string of their cattle come down with this highly contagious and painful disease caused by Moraxella bovis bacteria. In itself, the healthy bovine eye has adequate defense mechanisms to prevent M. bovis growth, but a number of factors particularly during the summer months come together that breakdown this natural protection and cause a pinkeye outbreak.

I find it surprising that pinkeye can literarily start with one animal; one eye for whatever reason starts to tear, which underlies the perfect environment for the M. bovis bacteria to thrive. The initial source of eye irritation can come from anywhere such as abrasive pasture grass, dust, wind, or excessive sunlight, yet by far the primary source of cattle eye irritation is the common face fly.

Flies are leading culprits

Face flies are naturally attracted to the head of cattle on pasture, and specifically attracted to the discharges of the eye. These flies have abrasive spongy mouthparts that stimulate the eye to tear, so they can feed off the secretions. Inadvertently, they fly from one individual transferring m.bovis from animals with clinical pinkeye or recovered pinkeye carriers (still harbour bacteria in inner eyelid surface) to healthy cattle. These flies also cause small scratches on the conjunctiva and corneas of the eyes when they feed, which makes it much easier for the M. bovis organisms to attach to the eye tissue and thrive.

Treating cattle infected with pinkeye can be straightforward, but nobody should wait for it to appear before medical action is taken. A sound program for pinkeye prevention may start with insecticidal and non-chemical control, which focuses around the head of the animal as well as takes into account that face flies spend only about 10 per cent of their adult life on the face of cattle. Face flies are usually found spending most of their time on fences, trees and other objects. In the fall, face flies tend to overwinter in cattle buildings.

Pinkeye control program

The underlying foundation of a good pinkeye control programs are:

• Ear tag protection. Plastic ear tags are impregnated with either organophosphates or pyrethroids. One tag per season is recommended per animal. Most people should be aware that the efficacy of the insecticide in ear tags is good for up to about five months of control.
• Strategic rotation of insecticides. It’s also common practice for producers to alternate organo- and pyrethrin-based tags every other year to reduce the chance of face-fly resistance. Note: a new ear tag has come out in recent years that contains both of these insecticides.
• Non-chemical and animal management. Some producers keep their cattle out of tall grass pasture and overgrown bush, which is not always practical, but reduces the incidence of eye irritation. In drylots, excessively dusty areas are controlled by various means. Ideally, infected animals should be isolated from the rest of the herd, because they are highly contagious.
• Nutrition prevention. Make sure nutrients that promote good eyesight and a functioning immune system (such as vitamin A, vitamin E, zinc, copper and selenium) are fed.
• Feed management. I know of one feedlot producer who adds water to his beef grower diet to keep the dust down. Another producer quit emptying dusty feedlot ration on the heads of the cattle during feeding time to avoid irritating feed getting in the cattle’s eyes.

Such methods to halt pinkeye in cattle are important because of the serious economic losses when an animal loses sight of even one eye. Pinkeye might be a summertime disease because of the associated risks involved, but implementing the proper treatment and prevention programs can help producers combat the effects of pinkeye, all year round.

The post Untreated pinkeye can be costly appeared first on Grainews.

I never told him, until there were about 10 cows left, that I discovered the pour-on jug had a breather-hole that I fail to punch open to allow air to replace the horn fly insecticide we were using. Two weeks later, he had to run his cattle through the chute once again because of an “unusual heavy” infestation of horn flies out on pasture.

It doesn’t take many

Oddly enough, it doesn’t take that many horn flies to have a significant pest problem on pasture. A nominal count of 200 horn flies on the back of each cow or calf can:

• Increase animal stress; make animals skittish and reduce grazing time.
• Decrease forage intake linked to a 20 per cent decrease in milk production.
• Encourage bunching and increased heat-stress severity.
• Spring calves are 15 to 20 lbs. lighter at weaning time.
• Reduce cattle immune function to fight disease.
• Spread of disease among cattle such as anaplasmosis.
• Replacement heifers have higher rates of infertility.

As this picture at the beginning of this article illustrates, one horn fly is very small (about four to five mm) and seems to get lost when hundreds of them are present on the back of an individual animal.

Horn flies are much smaller than a common stable, house or common face-fly; gray in colour with two dark stripes running along its body. Its head has two reddish compound-type eyes and has biting-mouth parts which it uses to pierce and suck blood from its cattle host; taking up to 20 to 25 blood meals daily.

Just imagine the explosive implications of 1,000 horn flies on each cow that seem even more attracted to the herd’s breeding bulls! Case-in-point: the University of Arkansas research estimates that a heavy infestation of 1,000 horn flies/cow can draw about 10 cc of blood per cow per day.

Effective treatments

Luckily, when a population explosion of horn flies does occurs, there are several proven methods that effectively can reduce horn flies counts on cattle by as much as 90 to 95 per cent. Most of these programs involve commercial insecticides, such as two timeless chemicals, namely: organophosphates and pyrethroids, both of which kill horn flies by disrupting vital nerve functions. Another class of insecticides called endectocides (ivomectin) can also be used in a similar manner.

Here is a breakdown of three of the most popular applications that dispense these insecticides in order to control horn fly numbers:

• Ear tags — Plastic ear-tags are impregnated with either organophosphates or pyrethroids. One tag per season is recommended per cow. Most people should be aware that the efficacy of the insecticide in ear-tags is good up to about five-month control. Most people are instructed to wait until June to maximize the ear-tag’s full benefits for tackling peak populations of horn-flies that occur in late-July and August in Western Canada. It’s also common practice for producers to alternate organo- and pyrethrin-based tags every other year to reduce the chance of horn fly resistance. It is also recommended to remove ear tags at the end of the grazing season for the same reason. Note: a new ear tag has come out in recent years that contains both of these insecticides.
• Back rubbers/oilers — A back rubber is usually a big, thick chain and mesh wrapped in a durable material and is treated with insecticide diluted with diesel fuel. Producers should check them on a weekly basis to see if they need to be recharged. If the pump-type back rubbers are used, it is a good idea to check them to assure that they are in good working order. It has been my experience to see the odd one leak insecticide all over the ground. Furthermore, the standard recommendation is to set them up to force cattle to pass by them. I asked a few cattle people about this advice and most of them said that cows are more than willing to regularly use them in order to rid themselves of horn flies.
• Pour-on insecticide — Efficacy of pour-on insecticides often depends on the type of active insecticide used (re: endectocides) as well as its carrier liquid dispensed on cattle. For example, in the past; it has been my experience that generic types of pour-ons had some difficulties in insecticide absorption rates upon cattle due to carriers that companies employed.

The post Tips to help keep horn flies off your cattle appeared first on Grainews.