• Black Tide - Pt. 2

• Calf Health

• Gelbvieh Guide

• Just 5 Questions

• Reads For Ranchers - Pt. 2

• The World According To
   Hooter McCormick

EDITORIALS

• TRAILS
• RIDING THE GAP

It can be challenging to catch a calf that’s still lively, and also challenging to deal with protective mamas. You want your cows to be good mothers, but some are aggressive when their calves are young, and dangerous to anyone handling the calves. In our herd we must deal with cows and calves at calving time--to iodine navels, ear tag, put rubber bands on the little bulls, move cows in and out of calving pens or barn—so the cows must be easy to manage. We respect a protective mother, but we also demand that she respect us. Any cow that can’t be safely handled is sold. A cow that is smart enough to respect us if we have a stick (not charging over us if we are working with her calf) can stay in the herd.

My husband Lynn and I work as a team, handling newborn calves or catching sick ones to treat. Most cows are not as aggressive when there are 2 people, partly because they are outnumbered and partly because they sense we are confident. If you are not afraid of a cow, she knows. If you ARE afraid, she knows that, too, and quickly takes advantage of you. When handling cattle, you must be confident, acting as the dominant “herd boss”. It’s easier to be confident if there are 2 of you—one to fend off the cow and the other to deal with the calf. It’s hard to hang onto a lively calf, treat him, and fend off the cow at the same time. But if someone is helping hold the calf and staring down the cow, you can concentrate on treating the calf quickly and properly.

The person keeping the cow away should have a weapon. Cows are smart. They know when you are defenseless, and when you are prepared to stand your ground with a stick to whack them across the nose. There have been instances when Lynn and I were treating calves out in a pasture and were saved from trampling only by quick action—like the time he quickly pulled off his belt and whacked the charging cow in the face with the belt buckle, or when the only thing we had for a weapon was the ear-tagging tool in my coat pocket (a 5 inch long small metal tube with sharp point on one end) which I poked into the cow’s nose as she started butting me.

Most cows will halt if you have a weapon they respect, just as they would halt and not threaten a more dominant cow. The tender nose is a good target to jab a cow. The bridge of the nose/face is best if you have a stout stick. Don’t hit a cow on top of the head or you may kill her. Don’t flail wildly with a whip or you may injure an eye. If you have no weapon, however, and she’s butting you, she will usually back off if you grab an ear and twist it hard, or poke her in the eye with your thumb or finger.

But we don’t want a cow to get that close. If we must catch a calf that has a mean mama, we carry a stout stick. You want something you can carry and hold while doctoring a calf, that you can use at close range, and sturdy enough to give a good rap across her face without breaking.

One of the most important rules to remember when working with cows and babies is no dogs. The presense of a dog in the vicinity or in the back of your pickup (even if he doesn’t bark) can upset a cow enough to get her on the fight, even before you get close to her calf. And if she’s on the fight, she’ll focus her aggression on you, even if the dog is out of her reach.

Getting Your Hands On Baby
If a calf is dull (concentrating on his own misery instead of being alert to what’s going on around him), you can often sneak up behind him and grab him before he knows you are there--if other calves don’t startle and mess up your sneak. If the calf is lying down, you can grab/tackle him around the neck (sneaking up from behind so he won’t see you coming). If he’s standing, grab a hind leg. If he sees you, he will run off. We do a 2 person sneak (one person to keep his attention) to catch a lively calf, before he realizes what’s happening. This usually works very well for any calf that hasn’t been caught before. After that, he’ll get suspicious and you’ll have a harder time catching him a second time. Most of our calves are not very wild and can always be caught the first time, since they are accustomed to having us walk through the herd. If you never walk through your cattle on foot, however, they may be too wild to get close to.

To catch a calf that needs treatment, one of us walks in front of him at a distance he is comfortable with and not threatened. That person distracts the calf to keep his attention, singing or making funny noises or movements, but not wierd enough to startle the calf—just enough to arouse his curiosity. This might mean hopping or waving your arms while the other person sneaks up quietly behind the entranced calf (in his blind spot as he is looking forward—ears up—at the “entertainer”) and grabs a hind leg, getting a good grip just above the fetlock joint. The front person then comes swiftly to grab the head, and the calf is caught. One of us gets a good hold on him and the other treats the calf. I usually straddle the calf’s neck with my legs, to hold his head still as I give him the medication. You can often be finished before mama even knows about it, if the cows are busy eating hay. But if the calf bellows when you grab him, and all the mamas come running, be prepared to fend them off.

If a calf is too big to catch, or suspicious because he’s been caught before, or needs follow-up treatment or intensive care, we bring the pair in from the field and put them in a small pen where we can corner the calf or get our hands on him again for subsequent treatments. If a calf is far from a corral and you don’t want to bring him and mama all the way home if he just needs one treatment, there are ways to capture him if he won’t let you sneak up close behind him. One method is a sheep hook (shepherds crook). We put a longer handle on ours, so we can snag a calf’s hind leg without having to get so close. A calf has a certain safety distance in which he feels secure. Unless he’s quite wild, or you’ve caught him before, this distance is short enough to get within range with a long-handled hook before he is alarmed.

The 2 person decoy distraction allows the calf-snagger a chance to get into position to catch a hind leg with the hook. A small calf that’s too wild or suspicious to grab by hand can usually be caught with the hook. It takes a lot of strength to hang onto a big calf with the hook, and some may kick out of it. There are some catching hooks made for calves, with a mechanism that locks onto the leg, making it impossible for one to kick free.

Another way to catch an elusive calf is to ease him behind a solid gate (if there’s one close by), catching him in the narrow V made by the gate and the fence. If there is no sturdy gate available, we may herd the calf between a fence and the feed truck, after parking the truck against the fence at an angle. You can walk the calf along the fence and into the trap.

This works best if you are feeding hay, stringing the hay close to the fence so all the cows and calves are close by. A calf won’t get as suspicious and wild if he’s with the herd, close to other cattle; he feels secure with the herd around him. Gently ease him through the herd along the fence and he’ll be in the trap made by the fence and the truck before he knows it.

A net wire or pole fence makes the best trap. A calf can shimmy through a barbed wire fence and get away, unless it’s very tight and has a lot of stays, holding the wires in place.

The trap trick won’t work unless there are other cattle there; the calf will see the trap and avoid going into it, and will also try to run toward other cattle rather than to your truck parked by the fence. But in a group of cattle clustered near the feed truck, he feels secure, and if you are patient and tricky you can catch him. A sneaky catch by a hind leg or by herding him into a trap to grab him is much easier on him (and you) than chasing him around.

Once you’ve treated him, assess his condition and decide if one treatment will be adequate or not. If there’s any question, bring him and mama to a “sick pen” so you can get hold of him easier for continuing treatment. Many calves relapse (and take more treatment the second time, to save them) if you don’t treat them soon enough the first time.

Scours—Intestinal Infections in Baby Calves
The term scours simply means diarrhea. This is the most common symptom of several types of intestinal infection. Some kinds of infection, however, are so acute they can kill a calf before diarrhea begins. For instance, “enterotoxemia” caused by Clostridium perfringens (and some other types of acute bacterial infection such as certain strains of E. coli) can produce toxins that go through the gut lining and into the bloodstream—and the calf may go into shock and die before there is any evidence of diarrhea. But in most types of infection, diarrhea is the main killer of baby calves, due to acid/base and electrolyte imbalance and dehydration.

Digestive tract infections can be caused by viral pathogens such as rotavirus or coronavirus, or by pathogenic bacteria or protozoa. Some of the most difficult cases (the most damaging and hard to treat, with high risk for fatal complications) are caused by bacteria, or a combination of bacteria and other pathogens.

Dehydration is often the actual cause of death when a calf dies of scours; he is losing body fluids faster than he can replace them since the damaged gut cannot absorb fluid. In early stages he may be still strong and lively, but as dehydration progresses he becomes dull, his mouth becomes dry, his skin is less elastic, his eyes look sunken and his legs become cold. Dehydration results from fluid and electrolyte loss; various body systems can no longer function. Without treatment to replace fluids and salts to reverse this condition, the calf becomes too weak to stand or nurse and his temperature drops into subnormal range. He then becomes comatose and dies. Often the best way to help the calf is to replace the fluids and salts he is losing, preferably at the first sign of diarrhea—before he gets weak.

Many cases of diarrhea are caused by a combination of viruses and bacteria, and in some cases are also complicated by protozoa. Some stockman think they can tell what type of scours it is by looking at the color and consistency of the feces, but some cases are not typical and many are caused by multiple agents. Few cases of diarrhea in young calves are simple infections; it can be hard to tell if you are dealing with viral or bacterial scours since signs are the same—profuse, watery diarrhea and progressive dehydration. Finding a pathogenic virus in a feces sample in a lab may not mean much, since these viruses are often present in normal animals. Just because it’s there doesn’t mean it is the cause (or only cause) of the diarrhea.

Age of Calf
The younger the calf, the more rapidly he may dehydrate, and the more often he needs fluid replacement. Except for some of the acute toxin-forming infections that can cause toxemia (toxins circulating through the bloodstream) most types of scours are deadliest in the first weeks of life. A calf becomes more resistant and his body more able to fight off the pathogens as he gets older. The younger calf is more apt to die if he’s not aggressively treated. He has less body reserves and is more vulnerable to dehydration, and his gut lining is less able to regenerate quickly if damaged; it takes him longer to recover.

The same kind of infection that would be a life or death emergency in a 2 or 3 day old calf is usually not so serious in a 3 week old calf. The bigger calf may still need treatment, but he’s more able to fight off the infection without as much gut damage or risk of serious dehydration. Any calf that scours at less than 2 weeks of age should be considered an emergency (given fluids and medication immediately), whereas an older calf is more likely to handle it with minimal treatment. If he is strong, hard to catch, and continues to nurse the cow, he may get over diarrhea quickly with just one treatment (or sometimes without treatment). But if he’s dull, not nursing, not feeling good, he needs help.

Factors That Make Calves More Vulnerable to Scours
There are many complexities that determine whether a calf will get sick during his first weeks of life. These include his health and immune status, weather, and level of pathogens in his environment (contaminated pens or pastures). If he’s a little premature, or compromised at birth by shortage of oxygen and acidosis (due to difficult birth) which interferes with his ability to absorb antibodies from his dam’s colostrum, or does not obtain adequate levels of antibodies from colostrum, he is at much higher risk for scours.

Many calves will start to scour at about 3 to 4 weeks of age if pastures are contaminated, because antibodies from colostrum are waning; the temporary immunity is about gone. This can happen even sooner if a calf did not nurse soon enough or get enough colostrum. Once the temporary immunity is gone, the calf must build his own immunity as he comes into contact with various pathogens.

Age and health of the dam can make a difference in how long the calf is protected. First calvers generally do not have as many antibodies in their colostrum as an adult cow.  Research has shown that risk of diarrhea in young calves born to heifers is 4 times greater than in calves of older cows. A very old cow, however, may have poor colostrum. If a cow is thin or underfed during pregnancy her calf may not be vigorous and her colostrum may not be very high in antibodies, making him doubly vulnerable to disease. Anything that interferes with the cow’s immune system (low energy, protein or trace minerals in diet, BVD infection, etc.) can keep her from creating a protective level of antibodies in her colostrum.

Weather and environment can be big factors, contributing to epidemics of scours. Cold, wet, windy weather or hot weather (or temperature changes from one extreme to another) can be stressful, and stress lowers immune defenses. During bad weather, stockmen often congregate the calving cows to watch them more closely or provide shelter, resulting in more contamination on calving grounds or in calving pens or barns. Overcrowding leads to more fecal contamination and more risk for diarrhea in young calves. Calves born later in the season are more at risk for scours than the calves born first; the environment for the later calves is already contaminated with feces from calves that have been sick.

Risk factors include using the same area for calving that was used for wintering the cows. The ground is already contaminated with manure. And if calving takes place in late winter or early spring or when the ground is wet or may be flooded and muddy, this leaves less high, dry clean area for calving—which congregates the cows into smaller areas. The larger the herd, the greater the chance for disease spread. Calfhood diarrhea is less common in a small group of cattle (spread over a larger area) than in a large confined group.

The primary source of infection is feces, from sick or healthy animals (including healthy cows and calves) since most of these pathogens can exist in healthy animals without causing illness. Most pathogens that cause diarrhea in calves (including rotavirus, coronavirus, cryptosporidium, coccidia, and sometimes E. coli or salmonella) are carried by adult cattle. But if any of these organisms get into a calf, his immune system may not be able to handle it and he gets sick. Calves that develop diarrhea act as multipliers for pathogens, spreading many times more numbers of these organisms in their feces, and soon there’s a herd outbreak. If a calf gets sick, the best thing to do is remove him and his mother from the herd to an isolation pen for treatment, so he won’t spread the “bug” all over the pasture.

Animal density plays a huge role in whether or not calves get sick. With many types of scours (viral, bacterial, protozoal) nearly every calf may encounter the pathogen during his first month of life but may not get sick if he has good immunity from colostrum or gets a very low dose of the pathogen when first exposed. A low dose may enable him to start building immunity. He gets a mild infection but not enough to overwhelm his defenses or damage the intestine enough to cause diarrhea—since it takes the pathogens awhile to multiply and do more damage. But if his first exposure is high (ingesting a large number of pathogens), he’s more likely to get sick. If you have 1 scouring calf in a 10 acre pasture, for instance, exposure level for other calves is much less than with 1 scouring calf per 50 square feet of space.

Since pathogens are present in feces of healthy animals, any place there’s high density of cattle (calving grounds and pens) or many cows going through a calving barn during a calving season, the population of pathogens (especially bacteria like E. coli) in the pen or barn will continue to increase through the calving season. Unless a pen or barn is periodically cleaned out (and disinfected, or left awhile with no animals in it), the calves exposed to that environment will be at high risk for scours.

Salmonella and E. coli bacteria can live a long time in the environment, from year to year in a damp place like a calving barn that didn’t get cleaned out. Sunshine helps, along with cleaning out all the old manure. Letting the barn sit empty and open all summer after you clean out all the old manure and bedding can help ensure there won’t be so many “bugs” there the next calving season.

First calvers’ babies have a higher incidence of scours, not only because heifers have lower levels of antibodies in their colostrum but they are also worse carriers of pathogens, shedding them in their feces. They are still young and their bodies are still responding to all sorts of new antigens; even if you vaccinate them they do not respond quite as well to the vaccine as an adult cow because they don’t have as much immune experience. A heifer that had a hard birth may be slow to mother her calf, and the calf may be slow to nurse. If he doesn’t suckle quickly, he may not absorb enough antibodies. If you ever have to give a heifer’s calf colostrum use some from an older cow, if possible.

Prevention
The best “treatment” for scours is prevention. Management to prevent scours includes a healthy, well-nourished cowherd, with vaccinations up to date. This includes BVD, since a persistently infected BVD calf (born with the virus, after having been infected during gestation) has a compromised immune system and is susceptible to all kinds of scours—and very difficult to treat successfully. Management factors to prevent a dirty environment (having cows calve in clean areas and putting the new pairs into clean pasture rather than into an area where calves have already been sick) is the most important aspect of prevention. Limiting the calf’s exposure to pathogens is the best insurance.

How to Check the Level of Dehydration
A calf that is only mildly dehydrated still has warm feet and elastic skin. If you pull up a pinch of skin on his neck, the skin will spring back into place very quickly. If he has lost 2 to 5 percent of his body weight in fluid loss, it will take 3 to 5 seconds for the pinch of skin to sink back into place, and his mucous membranes (such as his gums) will be dry instead of moist. If he is 8 percent dehydrated it takes 5 to 10 seconds for the fold of skin to return to normal, his legs and feet will be cold and his eyes look sunken. If he is 9 to 12 percent dehydrated, it takes more than 8 seconds for a skin pinch to sink back into place, his eyes are very sunken, and his gums are white. By this stage he is in shock, and near death.

Age At Which Various Pathogens Typically Affect Calves

• E. coli (enterotoxigenic types) - less than 3 days of age
• E. coli (attaching types) - 15 to 30 days of age
• Rotavirus - 2 to 15 days of age
• Coronavirus - 5 to 30 days of age
• Other viruses (including BVD) - 14 days up to several weeks of age
• Cryptosporidium (protozoa) - 5 to 35 days of age
• Coccidiosis (protozoa) - older than 21 days
• Salmonella - 5 to 42 days of age
• Clostridium perfringens (types B and C) - 5 to 15 days of age
• Clostridium perfringens (type D) - 1 to 4 months of age
• “colicky bloat” (toxin-forming, highly fatal acute bacterial infection as yet unidentified) - 3 weeks to 3 months of age

Viral Scours: Rotavirus and Coronavirus
Viral scours tend to strike baby calves during the first 3 weeks of life, whereas most types of bacterial scours can attack a calf at any age. If a calf gets sick in the first week of life, it’s usually due to viral scours or a certain type of E. coli bacteria. The appropriate antibiotics can halt bacterial scours but won’t deter a viral infection. You can usually help the calf, however, by giving fluid and electrolytes, along with gut soothing medications like Keopectate or Pepto Bismol. Antibiotics are only of value in halting possible secondary bacterial invaders.

Rotavirus
Rotaviruses are a common cause of diarrhea in many calves and are found on many farms. Once this virus is introduced (brought in by a new animal, or on someone’s feet or clothing—someone who was recently on a contaminated farm) it is very hard to eliminate. This virus remains stable in cattle feces for a long time, as well as in the air and on any surfaces it touches, and is resistant to most disinfectants. Once the virus is present on the farm, adult cattle serve as a source of infection for newborn calves, even though adults rarely become ill. Thus rotavirus tends to persist indefinitely once it is introduced.

The virus can lurk in barnyards, barns and pastures to cause new infections. Rotavirus diarrhea in calves is very contagious and can go through an entire group of calves—spread by fecal contamination of pasture, feed, bedding, water, dirty udders, human hands, etc. Even when cattle are in large pastures, there can be rapid spread of the virus among calves that come into contact with one another. The rotavirus is tough and aggressive and can attack a calf’s intestinal lining even without any prior damage or irritation to open the way for it. Some viruses only invade after an animal’s resistance is lowered by stress or the tissues are weakened by something else, but the rotavirus marches right in and starts the attack on its own. A common scenario, however, is a mixed infection of viruses and bacteria, which can make the diarrhea more deadly and harder to treat.

Calves can be infected soon after birth by the dam’s feces, or from contact with infected calves. Newborns are protected only during the first days of life while they still have some antibodies from colostrum active within their gut. Cows that have a high level of antibodies in colostrum give their calves protection from rotavirus, for as long as the antibodies are present in the calf’s intestine. Even though the exposed calf may still excrete the virus in his feces if he becomes infected, he won’t develop diarrhea while he is protected by antibodies in his intestine. Many calves are infected with rotavirus on farms where it exists, but not all of them develop diarrhea; some just shed the virus in their feces.

The main protection against rotavirus in the first week of life does not come from IgG antibodies absorbed into the blood and lymph systems through the intestinal lining, but from a different type of antibody (IgA) that remains in the gut. This protection lasts only as long as there are antibodies present in the intestine itself. This explains why rotavirus diarrhea occurs most commonly after 5 to 7 days of age, after there is no longer any colostrum in the cow’s milk. Diarrhea can hit as early as 2 days of age, however, if a calf didn’t get much colostrum or the antibody level in colostrum was low (as in first calf heifers’ colostrum). If the calf received a high level of antibodies (both absorbed and remaining in the gut) he has a much better chance of survival.

Prevention of rotavirus diarrhea depends on keeping conditions clean at calving and while calves are young, and on vaccination of cows in late pregnancy. If you have rotavirus on your farm, vaccinating the cows ahead of calving (to ensure a high level of antibodies in their colostrum) can help reduce the incidence and severity of diarrhea in their calves. Your vet can advise you on the vaccination options, and at what stage in gestation they will be most effective for development of peak antibody levels in colostrum by calving time. Rotavirus vaccine must generally be given within 40 days of calving. If you give it too far ahead, the cow will no longer have a high level of antibodies by the time she creates colostrum, and if you give it too close to calving she won’t have time to produce peak levels. Thus you need to know the calving dates of the cows, and vaccinate accordingly.

Factors that influence severity of diarrhea include age of the calf, amount of antibodies ingested at birth and in subsequent nursings, weather and temperature, and whether or not the infection is complicated with the presence of other pathogens such as bacteria or coronavirus. Calves are most susceptible to rotavirus between 1 and 3 weeks of age—after the initial protection from colostrum within the gut has declined and before the calves have mounted their own immunity. The highest mortality rates are in the youngest calves that did not receive adequate colostrum, especially if they are subjected to the stress of bad weather. Some of the most serious cases are also infected with bacteria like E. coli.

The incubation period for rotavirus infection is 18 to 24 hours. When the calf becomes sick he may have a fever and be dull and depressed for a few hours, then break with diarrhea. The runny feces may be very water, and often yellow-green to gray in color. In mild cases the calf may just be off feed for a day or two, but in severe cases with explosive watery diarrhea, calves will dehydrate quickly and need supportive care and fluids—given orally if the gut damage is not yet severe, or intravenously if his gut cannot absorb fluids.

Coronavirus
This family of viruses can cause acute diarrhea in calves, from 1 day to 3 months of age, but most commonly hits calves between 1 and 2 weeks of age. This type of diarrhea occurs most frequently during winter or early spring, since the virus survives best in a cool, moist environment. Many cattle herds are infected; most adult cattle have come in contact with coronaviruses at some point in their lives. A high percentage of cows shed the virus in their manure, especially during winter and at calving. Calves born to these “carrier” cows are at high risk of developing diarrhea. Coronavirus can also cause mild respiratory infection, especially in calves 2 weeks to 4 months of age.

Vaccinating pregnant cows with combination vaccine containing rotavirus, coronavirus and E. coli can reduce severe scours in newborn calves, if the calves get adequate colostrum. Vaccination won’t reduce seasonal shedding of coronavirus during the winter, but does seem to reduce the shedding at calving time, compared with non-vaccinated cows. Many veterinarians feel that the bacterial vaccines (for E. coli, and the C & D toxoid given for Clostridium perfringens) work better for creating a good response (and high level of antibodies) in the cow. The viral vaccines for rota and coronaviruses seem less dependable, but do help some herds.

One of the problems with trying to gain good immunity to the coronavirus is that there are several serotypes of this virus, and also some corona-like viruses that are different. The vaccine does not protect against these. If the vaccine works in your herd, you are probably dealing with a virus similar to that used in the vaccine. If vaccination does not seem to help, your herd may be affected by another strain.

One reason the vaccine against rota and coronavirus is often not effective is that neither virus stimulates a strong immune response from cows, either naturally or with vaccine. This is why cows carry these viruses in their bodies year after year. To protect against viral infection, it is essential that every calf gets good colostrum. The levels of antibodies produced in response to vaccination of cows are somewhat protective against the low number of viruses that are ordinarily shed by mature cows. But if a calf becomes sick with rotavirus or coronavirus, he will shed millions of virus particles in every squirt of diarrhea. Immunity conferred by vaccinating the cows (to pass antibodies to the calf) can be completely overwhelmed in the face of this kind of exposure—contact with infected, scouring calves. Even the calves that had good colostrum may get sick, if they remain in pastures where other calves have been scouring. Thus it is very important to make sure every calf gets a sufficient amount of colostrum, to keep an outbreak from getting started.

Another option is to administer an oral vaccine to the calves at birth. If vaccinating the cows has not helped, there is an oral antibody product (given to calves immediately after birth) that contains E. coli antibodies and coronavirus antibodies. This can be used if you choose not to vaccinate the cows or have not had a chance to vaccinate the cows. You can’t do both, however. If you vaccinate the cows ahead of calving, the maternal antibodies in the colostrum will counteract the oral antibodies you give the calf.

It is important to monitor calves closely, and check them often enough to know if one is getting sick. A calf with diarrhea should be removed from the herd and put with his mother in a “sick pen” for intensive treatment (fluids, etc.) so he can recover more quickly, and so he won’t contaminate the pasture and spread the infection to other calves.

Some years are worse than others for scours, whether or not you vaccinate. The weather—amount and timing of rainfall and snow, stress factors such as wind chill, how much mud or dry ground you have—can be the biggest factor in whether or not calves get sick. After a really bad year, some stockmen start a vaccination program and the next year is better so they feel the vaccine worked. But each year may be different. It’s hard to really know if the vaccine made the difference or if the calves would have been less likely to get sick because the weather was better and the ground was drier. A healthy environment is still the best protection against scours.