by: Heather Smith Thomas

Many ranchers experience a few cases of diarrhea in young calves, and some years are worse than others. Scours can be caused by certain kinds of bacteria, viruses or protozoa. Whether or not calves get sick is often related to multiple factors including exposure (whether calves come into contact with those pathogens), and stress. Good weather, clean ground, and stress reduction (which includes protecting calves from bad weather, along with not confining the animals too much during calving season) can help reduce incidence of scours.

Dr. Chris Clark (Associate Professor of Large Animal Medicine), Western College of Veterinary Medicine, University of Saskatchewan, says that there are two aspects to scours prevention. “You can try to make sure the calf is more resistant to the pathogens, and also try to reduce the number of pathogens (that the calf is exposed to) that cause scours,” says Clark.

Boosting Immunity – “The simple answer to this aspect of preventing scours is that it all comes down to colostrum,” he says. There must be a high level of antibodies in the cow's colostrum and the calf must nurse enough colostrum, very quickly after birth, to be adequately protected.

“You want to make sure your cows are vaccinated for scours, up-to-date on their vaccinations, and ideally they should be vaccinated relatively close to when they start calving. Then the immunity level will be the highest. The cow will have the highest possible level of antibodies in her blood, which means she will then have high levels in her colostrum,” he explains.

Also make sure the cow is in good body condition before calving, with proper level of nutrients when she gives birth. “This will also ensure that she can produce the best and largest amount of colostrum. As a rule of thumb, heifers' colostrum is never quite as good,” he says. They haven't had as much chance to become exposed to as many things and to build as strong immunity as an older cow.

“I've always worked from the principle that if you need to give a calf colostrum (if the calf can't nurse for some reason), it should be as much colostrum as possible and as fast as possible. This means about six pints in the first six hours and another six pints in the following six hours, to give the calf the best opportunity to absorb adequate antibodies.” You might be using frozen colostrum or some from another cow, or milked from the calf's own mother if for some reason he is unable to nurse her himself.

“If you don't have any colostrum available, you could consider using one of the high quality commercial substitutes. Make sure it's a good quality—one that is made from colostrum rather than one that was made by trying to extract antibodies from milk or blood.”

Preventing Exposure – The other part of the battle is trying to make sure your calving area is as clean as possible. “You don't want the cows in a wet, sloppy environment where they will have manure all over their teats. Otherwise that first mouthful of milk the calf gets will be loaded with pathogens,” he says. It's always a race between the pathogens and the antibodies in the colostrum, regarding which gets to the gut first. If the calf is nuzzling around the dirty cow, trying to suck on her brisket or flank or tries a few times on the teat before he actually latches on, the pathogens get a head start in this race.

“A lot depends on the time of year you calve, regarding how clean the environment might be. If weather isn't cold (necessitating grouping the cows for shelter) you can spread the cows out more, on clean pastures. Clean ground or green grass is ideal, but obviously if you are a producer who has to calve early in this part of the world (to have the cows calved before they go to summer pasture, for instance), you have to balance this. If you calve in January or February and must have the cows in a small pen, it may still be clean enough if the ground is frozen or there's a lot of snow.” If manure stays frozen, cows can stay clean.

“If a person ever finds themselves in a scours outbreak in the spring, during a thaw, often the best thing to do is just kick all the cows and calves out into a big field and spread them out,” says Clark. This may make it easier than trying to deal with a confined and more contaminated environment.

“Even if you try to keep the confined cows clean by putting out more bedding, you still can't win. Cows are very hard to keep clean when it's wet and sloppy,” he says. It can be a very uphill fight when you have a siege of bad weather.

Some years are just harder to prevent scours than others. “When you do everything right, you are loading the dice in your favor, but you still have to roll the dice. This is what makes the difference between a good producer and a poor one. The good producer, who tries hard to manage for scours prevention, may have an outbreak once every 10 years or so rather than every year. It's not that you can prevent all scours, every year. It's how often you have to deal with scours,” says Clark.

“I've known some good stockmen who get very upset and take it very hard when they deal with scours. They ask me what they should do next year to prevent this. But every year is different. Everything they were doing was right; it was just a bad year. I tell them not to turn their back on everything they've learned. There might be a couple of small things they could change, but if they are good stockmen and what they've been doing has been working for many years, they shouldn't change everything just because one thing was altered. Don't throw the baby out with the bathwater. Yet some people think they need to change everything, and be doing something different, just because they had a problem this year—maybe due to weather or feed issues--and they find themselves in a bad situation.” They may just have to treat some calves, but they can still come out all right if they are diligent.

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