Producers can keep young animals healthy by minimizing their exposure to manure
Calf prices have reached record highs, so keeping each one healthy is a good investment.
Scours is a common threat to young calves, and diligent biosecurity, cow immunization and a good dose of colostrum at birth are among the best defence tactics to prevent sickness.
“Scours is the blanket term we refer to when calves have diarrhea, and that can span anywhere from just having loose stool and still being happy to being flat out and near death,” said Claire Windeyer of the University of Calgary’s faculty of veterinary medicine.
“It embodies that whole spectrum of disease, and it can be caused by a lot of different pathogens. A lot of times you don’t know which pathogen it is. Often it is a combination of pathogens. It is rarely just one.”
The first three weeks of life are the primary challenge. Bacteria and viruses can spread through the herd and cause diarrhea. The weakened calf is then subject to secondary problems.
“Babies are the most vulnerable, and part of their growing up experience is becoming immune to some of those everyday pathogens that are in feces,” Windeyer said.
“When they are young and they are compromised or naïve, they are overwhelmed by the amount of pathogens.”
Good colostrum management, good pregnant cow nutrition and vaccines should provide a calf with adequate protection. This is known as passive immunity.
Calves that did not get enough colostrum are at high risk. Their guts are open to antibodies from the colostrum as well as any pathogens that may be present during that first day of life.
They need to receive a litre of colostrum within the first four hours of life and another litre within 12 hours.
“The ideal situation is they are up and drinking from their moms within an hour and you don’t have to worry about it,” Windeyer said.
Extra diligence is required if calving was difficult and the cow and calf are wobbly.
The calves may eat manure from the cow’s leg, the ground or the udder while they are trying to find the mother’s teat.
“Reducing calves’ exposure to the manure is almost more important than what bugs are in it,” she said.
Therefore, it is important to keep cows, bedding and surrounding pens clean. Reducing exposure to manure, wind and wetness gives calves a better start.
Treatment depends on how sick the calf is.
Talk with the veterinarian about the best approach for treatment and whether it can be done by the producer or a veterinarian.
Antibiotics may not help because the cause of the illness is usually unknown. However, calves can recover within 12 hours if the problem is caught early and they receive oral electrolytes.
“Calves are amazingly resilient and they can surprise you, even when they look like they are near death,” she said.
A host of pathogens lurk in manure, and many may be difficult to diagnose.
Calves may have picked up an infection from the many forms of E. coli or viruses such as rotovirus and coronavirus. They may also have been exposed to parasites such as cryptosporidium and coccidiosis.
Rotovirus can cause a mild diarrhea, dehydration and depression and open the door for other bugs to enter the system and sicken the animal.
Coronavirus tends to destroy more of the gut lining and can be more severe.
Both forms of the virus are present in scours vaccines, which are given to cows before calving.
The environment and housing conditions must be considered to reduce risk.
“Management is important to dilute the amount in the environment, trying to avoid the calf’s exposure to it and trying to make sure that calf is as strong and healthy,” she said.
The length of the calving season is also important to consider.
The first calves of the season are probably exposed to low concentrations of whatever pathogens are present. The later calves face more exposure to accumulated pathogens and greater risk of disease.
On-farm biosecurity is another good defence.
Veterinarians from Washington State University’s College of Veterinary Medicine suggested the following:
- Remove late gestation cows from areas heavily contaminated with feces, such as winter feeding grounds, a month before calving to reduce manure on the hides and further spreading infectious agents by carriers.
- Separate cows requiring more intensive monitoring, such as first calf heifers.
- Avoid moving cows into calving areas until immediately before delivery, or as late as practical.
- Ensure that calving pens are sanitized and well bedded before and between successive calving.
- Clean the perineum and particularly the udder of cows before delivery.
- Collect colostrum from clean, sanitized udders into clean containers. Refrigerate it immediately or freeze in volumes no larger than four litres. Do not pool between cows.
- Group heifers separately from cows during at least the last trimester of gestation.
- Use designated calving grounds, and calve heifers separately from cows. Such areas should not have been used by animals since the previous year’s calving season and should have been groomed shortly after the close of the calving season. It should be well drained and situated away from bottomlands, which tend to collect contaminants in standing water.
- Minimize the population density of cows as much as practical and reduce group size to less than 50 animals.
- Remove beef cow-calf pairs to a separate nursery area after bonding but within 24 hours of calving.
- Rotate feeding areas during the calving season to avoid fecal contamination and pathogen buildup.
- Calves demonstrating signs of lethargy or diarrhea should be removed from the group as soon as possible and placed into an isolation area.