Calf care experts draw full house to 20^th anniversary Healthy Calf Conference

Lilian Schaer for Veal Farmers of Ontario

It was a capacity crowd that gathered in Stratford for the 20^th anniversary edition of the popular Healthy Calf Conference. Led by Veal Farmers of Ontario (VFO), the one-day event tackled some of the industry’s most pressing calf management issues with a line-up of top tier experts.

University of Guelph calf research spotlight

New to the conference program this year was a spotlight on calf research at the University of Guelph. Ph.D. student Hannah McCarthy shared details of her research into feeding transition milk. Calves are born with a naïve immune system and feeding colostrum within hours of birth is considered critical to giving them a healthy start. Producers, however, can also feed calves transition milk in the first two to six days of their lives.

Transition milk is high in Immunoglobulin G (IgG) antibodies, but also contains lactoferrin and IGF-1, a hormone that influences bone and tissue growth.

“Feeding transition milk can improve transfer of passive immunity and gut development, and decrease preweaning diarrhea,” said McCarthy.

Post-doc Dr. Lucia Pisoni’s research focuses on how to manage transport stress in dairy-beef calves with nutrition. Her work has shown that in calves fed both high and low colostrum levels within hours of birth – 10 litres and two litres respectively – none had failure of passive immunity transfer when they were transported to an assembly centre at 14 days of age.

However, at arrival, calves only fed two litres of colostrum had a body weight about two kilograms lower than the calves who received the higher amount.

“What we learned from our research is that even with higher nutrition, transport will impact calves,” she said, adding that calves should be fed on arrival and not given electrolytes.

Diarrhea is a common problem in calf-rearing, affecting calf health and their average daily gain. Antimicrobials are often given, but when are they most effective? Ph.D. student Dr. Luiza Stachewski Zakia’s research is hoping to answer this question.

A calf that is systemically sick likely has dehydration, with sunken eyes, increased rectal temperature, absence of a suckle reflex and trouble standing. If it has at least two of these symptoms, it will need antibiotics, said Zakia, otherwise the treatment may do more harm than good by killing more good bacteria in the gut.

“What we found is that calves given antibiotics at the onset of diarrhea had a similar duration of illness as those we thought were systemically sick; it didn’t make the diarrhea shorter,” she said. “In fact, calves given antibiotics right at onset were more likely to die and had lower average daily gain.”

Pain management for calves

Pain control is more effective if done early, and Dr. Charlotte Winder of the University of Guelph discussed various pain interventions producers can use for different procedures or in different situations.

Removing horns, for example, is much less painful and invasive the earlier it is done in a calf’s life. Disbudding – whether by a disbudding iron or a caustic paste – will kill the tissue so it doesn’t form a horn, but there is no clear guidance at how old calves should be for the procedure.

“There are no studies looking at impact of age in disbudding, but do it well ahead of weaning,” said Winder. “Weaning will be most stressful for calves, so disbudding ahead of time to give them a chance to heal will avoid issues during weaning.”

Calves should be given both a local anesthetic and an anti-inflammatory to suppress pain both during and after the procedure.

When it comes to castration, all methods will cause pain, but a combination of local anesthetic and an anti-inflammatory will help control the impact. Winder suggested working with a veterinarian to determine which method, whether knife or band – is most appropriate.

Respiratory diseases and navel infections can also be treated with anti-inflammatories to reduce pain, fever and other discomfort in sick calves.

“If we can use pain mitigation before a procedure or as early as possible in disease conditions, it will be more effective. The nervous system is sensitized to transmission of pain, and we know that pain control is more effective if done early,” she said.

Taking the challenge out of weaning

Without a doubt, one of if not the most stressful periods of a calf’s life is weaning.

“You can do a lot of things wrong, but if you do it consistently, it’s better than changing it up all the time,” said Kathleen Shore of Grand Valley Fortifiers in kicking off her presentation on how to help calves through the weaning process.

According to Shore, weaning is a stage setting calves up for the next step, and it’s important to not create immunity challenges for the animals by stressing them out. While the timing of when to wean can depend on the vitality of the calf, a major way to minimize stress is to develop standardized processes that are slow, repeatable and consistent.

“The ultimate goal of weaning is to create a smooth transition from pre-ruminant to ruminant; research says smooth transition decreases illness and death and increases gain,” she said. “It requires adequate size and function of the rumen; the rumen has to work for the calf to be able to digest and if it’s not ready the calf will go backwards.”

Consistency is the key so avoid too much heat or cold, ensure good air circulation, and use patience when handling the animals.

“The early years affect how the animal will digest for the rest of their lives so in a calf, we have about 60 days to set them up for success. The gut microbiome changes very gradually during weaning and when something goes wrong nutritionally, the immune system has less to work with to develop a strong animal,” she said.

A gradual wean through a step-down process is best so the calves can adjust to what their new existence looks like. That could take the form of reducing meals or gradually reducing total milk consumption. This will drive them to gradually eat more grain; giving them a bit of hay can also be effective.

Moving calves into groups before weaning will also improve their performance as it takes one less stressor out of the mix.

“Weaning should be a protocol on-farm with clear steps on what you want done,” she says. “Take the time to do it well and it will pay off in dividends if the animals are ready, well-fed and heathy before weaning.”

Cattle health update and biosecurity recommendations

Current disease pressures facing the industry include long-time issues like respiratory diseases and calf diarrhea, but Salmonella Dublin has emerged as the most common form of Salmonella seen in the industry.

That’s according to veterinarian Dr. Cynthia Miltenburg of the Ontario Ministry of Agriculture, Food and Agribusiness, who noted that the disease is resistant to antimicrobials, so common respiratory treatment protocols often don’t work.

“This is why best biosecurity practices are important. You can easily bring in a new pathogen on people or vehicles, so own your biosecurity,” she says. “There are many tools out there to evaluate your biosecurity, so set the standard on what you need and want from your team and your visitors.”

Preconditioning and early disease detection to minimize antimicrobial use for respiratory disease

The conference’s keynote speaker was Dr. Bart Pardon, a professor at Ghent University in Belgium, who highlighted some of his research into reducing antimicrobial use for respiratory diseases through preconditioning and early disease detection.

There is huge pressure in Europe to reduce antimicrobial use, which is a challenge for the industry, he noted, but long term will give way to more sustainable production.

“The prevailing thought in Europe now is that industries that are unable to live without mass medication need to be rethought or abandoned and the veal industry is one that is in the scope of the EU authorities,” he said. “There is no need to panic, however, because there is so much knowledge that we can use that we currently don’t do.”

One tool is preconditioning calves to ensure they are fit for transport, which includes good body weight, sufficient colostrum uptake, and vaccination. As well, calves should be clinically healthy with no pneumonia showing on the ultrasound and Mycoplasma bovis negative status.

Lung ultrasonography is a game-changer on the farm; it takes only one to two minutes per calf and is the most reliable way to detect pneumonia and do so before a calf displays clinical signs.

“Early detection and short therapy are better cures, but you have to find calves in the subclinical phase before they start to show visible signs of disease,” he says. “That’s where the lung ultrasound is a golden opportunity. It requires training and dedication but it’s a great tool that can help move the industry forward.”

A more detailed article on Dr. Pardon’s presentation will be published in a future edition of Calf Care Corner.