10 takeaways from the Smart Calf Rearing Conference

The brightest minds in the global calf community converged in Madison, Wisconsin, at the end of September to discuss the latest concepts and strategies in raising dairy youngstock. Below are some key nuggets to bring back to the dairy.

1. Beyond IgG: Colostrum growth factors and immune cells shape the neonatal gut.

Besides IgG, colostrum also contains growth factors, antimicrobial peptides, cytokines and maternal leukocytes, which can reduce inflammation and immune activation in young calves. We also gleaned the latest colostrum benchmarks, including the optimal volume (10% of body weight), optimal enrichment strategies (up to 90 g/L IgG) and optimal time to measure serum total proteins (1 to 3 days of age).

2. The calf microbiome adjusts twice — at colostrum intake and rumen development.

The initial colonization of gut bacteria starts immediately after birth and aids in calf immune system development. This means that exposure to a dirty maternity has long-lasting consequences on calf health. Consumption of antibiotic-containing milk and weaning both greatly influence gut microbial diversity, impacting disease risk and rumen development, respectively.

3. Calf disease influences “disability-adjusted life years.”

Scientists from the University of Montreal are applying a human health concept called “disability-adjusted life years” to identify the most impactful health problems in calves. Of the parameters assessed in an on-farm survey, diarrhea and bovine respiratory disease (BRD) were the most impactful on most dairies, though the researchers admit that limited information could be gleaned from the lack of consistent, reliable herd records.

4. How to create pneumonia: Give them scours, make them cold, stress them out, and house stale air.

Dr. Terri Ollivett, a respected respiratory disease expert, shared her latest philosophies on identifying and preventing BRD in calves, including what’s new with lung ultrasounds and some top management benchmarks (i.e., meeting passive transfer goals and focusing on elevated early-life nutrition).

5. High-fat milk replacer supports calf resilience, but composition matters.

We commonly hear the pushback that high-fat milk replacers make fat calves that don’t eat starter. Dr. Juliette Wilms of Trouw Nutrition argues that higher fat deposition is not actually deleterious to young calves, as it promotes thermoregulation, stress response, and energy homeostasis while having no impact on starter intake. However, the fat makeup influences calf metabolism and development, suggesting dairy cream is superior to alternative fat sources.

6. The post-weaned heifer slump is real and costly.

Our current nutrition models do a good job in predicting calf growth but there’s room for improvement for post-weaned heifers. Data from over 18,000 heifers suggests that there is a long stagnation in heifer growth starting around 150 days of age or approximately 300 pounds, likely due to the numerous changes in heifer management at this age. Our focus is to strategize and limit pen moves, social competition and diet changes in this heifer cohort.

7. Early-life mammary tissue grows 25 times, but heat stress gets in the way.

While most of the calf’s organs grow 2-4 times from birth to weaning, the synthetic part of the mammary gland (called parenchyma) grows 25 times, meaning management factors that limit growth in this timeframe could have a detrimental impact on long-term productivity. Indeed, research from UW-Madison shows that prenatal heat stress derails mammary development all the way from birth to maturity, impacting milk yields for multiple lactations.

8. We transport 5 million calves a year; their welfare starts with how – and when – they’re moved.

Transported calf health and welfare depends on pre-transport management, transportation conditions, and post-transport care. Research is currently focused on optimizing factors like age at transport (the older the better), time in transit (the shorter the better) and fitness to transport (the greater the serum total protein, the better).

9. Pair-housing calves? Proven. Cow-calf pairing? Possible, but just getting started.

Putting calves in pairs or small groups has many proven benefits for calf growth and behavior, but there’s room for more research on calf health and cross-sucking. Meanwhile, the research investigating cow-calf pairing is in its infancy. We have much to learn about pairing feasibility, timing, and how systems impact physiology, production and workflow.

10. Progressive dairy farmers are investing in calves and people.

A calf management producer panel of Dean Helt (Helt Dairy LLC), Laura Raatz (Wagner Farms Inc.) and Sam Peetz (Rosy Lane Holsteins LLC) rounded out the conference. Some common themes discussed included current pros and cons to their calf facilities, innovations adopted to support and engage staff, and ongoing health challenges. As panel moderator, I walked away feeling inspired by the direction of calf raising in the Midwest and excited to support farmers in following their calf passions.

For more details on the Smart Calf Rearing Conference, reach out to your Vita Plus representative or check out this conference summary here. As your calf specialist team, we can’t wait to bring these concepts to our dairy customers!