Colostrum is critical for calf health, providing essential nutrients, antibodies, and growth factors needed in the first hours of life. Yet many dairy farms experience a seasonal drop in colostrum production, particularly in fall and winter. Understanding and managing this decline is key to supporting calf survival and herd success.
Why Colostrum Yields Decline in Cooler Months
Research shows that shorter daylight hours (photoperiod) and lower temperature-humidity index (THI) are linked to lower colostrum yields. A Texas study found that average colostrum yield per cow dropped from 14.5 lb (6.6 kg) in June to just 5.5 lb (2.5 kg) in December. Second-lactation and older cows were more affected than first-calf heifers.
A separate study in New York confirmed similar trends across 19,000 cows, though also showed variability between herds—suggesting other contributing factors are at play.
Additional Factors Impacting Production
Besides photoperiod and THI, other influences on colostrum yield include:
-
Dry period length
-
Calf birth weight and survival
-
Cow’s previous milk production
-
Transition stress and environmental conditions
-
Nutrition, though high nutrient levels alone don’t consistently increase yields
How to Support Colostrum Production
1. Maintain Optimal Dry Periods
Aim for 45–60 days. Shorter dry periods are linked to lower yields.
2. Reduce Stress for Dry Cows
Ensure steady access to clean water and quality feed.
3. Prioritize Timely Milking
Colostrum should be harvested within 8 hours of calving for best quality and volume.
4. Consider Oxytocin Use in First-Lactation Cows
Oxytocin may improve colostrum let down and yield, but consult a veterinarian first.
5. Evaluate Feed Additives
Products like choline or calcidiol have shown some promise in boosting colostrum output.
Planning Ahead for Low Supply
Build a Colostrum Bank:
Use a Brix refractometer to assess and freeze high-quality colostrum for future use.
Follow Storage Guidelines:
Store colostrum in clean containers, refrigerate for up to 1 day or freeze for up to 1 year.
Use Replacers When Needed:
Keep a quality colostrum replacer on hand that provides 300g of IgG, as recommended by the Dairy Calf and Heifer Association.
Final Takeaway
Seasonal drops in colostrum can be managed with the right preparation. By understanding the factors involved and applying proactive strategies, dairy farmers can help ensure every calf gets the healthy start it needs.
