Why is My Cow Not Coming into Heat Post-Calving?
Diagnosing delayed postpartum heat cycles. How negative energy balance, silent ovulation, and mineral blockages stop fertility.
The Post-Calving Fertility Delay
Postpartum anestrus is when a cow does not come into heat even 60 to 90 days after calving. The ideal calving interval is 12-13 months, which requires the cow to conceive by 85 days post-calving. Delayed heat cycles extend the dry period, reducing the farm's average milk production per cow.
Negative Energy Balance (The Starvation Effect)
High-yielding HF crossbred cows yield massive amounts of milk early in lactation. If their feed energy intake does not match this output, they enter a severe negative energy balance. The cow's body prioritizes milk and survival, shutting down the ovaries to prevent another pregnancy. Ovaries will remain inactive until energy balance stabilizes.
Deworming and Post-Calving Care
Uterine health and nutrition are linked. Deworm the cow 21 days after calving to clear internal parasites that consume nutrients. If a cow had a retained placenta or difficult birth, ensure she is treated fully for subclinical infections, as uterine inflammation blocks hormonal signals to the ovaries.
Rebuilding the Ovarian Cycle
To trigger cycling, feed 100-200g of bypass fat daily starting 2 weeks post-calving. This provides direct energy to the liver and ovaries. Feed 50g of chelated mineral mixture daily, focusing on phosphorus and vitamin A, which are essential for follicle development and ovulation.
Prevent postpartum delay by feeding bypass fats to bridge the energy gap early in lactation, deworming at 21 days, and supplementing with phosphorus-rich minerals.