It’s the middle of winter, and calving may or may not have started, so why are we already talking about breed back? Once calving starts, time seems to speed up (except for the all-night calving checks in a blizzard), and before we know it, we are kicking bulls out. An excellent time to review what it takes to get a cow rebred is months before that happens.
We spend a lot of time focusing on the importance of nutrition in late gestation and how it affects the growing calf, yet devote less time focusing on how important quality nutrition is to the cow. It’s crucial to ensure the cows’ macro needs are met year-round (protein, energy, calcium/phosphorus), and important to meet their mineral needs, especially since quality mineral is necessary to ensure their body functions and heals properly.
Important points to understand about cows:
• It can take 40-55 days for a non-bred cow in perfect weather conditions to gain 1 body condition score
Cows that calve at a body condition score (BCS) of 5 or higher will return to estrus quicker and breed back faster than cows that calve at a BCS of 4 or lower
• A minimum of 30 days is required for uterine involution to occur post calving
Expect the cow to be cycling and able to breed 45-60 days post calving (assuming no issues occurred)
The cow should see 1 heat before 50 days post-calving
• Peak lactation occurs 60 days post-calving
• Highest energy needs are 45-60 days post-calving
• Must breed back within 85 days post calving to maintain yearly interval (the earlier the cow calves in the season, the less likely she is to fall out of the herd)
Looking at the previous list, a lot is going on for the cow during the first 60 days post-calving. She has high energy needs to feed her calf, and her reproductive tract is healing. If she’s a spring calver, the weather outside is still frightful. This increases her maintenance needs, and then we expect her to start cycling so she can breed back ASAP. In that short window of time, regaining body condition is likely a tall order to fill.
Without going off on a tangent, it’s worth mentioning that fetal programming (the influence the maternal environment has on fetal development) can affect not only the current generation but at least the next generation of progeny as well. While we still have quite a bit to learn about this, we can use a starved cow as an example: her calf will be born assuming that it’s going to starve as well, and as a result, will never deposit muscle and fat the same way an animal whose needs have been met would. Additionally, if you keep that calf as a replacement, her calf would show similar tendencies even if her dam’s nutritional needs were eventually met.
In some cases, it might be too late to change late gestation nutrition. However, let us not forget about the cowherd once the calves have been born. If we want them to remain healthy, productive herd members, we need to ensure that we meet their needs and give them the best chance at sticking around.