Producers can take several steps to encourage cows to return to estrus faster after calving, boosting conception rates and ensuring calves are born earlier in the next calving season. Cows cycling early in the breeding season have higher pregnancy rates, leading to uniform calves and increased weaning weights.
To maintain a yearly calving interval, beef cows must recover from the nutrient and physical demands of calving and lactation and will have 80 to 85 days to return to estrus after calving to potentially maintain a yearly calving interval. Failure to successfully manage the post-partum interval is one of the major causes of reproductive loss, especially in young cows.
• Body condition score (BCS): Cows with a BCS greater than 5 at calving are more likely to cycle and conceive earlier. Nutritional management is crucial; cows losing weight post-calving are less likely to return to estrus.
• Temporary calf removal: Separating calves for 48 hours can trigger estrus in moderately conditioned cows (BCS 4-5). Early or complete weaning may be required for thin cows (BCS less than 4).
• Controlled internal drug release (CIDR): Progesterone devices can “jump-start” estrus in cows greater than 20 days post-calving. Useful for estrus synchronization in both artificial insemination and natural service.
• Bull exposure: The presence of a bull sometimes shortens the post-calving interval to estrus.
• Nutritional support: Provide the proper balance of protein and energy in diets before and during the breeding season to support the maintaining of cows in adequate body condition and weight gain for cows less than a BCS of 5. Proper nutrition promotes the resumption of estrus and can improve conception rates.
• Shortened breeding season: Encourage cows to calve earlier by limiting the breeding season, which increases pressure to conceive sooner.
Why manage late-calving cows? Managing late-calving cows is crucial to reduce reproductive risks and economic losses in fixed-breeding seasons. These cows often struggle with delayed conception and lower productivity.
Early-born calves exhibit higher weaning weights and superior reproductive performance. Early-calving cows have more opportunities to conceive in subsequent breeding seasons, enhancing herd efficiency and profitability.
Tools like the “Breeding Cost Cow-Q-Lator” can help producers calculate and compare expenses for different strategies. Another resource that allows producers to compare costs of protocols and generate calendars specific to timing of synchronization drugs, CIDR insertion and removal, and when to artificially inseminate is the Estrus Synchronization Planner. — Kacie McCarthy, Nebraska Extension cow-calf specialist, and Aaron Berger, Nebraska Extension educator
