Article originally appeared in Farm Progress (February 23, 2024).

Introduction

Calves born early in the calving season provide several advantages for beef cow-calf operations.

Advantages

The advantage for those marketing feeder calves comes from calves born early in the calving season having greater weaning weights than those born later in the calving season. Higher weaning weights equates to having more pounds of beef to market. Herds with a higher percentage of calves born early in the calving season have more uniform groups of feeder calves to sell than herds with greater calving distributions. Uniform groups of feeder calves are of greater interest to feeder calf buyers and often bring higher prices than groups that lack uniformity.

From the cow’s standpoint, cows that calve early in the calving season have more time to recover body condition and reproductive health before their next breeding season. They are more likely to be cycling at the start of the breeding season, conceive and therefore calve early again. 

Research reports heifers born in the first interval (21 days) in their calving season: 

• are larger and more likely to be cycling at the beginning of their first breeding season. 
•  have a higher percentage that also calve earlier in their first calving season. 
• exhibit greater longevity, averaging approximately one more year, compared to those that calved in the later intervals.  
•  wean larger calves during the first six seasons than those whose first calf was born in later intervals. 

A higher percentage of calves born in the first interval of the calving season leads to a larger pool of heifers to select replacements from. This is advantageous for those producers who want to be more selective when identifying potential replacement heifers.

For farmers who finish out their calf crop, early born steers have greater potential for higher value carcasses. Research comparing steer feedlot and carcass performance based on the calving interval they were born found steers born in the first 21-day interval of the calving season had greater hot carcass weights, marbling scores, and carcass value. Calves born in the first interval had a higher percent grading average choice or better.  However, rate of gain was not different. 

Calculating calving distribution

Calculating your herd’s calving distribution is one way producers can evaluate their herd’s reproductive performance. Calving distribution involves calculating the percent of calves born during each 21-day interval of the season, (21, 42, 63 and those born after 63 days).  Determining the start of the calving season can be done two ways according to Standardized Performance Analysis (SPA) guidelines. One method is to start 285 days after the bull turn-in date with the mature cows. The second way is to start when the third mature cow (3 years old and older) calves. Use the same method every year to evaluate how the herd is doing. 

Cow Herd Appraisal Performance Software (CHAPS, North Dakota State University) benchmarks reported whole herd average distribution of 63% of calves were born in the first 21 days of the calving season, 87% of the herd had calved by the end of the second 21-day period, and 96% by the third 21-day period. The benchmark data is available at https://www.ndsu.edu/chaps/

If your distribution is less than ideal a review of herd nutrition and management for opportunities for improvement is in order. Estrous synchronization programs are another tool that may help increase the percentage of calves born early, but they will not work well if nutrition and other management problems exist. Information about the various estrous synchronization programs and calendar schedules are available from the Beef Reproduction Task Force, https://beefrepro.org/

Summary

There are many advantages to having a high percentage of calves born early in the calving season. Take the time to calculate your calving season distribution to determine how your herd is doing and if there are opportunities for improvement.

Reviewed by: Ryan Sterry and Sandy Stuttgen