Benefits of a Shortened Breeding Season

Reprinted from the American Red Angus Magazine.

Written by Jaclyn N. Ketchum, Cliff Lamb, and Michael F. Smith,
Division of Animal Sciences, University of Missouri, and Department of Animal Science, Texas A&M University

Efficiency, sustainability, productivity and profitability – these words are used in conversations around the world including among cattlemen. How do cattlemen assimilate these goals into their herd? One way is by implementing a defined breeding season.

“Heifers that conceive earlier in the breeding season will calve earlier in the calving season and have a longer interval to rebreeding. Calves born earlier in the calving season will also be older and heavier at weaning,” stated Robert Cushman of U.S. Meat Animal Research Center. He added, “Heifers that calved early in the calving season with their first calf had increased longevity and kilograms weaned, compared with heifers that calved later in the calving season.”

Increased longevity and heavier weaning weights are two points that Cushman made. How does one go about increasing the proportion of females that conceive earlier in the breeding season? Perhaps the first place to start is a defined breeding season which translates into a defined calving season. This strategy is attractive not only because of the aforementioned advantages, but also for more uniform group management regarding nutrition and implementation of vaccination protocols.

Once a producer decides to shorten the breeding season, the task may seem daunting. Where do I start? How short a breeding season is practical? What if a large proportion of females come up open the first year? Am I really going to see an increase in profitability? Fortunately, producers can learn from experiences of others who have systematically shortened the breeding season without a decrease in profitability.

The University of Florida-North Florida Research and Education Center Beef Herd provides an excellent example of the benefits of reducing the length of a breeding season. Prior to 2008, bulls were turned in with heifers and cows for a 120-day breeding season. In 2008, Dr. Cliff Lamb, now Department Head at Texas A&M University, and his team implemented multiple reproductive management procedures, including estrous synchronization and fixed-time AI, to increase the proportion of females that conceive early and thereby decrease the length of the breeding season.

Lamb stated, “Prior to 2008 the breeding season was 120 days in length, and we felt that by committing to an estrous synchronization and AI program, we could shorten the breeding season and increase calf value. Committing to a fixed-time AI (FTAI) program required significant work and dedication, especially during the first four years because the length of the breeding season resulted in an extended calving season, such that cows were calving past the initiation of the next breeding season.”

Lamb said that while implementing this strategy required some effort after reducing the breeding season over five years from 120 to 70 days, almost all cows calved prior to initiation of the breeding season and were exposed to a single FTAI at the initiation of the breeding season. The net result was a more compact calving season that increased the value of calves by $169 per calf or an annual increase in calf value for the 300-head operation of $50,700 per year.

Prior to shortening the breeding season, pregnancy rates were 81 to 86 percent. Following implementation of FTAI in 2008, pregnancy rates generally increased from 84 to 92 percent to 94 percent. Also, the average calving date steadily decreased from 79.2 to 38.7 days, indicating that a larger proportion of calves were born earlier in the calving season, which increased calf age and weight at weaning. The first-year that estrous synchronization and AI was implemented, the per calf value increased by $87.

What if this approach is not quite what a producer had in mind or may seem out of reach? Perhaps the producer already has a defined breeding season but wants to shorten it further to obtain additional benefits or maybe the use of estrous synchronization and artificial insemination are not an option for the first few years.

A second example demonstrates how Tellan and Kayla Steffan of Amidon, North Dakota, managed to reduce the breeding season length of their commercial Red Angus herd from 60 to 45 days. Steffan explained why they wanted to reduce the number of days in their breeding season. “The decision to shorten our breeding season to 45 days was based on two factors: 1) we wanted to get away from calving in winter weather; and 2) we wanted a more uniform, consistent calf crop.”

To avoid winter calving, they had to calve later. “We figured that if we could calve later in the year, but have more cows calve in a tighter window of time, the average birth date would not move all that much compared to having a longer breeding season,” said Steffan.

In 2015, a 61-day breeding season was in place. In 2016 the Steffans implemented several changes, including shortening the breeding season to 45 days. “One thing that initially hurt the pocketbook was having about 20 percent of the cows open in the fall after tightening the breeding season,” said Steffan. “However, after looking at the cows in the open pen – mostly hard-doing cows that were less fertile – we saw that there would be beneficial effects long-term. Therefore, we were able to cull some cows that don’t fit our environment.”

In 2017, the Steffans initiated an estrous synchronization protocol and FTAI, however, they left the breeding season length the same as the year before. The 2018 calf crop represented the first set of AI-sired calves. “In 2018, we tightened the breeding season another five days. We artificially inseminated all the cows on one day and left the bulls out for 40 days. Again, the hard-doing cows showed up in the open pen, however, this time there were less of them,” Tellan commented.

“We finally saw a more uniform, consistent calf crop in the fall of 2018. When we started in 2015, we had five different weight groups of steer calves the day we sold. By the fall of 2018, every steer on the place went in the same draft, and that was pretty neat to see,” said Steffan. “The calves were somewhat lighter on shipping day by moving to a later calving date, but with a shorter breeding season they were more uniform. We get paid more per pound, and our inputs of labor, time, fuel and feed have decreased significantly, not to mention our quality of life has improved.”

Since implementing a defined breeding season, Steffan said, “The type of cow that works under our management is starting to become evident. They need to be of moderate frame with the ability to stay in good flesh year-round with minimal supplementation. Red Angus has helped us achieve these goals by being able to meet our needs. We select genetics for a maternal female that will have good feet, a good udder, fleshing ability and longevity. We feel what really sets Red Angus apart is the docility of the cattle. The steer calves from these cows can go into the feedlot and perform with the best in the industry. They really are the complete package.”

Transitioning to a Defined Breeding Season
Producers who have a year-long breeding season but want to implement a defined breeding season should access an article authored by Dr. Les Anderson titled, “Some Ideas on Converting from Year-Round Calving to a Controlled Calving Season.” This article may be accessed at https://u.osu.edu/beef/2016/07/20/some-ideas-on-converting-from-year-round-calving-to-a-controlled-breeding-season/. It outlines eight steps producers should implement to convert from year-round calving to a controlled calving season. Anderson has been collecting data from 75 different farms that have data from pre- and post-implementation of the strategy he proposed. Anderson said, “So far, we have increased pounds weaned per cow exposed 154 pounds on average after the second year.”

Producers who are interested in implementing a defined breeding season but are apprehensive should contact their Extension office or beef specialist for additional ideas better suited for their operation. If you have further questions or wish to see a timeline of how the breeding season was systematically shortened, please contact Jaclyn Ketchum.


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