Trading Up in
Herd Revenue
I
by Wes Ishmael
n any market, one of the most straightforward means of increasing
herd productivity and revenue might be one too easily taken for
granted: selecting heifers that breed early in the breeding season.
“Heifers that become pregnant early in their first breeding season
remain in the herd longer and are more productive,” says Cliff Lamb,
head of the animal science department at Texas A&M University.
“The number one reason we cull animals early in the herd is because
they fail to breed during the breeding season.” This was during an
annual Cattlemen’s College.
In fact, using data from the U.S. Meat Animal Research
Center—some 25,000 heifers—Lamb explained heifers that
became pregnant within the first 21 days of their first breeding
season weaned the equivalent of three-quarters of another calf
during their production lifetime, compared to heifers that didn’t
conceive until after 21 days.
“Age at puberty is a major factor that influences reproductive
success of beef heifers,” Lamb explains in, Prebreeding Management
for Successful Development of Beef Replacement Heifers. “Ideally,
heifers should reach puberty approximately 60 days before the
beginning of their first breeding season, increasing their chances
of becoming pregnant and allowing them to conceive earlier in the
season. The timing of first conception is also important to the overall
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productivity of a heifer.” He adds that mature cows that calve at the
beginning of the calving season also wean heavier calves.
Weight and age are two primary drivers of age at puberty in heifers;
adequate nutrition is key.
“It is important to consider that Bos taurus (European) beef heifers
generally reach puberty at 55–60% of their expected mature body
weight. With that in mind, the use of a target average daily gain (ADG)
is a common and effective way to prepare heifers for breeding,” Lamb
says. “It is recommended that Bos Indicus (Brahman) influenced
heifers achieve 60–65% of their mature body weight before the
breeding season starts. A nutritional program should be capable of
providing sufficient energy and protein to heifers so they can attain
this final target weight before the beginning of the breeding season.”
Proving It
During his tenure as assistant director of the University of Florida’s
North Florida Research and Education Center at Marianna, Lamb
and fellow researchers verified the real-world benefits of getting heifers
bred earlier in the season.
Lamb inherited management of a 300-head cow-calf operation. About
half the mamas are Angus or Sim-Angus; the other half are Brangus or
Braford. Management was loose and the calving season long.
• JANUARY 2020