Signifi cance of the investment Replacement heifers are the foundation of the
herd. This means that selection and development of future cows may be the most important activity in a cow-calf operation. Selecting genetics of replace- ment heifers is a 7- to 10-year investment decision. Program success is measured by the number of weaned heifers selected that produce a weaned calf after calving at 2 years of age, and then breed back to produce the second calf on time. Early maturing heifers are capable of being bred
early in a controlled breeding season and should wean a heavier calf. Research has shown that early- bred heifers will tend to breed early each breeding season for the rest of their reproductive lives and they wean heavier calves. There are primarily 3 heifer investment options: 1)
raise and develop your own, 2) purchase bred heifers and 3) run a custom heifer development business to sell heifers to clients. Heifers can represent future profitability and
genetic improvement; however, they can negatively impact profi ts by being non-productive for at least the fi rst 2-1/2 years of life during their development. The value of a bred heifer has approximately 2 times the value of an open heifer. “A bred heifer today is worth all of her future
annual net cash incomes, including her cull value, discounted back to today’s dol lars,”
says Harlan
Hughes, North Dakota State University professor emeritus.
Reproductive health Healthy calves are pro-
duced from healthy cows. Disease prevent ion in calves begins with build- ing immunity in the cow herd. A birth-to-weaning health program, proper weaning management and pre-breeding immuniza- tion are critical for devel- oping productive heifers. Heifers are more naïve
to many infectious agents than are cows, meaning that their immune system
82 The Cattleman April 2015
Heifer prices are high, so it is
important to make
good selections and develop them
properly to obtain a return on the investment.
has not been previously exposed to a particular dis- ease agent (antigen). Due to the lack of exposure, the heifer doesn’t form antibodies against the antigen and as a result, more losses occur in heifers from chronic diseases such as bovine viral diarrhea (BVD), leptospirosis (lepto) and exposure to neospora. A short breeding season allows ranchers to treat
a large group of heifers with reproductive disease vaccines 30 to 60 days prior to the breeding season. This allows an immunological peak to occur at the time of the most signifi cant reproductive disease challenge. Short breeding seasons also increase uni- formity, marketability and concentrate labor inputs. Heifers should be vaccinated for BVD, infectious
bovine rhinotracheitis (IBR), lepto and vibrio. Pre- breeding vaccinations should be timed so that the peak immunologic response coincides with disease exposure risk early in the breeding season. Heifers should receive a lepto booster vaccination when they are pregnancy checked. It is important to protect heifers from reproductive
diseases such as trichomoniasis (trich), a venereal disease in cattle. The disease causes early pregnancy loss and occasional late-term abortions. It may also extend the breeding and calving season. A critical component of a trich prevention pro-
gram is an executed biosecurity plan. While devel- oping and maintaining biosecurity is diffi cult,
it
is the cheapest and most effective means of disease control available. A dis- ease prevention program will not work without bi- osecurity. Purchase either virgin
bulls or bulls that have tested negative for trich. Maintain good perimeter fences and know whether your neighbors have ani- mals infected with trich. Know which bulls breed which cows, and test a bull for trich when calf production is lower than average. Wittum, et al, report-
ed that herds with calves persistently infected with BVD (BVD-PI), had 5 per-
thecattlemanmagazine.com
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