Dr. Joe: Criteria for Selecting Replacement Heifers

Published on Tue, 12/06/2016 - 8:48am

Criteria for Selecting Replacement Heifers

By Joeseph W. Ward, Ph.D.

One of the most important aspects of a cow-calf herd is the selection and proper development of replacement heifers.  Purchasing or raising high quality replacement heifers is an essential and major investment for the cow-calf herd whose costs must be supported by rest of the cow herd for up to three years.  The replacement heifer is the source of genetic improvement for the cow herd.  Many critical decisions have to be made in the process of selecting and growing replacement heifers.
Generally speaking, there are a number of criteria that should be considered when selecting or purchasing a replacement heifer for the cow herd.  For proper heifer replacement selection, there are series of production tests that the heifer must past in order to be selected as a replacement in the cow herd.  Consequently, these production tests and decisions in the selection process require maintaining good cow production records, keen observation and time.  The criteria include: body confirmation, soundness, frame size, sustainability, disposition, good udders, milking ability, calving ease, longevity and the ability of the heifer to become a fertile cow that produces a robust healthy calf annually.  A heifer that does not meet the criteria should be culled from the herd during any point in the selection process.  The selection process begins at birth and any compromise along this process will be costly and will likely propagate negativity in the cow herd.
It is understood that each operation has its environmental and management differences and may have certain goals and criteria that may be unique for their operation.  It is important for producers to set breeding program goals and select females that meet clearly defined goals.  Replacements must have the characteristics to get pregnant at 12-15 months of age and the ability to wean a healthy calf.  They must be able to rebreed and continue to produce a calf every year.  They also must be a source of genetic improvement introducing positive economic traits in fertility, progeny growth and progeny market weight.
During the selection process the producer should be asking the following questions.  Is the heifer at weaning time big enough to be considered?  Research studies have demonstrated that heifers that calved early in the breeding season were more sustainable in the herd.  They typically weaned heavier calves than heifers that calved later.  Bigger heifers grew faster before weaning and generally had more longevity in the cow herd.  Do the genetic prediction tools available best match the traits such as milk production and mature size?  Do they reach an optimum level based on the environment of the cows?  Your geographical location will strongly influence the traits desired in the selection process.  
Body condition of the heifer at the time of weaning is a good indicator of her sustainability in the cow herd.  Are the heifers in proper body condition (not too thin or too fat) and healthy?  Heifers that are overly fat at weaning have reduced milk production especially smaller-framed cattle.  Heifers that are much thinner than the rest of the calves in the herd may experience fertility issues and are likely a reflection of the dam’s inferior milking ability.  Often these types of heifers will be difficult to maintain body condition and may require higher maintenance needs.
A selection consideration that should not be overlooked is the disposition of the replacement heifer.  Is she the nervous or “upheaded” type?  Does the heifer appear to be docile and have a good disposition?  A replacement heifer with a poor disposition can be a real safety issue for the producer.  You don’t need to knowingly add disposition problems to the cow herd.  Also, the heifer’s ease of handling minimizes the stressors both for the rest of the cow herd as well as for the producer.  Historically, progeny that have disposition issues will not do well on pasture or in the feedlot.  

At weaning, evaluate each replacement heifer for height, body capacity, weight, structural soundness, thriftiness, and health.  Along with historical cow records and other production trait considerations the heifers should be ranked.  Ranking the heifers on traits such as 205-day adjusted weaning weight frame score allows for more of an unbiased selection process.  If a heifer is structurally unsound or does not meet a production parameter then eliminate her consideration as a replacement.  As difficult as it may seem at the time, keeping a heifer that does not meet the selection process criteria will be a costly long term mistake for the producer.
Weaning is a time of stress.  It is a time when the nutrition and management of the post weaning program should be carefully planned.  A good weaning program can prevent heifers from falling behind. It can overcome the weight loss and nutritional stressors observed at weaning.  Consultation with your nutritionist and veterinarian to provide proper feeding rations and health care programs are essential for a successful weaning program.  Your nutritional and health care program will vary considerably depending upon your geographical location and time of the year.  These programs should be planned so that at breeding the heifer should be in an excellent health status and have reached 65% of her mature body weight.  This period is often referred as the critical breeding weight (CBW).   The CBW is a function of both weaning weight and frame size.  The heifer’s weight and frame size versus the expected mature body size will help guide the nutritional considerations to achieve the appropriate daily gain per day from weaning until the desired breed date and critical breeding weight.  In practice producers often underestimate the weight of their mature cows so that heifers will not be fed appropriately.  The other extreme is feeding heifers like they are in a feedlot.  This is both costly and detrimental to the future production potential of the heifer.  
The replacement heifer program is an essential part of a successful and productive cow herd.  To select the best replacement heifers, the producer should use all available information and records in the process.  Every producer has their own specific goals in selecting female replacements.  These goals must be clearly defined and understood.  For the process to be successful, special considerations and critical management decisions have to be made in the selection of replacement heifers.   

The author, Joseph W. Ward, has a BS in Animal Science, a MS in Animal Nutrition from Purdue University and a Ph.D. from Oklahoma State University in Ruminant Nutrition.  Born and raised in Indiana on a livestock farm, Dr. Ward has consulted in Europe, the Far East, Oceania, and South Africa.  He has been active in animal production and animal feed manufacturing/processing since the early 80’s.  He is an organic inspector for crops, livestock and processing.  Currently, he serves as North America Product Manager for Phileo Lesaffre Animal Care. Dr. Joe can be reached at j.ward@phileo.lesaffre.com.