Heifers are one of the largest and most expensive inputs for a herd.
“Where do you want to be in five years? Where do you want to be in 10 years with your cow herd?” These are questions Dr. Jennifer Koziol, Texas Tech University associate professor of food animal medicine and surgery, encourages cattle producers to consider when selecting replacement females.
Koziol emphasizes the importance of strategic selection, advising producers to think long-term when selecting the next generation for their cow herd.
She recommends selecting heifers based on multiple factors beyond just appearance, including:
Birth Timing
- Select heifers born earlier in the breeding season. Early birth indicates better reproductive potential and means these heifers come from more fertile dams.“We want to pick heifers that were born earlier in the year... from dams that were the most fertile,” Koziol explains.
- Genetics
- Choose heifers from cows with long herd longevity
- Consider future herd goals such as carcass quality or maternal traits
- Look beyond just physical appearance - Environmental Compatibility
- Select heifers that match your specific environment by considering frame scores appropriate to your region. A cow’s size should match available feed resources. - Long-Term Perspective
- Think about herd goals five to 10 years in the future and select heifers that will contribute to those objectives
- Consider traits like fertility, growth and adaptability - Physical Traits
- Assess frame scores
- Examine feet and leg structure
- Look for overall structural soundness
Bottom line: She encourages producers to select replacements with a purpose, rather than just choosing the most attractive heifers.
“Focus on strategic, goal-oriented selection that supports long-term herd improvement,” she says.
Koziol was featured in a recent “Doc Talk” hosted by Dr. Dan Thomson. During the podcast, she shared strategies for producers to consider whether retaining or purchasing replacements.
She offers practical, research-backed guidance to support herd health and long-term profitability.
“I’m really passionate about thinking about how we do a better job on the preventative side, so we don’t get the backside and have problems,” she says.
Vaccination and Health Management
Heifer health is key to long-term success in the herd. Koziol shares the following guidance on heifer immunization:
- Use modified live vaccines at weaning to get the heifers’ immune response up and going
- Administer a booster four to six weeks after initial vaccination
- Repeat vaccination four to six weeks before breeding
She refers to research from Auburn University supporting this vaccination strategy, noting it provides the best immune response for first-calf heifers.
Nutrition and Growth Patterns
She says nutrition strategy isn’t one size fits all.
“We can really let those growth patterns of the heifers be driven by our feed resources,” Koziol says. “We know that we want to target those heifers to be about 55% to 60% of their mature cow weight at breeding.”
She explains producers can adjust average daily gains based on feed abundance. Adding heifers can “coast” when feed resources are limited.
Reproductive Assessment
“Reproductive tract scoring and pelvic measuring are two great things to make sure we’re breeding heifers that are going to do a good job for us,” Koziol suggests. “Work with your veterinarian to find problems and get rid of the problems before we either waste money breeding them, or we have to call our vet out in the middle of the night for a c-section.”
Reproductive tract scoring (RTS) helps identify which heifers are prepared for breeding. This process includes evaluating the uterus to make sure it and the ovaries are functioning and make sure the heifer is cycling. The original RTS system was a five-point system.
She suggests using an updated three-category system developed by Kansas State University:
- Ready category: Heifers actively cycling and prepared for breeding
- Intermediate category: Smaller reproductive tracts, not yet cycling
- Problem category: Incomplete reproductive tracts or potential fertility issues
She suggests combining RTS with pelvic measuring. The goal with pelvic measuring is to find heifers that are too small or abnormally shaped. The target pelvic area is approximately 130 centimeters squared.
“We’re looking for those heifers that are either too small or abnormally shaped, because those are going to be ones that have increased chances of dystocia,” she explains. “We don’t really have to select for bigger. We just have to find the ones that are too small.”
She suggests conducting the assessments four to six weeks before breeding. The assessments can help determine which heifers should be bred or if they should be culled.
Biosecurity Considerations
If you decide to buy replacement heifers or bred heifers, Koziol recommends producers consider these three measures to prevent disease transmission and to ensure smooth herd integration:
- Quarantine new animals for four to six weeks before commingling
- Verify vaccination records and disease status of incoming heifers
- Introduce new animals well before breeding season
Economics and Sustainability
She summarizes as expenses continue to increase, being economically minded is key to being sustainable and profitable.
Koziol reminds producers to view heifer development as a long-term investment — focus on preventative measures to reduce future veterinary costs.
Considering her suggestions, producers can identify and cull problematic heifers to use as an alternative income stream instead of an economic burden to building a productive and efficient herd.
