ORANGE CITY, Iowa – Three important factors go into incorporating a successful replacement heifer program: designing a genetic program, proper nutrition and a solid health program, said Beth Doran, Iowa State University beef specialist.

“Designing your genetic program, what are your objectives for this female?” she said. “How do you plan to market her calves? As registered seed stock, commercial seed stock, or market feeder steers and heifers? This answer will determine what EPD (expected progeny differences, which is a measure of genetic merit) a producer will look at more carefully.

“There are a lot of expected progeny differences such as calving ease, milk, weaning weight, yearling weight, marbling and ribeye area,” she added. “If selling registered seed stock, pedigree will be important. For instance, different bloodlines may be known for excelling in various traits, such as marbling, or calving ease.”

According to Doran, a replacement heifer is a female that has been selected to be bred and placed in the beef or milk herd: “Selection may occur as early as weaning (usually about seven months of age), or as late as 15 months (the typical age for breeding so she will calve when she turns two years old.”

She said proper nutrition is also important since the heifer should be developed to optimize her weight and body condition.

“A good goal is to have a replacement heifer calf at 65 percent of her estimated mature body weight at the time of first breeding (15 months of age), and 85 percent of her mature weight at the time of first calving (two years of age),” she said.

“For example, if her estimated mature weight is 1,300 pounds, the desired weight at breeding would be 845 pounds (1,300x.65), and at first calving would be 1,105 (1,300x.85),” she added. “At calving, a good goal is to aim for a body condition score of 6. Heifers that are too thin and underweight have trouble calving, produce poorer colostrum, re-breed slower, and have calves with poorer gains.”

On the other end of spectrum, she said heifers that are too fat deposit fat in their udder, which impairs milk production, and can also have more difficulty calving.

“A good goal is to strive for gains of 1.5 pounds (if small framed) to 2 pounds per day (if large-framed) when developing replacement heifers,” she said. “Work with your veterinarian to develop a solid health program.”

Asked if it’s better to buy or raise replacement heifers, she said there are pros and cons with both options.

“If the plan is to buy them, a producer can make faster genetic progress,” she said. “If buying a bred replacement heifer close to calving, this heifer will produce a calf that can be sold the same year and help reduce her initial cost.”

She said the con of buying a replacement is potentially introducing disease into the herd.

“The other con is cost,” she said. “Can you afford this heifer and if so, how many calves will she have to produce to offset her purchase price before getting a return on the investment?” she said.

“If the producer chooses to raise the replacement heifer, there is the lag time in production (from breeding the dam (mother of the animal) to weaning the first calf from the replacement heifer), and cost of maintaining the dam and the replacement heifer,” she added. “But biosecurity is easier to maintain with a closed herd.”

If possible, she said, farmers should look at the sire and dam of the replacement heifer and consider how they have performed in the herd.

“What has been the performance (weaning and yearling weights) of their calves?” she said. “How long has the sire and dam been in the herd? Usually, better producers are maintained in the herd for a longer period of time.”

She said there are phenotypic traits that should be visually evaluated, which are muscling, body condition, udders, feet and legs, and temperament.

“Look at the udder of the dam and also the udder development of the replacement heifer considering suspension of the udder in the dam and teat size for both animals,” she said. “There is a standard scoring system of 1 to 9 for udders and teats available from many breed associations.”

She said an udder scoring 9 would be very tight (highly desirable) versus a score of 1, which is pendulous (not desirable).

“A teat score of 1 would be a very large teat (undesirable), compared to a teat score of 9 that is very small,” she said. “However, most cattle seldom have a teat size of 9. The teats should be small, symmetrical, and more central in placement on the quarter.

“Don’t forget to look at feet and leg structure of the sire, dam and replacement heifer as these are also highly heritable,” she added.

There is also a standard industry scale for hoof claw shape and foot angle that also ranges from 1 to 9, with mid-range scores of 5, which is considered more desirable, she said.

“These are also available from various breed associations,” she said. “Consider the temperament of the sire, dam and replacement heifer as temperament is heritable. Animals with a poorer disposition can present a risk to the producer and/or employees.”

Dan Loy, Iowa State University professor of animal science and director of the Iowa Beef Center, said cattle producers have different criteria for culling (the departure of cows from the herd due to sale, slaughter, salvage, or death) cows from the herd.

“It could be unsoundness, disposition, production, or failure to re-breed,” he said. “The average herd culls about 20 percent of their cows each year.

“To maintain herd size, the producer must either purchase bred cows, or develop their own by raising or purchasing young heifers and developing them to their first calf and reproductive management that may include estrus synchronization (manipulating the females’ estrous cycle so they can be bred at about the same time), and artificial insemination,” he added.

He said producers should look at genetics that fit their resources and management.

“The heifers should have been developed with a feeding program that allows them to meet target weights to re-breed,” he said. “Are the heifers bred artificial insemination to bulls that fit your breeding goals?

“They should have been under a herd health program that includes preconditioning, or its equivalent,” he added. “Often, heifers will be screened for pelvic size and pregnancy-tested if they are bred heifers.”

He said whether producers should buy or raise their own heifers depends on costs, available feed, and other resources and facilities.

“Many smaller herds may find it simpler to buy heifers from a specialized heifer development operation than to try to raise just a few head,” he said.