Replacing the beef cow on Florida ranches creates opportunities and challenges for ranchers. Decisions you make about your replacement heifers can impact their longevity and lifelong productivity. We will discuss choices you can make while raising your own replacement heifers and also review the pros and cons of purchasing replacement heifers.
Lets start with how many heifers you potentially need annually. The current cull rate in Florida is 15-20%. So, that is your starting point. However, if you are looking to change the size of your herd you should adjust accordingly. Reasons for culling cows include age, pregnancy status, temperament, other reproductive reasons, poor calves, or physical unsoundness. This list alludes to some characteristics you should consider in your replacements.
Statistically speaking, most producers raise their own heifers. However, some purchase heifers because they don’t have the land to raise them separately, they lack the extra labor they need to manage them, they don’t have the time, they don’t want the extra cost of supplementation or feed, they don’t have the appropriate bull power to breed them to or they want to utilize what land they have towards their main cow herd that gives them a quicker return. If a producer only has a few employees, they may want to focus on operational improvements, like planting improved forages, maintaining fence lines or roads, or growing alternative crops to supplement income.
The benefits of purchasing go beyond management inputs. Purchasing heifers can give a producer instant improved genetics. Plus, they can be bought to fit right into your calving season preference. They are already bred, potentially docile, are up to date on vaccines and health protocols. These are all things the producer didn’t have to think about or spend time on.
However, 86% of producers do like to grow their own heifers. They do this because it’s tradition, they do it because they can control the genetics, vaccines, nutrition, they can control the breeding season length, and one major plus is that they are acclimated to your system (breeding season) and your environment. For example, if a south Florida producer buys a set of heifers from out of state those heifers may struggle with the environmental difference between the two locations. They may exhibit a lag in breeding, lose weight, or even lose a calf. The same goes for bulls. Bulls raised in the same geographic region can adapt quicker to a new home.
Let’s look at the economics behind raising heifers. The major expense is the heifer itself. Then there are the expenses like land rental or taxes. Other things are easy to put on paper because there are actual invoice or bill to pay for it…like fertilizer inputs, supplementation, cost of breeding (could be bulls or AI expenses), health expenses, paying for the vaccines, and the veterinary service. Other expenses include labor and equipment (tractors, feed bunks, fences, fuel, etc). Besides the inputs for each heifer, there is also the extra cost of paying for those heifers you have put resources in, but will give you nothing in return if they don’t breed. So, including all of those inputs, an average open heifer in 2025 would be worth $3,000 -$3,500.
To maximize homegrown replacements, all these management factors play into their longevity and productivity. Choosing the appropriate weaning weight, selecting the best, breeding at the optimal pubertal age, feeding or supplementing them, and setting them up on the best health foundation with vaccines, vitamins, and wormer can give a great platform for your next cow herd.
Separate and supplement! This process starts with weaning. The average weaning age is 9 months when calves weigh around 500-750lbs. However, some ranchers wean early, at 2-3 months, for a couple of reasons. They may want to give their mature cows optimal chance to breed back. Removing the calf can jump-start her reproductive cycle while also removing the stress of lactation, allowing her to put her energy into her body condition and her next calf. Some producers also see value in weaning at this age to aid in the docility process. Being around people and other stimulation can calm your calves faster and foster a quieter future herd. If you wean calves at this age, you will encounter extra supplementation costs as you will have to feed them longer.
If you wean at 9 months, you will be closer to their maturity age, and you will not need to feed as long or utilize your pasture space as long. Research suggests you use a 12-16% protein diet as well as a foundation of forage for best results.
In a study by Dr. Philipe Moriel (https://edis.ifas.ufl.edu/publication/AN335), utilized 4 weaning processes to determine the best reproductive outcome and weight gain results. Group NW retained calves with their mothers until 9 months with no supplementation. Group EWPAST involved early weaning at 3 months, followed by a ryegrass pasture supplemented with 1% body weight of concentrated feed, transitioned to 3 months of bahiagrass with the same feed. Group EW180 involved early weaning at 3 months, and a dry lot supplemented with 3.5% body weight concentrates. Group EW90 involved early weaning at 3 months on a dry lot with 3.5% body weight concentrate, followed by 3 months on a bahia grass pasture supplemented with 1% body weight concentrate
The outcome of the study was that the calves who were early weaned and put on a dry lot for 6 months with 3.5% body weight concentrate had a 78% pregnancy rate, compared to the next closest group of 70%. They reached their pubertal age quicker as well as their mature weight.
In terms of selection, emphasis should be placed on animals with more internal volume and capacity, natural muscling and fleshing ability. Traits to look for are spring of rib, depth of rib, natural thickness and shape down the top, thicker quartered, and width through the stifle.
Frame score is easily determined and should be used in the heifer selection process to eliminate those that do not fit predetermined production goals. Selecting heifers with frame scores of 4 to 6 will result in mature cow weights of 1100 to 1250 pounds.
Calves with poor disposition may be a physical risk to anyone who handles them. Not only do they pose a danger, but they may also display decreased performance as compared to their calmer counterparts. Femininity is exhibited by a longer, more refined head that is sharper about the poll. Females should possess a long, trim neck and be smooth about the shoulders. Replacement heifers are costly to develop, and the goal is to keep them in the herd as long as possible. These females must be structurally sound in their feet and legs. Heifers that are the heaviest are more likely to reach puberty sooner compared to their lighter-weight counterparts. By selecting 20 – 25% more heifers than you’ll need, you can cull late breeding or open heifers to offset production costs.
In order to maximize your investment, it is expected that heifers calve at 24 months. This means she should conceive at 13-14 months. Some producers push their herd to breed earlier than this, at 12 months. In order to achieve either one of these goals adequate nutrition is required. Heifers usually achieve puberty at 55-65% of their mature body weight. This is an easy method to presume heifers have achieved puberty. Another method is to utilize reproductive tract scoring to determine if the females are in fact ready to bred. The scale is 1-5 with 5 being most mature. Research indicated tract scores with a 4-5 show 20-30% higher pregnancy rates (https://edis.ifas.ufl.edu/publication/AN370).
One caveat in Florida is the influence of bos indicius genetics to increase heat tolerance. Bos indicus influenced heifers do not achieve puberty as early as the English breeds. Making it even more difficult for Bos indicus and Bos taurus crossbred heifers to become pregnant and calve at 24 months of age.
When considering your breeding cycle, it is wise to start your heifers earlier than your mature cow herd. This is done for a couple of reasons. One is that it may take a few extra cycles to get the heifers bred, depending on their reproductive maturity. The other reason is that when they have produced and weaned a calf, it may take them a couple of heat cycles to rebreed. This is because they are still growing at 24 months. They need to continue to increase their body weight while growing a calf.
Use low birth weight bulls as the heifers are not full grown when they calve and do not need the extra stress of a large calf. Something else to consider is to use younger, lighter bulls as the heifers are not at mature body weight, and this will reduce the stress of breeding. Be aware of selecting bulls for this singular reason, as this can limit your genetic potential and future use of the bulls. One bull can cover 25 females.
A heifer development health protocol should be created with the help of your veterinarian. It is advisable to provide your replacement heifers with the best health foundation prior to starting their reproductive journey.
Raising replacement heifers has unique challenges, and it is different for every producer. The future of your cow herd depends on these management decisions to give you the next best thing for your operation. Keep in mind to select what you want your cow herd to look like, separate, and supplement to reach their max potential, and look for at least 55-65% of mature body weight.
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