Cow-Calf Commentary for Iowa Cattleman Magazine
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By Beth Reynolds, Extension Beef Specialist, and Patrick Wall, Extension Beef Specialist
Heifer Retention: Have a plan
The decision to retain or purchase heifer replacements needs to be based on the cost of developing heifers, feed inventory and resources, and overall genetic goals for each operation. Ask yourself, do I have the genetic base I want, or can I purchase females to get me there quicker? In order to effectively build genetics through heifer retention, producers need to be purposeful and diligent with both short- and long-term goals in mind and have a plan on how to get there.
When it comes to a heifer retention, there are multiple factors making it easy to overlook one consideration or another. At this point in the year, a producer should already know if they are planning to retain heifers, and have already collected relevant data to help determine which heifers are the best replacement candidates. This includes calf birth date, calving ease, and weaning weight, plus the dam’s ID, fertility record, and udder and temperament scores at calving, and the sire ID. There should also be a plan to have adequate facilities in order to develop the heifers separate from the cow herd so the diet can be catered to unique nutritional needs. Producers should consider if the current high calving ease bull power will cover the additional females without the risk of inbreeding or, if new bulls will need purchased. Discuss a health care protocol with the local veterinarian early, so that beneficial procedures aren’t overlooked. Work with a nutritionist to tailor a ration to fit your growth goals without sacrificing reproductive performance. The nutrition plan needs to be based on current forage quality, feedstuff availability, and prices in order to develop heifers in a cost-effective manner.
There are a couple approaches to how many heifers will be developed and bred. A producer may choose to keep enough heifers to maintain herd size, or, they may keep all heifers that meet a set criteria with the intent of selling extras as bred females in winter or early spring. Consider using ultrasound to sex pregnancies in bred heifers at day 60-90 of gestation. If the herd is in expansion mode, keep more heifers that are carrying heifer pregnancies. If the herd is maintaining numbers or in reduction mode, consider retaining more bull calf pregnancies since bull/steer calves will generate more dollars at weaning. The groups of bred heifers destined for sale will also generate more dollars if the sex of the calf is known. Both raised and purchased feedstuff availability influence the number of heifers developed and should be valued using the current market.
Determining how many cull cows need replaced is largely influenced by the number of open cows at pregnancy diagnosis. However, throughout the year, and especially during calving season, make a list of cows that have bad temperaments, feet issues, poor udders, and overall are poor performers that are not improving the quality of your herd. This list should be used to cull more females if the market is ideal, and also serves as a list of animals you should reference if one of their progeny are being considered as replacement prospects. Understandably, multiple females on the cull list will be there simply due to age, but a hard look at past reproductive and overall performance is valuable to moving the herd genetics forward.
Right now is an opportune time to take a look at your cows on pasture. Evaluate the heifer calves as well and make a list of potential replacements. Pay attention to what females are holding their condition? Who has had health issues? Did all cows shed their hair coats in a timely manner, or are there some that took longer to shed and lost their tail switch due to low fescue tolerance? Utilize pen and paper and make a list of animals that stand out for both positive and negative characteristics. Come weaning, this list is valuable to begin sorting replacement females and getting them on a feed plan customized to meet heifer development goals. Whether you sort future replacement heifers at weaning or after a development phase, the majority of animals making the cut should be predetermined based on the information collected and analyzed from birth.
A traditional approach for replacement heifers is keeping the heaviest 15-20% of heifers at the time producers sort and market calves. Over time, this method can increase mature cow size, but it continues to be used. Weight has a high correlation with puberty, so there is logic in this approach. Not only are these females more likely to get bred based on reaching puberty earlier, they also were likely born earlier in the calving season, which is a desirable attribute when the end goal is to get females bred early. However, challenge yourself to do more on your own operation. If the first-born heifer is the heaviest, but was delivered through a hard pull, or is from one of the not so great dams, that heifer should not be considered a replacement prospect even though she looks great while sorting.
Having a list on hand removes the "rushed" feeling when making sorting decisions. Utilize the records taken throughout the year. There is real value in taking the extra second to jot down notes on a dam like, "crazy," "bad bag," or better yet, use the numeric scales that have been developed for cow disposition, udder score, hoof score, and body condition. Keep track of these records, reference them for relevant management decisions, and reap the benefits from genetics that perform well in your environment will have.