Preg check and cull replacement heifers early

Replacement heifer selection can affect the profitability of your herd for years to come.

The fall is the time when commercial cattle producers make their first cut for identifying replacement heifer calves, and their last cut on yearlings that had been exposed to calve next spring. Proper heifer selection is important because the heifers retained represent what a commercial producer’s herd makeup will be in the years to come.

The selection intensity a producer can apply varies by a number of factors including how many replacements they need, as well as how complete the potential replacements are identified regarding when they calved and who their dam is. Smaller, more intensely managed herds generally have cattle very well identified, while large extensive operations may have minimum individual identification information.

Starting with the heifer calves, removing what many refer to as the small “fur ball” calves is an easy first step. These calves are not thrifty due to chronic illness, have well below-average growth potential, or haven’t grown because of very poor milking dams. It doesn’t matter whether the inadequate milk was due to genetics or loss of quarters from factors like mastitis.

Although not the most scientific approach, a commercial producer should also cull heifers they feel are too “ugly” to make replacements, however they might define ugly. Any heifers that are noticeably hard doing should also be put in the cull pen.

A culling criterion that might be counter-intuitive to some is to remove the handful of heifers that are extreme outliers for large frame and growth. These heifers will become cows that get too big and are often hard doing, especially for rations and management aimed at the average size of the commercial cows in a herd. Often times, these big outlier heifers can be value-added by marketing them to an operation that wants bigger cows, which are kept on a higher plane of nutrition.

The next priority is to eliminate problem cattle, like heifers with bad dispositions (tightened up). A producer’s tolerance for disposition level will vary from operation to operation, but none of them want crazy cattle. First and foremost, they are dangerous to the people managing them. In addition, cattle with bad dispositions have been shown to have lower performance, especially in the feedyard, and will hang carcasses with lower quality grade than would be expected by their genetics for carcass traits.

It is not common for a lot of hoof and leg issues to show up in heifer calves, but those with problems should be quick culls as these problems will worsen with age. If dam information is known, heifers whose dams have functionally bad feet and/or udders should be culled.

Remember there is a difference between aesthetics and functional problems. Functional problems mean feet and legs that will result in early culling, or udder problems that will make it difficult for a calf to nurse or cause a loss of function. Anytime you need to get a cow in the chute to help a calf nurse, that cow should be on the cull list and her heifer calf should not be considered as a replacement.

For producers who are taking advantage of heterosis, selecting calves that will provide the most hybrid vigor should be a priority. This is important because the traits with the most heterosis are also low heritability traits, which include maternal traits and reproduction. The value of reproductive traits cannot be overly emphasized since they are the most economically important traits.

If a producer has the luxury of numbers and well identified heifers, selecting the heifers that calved early in the season will pay dividends. They are more likely to be out of the better cows for reproduction, as well as having an age and weight advantage when it comes time to breed them the next year.

After all these other boxes have been checked, a producer can select the better doing heifers with average or above-average growth. Enough heifers should be kept back so that a producer can continue to put selection pressure on when they are yearlings and again when they are pregnancy checked.

Genomics and later culling

Genomics are a powerful tool now available to commercial producers for selection of replacement heifers, and their use should be considered by every operation. There are a lot of recommendations, and pros and cons of using genomics at various stages of production. At the very least, commercial producers should consider testing “bubble” heifers—on the bubble of keeping or culling—prior to breeding in the spring to make the final decision on which ones to expose.

Also prior to exposure in the spring, a producer should do another sort prioritizing culling problem heifers for soundness, disposition, or inadequate growth to be cycling early in the season.

The fall is when a commercial producer makes their final cut on replacements from those that were AI’d or exposed to a bull. By far the biggest criteria for selection is reproductive status, so it is important to pregnancy check the exposed heifers. All open heifers should be culled after they have been challenged to a fairly short breeding season.

It cannot be overemphasized the importance of sorting the “wheat from the chaff” reproductively while they are still heifers. You hope that most all of the problem heifers in terms of soundness and disposition have already been removed by this time, but if any are identified with these problems when doing pregnancy checks, they should be culled.

In the end, having a plan that results in the retention of the most promising replacement heifers is important for any profitable commercial operation. As much as selection for the best heifers, it is just as much a process of getting rid of heifers with potential problems. Having as trouble-free herd as possible that excels in reproduction is the foundation for any profitable commercial herd, which all starts with heifer selection. — Dr. Bob Hough

(Dr. Bob Hough is the retired executive vice president of the Red Angus Association of America and freelance writer.)

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