Now more than ever economics are playing into cowherd decisions, and one of the most critical is selecting which heifer calves to keep at weaning for use as replacement heifers in the herd. Veterinarians can be instrumental in helping their beef clients retain the right ones.
“Feed costs continue to increase so investing monies into a replacement program is a long-term investment for the cattle producer,” says Tom Troxel, PhD, Extension beef cattle specialist, University of Arkansas. “Selecting and managing heifers from weaning to when the heifer is pregnant with her second calf is an investment into the ranch’s future.”
Troxel says at weaning, evaluate each heifer for weight, height, body capacity, structural soundness, health (thriftiness) and other important production traits. Rank the heifers on traits such as 205-day adjusted weaning weight and frame score. Select those heifers with above average 205-day adjusted weights.
Performance records are helpful in determining growth and reproductive potential and in identifying the calves from above average producing cows. It is desired to select heifers from dams that have shown a history of producing a heavy weaning weight calf every 365 days. The old rule of thumb to select the largest and oldest heifers because they will usually reach puberty earliest is still true. It also indicates that these heifers were conceived early in the breeding season, which gives some indication of dam fertility.
2011 is proving challenging with high feed prices and a shortage of pasture due to extreme drought in some areas. “During time of prolonged drought, it becomes even more important for producers to match forage quality and quantity with forage demand,” Troxel says. “Growing and pregnant heifers require a higher quality diet than mature cows. Therefore, growing replacement heifers during times of drought become even more expensive.”
During times of drought, producers will often reduce the number of heifers retained for the replacement program or not keep heifers at all. “If producers are going to retain heifers during times of drought it becomes even more important to select heifers from the top-producing cows,” he says. “Don’t keep marginal heifers. In addition, cull heifers as soon as possible when their performance isn’t satisfactory.
Mistakes when selecting heifers
The biggest mistake Troxel sees when selecting heifers for replacements is producers will keep heifers without knowing the productivity of their respective dams. “Generally speaking, many cow-calf producers do not keep the necessary records to identify their top-third producing cows,” he says. “Therefore, they are likely to keep replacements from cows in the middle or even from the bottom third based on productivity. We have data to support those cows in the top third of the herd (based on performance) generally stay in the top third year after year.” On the other hand, Troxel adds, cows in the bottom third generally stay in the bottom third year after year. “Don’t keep heifers from cows in the bottom third. It takes records to help make that decision.”
Troxel also recommends that if a heifer is structurally unsound, eliminate her from consideration. Take into consideration that heifers that are overly fat at weaning may be uneconomical as mothers. Select against extreme muscling patterns and frame sizes (large and small). Do not keep heifers that were twinned with a bull as these freemartins are usually sterile.
To read the full report Selection and Management of Beef Replacement Heifers, click here.