Development of replacement heifers
November 5, 2012
If only we knew if it will rain or I guess a better question would be when will we get moisture? If only we knew what the drought situation will be next spring and what the grass situation will in early spring and all of next year. If we knew the answers to these questions we probably wouldn't be in the cattle business but how much easier it would be to make decisions on how many pregnant females to keep for next year. Before discussing replacement heifers I will make a comment on pregnancy testing in the fall which many have already completed. I have not felt that routinely pregnancy testing in the fall and selling the opens in the fall was always the most economical practice when we considered the seasonality of prices – traditionally the lowest price is in the mid-fall. However, this year the drought makes me rethink this practice. Because of modern cow harvest throughout the summer one might ask if the fall low will be that much depressed. A lot of the normal fall run may already sold. Relatively good current cull prices coupled with record high costs one must question if any potentially non-productive females should be held over for a higher spring market. Exceptions may be where winter feed costs are relatively low. If harvested feeds must be fed one must have considerably higher prices in the spring to justify the cost. For example if a cow is fed hay costing $200 for six months then feed cost alone would be close to $600 for the 200 day period. That doesn't count other expenses. A 1,300 pound cow would need to bring about $.50 more per pound or in other words a $.70 per pound cow in the fall would need to bring close to $1.20 next spring to pay for the $200 hay. Obviously that is an extreme but I know some that are paying $200 for hay delivered and not much reserved winter grazing. With lots of winter and spring moisture perhaps cows will bring in excess of $1.20 but do you want to take that risk?
Back to replacement heifers. We know that cow numbers are at a record low. Jim Robb with the Livestock Marketing Information Association says maybe we will have 4 percent less cows this fall and with good green grass in the spring the stage will be set for record prices for pregnant replacement females. How many heifers should you keep and how should they be developed? Dr. Rick Funston, his graduate students and co-workers at the UNL West Central Research and Education Center continue do excellent work in heifer development and two articles were recently published in the 2013 Nebraska Beef Report (available at beef.unl.edu). Yes, it is a 2013 report in 2012. It is like when I used to dream about buying a new car. They released the new year's car the previous year – but I digress a little.
Dr. Funston's work has continued to look at lower cost in developing replacement heifers. I don't know the times I have read, heard, said and wrote that heifers need to be at least 65 percent of mature body weight at breeding time. Following up on work of Dr. Deutcher, the UNL West Central group has proven that is not necessary to achieve high reproductive performance. In one three year study with large numbers of heifers, they compared a combination of winter range and corn stalk grazing system versus starting on grazing winter range (98 days) and then followed up in dry lot. The heifers that spent the last 112 days in dry lot were 78 pounds heavier at breeding (63 percent of mature weight versus 57 percent of mature weight for the range – corn stalk heifers) than heifers developed on a combination of winter range and corn stalks however there were no differences in AI pregnancy or overall pregnancy. This was the same as Martin found in his PhD work at UNL West Central Research and Extension Center. They evaluated feed efficiency of the pregnant heifers in the last trimester of pregnancy while feeding ground hay in feeders and found a slight advantage to the heifer that were dry-lotted the previous winter. This is quite possibly a learned behavior result.
In another study they evaluated corn stalk grazing versus winter Sandhills range grazing. All performance traits were similar in this trial until the next fall when all heifers were grazed on cornstalks. Heifers that had grazed corn stalks as calves gained two times (.66 verse .32) more daily than similar heifers that winter-grazed range as calves. Many have suggested that if cattle have never grazed stalks before they have a learning curve to achieve in order to get the most from the stalks. All indications are that these yearlings that grazed stalks as calves remembered where the high quality parts of the stalks were, consumed these parts (grain and husk) immediately while the other heifers had to learn this over time. This suggests that perhaps yearling heifers in the last trimester of pregnancy may perform better if they are in the same environment as they encountered as weaned calves. This may not always be economically possible but something to consider.
As far as rate of development of replacement heifers is concerned those that keep development rates down usually keep costs lower and any open heifers are sold as open yearlings which are desirable feeder heifers going into the feedlot. If handled as a "stocker" or "yearling" the opportunity for a profit is much greater. Best of luck in dealing with these high costs in cattle production.