How Much is Too Much?

John F. Grimes, OSU Extension Beef Coordinator (this article first appeared in the March 2016 issue of The Ohio Farmer Magazine)

The onset of the 2016 calving season has provided a backdrop for one of the most frequently debated topics amongst cow-calf producers today.  These discussions are taking place in coffee shops, at local auction markets, and in the pasture.  While there are various ways to pose the question, many producers are debating the subject of whether the cow-calf industry has placed too much emphasis on calving ease in the breeding herd.

The beef industry has a vast array of breeds to utilize in herds located in a wide variety of environmental conditions across the country.  Your own personal production and marketing goals combined with any management and environmental constraints should determine the breeds selected to use in your operation.  The production traits that producers want to emphasize within their chosen breeds is always sure to strike up a healthy debate.

In my opinion, there really is no debate as to which traits should be prioritized in any operation.  The two traits of utmost important for any cow-calf operation are fertility and calving ease.  Simply put, if the cow or heifer doesn’t get bred or deliver a live calf on an annual basis, no amount of genetic merit in the other traits can compensate these losses.

The importance of fertility was addressed at the Cattlemen’s College held in conjunction with the recent 118th annual Cattle Industry Convention and National Cattleman’s Beef Association (NCBA) Trade Show.  Dr. Cliff Lamb, Professor and Assistant Director at the North Florida Research and Education Center at the University of Florida gave a compelling argument for the importance of reproduction.  Dr. Lamb informed the attendees that pregnancy has a four times greater impact on profitability than any other production trait.

Once the female is bred, calving ease comes to the forefront.  I don’t know of a single producer that wants to experience difficulties during calving season.  The primary negatives associated with calving difficulties are potential calf death loss and a slower return to cycling with females.  The primary question is how do you determine or interpret calving ease?  When making genetic selections, do you prioritize an animal’s actual birth weight, Birth Weight EPD, Calving Ease Direct (CED) EPD, or Calving Ease Maternal (CEM) EPD?

Two factors that increase the probability of dystocia are calf birth weight and pelvic area of the dam.  Actual birth weight of an animal may not be the best indicator of future calving difficulties as many environmental factors can impact birth weight.  Birth Weight EPD predicts an animal’s ability to transmit birth weight but not the potential for calving difficulties.

The CED EPD predicts the average difference in ease with which a sire’s calves will be born when he is bred to first-calf heifers.  It evaluates both birth weight and calving ease scores.  The CEM EPD predicts the average ease with which a sire’s daughters will calve as first-calf heifers when compared to daughters of other sires.  Each point of difference with each of these EPDs indicates the expected difference in the percentage of unassisted births.  For example if Bull A has a CED of +15 and Bull B’s CED is +5, you would expect Bull A to have 10% less assisted births with first-calf heifers than Bull B.  Remember that these EPDs are based on a first-calf heifer scenario and not mature cows.

A common complaint that I hear from some breeders today is that we have carried the emphasis on calving ease too far.  Research has shown that a typical beef female is capable of having 7% of their body weight in calf.  This means that a 1,200 lb. cow is capable of having an 84 lb. calf and a 1,400 lb. cow could deliver a 98 lb. calf.  Contrary to popular belief, not all commercial cows weigh 1,200 lbs. and I’m not so sure we need to see plenty of 100+ lb. calves out of our bigger cows!

Some believe that we have lowered calf birth weights to the point that we are sacrificing calf survivability and future performance.  I realize that we have some harsher environments where lighter calves may struggle with extreme heat or cold.  The individual producer should decide what weight is appropriate for their environment.  However, greater calving ease does not mean you have to sacrifice animal performance or carcass merit.  All major breeds have databases that can help any breeder identify animals that excel in multiple economically relevant traits.

I believe that the level of calving ease emphasized by any operation should be based on their particular labor and management constraints.  A part-time producer that works off the farm may need more calving ease than a full-time producer.  A producer that calves out large groups of heifers will need more calving ease than a producer with fewer heifers.  A producer than runs cattle on larger acreage cannot monitor calving situations as closely as a smaller producer on less acreage.

Smaller sized herds face particular challenges with calving ease considerations.  Smaller herds (less than 20-25 cows) typically use one natural service sire in their breeding programs.  These herds will often retain a small number of heifers as replacements.  These few heifers often result in a calving ease sire selected with potentially less performance being used on mature cows that could use more performance.  An alternative to this situation would be to artificially inseminate the heifers to proven calving ease sires, keep the ones that settle, and sell the opens.  Another alternative is to not retain heifer calves and buy replacement heifers or cows.  These alternatives would allow the breeder to purchase a bull better suited to the mature cows in the herd.