The keys to a successful cattle breeding program are pregnancy and calving rates, a leading beef cattle expert said at the recent South Carolina 2009 Cattlemen’s Day.

Optimizing a bull’s performance is the most effective tool in natural breeding.

Roger Ellis, a beef cattle veterinarian at the University of Georgia and guest speaker at the 2009 Cattlemen’s Day, said 90 percent of beef producers use bulls in natural breeding. The goal in a planned breeding program is to achieve the highest rate of pregnancy early in the breeding season.

Ellis said the four key attributes a bull must have are that it:

• Is physically capable of breeding.

• Has a willingness to mate.

• Has the capacity to produce semen.

• Has functionally normal spermatozoa.

The health of a bull’s spermatozoa contributes to the survival of the embryo, Ellis said. It’s not a widely published fact, but the beef animal is not a highly fertile animal, and only about 65 percent of fertilizations become pregnancies.

Twenty-five percent to 35 percent of pregnancies are lost in the cows. Those losses often are blamed on the bull, and it can be the bull’s fault in some cases, Ellis said.

For example, genetic deficiencies in the bull’s spermatozoa may mean that though it is capable of fertilization, it is not capable of sustaining an embryo.

“We’re looking to maximize the potential of that bull over its breeding lifetime,” Ellis said.

Clemson University’s Edisto Research and Education Center, Clemson Extension and the South Carolina Cattlemen’s Association hosted the 2009 Cattlemen’s Day at the annual Edisto Forage Bull Test Sale.

More than 150 people from across the Southeast saw about 50 purebred bulls on display and up for auction. To be included in the sale, all bulls had passed strict tests in the months leading up to the auction.

The average age of the bulls was 20 months and the average weight was about 1,600 pounds.

When all bids were in, 47 bulls sold for a total of $96,100. At an average price of $2,045, the total was 36 percent higher than at last year’s auction. The highest value bull sold for $3,700.

Thirty-five bulls were sold to South Carolina buyers, one each went to Georgia and North Carolina, and 10 went to Florida.