Bull or heifer? Dairy producers have long hedged their bets when breeding to ensure an adequate supply of heifer calves.

“Breeding always has had 50/50 odds,” says Shay Sunderland, technical services director for the Monsanto Company. Yet a breakthrough in semen technology should improve the odds of getting a heifer calf.

Decisive™ semen for Advanced Gender Selection will improve the odds from 50/50 to 85-percent predictability, Sunderland says. Across a couple of hundred pregnancies, about seven of every eight calves will be heifers, statistically speaking.

If producers can effectively target the number and quality of heifers born into their operations, they can accelerate genetic improvement and improve overall herd quality. This is achieved by sorting the semen to be used in A.I. for male and female bias. The key is to sort semen from proven, high-quality bulls while maintaining the overall reproductive performance that producers expect from their existing A.I. programs.

By the end of this year, Monsanto plans to announce which A.I. companies it will be working with in order to bring gender-sorted semen to the marketplace. Then, in the second half of 2006, gender-sorted semen will become commercially available.