Enabling genetic progress twice as fast in dairy

Sex-sorted semen allows dairy producers to control the ratio of bull-to-heifer calves and better manage their profits. De Vries has also found that the use of sex-sorted semen in Florida is enabling genetic progress in dairy herds to improve at a rate twice as fast as a decade ago.

Sex-sorted semen use continues to grow worldwide. It is being funded by the government in India for example, for both cattle and water buffalo.

New findings

Recently, the University of Florida Dairy Unit completed a review of 2023 reproduction protocols and semen decisions for its herd, which is about 520 cows and 500 heifers. In 2023, low first-service conception rates with sex-sorted semen and a lot of conventional dairy semen use resulted in the sale of over 260 dairy bull calves. The cost of using more sex-sorted semen in 2024 included an estimate of semen cost increase from US$20,400 to US$30,000 and a calf sales revenue increase from US$40,800 to U$133,500 per year. The expected net revenue increase would therefore be about US$83,100 in 2024.

About 50 crossbred beef-dairy calves were born in 2023. Crossbred calves were worth approximately US$300/head more than dairy bull calves in the fall of 2023, so more use of beef semen is being used this year.

Conception rates increased in the first 2 months of 2024 to 49% in heifers and 55% in cows. This was primarily the result of factors such as allowing only people with good conception rates to breed, and increased use of high fertility beef semen. De Vries noted that “these benefits add additional value to the beef-on-dairy programme”.

Going forward

Current efforts focus on monitoring conception rates and the weekly number of sex-sorted semen inseminations.

Several factors have so far resulted in too many or too few sex-sorted semen weekly inseminations, mainly that the number of heifers and cows that enroll in the synchronisation programmes has varied greatly from week to week.

“These variations are the consequences of a somewhat seasonal calving pattern due to heat stress, as well as variations in the weekly conception rates,” stated De Vries. “We are now implementing a better algorithm to automatically be more precise about making the required number of sex-sorted semen inseminations weekly, independent of the number of heifers and cows inseminated that week. Other areas of attention are the cow replacement strategy and when to make a heifer or cow a ‘do not breed’.”

Take a virtual tour of the University of Florida Dairy Unit.