Waikato farmer, Trevor Dawson, made sure he got his order in early for fresh Holstein-Friesian sexed semen this spring – he knew supply was limited and was keen to get a share of LIC’s 300,000- odd straws that went out during the early weeks of mating.
"Sexed has a number of benefits and is worth the investment in our view,” Trevor says. “We always put it over our better cows – the best ones on the day – mainly to increase our chances of getting a heifer calf and to avoid getting the bull calf.”
Use of LIC’s fresh sexed semen shows an average 90% chance of a heifer calf being born, at near-normal conception rates (compared to use of conventional semen); figures are based on data from field-trial work, together with data collected since the product’s release to the general market two years ago.
This spring, Trevor's Orini farm took about 120 straws, about the same number as it did in 2021.
A similar pattern exists at Trevor’s Horsham Downs farm, a split-calving operation that saw 143 sexed semen straws ordered last season, up from 112 in 2020, and 28 straws in 2018 (70 have been ordered for spring 2022, with more to be ordered next autumn).
The idea is for the farms to rachet-up the number of quality replacement calves, bringing about selection pressure on each emerging cohort within the herd.
“We’re also using it for our yearling mating,” Trevor says. “Friesian-over-Friesian, because we’ve noticed, over time, that a significant portion of our first calving difficulties are when the calf is born a male. It seems the female calves are easier on the young heifer giving birth.
“It’s worked very well; we’ve seldom had difficulty with sexed semen heifer calves. We’d only do Friesian-over-Friesian with sexed; if it wasn’t sexed, we’d use the KiwiCross. And if we can get a top-BW (breeding worth) female calf out of a yearling, we’re shortening our generation interval by a year.”
Shortening the generation interval is one of the most effective ways to increase the rate of genetic gain within a herd.
Premier Sires Forward Pack, which provides access to genomically-selected bulls, is the other main way of reducing the generation interval and ramping up the rate of genetic gain.
Today the ratio of Premier Sires farmers using LIC’s Forward Pack over the Daughter Proven option is three-to-one.
