At a DairyNZ event on the farm of Scott Henderson in Milton last month, Mr Henderson said pregnancy scanning of his herd had shown lower conception rates than expected.
He had used fresh LIC sexed semen for the artificial insemination of 40 of his top cows, which had a conception rate of 31% .
The LIC website promotes the use of female sexed semen enables farmers to generate more heifer replacements from their best-performing animals.
Mr Henderson said the cows the fresh sexed semen was used on were healthy and had no signs of mastitis or lameness.
VetSouth Balclutha veterinarian Dan Cragg said traditionally, fresh sexed semen had been considered the ‘‘way to go’’ and had a better conception rate than frozen sexed semen.
However, he had seen some ‘‘horrific fresh sexed semen conception rates’’ this year.
Traditionally, he had advised farmers to avoid using frozen sexed semen due to its poor performance and now fresh sexed semen was producing poor results.
‘‘It’s a good tool if it works but it can’t work from what I see.’’
LIC Taieri and South Otago agri manager Tim Johnson, who was at the event, said the conception rate using frozen sexed semen had produced better results than fresh sexed semen in New Zealand this season .
‘‘For fresh, the conception rate is slightly lower than what we are expecting.’’
SHAWN.MCAVINUE @alliedpress.co.nz
