Trial advances use of sexed semen with AI
Trial advances use of sexed semen with AI
By Emma Penny
FIELD trials using sex-selected semen and AI have successfully produced three heifer calves in the UK.
The news, announced by Cheshire-based breeding company Cogent last week, means that sperm sorted semen moves a step closer to commercial reality, and on-farm trials are now starting on some members farms.
Cogents Tim Heywood said the three heifer calves were the first born outside the US using sexed semen and AI.
"Producing a calf using sperm selected semen and AI is a significant step forward, and is immediately relevant to the mass market."
The heifer calves were born in late May in the Grosvenor herd, located at Cogents base. Heifers on natural heat were AId with fresh sexed semen – aiming to produce a heifer calf – then pregnancy scanned to confirm pregnancy and calf sex. All three heifers inseminated produced a heifer calf; a further five heifers are due to calve in early July.
"Weve had erratic conception rates; some have been really good, and others poor, but were carrying out research to improve them. Now we are within 10 percentage points of the 60-65% average conception rate for conventional AI in maiden heifers."
But development also means that frozen semen has been used to inseminate heifers over the last five months. "This will allow us to extend the benefits to our members."
On-farm trials using sperm sorted semen started two weeks ago. About 40 farms are involved, each with a minimum of eight, and a maximum of 16 heifers being AId. The trials will compare conventional and sexed semen, and will also look at dose rate – comparing conventional, low and very low doses. The inseminator used, AI position – whether inseminating in the body of the uterus or up the horn is best – and fresh or frozen semen will also be compared.
Heifers in farm trials will be AId over a three to four-month period, and results used to help refine the technique further before commercial release of sperm selected semen, probably next year, said Mr Heywood.
• Cogent plans to market its sexed semen as the Heifer Choice Programme, says Tim Heywood.
"Well be giving producers the choice to produce heifers, which cows they want to produce heifers from, and when. Producing a calf thats wanted and ensuring heifers calve easily must be right." *