The living proof that sexed semen works
Farming News - England
June 24, 1999

     The long-awaited proof that sexed semen works came with the arrival this week of the UK's first three AI heifer calves to be produced using this futuristic technique.
     This represents the most tangible evidence so far since breeding company Cogent took delivery of its first MoFlo cytometer last summer, and sets it well on the path to its stated goal of having sexed semen commercially available next year.
     "These are the first calves produced using AI from sexed semen anywhere in the world outside the US," declared Cogent's managing director Tim Heywood.
     "We are now doing further trials with 480 inseminations on members' farms and looking to refine the technique."
     The trials will involve maiden heifers synchronized with Crestar, and will aim to investigate the effects of semen dose rate and uterine deposition sites to ensure good conception rates.
     "We're aiming for 90 percent purity of sex and acceptable conception rates within 10 per cent of normal - it may be less than normal or it may be that we can produce better conception rates than normal," said Mr. Heywood.
     Although he would not be drawn on the all-important aspect of cost, he said that it would have to be "economically acceptable to breeders".
     "We expect to do 10,000 trial inseminations before we go commercial and offer it nationally," he said.
     To help generate sufficient semen throughput, Cogent will be taking delivery of two more semen-sorting machines this autumn which will be "working 24 hours a day, seven days a week".
     Although the first calves were all born using fresh semen, on-going trials involve frozen semen with deeper than normal deposition sites at two inches and four inches beyond the cervix.
     "We expect, in four years' time, to be producing only female Holstein calves," predicted Mr. Heywood.
     "This would help remove unwanted Holstein bulls and allow better producer selection in allowing replacements to be bred only from the very top herd members," he added.