Sexing semen may be controversial in humans, but it is a winner for the dairy industry.
When all you need is cows to milk, bull calves pose animal welfare issues.
Until now, using semen that has been identified as female has had poor conception rates, producing a calf in only 65 per cent of artificially inseminated cows.
Researchers have improved the technology and now conception rate is 90 per cent, leading to female calves.
Researchers at Dairy Australia are holding a webinar on May 27 to discuss artificial insemination using sexed semen as part of the InCalf series.
Bovine semen is sexed using a fluoro dye that binds to the DNA.
The Y chromosome is lighter and also has a negative electrical charge, and the X or female chromosome is positively charged.
When passed over an electrically charged plate, they are divided into X and Y.
Photo: Female chromosomes in semen are heavier, positively charged and kept to produce heifer calves. Read more (Dairy Australia)“Last year, 10 per cent of all AI straws used in Australia were sexed for female sperm,” said Dr Kathryn Davis, program manager of animal health and fertility at Dairy Australia.
“We have seen trials that have achieved 90 per cent conception, compared to a conventional AI program.
“That’s increased from the 65 per cent conception rate we used to see.”
Dr Davis, who is also a veterinarian, says 85 per of Australian dairies use artificial insemination to some extent, whereas only a few used the more advanced techniques of in-vitro fertilisation IVF, or egg flushing.
Egg flushing, used by studs, allows a large number of eggs to be fertilised outside the donor cow and implanted in genetically inferior cows.
She said Dairy Australia also had several research projects to identify positive genetic traits with the Australian Dairy Herd Improvement Scheme.
The genome selection included a healthier and fitter dairy cow, able to better resist mastitis or worm parasites.
Source: ABC Rural Australia
