Pregnancy rates lifted by AI plus embryo implant
By Jessica Buss
IMPLANTING beef embryos in problem breeding cows seven days after AI service doubles the chance of a successful pregnancy.
This is the claim of Canadian ET technician Chris Gwyn of Western Ontario Breeders (WOBI).
Increases in pregnancy rates were achieved in cows on their fourth to 12th service. These were bred pure to AI on natural heat, then after seven days a beef cross embryo was implanted by an ET technician.
"This increases the message to the cow that she is pregnant, either from the semen or embryo," he says. "When the calves were born half were purebred and half beef crosses.
"It is difficult to prove this works scientifically, but it is commercially viable."
WOBI is charging about £25 for the beef cross embryo, plus the cost of transfer. Sefaxs UK embryo transfer technician, Dick James, who charges £50 a direct transfer, hopes to provide a similar service as soon as these beef cross embryos are imported.
The price of these embryos has yet to be decided, but it is likely that it will cost about £100 for each embryo and transfer.
"This is good value for money for high-yielding cows that are difficult to get back in calf," says Mr James. "These are often the problem breeders because the signals given by the embryo are too weak to maintain pregnancy for a cow concentrating on producing high volumes of milk."
Mr James adds that direct transfer of embryos is proving successful in the UK. "Initial pregnancy rates were well in excess of 60% when cows were scanned 35 days after direct transfer of embryos on-farm."
• Producers in Canada are attempting to implant embryos by direct transfer. Canadian legislation allows them to put embryos in their own cows without vet supervision, unlike in the UK. However, ET is more difficult than AI, warns Mr Gwyn.
He knows 10 producers who would like training in direct transfer, but at WOBI the time to train them is not yet available.
"So, some have been attempting DIY ET without training."
Sefaxs UK embryo transfer technician Dick James says that direct transfer is proving successful in the UK. He cites initial pregnancy rates in excess of 60%.