WILSON da SILVA
BEFORE Professor Euan Roberts put his mind to it, sheep were impossible to artificially inseminate. Now the program he and his team have developed could mean the start of a growth industry in more accurate breeding of sheep.
“It takes the guesswork out of breeding,” he said. “The industry realises it can’t totally rely on judgment and marketing - they’ve got to be able to accurately measure the progeny of their sheep. This allows them to measure that.”
Working in the University of NSW’s Wool and Animal Sciences Department, he teamed up with Dr Doug Killen, of the Department of Agriculture. Together they adapted for sheep the human gynaecological techniques of laparoscopic observation and artificial insemination.
Although artificial insemination has been used in cattle for 30 years, sheep have proved extremely difficult to fertilise. The female cervix is so tough it is just about impossible for an inseminating tube to gain access.
To get around this, Professor Roberts’ team lays a ewe upside down on a metal cradle, makes two small incisions and inserts a laparoscope into its belly. Looking through the optical fibre “periscope”, the operator guides a semen-filled tube into the uterus, bypassing the cervix.
“All of a sudden, ram’s semen is marketable,” said Professor Roberts. “Over the next few years, we will probably see resources going into developing a semen trade.”
Using the technique, the UNSW team has been “progeny testing” the merino sheep offspring - accurately measuring the statistical likelihood of rams producing sheep with heavier fleece or with a finer coat. The ewes are inseminated, allowed to lamb, and the offspring analysed over two years.
About 2,300 ewes and 46 rams, supplied by three stud farms, are involved in the program, working from field stations in Hay and Deniliquin.