JIVET 'supercharges' sheep breeding

JIVET 'supercharges' sheep breeding


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Leahcim stud principal Andrew Michael hosted the JIVET trial at his property at Snowtown, SA.

Leahcim stud principal Andrew Michael hosted the JIVET trial at his property at Snowtown, SA.

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ANDREW Michael has taken sheep breeding into uncharted territory with a new program that is fast-tracking the speed of genetic gain in his flock.

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ANDREW Michael has taken sheep breeding into uncharted territory with a new program that is fast-tracking the speed of genetic gain in his flock.

The Snowtown, South Australia producer is the first to implement the JIVET – or juvenile in vitro embryo transfer – program at his Leahcim White Suffolk and Poll Merino studs.

Using a combination of traditional assessment techniques and DNA testing to identify superior stud genetics, 10 ewe lambs and a number of rams lambs were selected only a few weeks after birth.

A total of 465 eggs were then harvested from ewe lambs between 6-8 weeks of age, which is during a peak period for egg production in young females.

This allows breeders to leapfrog the 18-month maturation period of a ewe lamb and proliferate their desired genetics faster.

"For the first time we can do rapid genetic evaluation and do it very accurately, and this dramatically shortens the genetic intervals," Mr Michael said.

"The dollar returns are staggering – we estimate the superior genetics will deliver an $8 increase in returns from every ewe lamb every year compared to a figure of just over $2/ewe/year for our conventional program."

The eggs were then joined with the young rams' semen in a test tube, embryos then implanted and carried to term in a mature ewe.

The high number of eggs allowed Mr Michael to make multiple crosses with each of the ewes, allowing the genes to be spread out while at the same time accelerating the rate of genetic improvement in the flock.

Born in the first week of November, the first drop of JIVET prodigy delivered 25 ewe and 25 ram lambs from 14 different genetic combinations.

While the first JIVET trial took a total of 10-13 weeks to complete, Mr Michael anticipates this could be reduced to just four to six weeks as DNA testing and in vitro fertilisation processes improve.

"We need to make this breeding technology a winner so that we can pass on faster rates of genetic gain to mainstream producers so that they can also make major advancements in a very short space of time," he said.

However Dr Iona Macleod from Melbourne University's Department of Agriculture and Food Systems said the success of a program such as JIVET came down to being able to accurately test for desired genes at such a young age.

"A good example is fertility. Fertility has a very low heritability – but it is heritable," she said.

"It's hard to get a good breeding value on it in an individual. That's something that there's quite a lot of work being done on, to improve the accuracy of the DNA testing for the breeding values you can get."

The risk of inbreeding was another hazard that Ms Macrae flagged, sighting a study done by Tom Granleese on the benefits of JIVET in optimised sheep breeding programs.

"His study showed there's massive potential improvements, but they would quickly be undone if inbreeding was allowed to occur in the program," she said.

However controlling this could be done easily as long as the extensive pedigree information collected in a program like JIVET was monitored.

Mr Michael said within two weeks of being born, the lambs were already expressing muscle patterns that he had not encountered before in his flock and were a rival to the best British breed stock he had seen.

The next joining will occur in line with the remainder of his naturally joined stud flock, allowing for bench-marked, real-time comparisons for growth and performance.

"By April 2015 we should have phenotypic data from the full group of JIVET and non-JIVET lambs," he said.

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