Source:  Australian Sheep Breeders Compendium 2021

Scanning rates have been lifted by 60pc in one cross.

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Sheep breeder and geneticist Colin Earl, based at Struan in the south-east of South Australia believes there is enormous potential for the shedding sheep as a low-labour alternative in the sheep-wheat zones of Australia and overseas, particularly in South America.

Acting on his ambition, Mr Earl has spent the past decade developing a new breed which he has named Prolific White.

“I developed the Prolific White after visiting Brazil where 1 was transferring Dorper embryos and conducting a speaking tour,” Mr Earl said.

“I thought a more prolific, faster growing breed would be useful there where they had so much cheap labour to care for them and they also lamb down indoors.

“Doing similar work in China I had the opportunity to see the prolific Hu sheep production systems.”

Mr Earl said the Chinese sheep had the same gene as he bred into the Multimeat breed but the Hu sheep had very poor growth rates.

“I came to the opinion that there was the need for a truly prolific, good growth shedding breed of sheep in a number of countries around the world,” he said.

“After 10 years of breeding we now have such a sheep and interestingly our first exports have gone to Russia to be involved in intensive sheep production there.”

Mr Earl pointed out the advantages of using Prolific White rams to increase the fertility in shedding breeds.

“We have seen scanning rates lifted by 60 per cent with one cross,” he said.
“So if you mate an Aussie White or a Dorper to a Prolific White ram the daughters will scan at a 60pc higher rate.
“They are able to do this because all Prolific White rams carry two copies of the Booroola gene.
“Each daughter then carries one copy of the gene which causes them to release more oocytes which are fertilised to produce more lambs.”

Mr Earl said the Prolific White breed was developed to make it possible for cleanskin and shedding breeds to be profitable.

“With minimal skin value and relatively low lambing percentages it was always going to be difficult for those genotypes to be commercially competitive with mainstream breeds,” he said.
“The genotypes used in the development of cleanskin and shedding sheep all have modest scanning rates making selection for higher reproductive rates difficult.”

The Prolific White was developed from the Multimeat which carries the Booroola gene being crossed initially with Dorpers from Dennis Russell to take the wool off them.

Infusions of other elite shedding genetics followed while DNA testing was carried out to ensure the gene was retained.

Mr Earl noted the principal characteristics apart from shedding have been good feet and growth.

“The result is a moderate-sized sheep with good growth and carcase characteristics, which carries two copies of the Booroola gene,” he said.
“Limited releases of the rams has shown that the daughter do scan in excess of 200pc at an individual mating.”

Mr Earl said a limited number of rams will be available this year for lease to commercial producers.

“The lease fee will be $600 per year and the rams remain on the producer’s property for the duration of the lease until they go to market,” he said.

On the family farm near Struan, SA, John Mossop has been using Prolific White rams for the past three years, having originally joined his base ewes to Cashmore Nudies.
Mr Mossop said the breed is what he was looking for to complement the cropping operation.

“I wanted an easy-care sheep and something that was tough and highly fertile,” he said.
“We run 1300 ewes and the shedding sheep fit with our operation.
“Our scanning percentage of Prolific White cross is in excess of 200pc and our lambing percentage last year was 158pc.”

The lambs are sought by the market and Mr Mossop said last year’s July-drop lambs averaged 26 to 29kg dressed weight when sold in December and they returned from a bit over $200 to $230 for the entire drop.

Australia’s only Prolific Shedder – 200% scanning with one cross

It has taken 10 years of selection to produce the Prolific White sheep to marketable quality.