Booroola is a prolificacy gene that can be bred into any flock/breed of sheep. It was first discovered in 1959 in a flock of Merinos in Australia, that had been inadvertently bred to Garole sheep back in the 1800's. The Garole breed is the origin of the Booroola gene. They named the gene Booroola after the farm it was discovered on. Many countries have used the Booroola gene to increase the productivity of their native sheep.
Initially, due to using the B-gene from Booroola Merino stock, the B-gene carrying rams were all horned. It took several generations to breed out the horns to now have polled Booroola stock.
All lambs sired by a BB Ram will have 1 copy of the gene, which will dictate that the B+ ewe has 1.1 more lambs per lambing due to increased ovulation. If using a B+ animal, half of the progeny will be B+, but when sampling to determine which have the gene, testing is simple and inexpensive
Booroola Genotype BB
Dam: PASF BO 226P (B+)
Steve is polled, and a very correct, well built ram. He is homozygous for the Booroola gene, therefore all of his offspring will carry a copy of the B gene.