Booroola Fecundity Gene Test (FecB)
The Booroola or FecB gene increases the ovulation rate and the number of lambs born in sheep. DNA testing by Genomnz™ can identify whether animals have zero, one, or two copies of the Booroola fecundity gene.
The Booroola or FecB gene was first identified from analysis of litter size and ovulation rates among selected strains of Australian Merino. Subsequently the gene has been introduced in a range of other breeds.
Animals can inherit the Booroola gene from just one parent (single copy) or from both parents (double copy). A single copy of the Booroola gene increases ovulation rate, on average, by 1.6 ovulations per cycle which typically equates to one extra lamb born. Two copies of the Booroola gene increase the average ovulation rate by 3.2 ovulations per cycle. Typically, this equates to one or two extra lambs being born.
Test Results
Gene mapping research has identified the specific DNA code thought to cause the high ovulation rate of Booroola animals. Booroola gene carriers have a natural change (mutation) in the sheep DNA sequence from an adenine (A) nucleotide to a guanine (G) nucleotide at position 746 of the BMPR-1B gene. This kind of mutation is known as a SNP (single nucleotide polymorphism).
The test identifies three classes of animal:
BB or Double copy (homozygote)
Where the BMPR-1B genotype is GG, the animal has two copies of the Booroola fecundity gene. We expect females will have a high ovulation rate (+3.2) and number of lambs born. This animal has inherited the Booroola gene from both its mother and its father. The animal will pass a copy of the gene on to all its progeny.
B+ or Single copy (heterozygote)
Where the BMPR-1B genotype is AG, the animal has one copy of the Booroola fecundity gene and one copy of the 'normal' gene (found in other types of sheep). We expect females will have an increased ovulation rate (+1.6) and number of lambs born. This type of animal will only pass the gene on to about half its offspring.
++ or Non-carrier
Where the genotype is AA, the animal does not contain the Booroola fecundity gene.
The standard method for collecting sheep samples is by easiTrace™ samplers. We also accept blood, tissue, and semen. See our sample types page for more information and sampling instructions.
Please see our sample submission page for information about submitting sheep samples or download our submission form.