Combined effects of the Booroola, Vacaria and Embrapa mutations on ovulation rate in a sheep flock with unique genetic background

Context Improve lamb meat production in southern Brazil using genotype-assisted selection to enhance prolificacy. Aim To evaluate the effect of the combined presence of single-nucleotide polymorphisms in the BMP1R (Booroola) and GDF9 (Vacaria, Embrapa) genes on ovulation rate. Methods Ewes were genotyped using the tetra-primer amplification–refractory mutation system–polymerase chain reaction technique. Ovulation rate was assessed via laparoscopy following estrus synchronization with intravaginal progesterone sponges. Key results The presence of the Vacaria (FecGV), Embrapa (FecGE), and Booroola (FecBB) alleles in different possible combinations adds between two and three ovulations in the corresponding genotypes. Conclusions The effects of the FecGE, FecGV, and FecBB alleles on ovulation rate are additive and should be utilized individually or in pairs with the FecGE, avoiding excessive prolificacy when all three alleles are present in the same ewes. Implications Genotype-assisted selection enables the development of genetically distinct lines tailored for different production systems based on desired levels of prolificacy. This strategy can be integrated with the selection of other major genes affecting productive traits, such as increased carcass yield and spontaneous wool shedding.