Laparoscopic ovum pick-up (LOPU) en ovejas Rasa aragonesa portadoras o no del alelo FecXR del gen BMP15: rendimiento, diámetro folicular y efecto del tratamiento estimulatorio con FSH

Abstract

A new polymorphism in the Bone Morphogenetic Protein 15 gene (FecXR allele) causing increased prolificacy in heterozygous ewes (R+) by an increase in ovulation rate has been recently described in Rasa Aragonesa ewes. Data from 2,172 follicles aspirated by the LOPU technique, with and without FSH treatment, in 16 R+ and 16 non carrier (++) ewes during 11 sessions were analyzed. Without FSH, the number of follicles present in the ovary was not significantly different between R+ and ++ ewes (9.7 and 9.2, respectively). FSH treatment led to 17.8 follicles in R+ ewes, mainly increasing 4 and 5 mm follicles (+11.2% and 9.7%, P<0.0001 for both) while in ++ ewes it produced 15.3 follicles, by increasing the percentage of 5, 6 and >6 mm follicles (+11.7% P<0.0001, +6.9% P<0.01 and +5.6% P<0.05, respectively). In conclusion, R+ ewes did not present a higher number of ovarian follicles, but their follicular population presented a significantly lower diameter. Further studies are necessary to determine if FSH sensitivity is increased in ewes carrying this polymorphism.