title: Boar sperm with defective motility are discriminated in the backflow moments after insemination.
abstract: During insemination, a large number of spermatozoa are deposited in the female genital tract, but a very low percentage is able to colonize the site of fertilization. The influx of neutrophils into the uterine lumen and semen reflux (backflow) are known mechanisms that decrease the number of spermatozoa within the uterus. No report has attempted to ascertain whether the backflow is a random or selective process of the spermatozoa. In this work, sows were inseminated using two populations of spermatozoa in the same proportion: (1) unstained spermatozoa with high motility and (2) stained spermatozoa with low, medium, or high motility. Volume, number, and percentage of stained spermatozoa were evaluated in the backflow (collected at 0-15, 16-30, and 31-60 minutes after insemination). This article provides evidence that (1) the motility characteristics of the spermatozoa do not influence the percentage of sows with backflow, the volume and number of spermatozoa in the backflow; (2) the discarding of spermatozoa in the backflow is not specific during the first moments after insemination (0-15 minutes), whereas later (16-60 minutes), spermatozoa with defective motility (low and medium groups) are discarded in a higher proportion than high group in the backflow ([16-30 minutes: low, 85.13 ± 4.32%; medium, 72.99 ± 5.05%; and high, 54.91 ± 2.38%; P < 0.0001; 31-60 minutes: low, 87.16 ± 6.01%; medium, 87.02 ± 4.01%; and high, 59.35 ± 2.86%; P = 0.001]). Spermatozoa with poor motility are discarded in the backflow probably as a selective process, on the part of the female genital tract or as a result of the intrinsic low spermatozoa motility.
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Boehringer-Ingelheim S.A., Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Hernández-Caravaca
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Soriano-Úbeda
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Matás
authors.affiliation: Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain; Department of Cell Biology and Histology, Faculty of Medicine, University of Murcia, Murcia, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Izquierdo-Rico
authors.affiliation: Department of Physiology, Faculty of Veterinary Science, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", University of Murcia, Murcia, Spain; Institute for Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain. Electronic address: fagarcia@um.es.
authors.forename: F A
authors.initials: FA
authors.lastname: García-Vázquez
mesh_terms: D000818:Animals; D005260:Female; D005306:Fertilization; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D013076:Sperm Count; D013081:Sperm Motility / Q000502:physiology*; D013552:Swine / Q000502:physiology*; D013997:Time Factors
keywords: Backflow; Motility; Porcine; Spermatozoa; Uterus selection