title: Season-induced changes in bovine sperm motility following a freeze-thaw procedure.
abstract: Decreased conception rate of dairy cows in the summer is mainly associated with the deleterious effects of environmental thermal stress on the female reproductive tract. Here, we suggest that decreased reproductive performance might be partially due to inferior-quality semen. Semen from five representative bulls was collected in summer (August to September) and winter (December to January) and evaluated with a computerized sperm-quality analyzer for bulls (SQA-Vb). No seasonal effect was found in fresh ejaculate, but sperm examined post-thawing showed lower velocity, motility and progressive motility (P<0.04) in summer vs. winter samples. Element concentrations in the seminal plasma, determined by inductively coupled plasma-atomic emission spectrometry, differed between seasons, with higher (P<0.01) concentration values of K, Mg, Na and S elements in winter vs. summer samples. Therefore, season-induced alterations in seminal plasma element concentration should be taken into account when using an extender for cryopreservation. Acrosome integrity was assessed by a triple-fluorescence test using Hoechst 33342, fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and propidium iodide. Acrosome reaction was examined by a one-step staining method using FITC-PSA. The proportion of sperm cells with a damaged acrosome post-thawing tended to be higher (P<0.07) in semen collected during the summer vs. winter. Such alterations suggest that seasonal reductions in sperm function might also be involved in the decreased conception rate of dairy cows in summer.
authors.affiliation: The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 76100, Israel.
authors.forename: Shlomo
authors.initials: S
authors.lastname: Orgal
authors.forename: Yoel
authors.initials: Y
authors.lastname: Zeron
authors.forename: Nili
authors.initials: N
authors.lastname: Elior
authors.forename: David
authors.initials: D
authors.lastname: Biran
authors.forename: Eran
authors.initials: E
authors.lastname: Friedman
authors.forename: Shaked
authors.initials: S
authors.lastname: Druker
authors.forename: Zvi
authors.initials: Z
authors.lastname: Roth
mesh_terms: D000177:Acrosome / Q000378:metabolism; D020101:Acrosome Reaction; D000818:Animals; D017849:Animals, Inbred Strains; D002417:Cattle / Q000502:physiology*; D003612:Dairying; D005260:Female; D007557:Israel; D008274:Magnesium / Q000032:analysis; D008297:Male; D008856:Microscopy, Fluorescence / Q000662:veterinary; D011188:Potassium / Q000032:analysis; D012621:Seasons; D012661:Semen / Q000737:chemistry / Q000166:cytology; D055101:Semen Analysis / Q000662:veterinary; D012662:Semen Preservation / Q000009:adverse effects / Q000662:veterinary*; D012964:Sodium / Q000032:analysis; D013054:Spectrophotometry, Atomic / Q000662:veterinary; D013081:Sperm Motility
chemical_list: D012964:Sodium; D008274:Magnesium; D011188:Potassium