Moribund sperm in frozen-thawed semen, and sperm motion end points post-thaw and post-swim-up, are related to fertility in Holstein AI bulls》.pdfVIP

Available online at Theriogenology 77 (2012) 940–951 Moribund sperm in frozen-thawed semen, and sperm motion end points post-thaw and post-swim-up, are related to fertility in Holstein AI bulls a b c d a,c a, H. Shojaei , T. Kroetsch , R. Wilde , P. Blondin , J.P. Kastelic , J.C. Thundathil * a Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1 b The Semex Alliance, Guelph, Ontario, Canada N1G 3Z2 c Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, AB, Canada T1J 4B1 d L’Alliance Boviteq, Inc., Saint-Hyacinthe, QC, Canada J2T 5H1 Received 14 April 2011; received in revised form 14 September 2011; accepted 26 September 2011 Abstract The objectives were to compare testicular physical characteristics and post-thaw sperm characteristics and their associations with fertility in Holstein bulls used for AI. Ten Holstein bulls (4–5 y old) were classified as either high-fertility (HF) or low-fertility (LF; n 5 each), based on adjusted 56-d non-return rates [non-return rate (NRR); range (mean SD): 55.6 4.6 to 71.8 1.3%). Testicular physical characteristics were not significantly different between the two groups. Four ejaculates were collected from each bull and cryopreserved. Several indexes of sperm motion (based on computer-assisted sperm an