Under-nutrition reduces spermatogenic efficiency and sperm velocity, and increases sperm DNA damage in sexually mature male sheep

摘要

We tested whether the quality of spermatozoa from mature male sheep would be affected during nutrition-induced changes in testicular mass. Merino rams were fed for 65 days with diets that increased, maintained or decreased body and testis mass (n = 8 per group). In semen collected on Days 56 and 63, underfed rams had less sperms per ejaculate than wellfed rams (P < 0.05) and a lower sperm velocity (computer-assisted semen analysis) than well-fed or maintenance-fed rams (P < 0.05). Sperm chromatin structure assay revealed more sperm DNA damage in underfed rams than in well-fed rams (P < 0.05). The amount of sperm DNA damage was inversely correlated with change in scrotal circumference (r= -0.6, P < 0.05), the percentages of progressive motile sperm (r= -0.8; P < 0.01) and motile sperm (r = -0.6, P < 0.05), and the numbers of sperms per gram of testis (r= -0.55, P < 0.05). In testicular tissue collected on Day 65, underfed rams had fewer sperm per gram of testis than rams in the other two groups (P < 0.001). We conclude that, in adult rams, underfeeding reduces spermatogenic efficiency and that this response is associated with a reduction in spermatozoal quality. (C) 2014 Elsevier B.V. All rights reserved.C1 [Guan, Yongjuan; Malecki, Irek A.; Hawken, Penelope A. R.; Martin, Graeme B.] Univ Western Australia, UWA Inst Agr M082, Crawley, WA 6009, Australia. [Guan, Yongjuan; Malecki, Irek A.; Hawken, Penelope A. R.; Martin, Graeme B.] Univ Western Australia, Sch Anim Biol M082, Crawley, WA 6009, Australia. [Malecki, Irek A.] Univ Stellenbosch, Dept Anim Sci, ZA-7600 Matieland, South Africa. [Linden, Matthew D.] Univ Western Australia, Ctr Microscopy Characterisat & Anal, Perth, WA 6009, Australia. [Martin, Graeme B.] Univ Oxford, Nuffield Dept Obstet & Gynaecol, Oxford OX3 9DU, England.RP Martin, GB (reprint author), Univ Western Australia, Sch Anim Biol M085, 35 Stirling Highway, Crawley, WA 6009, Australia.EM graeme.martin@uwa.edu.auRI Martin, Graeme/A-2618-2008OI Martin, Graeme/0000-0002-1905-7934FU UWA School of Animal Biology and Yongjuan Guan; University of Western AustraliaFX This project was funded by the UWA School of Animal Biology and Yongjuan Guan was financially supported by a Scholarship for International Research Fees from the University of Western Australia. The authors are very grateful to Dr John Milton (School of Animal Biology, University of Western Australia) for designing the nutrition treatments. For assistance in handling the animals, we thank Mr. Matt Wilmot (CSIRO, Perth, Western Australia), Dr. Cesar Rosales Nieto and Mr. Gary Cass (School of Animal Biology, University of Western Australia). We would like to thank Dr. Anne Jequier (Pivet Medical, Perth, Western Australia) for her guidance on techniques, and Mr. Sheng Zhang (Zhejiang University, China), Ms. Margaret Blackberry, Dr. Trina Jorre de St Jorre and Mr. Fahad Almohsen (School of Animal Biology, University of Western Australia) for help with the collection and preservation of tissue.NR 50