title: Under-nutrition reduces spermatogenic efficiency and sperm velocity, and increases sperm DNA damage in sexually mature male sheep.
abstract: 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 well-fed 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.
authors.affiliation: UWA Institute of Agriculture M082, and School of Animal Biology M082, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
authors.forename: Yongjuan
authors.initials: Y
authors.lastname: Guan
authors.affiliation: UWA Institute of Agriculture M082, and School of Animal Biology M082, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia; Department of Animal Sciences, University of Stellenbosch, Matieland 7600, South Africa.
authors.forename: Irek A
authors.initials: IA
authors.lastname: Malecki
authors.affiliation: UWA Institute of Agriculture M082, and School of Animal Biology M082, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
authors.forename: Penelope A R
authors.initials: PA
authors.lastname: Hawken
authors.affiliation: Centre for Microscopy, Characterisation & Analysis, University of Western Australia, Perth, Western Australia 6009, Australia.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Linden
authors.affiliation: UWA Institute of Agriculture M082, and School of Animal Biology M082, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia; Nuffield Department of Obstetrics & Gynaecology, University of Oxford, Oxford OX3 9DU, UK. Electronic address: graeme.martin@uwa.edu.au.
authors.forename: Graeme B
authors.initials: GB
authors.lastname: Martin
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004249:DNA Damage / Q000187:drug effects*; D004032:Diet / Q000662:veterinary*; D008297:Male; D055101:Semen Analysis / Q000662:veterinary; D012756:Sheep / Q000502:physiology*; D013081:Sperm Motility / Q000502:physiology*; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000033:anatomy & histology
keywords: DNA damage; Ram; Sperm motility; Sperm number