نتایج جستجو برای: sperm characteristics

تعداد نتایج: 695042  

Journal: :Fertility and sterility 1997
R K Sharma O F Padron A J Thomas A Agarwal

OBJECTIVE To identify whether the cause, site of ductal obstruction, and characteristics of fluid aspirates are associated with the cryosurvival and fertility after thawing of sperm obtained during reconstruction of the excurrent ducts with microsurgical epididymal sperm aspiration, vasal sperm aspiration, or both. DESIGN Prospective study. SETTING Andrology center at a tertiary care instit...

Journal: :veterinary research forum 2012
mahdi eghbali sayed mortaza alavi-shoushtari siamak asri-rezaei mohammad-hassan khadem ansari

in order to determine iron and lead content of seminal plasma in water buffalo and to study their associations with the semen characteristics, 54 semen samples were collected from 10 buffalo bulls. the semen characteristics were evaluated; its iron and lead content were estimated by atomic absorption spectrophotometer. the iron and lead content of the seminal plasma (mean ± sem) was recorded as...

2013
Dayanidhi Kumar Sujith Raj Salian Guruprasad Kalthur Shubhashree Uppangala Sandhya Kumari Srinivas Challapalli Srinidhi Gururajarao Chandraguthi Hanumanthappa Krishnamurthy Navya Jain Pratap Kumar Satish Kumar Adiga

BACKGROUND Cytogenetic studies have demonstrated that low levels of chronic radiation exposure can potentially increase the frequency of chromosomal aberrations and aneuploidy in somatic cells. Epidemiological studies have shown that health workers occupationally exposed to ionizing radiation bear an increased risk of hematological malignancies. OBJECTIVES To find the influence of occupationa...

2013
Leticia Zoccolaro Oliveira Pablo Daniel Reeb Fabio Morato Monteiro Janaina Torres Carreira

Even though a practical in vitro semen assay for determining bull fertility would be of great benefit to reproductive programs [6], it is unlikely that the evaluation of a single sperm characteristic may reflect the real sperm fertilization capacity of a semen sample. Hence, finding a set of sperm characteristics considered important for predicting conception rate would be a useful method of mo...

Journal: :Reproduction 2011
Stefan Lüpold Joachim Wistuba Oliver S Damm James W Rivers Tim R Birkhead

The outcome of sperm competition (i.e. competition for fertilization between ejaculates from different males) is primarily determined by the relative number and quality of rival sperm. Therefore, the testes are under strong selection to maximize both sperm number and quality, which are likely to result in trade-offs in the process of spermatogenesis (e.g. between the rate of spermatogenesis and...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2009
John L Fitzpatrick Robert Montgomerie Julie K Desjardins Kelly A Stiver Niclas Kolm Sigal Balshine

Sperm competition, the contest among ejaculates from rival males to fertilize ova of a female, is a common and powerful evolutionary force influencing ejaculate traits. During competitive interactions between ejaculates, longer and faster spermatozoa are expected to have an edge; however, to date, there has been mixed support for this key prediction from sperm competition theory. Here, we use t...

Journal: :iranian journal of applied animal science 2015
j. miro f. requena h. marin j. jordana e. aguera

sperm selection techniques have became an important tool to improve sub fertile ejaculates. the main aim of this study was to assess the dynamics of motile sperm subpopulations of ejaculates from subfertile stallions subjected to density gradient centrifugation (dgc) involving a double layer colloid [dgc2], before and after storage for 24 and 48 hours. ejaculates from eight stallions with ferti...

2010
Davendra Kumar Anil Joshi S. M. K. Naqvi

The present study was conducted to compare sperm motion characteristics of adult Malpura and Bharat Merino rams by the computer-aided sperm analysis (CASA) technique. Malpura is a hardy native sheep breed of the semi-arid tropical environment and Bharat Merino is a crossbred evolved in the same environment by crossing native sheep with exotic rams. Semen was collected from 8 donor rams of each ...

Journal: :Journal of animal science 2009
M L Looper R W Rorie C N Person T D Lester D M Hallford G E Aiken C A Roberts G E Rottinghaus C F Rosenkrans

Sixteen (mean age = 1.1 +/- 0.1 yr; mean BW = 478 +/- 34 kg) Brahman-influenced bulls were used to determine the influence of fescue type on sperm characteristics and serum concentrations of prolactin, cortisol, and testosterone. Bulls were blocked by BW, scrotal circumference (SC), and pregrazing sperm characteristics and randomly assigned to graze toxic endophyte-infected (EI; 4 bulls/pasture...

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