While sperm competition risk favours males transferring many sperm to secure fertilizations, females of a variety of species actively reduce sperm numbers reaching their reproductive tract, e.g. by extrusion or killing. Potential benefits of spermicide to females include nutritional gains, influence over sperm storage and paternity, and the elimination of sperm bearing somatic mutations that wo...

Experimental studies in insects have shown how sperm competition can be a potent selective force acting on an array of male reproductive traits . However, the role of sperm quality in determining paternity in insects has been neglected, despite the fact that sperm quality has been shown to influence the outcome of sperm competition in vertebrates . A recent comparative analysis found that males...

background: phenol is an estrogenic and toxic compound and people are widely exposed to it, in different ways.  objectives: the aim of this study was to determine  the  negative effects of phenol on the fertility of male mice, by investigating sperm parameters including viability, motility, fertility rates and daily sperm production (dsp). methods: a total of 106 adult nih mice were divided int...

In most species, females mate multiply within a reproductive cycle, invoking post-copulatory selection on ejaculatory components. Much research has focused on disentangling the key traits important in deciding the outcomes of sperm competition and investigating patterns of covariance among these traits. Less attention has focused on the degree to which such patterns might be context-dependent. ...

Background: Vitamin E is believed to be the primary component of the antioxidant system in spermatozoa. There is a relationship between activity of these antioxidant and function of sperm. Vitamins E and C which are belong to non-enzymatic antioxidant are used as a supplemented drug to improve sperm quality and male fertility. The present study was carried out to investigate the positive effect...

The objectives of this study were to investigate the effects of testis-epididymis cool storage on viability and progressive motility of buffalo epididymal sperm (EP) and to compare the influences of two basic semen extenders on post thaw EP viability and progressive motility. Abattoir collected buffalo testicles were allotted to three storage times (0 h: n = 10; 24 h: n = 10 and 48 h: n = 12). ...

reactive oxygen species (ros) generation, induced by the cryopreservation process, can be responsible for mammalian sperm damage. curcumin is known as an effective antioxidant against oxidative stress. the aim of this study was to evaluate the effects of curcumin on sperm count, motility and viability, semen total antioxidant capacity and dna integrity of rat spermatozoa during semen freeze-tha...

Background: Aluminum, as an environmental pollutant, can exert oxidative stress on spermatogenesis and sperm morphology. Silymarin, an effective substance extracted from Silybum marianum, is a potent antioxidant which inhibits oxidative stress. Due to the damaging effects of aluminum on the male reproductive system as well as sperm and the role of silymarin, this study was performed to investig...

objective(s):althoughroutinely applied in assisted reproductive technology, human sperm cryopreservation is not a completely successful procedure. adverse effects of cryopreservation on the fertilization capacity, motility, morphology, and viability of spermatozoa have been proven; cryopreservation has also shown a role in sperm dna fragmentation and infertility. the post-thaw survival of sperm...

the aim of this study was to evaluate the effects of the addition of antioxidants (vitamin e, β- mercaptoethanol and their combination) to semen extender.  progressive motility, viability and ph of fresh ram semen were examined. ejaculate samples were collected with artificial vagina from three ghezel-merinose rams (3 years old) during non- breeding reproduction season. semen was diluted with a...