BACKGROUND Psychological factor alters fertility hormones and contributes to male infertility. Anxiety and depression are common manifestations of psychological distress. Cytochrome P-4501A1 (CYP1A1) metabolizes xenobiotics and fertility hormones that influence male fertility. The effect of CYP1A1 polymorphism on male fertility has remained controversial. The present study was designed to asses...

Artificial insemination (AI) can help to avoid inbreeding and genetic degeneration for sustaining genetically healthy populations of endangered species in captivity. Collection of a sufficient quantity of viable sperm is an essential first step in the AI process. In the present study, we examined the effects of frequent electroejaculation on semen characteristics in a Siberian tiger. We collect...

semen quality and its relationship to fertility are major concern in animal production. the aim of this study was to assess the relationship between frozen thawed sperm characteristics and fertility following in vivo fertility through artificial insemination(ai). semen samples were collected from four buffalo bulls. semen volume and sperm concentration appeared to be significantly different (p0...

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may ...

The range of variability in the population distribution characteristics of sperm DNA content was surveyed in a selected group of donors. The donors included identical twins, carriers of chromosomal translocations, and oligospermics. The DNA content of sperm was measured individually in an automated cytofluorometer. In contrast to normal donors with high sperm counts and relatively constant moda...

In the present study, bull sperm in the first and second ejaculates were divided into subpopulations based on their motility characteristics using a cluster analysis of data from computer-assisted sperm motility analysis (CASA). Semen samples were collected from 4 Japanese black bulls. Data from 9,228 motile sperm were classified into 4 clusters; 1) very rapid and progressively motile sperm, 2)...

Bulls vary greatly in semen quality, both among bulls and among ejaculates within a bull. Therefore, semen is evaluated routinely using those characteristics that are known to affect fertility. These include general appearance of the semen, volume of the ejaculate, concentration of sperm, motility, metabolic activity, percent live/dead and morphological abnormalities. The minimum levels for a s...

BACKGROUND Sperm cryopreservation has become an indispensable tool in biology. Initially, studies were aimed towards the development of efficient freezing protocols in different species that would allow for an efficient storage of semen samples for long periods of time, ensuring its viability. Nowadays, it is widely known that an important individual component exists in the cryoresistance of se...

Characteristics of the developmental stages of spermatids during spermiogenesis and phylogenetic classicfication of the species using sperm ultrastructures in male Crassostrea ariakensis were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of Ostreidae. Ultrastructures of mature sperms...