Semen characteristics and fertility in the bull

Abstract

1. Certain characteristics of bull semen have been examined at four artificial insemination centres in England. One hundred and twenty-one samples of semen, comprising 168 ejaculates from seventysix bulls of seven breeds, were examined. The semen from 119 tested samples was subsequently used to inseminate 4604 cows.The following semen characteristics were studied: volume of ejaculate; concentration of spermatozoa; incidence of dead spermatozoa; incidence of morphologically abnormal spermatozoa; initial fructose concentration; resistance of spermatozoa to temporature shock; methylene-blue reduction; O2 uptake; fructose utilization; visual evaluation of motility; impedance change frequency; and fertilizing capacity (conception rate).A clinical examination was made of the reproductive organs of each bull.2. Variations in the concentration of living spermatozoa and in the incidence of dead spermatozoa were found to account for most of the variations in the metabolic activity of semon: they also largely explained differences in physical activity as assessed by visual estimation of motility or by impedance change frequency.3. Although the rates of methylene-blue reduction, O2 uptake and fructolysis showed a close correlation with the numbers of living spermatozoa present, O2 uptake and fructolysis per living cell decreased with increasing cell concentration.4. Variations in metabolic activity showed no correlation with variations in the morphological characteristics of the spermatozoa, except in the case of spermatozoa with bent tails. These forms occurred in some samples as a result of staining treatment, but their incidence was positively correlated with the O2 uptake and fructolysis per living cell.5. There was evidence that highly active spermatozoa are more resistant to temperature shock than less active spermatozoa.

Metabolism of Turkey Semen as Affected by the Environment of Donor Birds , ,

“…In turn, this quality is correlated with their fertilizing capacity Herman 1941, 1944;Bishop et a!., 1954). While no similar observations were made in the present study, it is not inconceivable that the environment 3 spermatozoa, because of its impaired oxidative activity, had a shorter functional life span both in vitro and in the oviduct.…”

“…In fact, the latter investigators reported a negative correlation between sperm respiration and semen fertilizing capacity. Bishop et al (1954) concluded that most of the variation in the oxygen uptake by bull semen can be accounted for by sperm concentration and abnormal spermatozoa.…”

Effect of heat stress on the fertility of male mice in vivo and in vitro

“…Spermatozoa were released from the epididymides from each male in 0.5 mL bicarbonatebuffered HTF under oil using puncture with a 26-gauge needle and slight pressure and allowed to disperse for 20 min. The spermatozoa were then counted and their motility assessed in a haemocytometer and the live : dead ratio determined after staining with nigrosin and eosin (Bishop et al 1954). The spermatozoa suspensions were diluted so that each contained 1-2 million motile spermatozoa per mL, and droplets of 50 µL were placed in a 35-mm dish, overlaid with 2 mL paraffin oil and put in an incubator at 37 • C in an atmosphere of 5% CO 2 : 95% air.…”

The Effect of pH on Ram Sperm Collective Motility Driven by Mitochondrial Respiration

“…I n addition, this range was chosen because spontaneous p H changes in semen occur within these limits. Semen metabolism and motility have been intensively studied in view of their correlation with semen fertilizing capacity (Bishop et al 1954;Freund & Peterson 1976;Linford et al 1976). Our findings show that sperm collective motility driven by mitochondrial respiration was influenced by the pH of the medium.…”