Variation In Semen Characteristics Research Articles

Monthly and seasonal variations in semen characteristics and serum testosterone and triiodothyronine levels in Barki, Damascus mule goats and their crosses under subtropical conditions

Monthly and seasonal variations in semen characteristics and serum testosterone and triiodothyronine levels in Barki, Damascus mule goats and their crosses under subtropical conditions

Seasonal variation in semen characteristics of Chios and Friesian rams in Greece

Five Chios and five Friesian rams were used to study the effect of season on semen production. Semen samples were collected with an artificial vagina. In spite of the large variation of most of the semen characteristics among rams of the two breeds, seasonal variation in semen quantity (volume, concentration and total number of spermatozoa per ejaculate) and quality (percentage of motile spermatozoa, sperm progressive motility and percentage of abnormal spermatozoa) were significant ( P < 0.05). The best semen was produced mainly during autumn and the worst during spring (semen volume: 1.47 ml in Chios and 1.48 ml in Friesian rams versus 1.24 ml in Chios and 1.07 ml in Friesian rams; percentage of abnormal sperm: 5.66% in Chios and 5.42% in Friesian rams versus 8.22% in Chios and 7.75% in Friesian rams; total sperm/ejaculate (× 10 9): 7.05 in Chios and 6.74 in Friesian rams versus 4.09 in Chios and 4.05 in Friesian rams). The magnitude of these seasonal effects was not sufficient to prevent rams from being used for breeding throughout the year. However, the existence of differences among rams within each breed in semen quality and quantity makes it necessary to perform a semen evaluation on individual basis in order to select the best males before they are used for breeding.

Seasonal variations in semen quality of local and crossbred rams raised in the United Arab Emirates.

A total number of 900 semen ejaculates were collected by means of artificial vagina from 10 rams (five local and five crossbreed 'local x chios'). Each ram was scheduled for semen collection three times per week at equal intervals for approximately two months in each season. At each collection, two separate successive ejaculates were obtained. Semen ejaculates were tested for volume, pH, mass motility, methylene blue reduction time (MBRT) and sperm-cell concentration per milliliter. Sex drive of rams was estimated by measuring the reaction time (RT). The time from the first to the second ejaculate was also recorded (TBE). Data of the two breeds show that the overall means for seminal attributes were 0.75 ml, 6.82, 4.2, 216.1 s and 5102.26 x 10(6) sperm/ml, respectively. In both breeds the overall means for RT and TBE were 43.7 and 152.3 s, respectively. Excluding ejaculate volume and MBRT, breed of ram was without significant effect on the investigated seminal characters, and sex drive parameters. Semen of the second ejaculate was significantly (P < 0.01) less in volume, greater in motility, closer to neutrality, less in sperm-cell concentration. MBRT of the two ejaculates differed nonsignificantly. However, characteristics of the second ejaculate fell within the normal range of high quality semen. Although the tested rams are continuous breeding animals, yet seasonal variations in semen characteristics were observed. The best-quality semen occurred in winter (volume, 0.77 ml; pH, 6.95; motility, 4.53; MBRT, 3.24 min. and sperm concentration, 4932.72 x 10(6)/ml). According to the known indices of semen quality of the ram, semen of the other seasons is judged to be of good quality. The mean RT for both breeds was less than one minute. Breed effect on RT and BET was insignificant. Season of the year exerted a significant (P < 0.01) effect on RT. The shortest time was recorded in summer, whereas the longest one was that of autumn. This indicates that the high ambient temperature of summer, prevailing in this locality, did not decrease the sexual activity of the tested rams.

Comparative study between Sinai and Rahmani sheep: 1- Some reproductive parameters of ewes and seasonal variation in semen characteristics

Comparative study between Sinai and Rahmani sheep: 1- Some reproductive parameters of ewes and seasonal variation in semen characteristics

Annual variation in semen characteristics and plasma hormone levels in men undergoing vasectomy

Prevasectomy levels of plasma luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), estradiol (E2), and 20 alpha-dihydroprogesterone (20 alpha-DHP), as well as semen analyses including semen volume, sperm count, and sperm motility from 260 healthy men were evaluated for annual changes. A statistically significant (P less than or equal to 0.015) high-amplitude seasonal variation with the peak in April to May was detected in semen volume, sperm count, and sperm motility. A statistically significant (P less than or equal to 0.04) annual change of moderate T to large FSH amplitude was detected in each of the five plasma endocrine variables as well. Plasma LH, T, and E2 peaked in autumn, while FSH and 20 alpha-DHP peaked in summer. Analysis of postvasectomy LH, FSH, E2, 20 alpha-DHP, and T blood levels for the 3 years following vasectomy revealed loss of seasonal rhythmicity as a group phenomenon in LH, E2, and T. The amplitude of the seasonal variation in FSH was decreased and that in 20 alpha-DHP was unchanged compared with before-vasectomy baselines. For those annual rhythms which persisted following vasectomy, the peak time was unchanged. Compared with the prevasectomy group annual mean, that for each of the endocrine values was unchanged, except for that of LH and T, which was slightly, yet statistically significantly, elevated. The existence of prominent annual variation implicates their consideration in the design of research protocols involving investigation of reproductive phenomena in human beings.

Seasonal variation in semen characteristics and the fertility of finn cross rams subjected to frequent ejaculation

Three Finn cross rams were put on a daily regime of five successive ejaculations for 17 consecutive days in June, August–September, November–December and March. The semen characteristics of the first and fifth ejaculates, and the fertility of the ewes receiving these ejaculates, were examined. Ewes were inseminated once, either naturally or artificially, 51–54 hours after the end of a hormone treatment for synchronization or induction of oestrus. The semen volume, sperm density, sperm number and the percentage of abnormal spermatozoa decreased from the first to the fifth ejaculate from 0.58 to 0.49 ml; 3.6 to 2.9 × 10 9; 2.2 to 1.5 × 10 9; and from 13.9% to 11.1%, respectively. A significant season × ejaculate interaction on sperm density and number was found. The sperm density, sperm number and percentage of abnormal spermatozoa also decreased in the course of the 17-day experimental periods (b = -0.058 × 10 9, −0.039 × 10 9, and −0.28%, respectively). The mean percentage of abnormal spermatozoa of the first and fifth ejaculates was higher in March (20.8%) than in June (7.1%), August–September (8.5) and November–December (13.5%). The fertility of the sperm, assessed by the lambing rates of the ewes, was not significantly different after artificial insemination (53.0%) from that obtained after natural service (61.7%); during the first days (45.0%) from that found during the last days (53.2%) of the 17-day experimental periods; and of the first ejaculate (54.4%) from the fertility of the fifth ejaculate (59.5%). A significant decrease was observed in sperm fertility in March (36% lambing rate vs 54–70% in the other seasons). It is concluded that an ejaculation frequency of five successive ejaculations for 17 consecutive days does not affect the fertility of Finn cross rams, irrespective of the season of semen collection.

Seasonal variation in semen characteristics of White Leghorn, New Hampshire and indigenous chicken in Iraq

1. The effects of season, temperature, humidity and light on semen volume, pH, concentration, motility and the proportions of dead and abnormal spermatozoa were investigated on White Leghorn, New Hampshire and Iraqi cockerels. 2. All semen characteristics, with the exception of pH, were significantly influenced by season. 3. The semen quality of the Iraqi breed was similar to that of the New Hampshire breed.

Seasonal variation in semen characteristics of Friesian bulls in Iraq

SummaryA total of 1659 ejaculates was collected from four Friesian bulls imported from Europe and ten of their offspring born in Iraq while in regular artificial service at the Abu-Ghraib Experiment Station. The work covered a period from 1 January 1965 to 30 June 1967.The five semen characteristics, volume, density, mass activity, individual motility and pH were studied and the influence of age of bull and season on these characters was investigated. The relationships between the characters were also investigated.Deterioration was observed in volume of ejaculate, density, mass activity and individual motility in the Iraqi Friesians. Influence of season on all semen characters lacked significance with the exception of mass motility in the European Friesian bulls (P &lt; 0·05). Highly significant positive correlations were found between most of the characters studied.

Seasonal Variations in Semen Characteristics of Adult Fayomi Cocks

DURING the coarse of domestication, there were pronounced changes in the reproductive phenomena of the male. One major effect of domestication is the spreading out of the breeding season throughout the year. This has been induced in the domestic chicken and is still bearing its function in the other domestic species like turkeys, geese and ducks.In the domestic chicken, semen production bears a close association with the varying seasons of the year. This association varies widely according to different latitudes, localities and breeds. In Missouri (35°N.) with New Hampshire cocks, the peak in semen production is reached during April and May, while the lowest values are observed during September (Parker, McKenzie and Kempster, 1942). At the same latitude, semen characteristics show seasonal decline from their highest values during late winter to the lowest values in midsummer (Munro, 1938; Burrows and Titus, 1939; Wheeler and Andrews, 1943). Only sperm concentration …

Seasonal variations in semen characteristics of sheep in the subtropics

Semen samples were collected from twelve fattailed rams of two breeds (nine Ossimi and three Rahmani), by the use of an artificial vagina. They were kept under natural conditions at Cairo, Egypt (30° N.). Three collections were made each month throughout one year (1951–2).