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Testicular parameters, parenchymal spermatid concentration, and epididymal sperm reserves were measured in tracts obtained from 16 Awassi rams classified into three age groups (1, 1·5 and 2·5 years old). Between 1 and 2·5 years of age the paired testis weight increased from 164·9 to 315·2 g, the testicular spermatid number (x 10 9 ) increased from 15·9 to 55·8, and the total epididymal sperm reserves (x 10 9 ) increased from 11·1 to 98·8.Significant correlations were found between the paired testis parenchyma weight and all testicular dimensions and size. Testicular spermatid numbers and concentration were correlated with paired testis weight (r = 0·91 and 0·63), paired testis volume (r = 0·92 and 0·64) and all testicular measurements, particularly paired length x depth (r = 0·92 and O· 66).Regression coefficients between all parameters were essentially linear and highly significant, allowing accurate predictions of testis weight, volume and spermatid numbers to be made. The total epididymal sperm reserves and the sperm content of each of the caput, corpus and cauda of the epididymis were correlated with the paired weights of the epididymis (r = 0·73,0·75,0·73 and 0·70), the testis (r = 0·76, 0·83, 0·91 and 0·72), the total spermatid numbers in testicular homogenates (r = 0·70, 0·85, 0·91 and 0·64), and spermatid concentration (r = 0·56, 0·75, 0·72 and 0·49). The storage capacity of the cauda epididymides appeared to develop more slowly than the rate of sperm production because at 2·5 years of age it was about 1 ·5 and 2·8 times that in rams aged 1·5 and 1 year respectively. IntroductionIn Iraq the fat-tailed Awassi is one of the major and most popular breeds of sheep. Information on the reproductive performance of this breed and particularly of the rams is very limited (Juma and Dessouky 1969;Injidi 1974). The aim of the present work was to quantify the sperm producing potential and epididymal sperm reserves of Awassi rams in relation to age, to establish their correlation with testis size and weight, and to find out how far the variations in epididymal sperm reserves relate to testicular sperm production.

ContentsThe present study aimed to investigate the influencc on bovine spermatozoa of nitroglycerin (1,2,3-propanetriol trinitrate), which is known for its stimulating effect on the cGMP pathway. Rcsults revealed that the motility of spermatozoa from the nitroglycerin-treated samples was significantly improved compared with the control samples and this improvement was demonstrable for up to 2 hours. Meanwhile, live sperm percentage and the percentage oP spermatozoa with intact acrosomes were not affected. In addition, significant improvement in the cervical mucus penetrability of spermatozna from the treated samples could be detected. It could, therefore, be infcrred that cGMP plays an important role in enhancing bovine sperm motility. Inhalt Stimulation des zyklischen Guanosin Munophosphat (cGMP) Reaktionsweges hinsichtlich verschievener Spermoparameter beim RindDie Studie hatte zum Ziel, den EinfluB von Nitroglyzerin (1,2,3-Propanetrioltrinitat), dessen stimulierender Effekt auf den cGMP-Reaktionweg bekannt ist, auf Rindersperma zu untersuchen. Die Ergebnisse zeigen, daR dic Spermamotilitiit in mit Nitroglyzerin behandclten Proben signifikant uber denen dcr Kontrollgruppe lagen und daB dieser Anstieg fur bis ZLI 2 Stunden anhielt. Dabei wurde der Prozentsatz lebender und Akrosom-intakter Samenzellen nicht beeinfluat. AuMerdem konnte gezeigt werden, daR das Penetrationsvermtigen der Spermien gegenuber Zervicalmukus erhoht war. Hieraus laljt sich ableiten, daB cGMP eine wichtige Rolle fur die Motilitatssteigeruiig von Bullensperma spieit.

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