AGE-RELATED CHANGES AND SEASONAL VARIATIONS IN THE DAILY SPERM PRODUCTION OF THE STALLION | ||||
| Veterinary Medical Journal (Giza) | ||||
| Volume 40, Issue 3, July 1992, Page 73-85 PDF (4.16 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/vmjg.1992.372623 | ||||
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| Author | ||||
| MOSTAFA ABOU-AHMED* | ||||
| Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt. | ||||
| Abstract | ||||
| Fifty-six testes were collected from 28 Arab and native stallions (aged 3 to 18 years) along a complete annual cycle to determine the influence of age and season on the daily sperm production (DSP) by a quantitive histological technique. Overall mean values for testicular measurements, percentage of seminiferous tubules (SNT%), corrected number of spermatids and diameter of SNT/stage I cross-section were given in the text. Estimates of 4.39 x 107 sperm/testis/day, 8.77 x 109 sperm/ stallion/day and 28.45 x 106 sperm/g parenchyma were noted. highly significant (P < 0.01) increase with age in these traits was evident up to 13 years old stallions, where peak values of 5.30 x 107, 10.60 x 109 and 33.67 x 109 for the foregoing parameters were achieved. On the other hand, testicular weight, parenchymal weight, number of spermatids per stage I tubule cross-section and DSP/g accounted for 64%, 63%, 67% and 86% of the variation in the DSP/testis, respectively. Age- related changes in the above mentioned parameters were also scrutinized. The onset of breeding season (December-May) in Arab and native hors was associated with a significant increase in testicular weight (13%), parenchymal weight (14%), diameter of SNT/ Sage I cross-section (8%), corrected number of spermatids/stage I tubule cross- Section (15. %), DSP/testis (27%) and DSP/stallion (27%). The production of Sperm (per testis/day or stallion/day) was lowest (3.66 x 109 vs 5.01 x 109 and 7.33 x 109 vs 10.03 x 109; P<0.01) in the non-breeding season, averaging only 73% of the DSP in the breeding season. Therefore, stallions are capable of producing Significantly more spermatozoa (2.70 x 109 additional sperm/stallion/day) in the breeding season and could supply sufficient numbers of sperm for insemination of more mares at this time. | ||||
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