Abstract
Two experiments were conducted to characterize scrotal surface temperature (SST) in bulls treated with gonadotropin releasing hormone (GnRH). In Experiment 1, Angus bulls (n = 10, 18 mo, 597 kg) were given GnRH (400 ng/kg) or saline, IV. Bottom SST increased approximately 1.7 degrees C (P < 0.005) over time (0 to 90 min) at an ambient temperature of 5 degrees C. However, there was no significant effect of GnRH treatment and temperature increases were attributed to stress. When the experiment was repeated at an ambient temperature of 25 degrees C, SST was elevated prior to treatment, with no subsequent significant increase. Experiment 2 was conducted with Charolais bulls (n = 6, 12-14 mo, 517 kg) with an emphasis on minimizing stress. Bottom SST increased approximately 2 degrees C (P < 0.05) between 0 and 45 min after GnRH treatment, supporting the hypothesis that GnRH treatment increases SST in bulls. In conclusion, it was apparent that stress, high ambient temperatures, and GnRH treatment can all increase SST in bulls.
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- Chandolia R. K., Honaramooz A., Bartlewski P. M., Beard A. P., Rawlings N. C. Effects of treatment with LH releasing hormone before the early increase in LH secretion on endocrine and reproductive development in bull calves. J Reprod Fertil. 1997 Sep;111(1):41–50. doi: 10.1530/jrf.0.1110041. [DOI] [PubMed] [Google Scholar]
- Cook R. B., Coulter G. H., Kastelic J. P. The testicular vascular cone, scrotal thermoregulation, and their relationship to sperm production and seminal quality in beef bulls. Theriogenology. 1994 Feb 2;41(3):653–671. doi: 10.1016/0093-691x(94)90175-i. [DOI] [PubMed] [Google Scholar]
- Damber J. E., Bergh A., Daehlin L. Stimulatory effect of an LHRH-agonist on testicular blood flow in hypophysectomized rats. Int J Androl. 1984 Jun;7(3):236–243. doi: 10.1111/j.1365-2605.1984.tb00780.x. [DOI] [PubMed] [Google Scholar]
- Gábor G., Sasser R. G., Kastelic J. P., Coulter G. H., Everson D. O., Falkay G., Mézes M., Bozó S., Cook R. B., Csik J. V. Endocrine and thermal responses to GnRH treatment and prediction of sperm output and viability in holstein-Friesian breeding bulls. Theriogenology. 1998 Jul 15;50(2):177–183. doi: 10.1016/s0093-691x(98)00124-1. [DOI] [PubMed] [Google Scholar]
- Gábor G., Sasser R. G., Kastelic J. P., Coulter G. H., Falkay G., Mézes M., Bozó S., Völgyi-Csík J., Bárány I., Szász F., Jr Morphologic, endocrine and thermographic measurements of testicles in comparison with semen characteristics in mature Holstein-Friesian breeding bulls. Anim Reprod Sci. 1998 May 15;51(3):215–224. doi: 10.1016/s0378-4320(98)00077-3. [DOI] [PubMed] [Google Scholar]
- Gábor G., Sasser R. G., Kastelic J. P., Mézes M., Falkay G., Bozó S., Csík J. V., Bárány I., Hidas A., Szász F., Jr Computer analysis of video and ultrasonographic images for evaluation of bull testes. Theriogenology. 1998 Jul 15;50(2):223–228. doi: 10.1016/s0093-691x(98)00129-0. [DOI] [PubMed] [Google Scholar]
- Kaufmann C., Kündig H., Binder H., Thun R. Messung von Stressparametern bei Nutztieren mittels aktiver Telemetrie. Schweiz Arch Tierheilkd. 1996;138(5):234–240. [PubMed] [Google Scholar]
- Post T. B., Christensen H. R., Seifert G. W. Reproductive performance and productive traits of beef bulls selected for different levels of testosterone response to GnRH. Theriogenology. 1987 Feb;27(2):317–328. doi: 10.1016/0093-691x(87)90220-2. [DOI] [PubMed] [Google Scholar]
- Schanbacher B. D., Echternkamp S. E. Testicular steroid secretion in response to GnRH-mediated LH and FSH release in bulls. J Anim Sci. 1978 Aug;47(2):514–520. doi: 10.2527/jas1978.472514x. [DOI] [PubMed] [Google Scholar]