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. 2022 Mar-Apr;12(2):171-181.
doi: 10.5455/OVJ.2022.v12.i2.3. Epub 2022 Mar 11.

Suppression of reproductive function in juvenile rams by a slow-release gonadotropin-releasing hormone implant

Luise Prestel  1 , Jessica Joerling  2 , Klaus Failing  3 , Henrik Wagner  1 , Axel Wehrend  1
Affiliations

Suppression of reproductive function in juvenile rams by a slow-release gonadotropin-releasing hormone implant

Luise Prestel et al. Open Vet J. 2022 Mar-Apr.

Abstract

Background: Regarding animal welfare and reversible suppression of reproduction the need for alternatives to surgical castration, like slow-release gonadotropin-releasing hormone (GnRH) implants, is increasing.

Aim: In this study, we evaluated whether the onset of puberty can be suppressed by implantation of a slow-release GnRH implant (4.7 mg deslorelin) in juvenile rams.

Methods: Seven juvenile rams (3-5.5 months) were treated with the GnRH analog deslorelin to analyze the effects on testicular development, sonographic findings of testicular tissue, testosterone concentration in the blood, spermatogenesis, and sperm parameters from the epididymis after castration. Seven rams of the same age without an implant served as controls.

Results: Follow-up examinations were conducted over 5 months, after which four rams per group were castrated. No significant group differences were found in the andrological parameters on the group level, but testicular development was suppressed in three rams in the treated group. Histological examination revealed spermatogenesis in the testicular tissue in three of four animals treated with a GnRH analog.

Conclusion: The onset of puberty in juvenile rams cannot be reliably suppressed by using the slow-release GnRH implant Suprelorin®.

Keywords: Castration; Hormonal downregulation; Male; Puberty; Sheep.

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Conflict of interest statement

The authors declare that there is no conflict of interest.

Figures

Fig. 1.
Fig. 1.. Sonographic image of the testicular tissue (Honda HS- 1500 VET, 7.5 MHz, transrectal probe) presenting moderate echogenicity, and the mediastinum testis presenting as a hyperechogenic structure. The ROIs were located on both sides of the mediastinum testis with a basal area of 0.25 cm2.
Fig. 2.
Fig. 2.. Different testicular convolute sizes of a ram after treatment with deslorelin (right) and without treatment (left).
Fig. 3.
Fig. 3.. Testis and epididymal body (from top to bottom). Each from a sheep with normal (left) and completely suppressed spermatogenesis (right). H&E staining, 100× magnification.
See this image and copyright information in PMC

References

    1. Adams T.E. Using gonadotropin-releasing hormone (GnRH) and GnRH analogs to modulate testis function and enhance the productivity of domestic animals. Anim. Reprod. Sci. 2005;88:127–139. - PubMed
    1. Aponte P.M, Gutierrez-Reinoso M.A, Sanchez-Cepeda E.G, Garcia-Herreros M. Active immunization against GnRH in pre-pubertal domestic mammals: testicular morphometry, histopathology and endocrine responses in rabbits, guinea pigs and ram lambs. Animal. 2018;12:784–793. - PubMed
    1. Aravindakshan J.P, Honaramooz A, Bartlewski P.M, Beard A.P, Pierson R.A, Rawlings N.C. Pattern of gonadotropin secretion and ultrasonographic evaluation of developmental changes in the testis of early and late maturing bull calves. Theriogenology. 2000;54:339–354. - PubMed
    1. Belibasaki K. Sexual activity and body and testis growth in prepubertal ram lambs of Friesland, Chios, Karagouniki and Serres dairy sheep in Greece. Small Rumin. Res. 2000;37:109–113. - PubMed
    1. Brinsko S.P, Squires E.L, Pickett B.W, Nett T.M. Gonadal and pituitary responsiveness of stallions is not down-regulated by prolonged pulsatile administration of GnRH. J. Androl. 1998;19:100–109. - PubMed

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