Testicular Morphological and Ultrasonographic Characterization of Male Gray Brocket Deers (Mazama gouazoubira) in Different Reproductive Status

Duanny Murinelly de Souza Cunha, Mirley Barbosa de Souza, Bruna Farias Brito, Vítor Lima Torres, Thales Gothardo Pereira Nunes, Samuel Salgado Tavares, Daniel de Araujo Viana, Lúcia Daniel Machado da Silva, Leda Maria Costa Pereira, Dárcio Ítalo Alves Teixeira

Abstract


Background: Gray brocket deer (Mazama gouazoubira) populations have been declining due to human intervention. Yet, only a few studies have assessed ultrasonographic testicular characteristics in cervids. Considering the relevance of monitoring testicular size, blood flow, and parenchyma, the present study aims to establish baseline information on scrotal circumference, testicular volume, and spectral Doppler parameters, to describe differences among adult male gray brocket deer in different reproductive status, and to correlate ultrasound parameters with testes size measurements.

Materials, Methods & Results: Six adult male gray brocket deers were used in the study. Scrotal circumference and testicular volume were measured. B mode ultrasound images of testes (longitudinal and cross-sectional views) and epididymes were subjected to computer-assisted analysis, obtaining the numerical pixel values (NPV) and pixel standard deviation (PSD). Using spectral Doppler, supratesticular artery blood flow velocities (peak systolic velocity - PSV, end diastolic velocity - EDV, time-average maximum velocity - TAMAX, resistivity - RI and pulsatility indices - PI) were obtained. Semen was analyzed through total motility, vigor, and concentration tests. Three animals were normospermic (F+ group) and three were oligo/azoospermic (F- group). Groups were compared using were compared using a one-way ANOVA or Kruskal-Wallis followed by Student-Newman-Keuls (SNK) test. Ultrasound parameters were correlated to testes size parameters using Pearson’s correlation for parametric variables and Spearman’s correlation for non-parametric variables. F+ group presented significantly higher scrotal circumference (14.57 ± 1.19 cm), testicular volume (26.18 ± 4.94 cm3), and testes cross-sectional NPV (69.88 ± 24.00) and PSD (10.78 ± 3.42) than group F- (NPV: 28.26 ± 13.75, PSD: 6.70 ± 1.84). No significant differences were observed between the groups regarding the spectral Doppler ultrasound parameters. Significant correlations were observed between scrotal circumference and longitudinal (r = 0.76) and cross-sectional testes NPV (r = 0.89), and testicular volume was correlated with longitudinal (r = 0.78) and cross-sectional testes NPV (r = 0.91) and with cross-sectional testes PSD (ρ = 0.82).

Discussion: Increased testicular echogenicity (higher NPV) has been positively associated with improved testicular growth, cell population expansion, inner and outer seminiferous tubules diameter, spermatids percentages and testis weight. In addition, more heterogenous testes (higher PSD) were associated with higher sperm output. It was suggested that the animals in group F- had compromised testicular development and spermatogenesis. The correlation observed between testes NPV and scrotal circumference was proposed to be associated with seminiferous tubules impairment. The F- group showed lower testicular volume, NPVs and PSDs in cross-sectional testicular images, suggesting higher protein levels and lower lipid contents were present in their parenchyma, influencing in testicular echogenicity and echotexture. No differences in spectral Doppler parameters were observed between the two groups. Also observed in stallions. However, PSV, EDV, TAMAX could be potential infertility indicators in other mammalians. These different results may be due to different locations of the evaluated vessel, species and techniques, age, ambient temperature, pathological conditions, and anaesthesia. Thus, it is suggested that scrotal circumference, testicular volume, and testes NPV are good indicators of male reproductive health in gray brocket deer and may help with better male selection in the species.


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Ahmadi B., Lau C.P.S., Giffin J., Santos N., Hahnel, A., Raeside J., Christie H. & Bartlewski P.M. 2012. Suitability of epididymal and testicular ultrasonography and computerized image analysis for assessment of current and future semen quality in the ram. Experimental Biology and Medicine. 237(2): 186-193.

Ahmadi B., Mirshahi A., Giffin J., Oliveira M.E.F., Gao L., Hahnel A. & Bartlewski P.M. 2013. Preliminary assessment of the quantitative relationships between testicular tissue composition and ultrasonographic image attributes in the ram. Veterinary Journal. 198(1): 282-285.

Ali K.M., Ahmad N., Akhtar N., Ali S., Ahmad M. & Younis M. 2011. Ultrasound imaging of testes and epididymides of normal and infertile breeding bulls. Pakistan Veterinary Journal. 31(4): 345-350.

Arteaga A.A., Barth A.D. & Brito L.F.C. 2005. Relationship between semen quality and pixel-intensity of testicular ultrasonograms after scrotal insulation in beef bulls. Theriogenology. 64(2): 408-415.

Barth A.D. & Waldner C.L. 2002. Factors affecting breeding soundness classification Veterinary Medicine. Canadian Veterinary Journal. 43: 274-284.

Bartlewski P.M., Giffin J.L., Oluwole O.A. & Hahnel A.C. 2017. Prospective ultrasonographic and endocrine predictors of spermatogenic onset in ram lambs. Animal Reproduction Science. 179: 44-48.

Batissaco L., Celeghini E.C.C., Pinaffi F.L.V., Oliveira B.M.M., Andrade A.F.C., Recalde E.C.S. & Fernandes C.B. 2013. Correlations between testicular hemodynamic and sperm characteristics in rams. Brazilian Journal of Veterinary Research and Animal Science. 50(5): 384-395.

Baumgartner C., Bollerhey M., Ebner J., Laacke-Singer L., Schuster T. & Erhardt W. 2010. Effects of ketamine-xylazine intravenous bolus injection on cardiovascular function in rabbits. Canadian Journal of Veterinary Research. 74(3): 200-208.

Biagiotti G., Cavallini G., Modenini F., Vitali G. & Gianaroli L. 2002. Spermatogenesis and spectral echo-colour Doppler traces from the main testicular artery. BJU International. 90(9): 903-908.

Black-Decima P. & Vogliotti A. 2016. Mazama gouazoubira. The IUCN Red List of Threatened Species 2016. 56p. e.T29620A22154584. http://dx.doi.org/10.2305

Bousmaha F. & Khoudja F.B. 2012. Comparative and pathological study of the testis and epididymis in rams, bucks and bulls of Algeria. Asian Journal of Animal and Veterinary Advances. 7(10): 950-959.

Brito L.F.C., Barth A.D., Wilde R.E. & Kastelic J.P. 2012. Testicular ultrasonogram pixel intensity during sexual development and its relationship with semen quality, sperm production, and quantitative testicular histology in beef bulls. Theriogenology. 78(1): 69-76.

Cheng F., Wu J., Chan J.P., Wang J., Fung H., Colenbrander B. & Tung K. 2004. The effect of different extenders on post-thaw sperm survival , acrosomal integrity and longevity in cryopreserved semen of Formosan Sika deer and Formosan Sambar deer. Theriogenology. 61(9): 1605-1616.

Condorelli R., Calogero A.E. & La Vignera S. 2013. Relationship between testicular volume and conventional or nonconventional sperm parameters. International Journal of Endocrinology. 2013: 1-7.

Costa K.L.C., Matta S.L.P., Gomes M.L.M., Paula T.A.R., Freitas K.M., Carvalho F.A.R., Silveira J.A., Dolder H. & Mendis-Handagama S.M.L.C. 2011. Histomorphometric evaluation of the neotropical brown brocket deer Mazama gouazoubira testis, with an emphasis on cell population indexes of spermatogenic yield. Animal Reproduction Science. 127(34): 202-212.

Cursino M.S. & Duarte J.M.B. 2016. Using sperm morphometry and multivariate analysis to differentiate species of gray Mazama. Royal Society Open Science. 3(11): 1-9.

Dana N., Tegegne A. & Shenkoru T. 2000. Feed intake, sperm output and seminal characteristics of Ethiopian highland sheep supplemented with different levels of leucaena (Leucaena leucocephala) leaf hay. Animal Feed Science and Technology. 86: 239-249.

Duarte J. & Garcia J. 1995. Assisted reproduction in brazilian Cervidae. Revista Brasileira de Reprodução Animal. 19(1-2): 111-121.

Duguma G., Cloete S.W.P., Schoeman S.J. & Jordaan G.F. 2002. Genetic parameters of testicular measurements in Merino rams and the influence of scrotal circumference on total flock fertility. South African Journal of Animal Science. 32(2): 76-82.

Evans A.C.O., Pierson R.A., Garcia A., McDougall L.M., Hrudka F. & Rawlings N.C. 1996. Changes in circulating hormone concentrations, testes histology and testes ultrasonography during sexual maturation in beef bulls. Theriogenology. 46(2): 345-357.

Foster R.A. 2009. Sistema reprodutivo do macho. In: McGavin M.D. & Zachary J.F. (Eds). Bases da Patologia em Veterinária. 4.ed. Rio de Janeiro: Elsevier, pp.1317-1348.

Giffin J.L., Franks S.E., Rodriguez-Sosa J.R., Hahnel A. & Bartlewski P.M. 2009. A Study of Morphological and Haemodynamic Determinants of Testicular Echotexture Characteristics in the Ram. Experimental Biology and Medicine. 234(7): 794-801.

Goeritz F., Quest M., Wagener A., Fassbender M., Broich A., Hildebrandt T.B., Hofmann R.R. & Blottner S. 2003. Seasonal timing of sperm production in roe deer: Interrelationship among changes in ejaculate parameters, morphology and function of testis and accessory glands. Theriogenology. 59(7): 1487-1502.

Gosch B., Bartolomaeus T. & Fischer K. 1989. Light and scanning electron microscopy of fallow deer (Dama dama) spermatozoa. Journal of Reproduction and Fertility. 87(1): 187-192.

Gumbsch P., Gabler C. & Holzmann A. 2002. Colour-coded duplex sonography of the testes of dogs. The Veterinary Record. 151(5): 140-145.

Günzel-Apel A., Möhrke C. & Nautrup C. 2001. Colour-coded and pulsed Doppler sonography of the canine testis, epididymis and prostate gland: Physiological and pathological findings. Reproduction in Domestic Animals. 36: 236-240.

Hedia M.G., El-Belely M.S., Ismail S.T. & El-Maaty A.M.A. 2019. Monthly changes in testicular blood flow dynamics and their association with testicular volume, plasma steroid hormones profile and semen characteristics in rams. Theriogenology. 123: 68-73.

Javed M.T., Khan A. & Naz N.A. 2001. Studies on abnormal buffalo bulls with reference to scrotal circumference, semen characteristics, seminal plasma hormones and their association with testicular and epididymal histopathology. Veterinarski Arhiv. 71(4): 223-236.

Kutzler M., Tyson R., Grimes M. & Timm K. 2011. Determination of testicular blood flow in camelids using vascular casting and color pulsed-wave doppler ultrasonography. Veterinary Medicine International. 2011(4): 638602.

Madrid N., Ott R.S., Veeramachaneni D.N., Parrett D.F., Vanderwert W. & Willms C.L. 1988. Scrotal circumference, seminal characteristics, and testicular lesions of yearling Angus bulls. American Journal of Veterinary Research. 49(4): 579-585.

Martinez-Pastor F., Guerra C., Kaabi M., Garcia-Macias V., Paz P., Alvarez M., Herraez P. & Anel L. 2005. Season effect on genitalia and epididymal sperm from Iberian red deer, roe deer and Cantabrian chamois. Theriogenology. 63(7): 1857-1875.

Monfort S.L., Brown J.L., Bush M., Wood T.C., Wemmer C., Vargas A., Williamson L.R., Montali R.J. & Wildt D.E. 1993. Circannual inter-relationships among reproductive hormones, gross morphometry, behaviour, ejaculate characteristics and testicular histology in Eld’s deer stags (Cervus eldi thamin). Journal of Reproduction and Fertility. 98(2): 471-480.

Moxon R., Bright L., Pritchard B., Bowen I.M., Souza M.B., Silva L.D.M. & England G.C.W. 2015. Digital image analysis of testicular and prostatic ultrasonographic echogencity and heterogeneity in dogs and the relation to semen quality. Animal Reproduction Science. 160: 112-119.

Ortiz-Rodriguez J., Anel-Lopez L., Martín-Muñoz P., Álvarez M., Gaitskell-Phillips G., Anel L., Rodríguez-Medina P., Peña F. & Ferrusola C. 2017. Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions. PLoS ONE. 12(5): 1-22.

Palasz A.T., Cates W.F., Barth A.D. & Mapletoft R.J. 1994. The relationship between scrotal circumference and quantitative testicular traits in yearling beef bulls. Theriogenology. 42(4): 715-726.

Pintus E. & Ros-Santaella J.L. 2014. Assisted reproductive technologies in deer (Artiodactyla, Cervidae): a review. Scientia Agriculturae Bohemica. 45(2): 136-146.

Pozor M., Morrissey H., Albanese V., Khouzam N., Deriberprey A., Macpherson M.L. & Kelleman A.A. 2017. Relationship between echotextural and histomorphometric characteristics of stallion testes. Theriogenology. 99: 134-145.

Pozor M.A. & McDonnell S.M. 2004. Color Doppler ultrasound evaluation of testicular blood flow in stallions. Theriogenology. 61(5): 799-810.

Ribeiro M. da S., Quirino C.R., Junior A.B. & Pacheco A. 2017. Biometry and ultrasound evaluation of testicles and accessory glands in Santa Ines rams. Revista Brasileira de Zootecnia. 46(4): 317-323.

Rola L.D., Zanetti E.D.S. & Duarte J.M.B. 2013. Evaluation of semen characteristics of the species Mazama americana in captivity. Animal Production Science. 53(5): 472-477.

Samir H., Nyametease P., Nagaoka K. & Watanabe G. 2018. Effect of seasonality on testicular blood flow as determined by color Doppler ultrasonography and hormonal profiles in Shiba goats. Animal Reproduction Science. 197(October): 185-192. doi: 10.1016/j.anireprosci.2018.08.027.

Singh A.K., Brar P.S. & Cheema R.S. 2014. Relationships among frozen-thawed semen fertility, physical parameters, certain routine sperm characteristics and testosterone in breeding Murrah buffalo ( Bubalus bubalis ) bulls. Veterinary World. 7(9): 644-651.

Souza M.B., England G.C.W., Mota Filho A.C., Ackermann C.L., Sousa C.V.S., Carvalho G.G., Silva H.V.R., Pinto J.N., Linhares J.C.S., Oba E. & Silva L.D.M. 2015. Semen quality, testicular B-mode and Doppler ultrasound, and serum testosterone concentrations in dogs with established infertility. Theriogenology. 84(5): 805-810.

Strina A., Corda A., Nieddu S., Solinas G., Lilliu M., Zedda M.T., Pau S. & Ledda S. 2016. Annual variations in resistive index (RI) of testicular artery, volume measurements and testosterone levels in bucks. Comparative Clinical Pathology. 25(2): 409-413.

Ugwu S.O.C. 2009. Relationship between scrotal circumference, in situ testicular measurements and sperm reserves in the West African dwarf bucks. African Journal of Biotechnology. 8(7): 1354-1357.

Ungerfeld R., Villagrán M., Lacuesta L., Vazquez N. & Pérez W. 2017. Asymmetrical size and functionality of the pampas deer (Ozotoceros bezoarticus) testes: Right testis is bigger but left testis is more efficient in spermatogenesis. Journal of Veterinary Medicine Series C: Anatomia Histologia Embryologia. 46(6): 547-551.




DOI: https://doi.org/10.22456/1679-9216.98311

Copyright (c) 2019 Duanny Murinelly de Souza Cunha, Mirley Barbosa de Souza, Bruna Farias Brito, Vítor Lima Torres, Thales Gothardo Pereira Nunes, Samuel Salgado Tavares, Daniel de Araujo Viana, Lúcia Daniel Machado da Silva, Leda Maria Costa Pereira, Dárcio Ítalo Alves Teixeira

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