Medición Testicular en Sementales de Raza Caballo Chileno Enteros y Castrados Unilateralmente

Abstract

El objetivo del presente estudio fue establecer el tamaño testicular y estimar la producción espermática diaria (PED) en sementales de raza Caballo Chileno enteros y castrados unilateralmente. Se estudiaron 61 sementales (31 con ambos testículos y 30 castrados unilateralmente), de 3 a 20 años de edad. Se midió el alto, ancho y largo de los testículos con un vernier escrotal, se calculó el volumen testicular (VT) y se estimó la PED utilizando las fórmulas propuestas por Sertich (2011). Las medidas testiculares en los sementales con ambos testículos fueron mayores a las esperadas y sin diferencia estadística entre testículos contralaterales en sementales enteros. La PED estimada en sementales con ambos testículos fue de 7.67 ± 2.32 x 109 espermatozoides. En los sementales castrados unilateralmente no hubo diferencias de tamaño relacionadas con el testículo que mantenían, pero el alto, ancho y VT fueron mayores que en los sementales enteros (p<0.05). La PED estimada en sementales castrados unilateralmente fue de 5.13 ± 1.84 x 109 espermatozoides, lo cual es 33% menor que en caballos enteros (p<0.0001). Los resultados permiten concluir que las medidas testiculares de los sementales de raza Caballo Chileno son mayores a las esperadas para su tamaño corporal.<br /><br />

Hemicastration in Chilean rodeo stallions in competition

“…The absence of statistical differences in relation to the most frequently removed testicle, suggests that there is no predisposition to problems in a certain testicle. This coincides with the study by Muñoz-Alonzo et al (2016), in addition, these researchers reported that in the Chilean Horse stallions there are no significant differences in the size of both testicles in intact stallions.…”

“…This could be due to that no other sport equine populations performs lateral canter in the way that the Chilean Horse does. Also, Chilean Horse Stallions have been reported with a high relative testicular size (Muñoz-Alonzo et al 2016). Most of the reports in the literature, correspond to statistical information on the hemicastration of stallions with unilateral testicular lesions (de Ban 1970, Maxwell 2005 or cryptorchidism performed in clinical centers (Cox et al 1979, Varner andSchumacher 1998, Mueller 2 http://www.caballoyrodeo.cl/portal_rodeo/stat/port/resultados.html and Parks 1999, Searle et al 1999, Lu 2005, Marshall et al 2007, Hartman et al 2015, Huppes et al 2017.…”

“…In the Chilean rodeo the stallions could suffer testicular trauma during the lateral movement at canter, associated with the anatomical position of the testicles and the muscles of the thighs (Apaoblaza 2015). In addition, the risk of suffering a testicular traumatism is greater considering that it has been reported that the testicular size in Chilean stallions is proportionally greater than expected for a pony (Muñoz-Alonzo et al 2016), and similar to the testicular size of Dutch warmblood stallions or a draft stallions at 4 years of age (Parlevliet et al 1994, Stout andColenbrander 2011). Muñoz-Alonzo et al (2016), reported that many of the stallions participating in the Chilean rodeo are unilaterally castrated with the purpose of improving their performance.…”

“…In addition, the risk of suffering a testicular traumatism is greater considering that it has been reported that the testicular size in Chilean stallions is proportionally greater than expected for a pony (Muñoz-Alonzo et al 2016), and similar to the testicular size of Dutch warmblood stallions or a draft stallions at 4 years of age (Parlevliet et al 1994, Stout andColenbrander 2011). Muñoz-Alonzo et al (2016), reported that many of the stallions participating in the Chilean rodeo are unilaterally castrated with the purpose of improving their performance. Because there are few studies regarding hemicastration in the Chilean Horse stallions (Apaoblaza 2015, Muñoz-Alonzo et al 2016, the objectives of this study were to: a) establish the frequency, age and reason for hemicastration, b) determine the most frequently removed testicle and c) compare the athletic performance between unilaterally castrated and intact Chilean rodeo stallions participating in the 2016 Chilean rodeo qualifying rounds and National Championship.…”

“…Muñoz-Alonzo et al (2016), reported that many of the stallions participating in the Chilean rodeo are unilaterally castrated with the purpose of improving their performance. Because there are few studies regarding hemicastration in the Chilean Horse stallions (Apaoblaza 2015, Muñoz-Alonzo et al 2016, the objectives of this study were to: a) establish the frequency, age and reason for hemicastration, b) determine the most frequently removed testicle and c) compare the athletic performance between unilaterally castrated and intact Chilean rodeo stallions participating in the 2016 Chilean rodeo qualifying rounds and National Championship.…”