Testicular echotexture is not a viable method to indirectly evaluate the spermatogenic parameters in Nelore bulls

Abstract

ABSTRACT. The objective of this study was to evaluate the testicular echotexture of Nelore bulls and to correlate it with spermatogenic parameters. Forty one bulls aged 3-5 years, with body weight of 510.2 ± 21.61 kg were selected for the study. The animals were subjected to ultrasonography, using a portable device coupled with a linear transducer at a frequency of 7.5 MHz. Immediately afterwards they were castrated and the testicular tissue was treated with Karnovsky fixative. Next, the fragments were embedded in glycol methacrylate and stained with toluidine blue-1% sodium borate solution. The average pixel intensity in the testicular parenchyma was determined for 1,600-mm 2 surface sections. The right and left testicles and the area between the two testicles resulted in average pixel intensities of 105.22 ± 13.58, 107.95 ± 12.82, and 106.59 ± 11.43, respectively. The efficiency coefficient of spermatogonial mitosis was 19.74; meiotic index was 2.63, and overall yield of spermatogenesis was 52.0. No correlation (P>0.05) was observed between testicular echotexture and any of the measured morphometric parameters. These results suggest that testicular echotexture was not a viable method for the indirect analysis of cellular population in the seminiferous epithelium, intrinsic spermatogenic performance, or the Sertoli cell index in Nelore bulls.Key words: testicular parenchyma, morphometry, ultrasonography, bovine. RESUMEN.El objetivo de este estudio fue evaluar la ecotextura testicular de los toros Nelore y correlacionarlo con los parámetros de espermatogénesis. Para este propósito, 41 toros de edades de 3-5 años y con pesos corporales en el intervalo de 510,2 ± 21,61 kg fueron seleccionados para el estudio. Los toros se sometieron a ecografía, utilizando un dispositivo portátil junto con un transductor lineal a una frecuencia de 7,5 MHz. Inmediatamente después, los animales fueron castrados, y el tejido testicular se trató con Karnovsky fijador. Los fragmentos testiculares se incluyeron en metacrilato de glicol y se tiñeron con una solución de borato de sodio-azul de toluidina al 1%. La intensidad media de pixeles en el parénquima testicular se determinó para secciones de superficie de 1.600 mm 2 . Los El área entre los dos testículos derecho e izquierdo dieron lugar a la intensidad media de los pixeles de 105,22 ± 13,58, 107,95 ± 12,82 y 106,59 ± 11,43, respectivamente. El coeficiente de eficiencia de la mitosis espermatogonial fue 19,74; Índice meiótico fue 2,63, y el rendimiento global del espermatogénesis alcanzó el 52,0. No se observó correlación (P>0,05) entre ecotextura testicular y cualquiera de los parámetros morfométricos medidos. Estos resultados sugieren que ecotextura testicular no es un método viable para el análisis indirecto de la población celular en el epitelio seminífero, el rendimiento de la espermatogénesis intrínseco, o el índice de células de Sertoli en toros Nelore.

Salmon oil supplementation in dogs affects the blood flow of testicular arteries

“…(2015), since the tunica albuginea echogenicity does not change. We conclude that this method has advantages compared to the simple measurement of pixel intensity performed by other researchers (Dias et al., 2017; Oliveira Pinho et al., 2013; Tomlinson et al., 2017).…”

“…(2015) showed that mean testicular heterogeneity was positively correlated with the total spermatozoal output. However, other researchers did not find a correlation between pixel intensity and sperm production or semen quality in dogs (Dias et al., 2017; Pinho et al., 2012; Tomlinson et al., 2017). Many researchers have reported that testicular echogenicity increases during sexual development directly with seminiferous tubules growth (Camela et al., 2018; Hamm & Fobbe, 1995; Pozor et al., 2017; Silva et al., 2012).…”

Effects of immunocastration performed at two live weights on the growth physiology, temperament and testicular development of feral beef bulls

“…However, in our study conditions, neither the initial LW nor immunocastration affected the pixel intensity of the testicles, although a later histological and immunohistochemical study of the testicular parenchyma revealed a decrease in the diameter of the seminiferous tubules and an abnormal cell population in VA animals (Monleón et al, ). In this sense, some authors have suggested that testicular echogenicity is not a viable method for the indirect analysis of cellular population in the seminiferous epithelium, intrinsic spermatogenic performance, or the Sertoli cell index or semen quality (Dias et al, ).…”

“…[Correction added on 20 November 2019, after first online publication: 'Monleón et al, in press' has been updated to 'Monleón et al, 2020'. ] In this sense, some authors have suggested that testicular echogenicity is not a viable method for the indirect analysis of cellular population in the seminiferous epithelium, intrinsic spermatogenic performance, or the Sertoli cell index or semen quality (Dias et al, 2017).…”