Prediction of the semen production by morphological measures of the testis (scrotal circumference, testicular echotexture and tonometry) in Holstein-Friesian bulls.

Autor:in

Gabor, G; Holzmann, A; Gyorkos, I; Sarlos, P

Abstrakt

Earlier examinations of the scrotal circumference (SC), testicular (consistency) tonometry (TM) and testicular echotexture (ET) suggested that SC, TM and ultrasonography may be useful to estimate the sperm output. The objectives were to determine the prediction value of the SC, ultrasonographic ET of the testis and testicular consistency (TM) for the semen production in Holstein-Friesian bulls (n=29, average age, 18.0 mo). The ET was measured with standardized gain and pressure (between the transducer and the testis), by a B-mode echograph and a 8 MHz linear transducer. Pixel analysis was performed with custom software (TesTracto) just under the tunica albuginea. The average ET of the ultrasonograms were indicated on a 256 gray scale (0=black, 255=white). The consistency of the testis was measured by an electronic (auto-freeze function at a standard pressure) tonometer. Semen was collected by artificial vagina twice a week 8 wks apart and total sperm number per ejaculate was determined (TSN). Semen evaluation was carried out by a phase-contrast microscope (Zeiss-Laboval) with heating stage. A Makler chamber, a video camera and a card for digitalization were used for the recording of a 2 sec long video exposure for each ejaculate on the hard disk of a computer. A self developed computer assisted semen analyzing software (CASPAR) was used for the evaluation of the percentage of live sperm cells, linear motility and the mean speed of the spermatozoa. Pearson correlation coefficients were determined for these data (SAS). The SC and the age positively correlated with the TSN (r=0.48 and r=0.40; P<0.01), while ET showed a negative correlation with the live percentage of spermatozoa (r=-0.37; P<0.05). These data suggest that the older bulls have bigger testis size and the bigger testis produces more spermatozoa, and has lower value of the ET (SC vs. ET r=-.48 P<0.01). The lower ET probably means more fluid (or blood) in the testicular parenchyma, and better thermoregulation, which results in more live sperm cells in the ejaculate. No correlation were found among the morphological measures, the linear motility and the mean speed of the spermatozoa.

Dokumententyp

Abstract

WoS ID

WOS:000087862300637

Präsentationsart

Vortrag

Konferenzort

University of Wisconsin, Madison, WI