Caliper and ultrasonographic measurements of bovine testicles and a mathematical formula for determining testicular volume and weight in vivo.

摘要

In the 1st of 2 experiments, testes length and width measurements were taken on 10 bulls using callipers and an ultrasound unit. The volume of each testis was determined by water displacement. For testis length, calliper measurement was more accurate than ultrasound (r2 = 0.8023 vs. 0.5111; P<0.05), while for width accuracy was lower for callipers than for ultrasound (r2 = 0.7313 vs. 0.8310). In the 2nd experiment, testes were recovered from 48 bulls at slaughter and length, width and volume were recorded. The reliability of the prolate spheroid formula (V = 0.5236(L)(W)2; where V, L and W are volume, length and width respectively) for determining testis volume was tested using data on individual testicles from the 2 experiments. The formula predicted volume with a high degree of accuracy (r2 = 0.8928). A modified prolate spheroid formula was derived for predicting testis weight; its r2 value was 0.9084. Values of r2 for correlations of predicted testis volume and weight, using calliper measurements, with actual values obtained on excised testes were 0.5497 and 0.6340 respectively. Corresponding r2 values for ultrasound measurements were 0.3276 and 0.6249.