Spermatozoa and testes in the boar: correlative analysis of sperm morphologic features, seminiferous epithelial area, and testes weight.

Testicular tissue and sperm from the cauda epididymidis of 300 boars were obtained in 6 collections during 1 year at a Chicago abattoir. Seventy-five boars (25%) had - 1 sperm abnormality present at rates that could result in infertility. These abnormalities and their frequency criteria were: proximal droplets > or = 15%, loose heads > or = 10%, abnormal middle pieces > or = 10%, abnormal acrosomes > or = 10%, bent tails > or = 15%, coiled tails > or = 15%, and abnormal head shapes > 5%. These 75 abnormal boars were then compared with a control group of 75 boars selected at random from the remaining 225 boars. Frequency of sperm abnormalities, testicular and epididymal weights, relative seminiferous epithelial areas (SEA), and the degree of testicular lesions were used in making comparisons. Testicular lesions were scored on a scale of 1 (normal) to 5. The SEA was measured and was expressed as the mean area of 50 tubules. The SEA was negatively correlated with proximal droplets and abnormal middle pieces in abnormal boars and abnormal head shapes in control boars. The mean SEA was 8.71 and 5.60 cm2 for control and abnormal boars, respectively. The overall mean score for testicular lesions was 1.72 and 3.17 for control and abnormal boars, respectively.