CHARACTERISTICS OF CHIMPANZEE (PAN-TROGLODYTES) EJACULATES COLLECTED BY RECTAL PROBE ELECTROSTIMULATION AND BY ARTIFICIAL VAGINA

This study compares characteristics of ejaculates collected from 16 ad ult male chimpanzees using rectal probe electrostimulation (RPE) and f rom 10 adult male chimpanzees trained to use an artificial vagina (AV) . Ejaculate weight, semen volume, and sperm number were significantly lower (P < 0.01) and percentage liquefaction was significantly higher (P < 0.01) in ejaculates collected by RPE. Percentages of motile sperm and of live sperm in semen did not differ significantly between the t wo collection methods. Total amounts of protein and of a-glucosidase a ctivity were significantly lower (P < 0.01) in seminal fluid from RPE samples. For ejaculates collected by RPE, semen volume correlated posi tively with protein (r = 0.8640, P < 0.001), fructose (r = 0.6976, P < 0.001), and citrate (r = 0.6976, P < 0.001); sperm number correlated positively with a-glucosidase activity (r = 0.6547, P < 0.001); and pr otein correlated positively with fructose (r = 0.5906, P < 0.002), cit rate (r = 0.5926, P < 0.002) and cy-glucosidase activity (r = 0.6006, P < 0.001). For ejaculates collected by AV, semen volume correlated po sitively with percentage liquefaction (r = 0.6058, P < 0.001), protein (r = 0.8055, P < 0.001), fructose (r = 0.6606, P < 0.001), and citrat e (r = 0.8272, P < 0.001); sperm number correlated positively with per centage of motile sperm (r = 0.4196, P 0.004); percentage of motile sp erm correlated positively with percentage of live sperm (r = 0.4388, P < 0.002); and, protein correlated positively with fructose (r = 0.694 7, P < 0.002) and with citrate (r = 0.5926, P < 0.002). These data sho w that there is a significant difference in semen parameters and in bi ochemical parameters of ejaculates obtained by RPE and by AV. (C) 1995 Wiley-Liss, Inc.