Collection and evaluation of semen from captive howler monkeys (Alouatta caraya).

Semen samples (n=58) were collected by electroejaculation from nine adult male howler monkeys (Alouatta caraya) between November 2000 and August 2001 at the National Primates Center, Ananindeua, Brazil. The ejaculates were free of coagulum. Mean (+/-S.D.) values were: volume, 0.09 +/- 0.05 ml; pH, 8.1 +/- 0.5; concentration 649.5 +/- 926.7 x 10(6) sperm/ml; progressive motility, 75.8 +/- 18.1%; forward progressive sperm motility (scale, 0-5), 3.5 +/- 1.0; live spermatozoa, 68.3 +/- 15.0%; primary defects, 9.6 +/- 4.5%; and secondary defects, 11.8 +/- 4.6%. There were high correlations between motility and live sperm (r = 0.91, P < 0.01), motility and forward progressive sperm motility (r = 0.84, P < 0.01) and between forward progressive sperm motility and live sperm (r = 0.78, P < 0.01). There were no alterations observed during clinical examinations and hematological analysis performed before and after semen collection. Therefore, the method was considered safe and efficient. It can be used for the evaluation of the breeding potential of male howler monkeys in captivity and for the establishment of new assisted reproductive technology (ART) for threatened species of neotropical primates.