ARTIFICIAL-INSEMINATION IN CALLITHRIX-JACCHUS USING FRESH OR CRYOPRESERVED SPERM

Assisted reproductive techniques are needed urgently to facilitate the captive breeding of many New World primate species which are endanger ed in the wild and to assist the effective genetic management of small colonies. A protocol was devised for artificial insemination in the c ommon marmoset, Callithrix jacchus, using ejaculated sperm obtained by vaginal washing after copulation. A double insemination protocol was employed, with the first insemination taking place the day before ovul ation was expected to occur and the second 48 h later. All six females inseminated with fresh ejaculated sperm became pregnant, delivering a total of 16 offspring at term. The gestation lengths and litter sizes were not statistically different from those observed in pregnancies f ollowing natural mating. The insemination protocol was adapted for use with cryopreserved ejaculated sperm by including an additional insemi nation on the day of expected ovulation, to take into account differen ces in the capacitation time of frozen-thawed sperm compared to fresh sperm. Three out of six females inseminated according to this triple i nsemination schedule, conceived, although one female subsequently reso rbed twin foetuses approximately 100 days later. The remaining two pre gnant females delivered four babies at term, one singleton and one set of triplets. In the final group, six females were inseminated with lo w doses of cryopreserved epididymal sperm using the same triple insemi nation protocol used for frozen-thawed ejaculated sperm. One female co nceived, delivering triplets. (C) 1998 Published by Elsevier Science B .V. All rights reserved.