Female reproduction characteristics in a large-scale breeding colony of cynomolgus monkeys (Macaca fascicularis).

We studied two mating systems for a large-scale breeding colony of cynomolgus monkeys: (i) a 3-day timed system that keeps one female and one male together in a cage for 3 days beginning 11 days after menstruation, and (ii) a 7-day timed system beginning 9 days after menstruation. Regardless of the mating system used, we propose a practical definition of an infertile female as one that does not become pregnant in up to six pairings. If we eliminate these animals from the breeding colony, the pregnancy rates would be 3.

Simian betaretrovirus infection in a colony of cynomolgus monkeys (Macaca fascicularis).

Of the 419 laboratory-bred cynomolgus macaques (Macaca fascicularis) in a breeding colony at our institution, 397 (95%) exhibited antibodies or viral RNA (or both) specific for simian betaretrovirus (SRV) in plasma. Pregnant monkeys (n= 95) and their offspring were tested to evaluate maternal-infant infection with SRV. At parturition, the first group of pregnant monkeys (n = 76) was antibody-positive but RNA-negative, the second group (n = 14 monkeys) was positive for both antibody and RNA, and the last group (n = 5) was antibody-negative but RNA-positive.