Single injection of eCG/hCG leads to successful estrous synchronization in the collared peccary (Pecari tajacu Linnaeus, 1758).

The establishment of protocols for the control of the ovarian function of collared peccaries is recommended for the development of assisted reproductive techniques. The goals were to (1) compare a gonadotropin combination with prostaglandin analogue to synchronize timing of onset of estrus among animals, and (2) elucidate the effects of the most desirable protocol for performing an artificial insemination study and macroscopic evaluation of the ovaries. Three of five females treated with a double administration of 120 μg prostaglandin (cloprostenol) at a 9-day interval expressed symptoms of estrus 9 days after the second injection. One female presented estrus after 6 days, whereas other did not respond to the treatment. All females (5/5) treated with a single dose containing 400 IU eCG and 200 IU hCG manifested estrus 6 days after the hormone injection. In a second experiment, ten females that were estrous synchronized using eCG/hCG, were artificially inseminated with fresh semen and monitored for pregnancy every 30 days. Although there was no detection of fetuses by ultrasonic examination, seven females (7/10) had greater than basal progesterone values for 60 days after the treatments were imposed. Ovaries from two females treated with eCG/hCG were collected 6 days post-injection. There was confirmation of an ovarian stimulation as a result of the presence of 88 and 25 antral follicles, as well as three and eight hemorrhagic structures in ovaries of each female, respectively. It, therefore, is proposed that eCG/hCG can be used as an effective treatment for estrous synchronization in collared peccaries.