Fetal Development of the Collared Peccary

Forty-three known aged embryos and fetuses were obtained from captive collared peccaries (Dicotyles tajacu). Fetuses were weighed, measured, and described. Litter size ranged from one to four and averaged two. There was 9.6 percent intrauterine mortality of fetuses. Fetuses were equally distributed in the left and right horns of the uterus, although a few ova migrated before implantation. Of 36 fetuses which were sexed, 63 percent were females and 37 percent were males. Hindhoof length, weight, forehead-rump length, shoulder height, ear length, and hindfoot length of the fetuses were significantly correlated with their age (P < .05). Ear length and hind-foot length were the most highly correlated and can be used to estimate ages. Single and quadruple fetuses deviate most from calculated regression lines. Sex does not seem to influence fetal size.