Effects of two space allowances on cortisol levels, agonistic behavior and their relationship with the ovarian cycle of the collared peccary (Pecari tajacu) in captivity

Two groups, each of seven mature females and one vasectomized male, of collared peccaries (Pecari tajacu) in captivity were used to compare two treatments based on either 5 and 20 m2/animal. Blood plasma levels of cortisol and progesterone were measured by radioimmunoassay. Variations in plasma concentration of progesterones were used to detect stages of ovarian cyclicity. Sexual and agonistic behaviors were measured by the scan sampling method. Results obtained with the 5 and 20 m2/animal treatments were: concentration of cortisol, 7.86 to 11.85 and 7.76 to 12.10 μg/dl; duration of the estrous cycle was 28.5 + 9.5 and 24.6 + 3.4 d, respectively, with no differences between treatments (P < 0.05). The corresponding values for proportion of sexual behavior were 2.40 and 2.19% those for agnostic behavior were 1.54 and 2.10%, the latter difference being significant (P > 0.05). It is concluded that mixed groups of collared peccaries with one sole male can be submitted to a housing density of 5 m2/animal without affecting the blood level of cortisol, the agonistic behavior or the cyclical ovarian activity