HORMONAL AND BEHAVIORAL MONITORING OF OVARIAN CYCLES IN PECCARIES

This study was conducted in the framework of a program assessing the e conomic viability of raising collared (Tayassu tajacu) and white-lippe d (T. pecari) peccaries in captivity. In collared peccary, previous st udies suggested an ovarian or oestrous cycle of 22-24 days. Our result s indicated a much longer cycle length. Based on progesterone measurem ents, ovarian cyclicity averaged 27.8 +/- 1.5 days (range 23-34). The duration of female receptivity, assessed from behavioural observations (acceptation of male mounting), was 4 +/- 2.9 days. Behavioural oestr us was recorded in only 33 of 47 cycles (70.2%). The oestrus detection rate varied individually from 50 to 87%. In white-lipped peccary, ave rage cycle length was 29.7 +/- 0.8 days (range 25-32). Behavioural oes trus was much longer than in the collared peccary (5.7 +/- 4.7 days). The oestrus detection rate averaged 58%. Therefore;in both species, be havioural information, although helpful, is not the most reliable meth od for detecting the time of ovulation. Measurement of progesterone is a more accurate method. This initial study was based on hormone deter mination in plasma. Further development will test if non invasive meth ods -analysis of urinary and faecal steroids -would be easily applicab le for the management of breeding herds of peccaries.