TDK conference 2019

Nowadays ELISA or RIA kits are widely used to measure faecal or salivary estrogen and progestagen metabolites for monitoring ovarian cycle and pregnancy in humans and in different species of domestic and zoo animals. Our aims were to determine if these less stressful and painful non-invasive methods were applicable in the giant anteater and to compare the results of salivary hormones to the faecal ones. Furthermore, we wanted to improve our knowledge about giant anteater’s ovarian cycle to help the success of zoo breeding programmes.

In this study we collected samples from two males and two females, in two different zoos. At Jászberény Zoo we collected faeces and saliva samples three times a week for three months from a 6-year-old male and a 7-year-old female. At Nyíregyháza Zoo we collected the samples twice a week for two months from a 6-year-old male and a 7-year-old female. According to the literature data, two months is the general length of the polyostric giant anteater’s ovarian cycle. The animals from Nyíregyháza previously had offsprings two times, however the animals from Jászberény didn’t have any before. The anatomical and physiological characteristics of the anteater made us to come up with a special way of collecting saliva samples. We tried to increase the saliva production by showing food to the animal before collecting the sample. Then we wiped out the saliva from the animal’s mouth and lips before eating with a cotton swab. By knowing the exact weight of the swabs, we knew how much methanol/distilled water mixture we need to dilute the samples. After that, we measured the level of progesterone in the female’s saliva and the testosterone in the male’s saliva using radioimmunoassay.

Our results showed that the hormone determinations both in faeces and in saliva are appropriate tools for monitoring the anteater’s ovarian cycle and reproductive biology. Faecal and salivary hormone levels correlated, and they reflected to the actual behaviour of the animals. We found 40-45 days long estous cycle in the investigated females (instead of the 60-65 days mentioned in the literature; progesterone level range: 139.42-624.39 ng/g). Valuable results were obtained about the male individuals’ reproductive biology by assessing the measured testosterone (range: 0.506-1.863 µg/g). Faeces proved to be a more applicable sample to monitor ovarian cycle than saliva for practical reasons, as sample collection was easier in the field and preparation was easier in the laboratory. We highly recommend non-invasive methods over invasive ones not only for animal welfare but also for financial reasons because this way you do not need expensive, anteater-specialised stocks which are dangerous for the animal, neither veterinary knowledge like blood taking, so it is doable for the zoo staff. The most important advantage is, that it is not much pain and stress for the animal.