Relationship between gonadal steroid hormones and vulvar bleeding in southern tamandua, Tamandua tetradactyla

Abstract

This study aimed at demonstrating the profiles of circulating gonadal steroid hormones during the estrous cycle and pregnancy in a southern tamandua (Tamandua tetradactyla). Additionally, this study clarified the relationship between vulvar bleeding and hormonal changes. The concentrations of serum progesterone (P(4)) and estradiol-17β (E(2)) were determined by enzyme immunoassays. Serum P(4) and E(2) concentrations changed cyclically and the estrous cycle length (± SD) based on the E(2) cycles was 44.3 ± 4.5 days. Vulvar bleeding started to be seen at the decreasing of P(4). The cycle length for vulvar bleeding was 43.3 ± 4.2 days. Interval from the first day of bleeding to the peak of E(2) concentration was 23.1 ± 3.1 days. Serum P(4) during pregnancy remained high and E(2) increased 8 weeks after conception and remained high until parturition. The female delivered normally after a 165 day-pregnancy period and reared the offspring well. Approximately 3 weeks after parturition, serum E(2) and P(4) cycles resumed. Visual bleeding may be useful as a real-time indicator for understanding the ovarian cycle of southern tamanduas, and estrus could be expected approximately 3 weeks after the first bleeding.

Fecal estrogen, progestagen and glucocorticoid metabolites during the estrous cycle and pregnancy in the giant anteater (Myrmecophaga tridactyla): evidence for delayed implantation

“…Females in our study had similar gestational lengths as previously reported for giant anteaters and longer than reported for tamandua [1,3,10,27] (Table 3). By examining three complete pregnancies, we were able to confirm that elevated concentrations of fecal estrogens and P4 occured only during the late gestational period as previously summarized by Patzl et al [10].…”

“…These changes also initiate a secondary surge in progestagens during late pregnancy by luteal cells, the feto–placental unit, or another extra–gonadal source following implantation [30,34]. Elevation of fecal estrogens during late pregnancy in xenarthrans and other species also supports fetal development, and is the result of greater aromatase activity in the corpus lutea and the placenta, as well as the result of increased hepatic clearance of estrogens prior to fecal excretion [10,13,27,34,35]. Fecal estrogens and progestagens returned to baseline levels within 11 days of parturition, and estrous cycling post–partum was observed to resume in as little as 60 days similar to that reported by Patzl et al [10].…”

Assessment of adrenocortical activity and behavior of the collared anteater (Tamandua tetradactyla) in response to food‐based environmental enrichment

“…Nevertheless, such a method warrants a solid validation if applied in a species for the first time (Palme et al, ; Touma & Palme, ; Sheriff et al, ). To our best knowledge, this hormone monitoring strategy has not been employed in the collared anteater to study adrenocortical response to stressors; only a few studies have been conducted to test other steroids in collared anteaters (Hay et al, ; Kusuda et al, ) or other species of the superorder (Mühlbauer et al, ; Superina et al, ; Howell‐Stephens et al, ).…”

Monitoring the reproductive physiology of six‐banded armadillos (Euphractus sexcinctus, Linnaeus, 1758) through different techniques

“…The monitoring of the changes in the vulval appearance during the oestrous cycle was conducted according to the methodology previously reported for the Southern Tamandua ( Tamandua tetradactyla ; Kusuda et al., ). Examination of the vulval appearance included the observation and subsequent description of the labia and commissures of the vulva, and mucus in the vestibulum vaginae.…”