Characterization of seasonal reproduction patterns in female pichis Zaedyus pichiy (Xenarthra: Dasypodidae) estimated by fecal sex steroid metabolites and ovarian histology

Reproductive strategies vary considerably among species, but most studies have focused on a very limited number of mammalian species. Knowledge of the reproductive cycle and behavior is essential for developing and implementing in situ and ex situ conservation strategies for threatened and endangered species. This study aimed at characterizing the seasonal reproductive pattern of female pichis Zaedyus pichiy, a threatened small armadillo native to arid regions of Argentina and Chile, through direct observations, histological studies, and by measuring fecal immunoreactive estrogens, progestagens and glucocorticoids in 10 wild-born, captive pichis and in free-ranging individuals. Results suggest that pichis are seasonal breeders that give birth to one yearly litter of 1–2 offspring, which do not leave the burrow until they are weaned at approximately 37 days. Ovarian follicular growth seems to occur throughout the year. Fecal progestagen, estrogen and glucocorticoid concentrations were minimal during the first half of pregnancy, increased to peak concentrations of up to 3500, 200 and 200 ng/g dry feces, respectively, and decreased before parturition. Postpartum progestagen concentrations were greater in lactating females than females that aborted or did not raise their offspring (p < 0.0001), which is probably related to an elevated corticosteroid synthesis that contributes to maintain lactation, given that fecal glucocorticoid concentrations were of similar pattern. Observations of a second pregnancy after late abortion or death of the newborn litter and sustained follicular growth during pregnancy and lactation suggest that female pichis can become receptive briefly after having lost their litter. Fecal estrogen and progestagen concentrations of non-pregnant, non-lactating females did not have a well-defined hormonal cyclic pattern, and corpora lutea were only observed in pregnant females.     

Excretion of radiolabeled estradiol metabolites in the slow loris (Nycticebus coucang)

The excretion pattern of estradiol was studied in the slow loris Nycticebus coucang) and the ring-tailed lemur (Lemur catta) in order to compare steroid excretion in two representative prosimian species. Daily urinary estrone conjugate measurements in the female loris provided little information when applied over prolonged periods. As a result of these negative data, a metabolic study was performed to determine if estrogen excretion patterns in the slow loris differed from those in the lemur, where urinary assays proved a useful tool in characterizing reproductive cycles. Radio-labeled estradiol was injected intravenously, and serial urine and fecal collections were analyzed for radiolabeled metabolites. The results of these studies demonstrate that more than 92% of the radiolabel was excreted in the feces of the loris, in contrast to only 16% excreted in the feces of the lemur.     

Effect of paternal age on the birth sex ratio in captive populations of aye‐aye (Daubentonia madagascariensis (Gmelin))

For the management of captive populations of zoo animals, it is important to elucidate factors that affect the offspring birth sex ratio. On the basis of the sex allocation theory, the Trivers–Willard and mate attractive/quality hypotheses predict that maternal and paternal conditions affect offspring birth sex ratios. We examined these predictions for the birth sex ratio of aye‐aye Daubentonia madagascariensis (Gmelin) by analyzing the pedigree information in the International Studbook. We found that the birth sex ratio of the aye‐aye was affected by the paternal age, but not maternal age and other environmental factors (birth year, season, and institution). The younger the sire, the more the offspring sex ratio was biased toward males. These results are useful for the effective population management of captive aye‐aye and illustrated the usefulness of the sex allocation theory in the sex ratio management of zoo animals.     

Reflections of ecological differences? Stress responses of sympatric Alpine chamois and red deer to weather,forage quality,and human disturbance

Depending on the habitats they live in, temperate ungulates have adapted to different degrees to seasonally changing forage and weather conditions, and to specific escape strategies from predators. Alpine chamois, a mountain ungulate, and red deer, originally adapted to open plains, would therefore be expected to differ in their physiological responses to potential stressors. Based on 742 chamois and 1557 red deer fecal samples collected year‐round every 2 weeks for 4 years at the same locations within a strictly protected area in the Swiss Alps, we analyzed glucocorticoid metabolite (FGM) concentrations for both species. Results from linear mixed effects models revealed no physiological stress response to changing visitor numbers, but instead to drought conditions for both species during summer. In winter, FGM concentrations increased with increasing snow height in both species, but this response was modulated by temperature in red deer. Chamois showed a stronger stress response to increasing snow height during November and December than between January and March, while FGM concentrations increased with decreasing temperature throughout winter. An increase in FGM concentrations with decreasing forage digestibility during winter was found only for red deer. The results are thus partly in contradiction to expectations based on feeding type and adaptations to different habitats between the two species. The lack of a response to forage digestibility in chamois may reflect either better adaptation to difficult feeding conditions in subalpine forests, or, by contrast, strong constraints imposed by forage quality. The similar responses of both species to weather conditions in winter suggest that climatic factors at the elevations examined here are sufficiently harsh to be limiting to temperate ungulates regardless of their specific adaptations to this environment.     

Stress Assessment in Small Ruminants Kept on City Farms in Southern Germany

Sheep and goats are frequently used in nonhuman animal-assisted activities on city farms. There are few data available on this type of usage of small ruminants. Health evaluations, behavioral observations (feeding, resting, comfort, explorative and social behaviors), behavioral tests (human approach tests and touch test), and measurements of fecal cortisol metabolites and heart rate were performed to assess stress levels in 25 sheep and 32 goats on 7 city farms and 2 activity playgrounds in Germany. No evidence was found that the animals suffered from major distress. Health evaluations, behavioral observations, and behavioral tests proved to be the methods of stress assessment most suitable for routine on-farm checks in these settings.     

Mechanisms of brain inactivation of centrally-acting thyrotrophin-releasing hormone (TRH) analogues: a high-performance liquid chromatography study

High-performance liquid chromatography (HPLC) was used to investigate the degradation in vitro of several centrally-acting analogues of thyrotrophin-releasing hormone (TRH) by two subcellular fractions prepared from different areas of rat brain. Of the seven analogues studied, RX77368 (pGlu-His-(3,3'-dimethyl)-ProNH2) was the most stable analogue, showing only a small amount of degradation by the particulate fraction containing a pyroglutamyl aminopeptidase, whereas the other analogues (RX74355, CG3509, CG3703, [3MeHis]TRH, PGHPA and MK771) showed varying degrees of resistance to degradation by this enzyme and the proline endopeptidase in the soluble fraction. However, TRH was rapidly inactivated to its deamidated form, TRH-OH and the histidyl-proline diketopiperazine by both fractions. The relative stability of these TRH analogues to enzyme action may provide some explanation for their enhanced biological activity in vivo.