Stress reactivity near birth affects nest building timing and offspring number and survival in the European rabbit (Oryctolagus cuniculus)

Abstract

The physiological response to stressors has great importance, and its variance has an adaptive role in the survival of individuals. This study describes the effects of stress-axis activation on maternal behavior during the birthing process (parturition) in captive rabbits (Oryctolagus cuniculus). In this species, chances of survival are strongly influenced by nest quality. Thus, maternal care is initiated with nest preparation in late pregnancy, which itself is subject to strict and complex hormonal regulation. Among these hormones, progesterone is one of the most dominant in the process of nest construction. We have demonstrated that its level is altered by the level of cortisol elevation in the animal in question, potentially having an influence on the preparation of the nest for the newborn kittens. We found that does that had a constant and un-elevated level of cortisol metabolite while delivering their litters performed better than those individuals that showed an increased corticoid response around parturition. The latter group exhibited a perceptible delay in the building of their nests, and in addition, further losses were also experienced in their already smaller litters. As the quality of the nest itself proved to be was in no way inferior to those of the other group, this higher kitten-mortality rate may be attributed to impaired maternal behavior. Individual variances in cortisol levels may also result in subtle changes in hormonal regulation, potentially affecting the expression of maternal behavior. We have concluded that the higher level of cortisol detected in more-sensitive does effectively disrupts the natural hormonal regulation involved in their nest-building processes.

Maternal cortisol level around conception is associated with offspring sex ratio in captive European wild rabbit (Oryctolagus cuniculus)

“…(Fajer et al, 1971). In case of wild rabbits, a positive correlation was also found between cortisol and progesterone values measured on the day of parturition (Benedek et al, 2021), which can be explained with a common metabolic pathway, as some progesterone is released into the bloodstream before it is converted to cortisol (Beaulieu-McCoy et al, 2017).…”

“…Samples were stored at -20 °C until extraction. Cortisol and progesterone levels were measured from faeces based on their breakdown products using an RIA method according to Benedek et al, (2021). After freeze-drying, the samples were ground, homogenized, and mixed thoroughly.…”

Induced Stress and Tactile Stimulation Applied to Primiparous does and their Consequences on Maternal Behavior, Human-Animal Relationships, and Future Offspringˊs Sexual Disorders

“…Studies in the domestic rabbit revealed that different elements of the behavioral sequence, such as digging, collection and carrying of nest material are under hormonal control (Zarrow et al1963;González-Mariscal et al, 2016). Furthermore, physiological state, genetic factors and individual's social environment, could conceivably alter the females'burrow and nest building behavior, modifying the timing of the hormonal signals involved (González-Redondo 2010; Benedek et al 2021).…”

“…According to Benedek et al (2021), progesterone is one of the most dominant in the process of nest construction. The authors demonstrated that its level is altered by the level of cortisol elevation in the animal, which potentially influence the preparation of the nest for the newborn kittens.…”

The Impact of Transportation on the Cortisol Level of Dwarf Rabbits Bred to Animal-Assisted Interventions

“…According to Benedek et al [ 53 ], 24 h after the pressure of stress the decomposition of the hormone cortisol appears in the feces.…”