Theriogenology wild最新文献

The main drawback in developing in vitro embryo production (IVP) systems in wild species, such as the Iberian red deer, is that access to these animals is usually restricted, and long distances from the collection site to the laboratory are usually inevitable. Prolonged ovary storage is known to negatively influence the quality and developmental competence of the oocytes used for IVP. To overcome this issue, we evaluated the effect of adding a caspase-3 inhibitor, z-DEVD-fmk, to the in vitro maturation media to improve the quality and developmental potential of Iberian red deer oocytes. Oocytes were in vitro matured with and without z-DEVD-fmk, and the following parameters were analyzed: viability, early apoptosis, caspase-3 activity, DNA fragmentation, and relative abundance of mRNA transcript related to apoptosis. Moreover, oocyte maturation and blastocyst rates were also assessed. The results showed that z-DEVD-fmk decreased early apoptosis (inhibitor= 44.44 ± 3.6% vs. control= 60 ± 2.79%), DNA fragmentation (inhibitor= 57.83 ± 1.91% vs. control= 74.62 ± 1.91%), caspase-3 activity (inhibitor= 41.88 ± 3.42% vs. control= 67.10 ± 3.42%) and the relative abundance of TP53 and ITM2B transcripts, as well as increased the number of live (inhibitor= 41.48 ± 2.32% vs. control= 20 ± 1.8%) and in vitro-matured oocytes (inhibitor= 88.18 ± 1.99% vs. control= 74.01 ± 1.99%) rates. Nevertheless, the blastocyst production was not different between both experimental groups (inhibitor: 7.35 ± 2.30 vs. control: 13.77 ± 2.30). The supplementation of z-DEVD-fmk to the maturation medium improved the quality of Iberian red deer oocytes. Further research and alternative strategies are needed to evaluate if this inhibitor could still enhance the developmental potential of oocytes during prolonged ovarian transport.

The giant anteater (superorder Xenarthra) is listed as Vulnerable by the International Union for Conservation of Nature (IUCN) and a low reproductive rate is considered one of the factors contributing to population decline of the species. Nevertheless, little is known on reproductive features in male giant anteaters and, in this regard, microscopic testis morphology and spermatogenesis were studied in roadkill specimens in Brazil. Characteristics of germ cell populations resembled descriptions in other eutherian mammals including other xenarthran species. Furthermore, eight stages of the seminiferous epithelium cycle could be defined. The proposed staging system offers baseline data for assessing impairments or seasonal changes in spermatogenesis and thus allows future studies on reproductive health and reproductive seasonality in male giant anteaters.

Animal capture is essential in conservation and management programs, both for captive and wild species. This paper describes the effect of midazolam sedation in domestic and wild phasianids with respect to dorso-abdominal massage for obtaining semen samples, and on the quality of the sperm thus collected. Three experiments were performed. Experiment 1 - Determination, with respect to semen quality, of the optimum midazolam treatment for sedation in the domestic chicken. This involved sedating birds with either: 1) 2 mL of saline (control [C]), 2) 2 mg/kg of midazolam (low dose [LD]), 3) 6 mg/kg of midazolam (high dose [HD]), or 4) 6 mg/kg of midazolam and waiting 10 min before starting to massage (HD-10) (all performed in duplicate). The response time to the sedative (T1) was recorded, as were the times from the start of massage to ejaculation (T2) and its end (T3). The proportion of animals that showed stress during massage was noted via their waking, wing flapping, and the heterophil-lymphocyte ratio. The volume of all sperm samples obtained was determined, along with sperm concentration, motility, viability, and DNA integrity. Experiment 2 - The same determinations were made in captive red-legged partridges. Experiment 3 - The effect of the discovered optimum conditions (HD-10) for the above species was examined in the capercaillie (a wild species). Sperm quality was not affected by sedation with midazolam in any of the examined species, although the capercaillies and partridges were more nervous during semen collection than were the chickens.

Mammals are categorized along an altricial-precocial spectrum based on degrees of neonatal development. Altricial neonates are immature at birth and dependent on care, whereas precocial neonates are relatively well developed and independent post-partum. The Eurasian beaver (Castor fiber) is a large, semiaquatic, relatively precocial mammal in the order Rodentia. However, the extended care of kits in burrows begs the question of why beavers have precocial characteristics. A study of fetal development might enable understanding of the traits that are significant for neonatal survival. The present study examined external morphological characteristics, external biometry and the development of internal organs in 80 Eurasian beaver fetuses (crown-rump length [CRL], 2.5–19.3 cm) derived from 33 wild pregnant females hunted in Norway (33 gestational age). We also created equations to predict fetal ages from biometric parameters based on a linear relationship between biometric parameters and fetal ages estimated from fetal weight. Fetal features appeared in the following chronological order; eyelid bulbs and tactile hairs (CRL ≥ 7.3 cm), outer ears, claws, skin differentiation (CRL ≥ 8.9 cm), and hair coverage and tooth eruption (CRL ≥ 9.4 cm). All biometric parameters increased linearly and positively as the CRL increased and did not tend to stabilize. Notably, slopes of hindfoot parameters were higher than those of forefeet, suggesting that the hindfeet of beavers grow faster than forefeet, as they do in other semi-aquatic mammals. Our calculations revealed that dorsal length, CRL, thoracic and abdominal circumferences were candidate predictors of fetal age due to a high coefficient of determination (≥ 0.95) and broad range (≥ 10 cm). Our findings revealed that beaver growth was precocial in terms of differentiated skin, hair coverage, and tooth eruption, but not fully completed, as none of the fetuses had open eyes. The rapid growth of the hindfoot and some precocial traits (skin and hair differentiation) may be involved with the ability of neonatal beavers to move in water.

Assisted reproductive technologies (ARTs) have been proposed as a potential complementary strategy to other conservation efforts aimed at addressing the pressing challenges associated with managing endangered species. The Equidae family belongs to the order Perissodactyla and comprises various species, including domestic horses, donkeys, wild asses, zebras, and the Przewalski's horse, all of which belong to the genus Equus. Unfortunately, numerous subspecies of this order have become extinct in recent centuries, and many extant species are currently at risk of extinction. Recent decades have witnessed considerable progress in in vitro technologies, particularly in the domestic horse, including gamete collection and cryopreservation, as well as the successful production of embryos through in vitro fertilization techniques and cloning. Furthermore, some progress has been made in domestic donkeys and other wild equid species. However, for the majority of endangered species, effective ARTs protocols are not yet available. This review summarizes the main advances made in in vitro assisted reproductive technologies and genetic conservation efforts in equids and discuss the challenges and future prospects of these technologies in the context of wild equid conservation.

Whooping cranes (Grus americana) are naturally seasonal breeders and rely on wetland habitats throughout the annual cycle. However, captive cranes are commonly housed in dry outdoor pens, which may lack key environmental stimuli that in turn compromise reproduction. Our study sought to first, assess seasonal patterns of reproductive hormones in successful versus non-successful bird pairs and second, determine endocrine responses to alterations in enclosure environments. Fecal samples were collected from eight crane pairs year-round for 3 consecutive years, once a week during non-breeding season and three times a week during the breeding season. During Year 1, all pairs were housed in traditional dry pens, whereas during January of Year 2 all pairs were moved to either new dry pens (control, n = 4) or ponded pens (wetland, n = 4) and remained in the same pen until the end of the study. Fecal samples were assessed for gonadal (year-round) and adrenal (breeding season only) hormones. Estrogen and progestagen metabolite concentrations were low during non-breeding season in all females. However, as birds transition into a breeding season, gonadal hormone concentrations significantly increased (p < 0.001) in laying females but not in non-laying individuals. Androgen metabolite concentrations during breeding seasons were higher (p < 0.001) in males paired with non-laying females, with no variations observed during non-breeding months and within birds of the same reproductive output. We observed significant effect of enclosure environment on ovarian function of female whooping cranes. Specifically, mean estrogen metabolite concentrations increased after birds were moved from dry pen to wetland enclosures (Year 1: 349.1 ± 83.4 ng/g feces; Year 2: 382.7 ± 82.9 ng/g feces; Year 3: 556.5 ± 85.4 ng/g feces, p = 0.008 and 0.019 respectively,), whereas those of the control females remained constant. Further, estrogen concentration assessed during breeding season of Year 3 in females housed in wetland pens was higher than birds housed in a dry pen (556.5 ± 85.4 vs 311.7 ± 85.12 ng/g feces; p = 0.019). The number of eggs laid increased in three of the four pairs housed in the wetland pens, while there was no change in egg production in control birds (9 vs. 2 combined number of eggs produced by all pairs in each respective group in Year 3). Finally, moving birds to an enclosure that mimic natural environment did not impact androgen or glucocorticoid excretion. The findings demonstrate that differences in gonadal hormone production between laying and non-laying whooping crane females exist primarily during the breeding season, and that a more natural environment can have a positive influence on ovarian function in female whooping cranes.