Vitrogen (Brazil)

The aim of this study was to investigate the effects of 10 mg/kg/week of nandrolone decanoate (DECA - Deca Durabolin®) on body composition, hormonal levels, spermatic parameters, redox status, and morphometric parameters of testicle and epididymis; furthermore, the fertility capacity of Wistar rats was measured thought in vitro fertilization (IVF). The animals (n = 16) were divided into two groups: control group (CTRL, n = 8), which received only vehicle composed by peanut oil and 10% of the benzoic alcohol and nandrolone decanoate group (DECA, n = 8), which received intramuscular injections of DECA for 8 weeks, both groups were treated for 8 weeks. The results demonstrate significative decrease in visceral fat, testosterone levels, and thiol content on epididymis, reduction on normal sperm parameters, and deleterious effect on testicles and epididymis tissue morphology showing reduction of germ height and luminal diameter on the DECA group. Thus, it can be concluded that high doses of nandrolone decanoate impairs male reproductive parameters.

Carvacrol (C10H14O), an efficient phenolic antioxidant substance for several cell types, may become a useful antioxidant for female germ cells and embryo culture. This study investigates the effects of carvacrol supplementation on bovine oocytes in in vitro maturation (IVM) and embryo production. In total, 1222 cumulus-oocyte complexes were cultured in TCM-199+ alone (control treatment) or supplemented with carvacrol at the concentrations of 3 µM (Carv-3), 12.5 µM (Carv-12.5), or 25 µM (Carv-25). After IVM, the oocytes were subjected to in vitro fertilization and embryo production, and the spent medium post-IVM was used for evaluating the levels of reactive oxygen species and the antioxidant capacity (2,2-diphenyl-1-picryl-hydrazyl-hydrate and 2,2'-azinobis-3-ethyl-benzothiozoline-6-sulphonic acid quantification). A greater (P < 0.05) antioxidant potential was observed in the spent medium of all carvacrol-treated groups compared with the control medium. Moreover, the addition of carvacrol to the maturation medium did not affect (P > 0.05) blastocyst production on days 7 and 10 of culture; however, the total number of cells per blastocyst was reduced (P < 0.05) in two carvacrol-treated groups (Carv-3 and Carv-25). In conclusion, carvacrol demonstrated a high antioxidant capacity in the spent medium after oocyte maturation; however, although embryo production was not affected, in general, carvacrol addition to IVM medium reduced the total number of cells per blastocyst. Therefore, due to the high antioxidant capacity of carvacrol, new experiments are warranted to investigate the beneficial effects of lower concentrations of carvacrol on embryo production in cattle and other species.

We understand and share the same concerns raised by Caravaggi et al. (2021), since we are all scientists, and we take scientific rigour seriously in our work. The paper published by Araujo et al. (2021) had authorization for scientific activities issued by SISBIO/ICMBio/MMA (no. 46031-4) and it was approved by two Ethics Committee on Animal Use (Federal University of Mato Grosso do Sul, no. 727/2015, and Federal University of Viçosa, no. 79/2015). Such authorizations were amended to the Acknowledgements in the version paged on 27 November 2020, before been assigned to an issue. In this way, the paper not only did not neglect ethics but was approved by three recognized research institutions. The authors of the questioned paper have been working for two or more decades generating data from free-living captures for conservation. Data on animal welfare, degree of injury, use of baits or attractants, response time, degree of risk to the animal and the team, among others, are systematically collected by experienced researchers from our group. Such data were part of the original manuscript but were removed when transformed into Practical Tools. We look forward to the opportunity of MEE to present this data in full, as our right of reply to Caravaggi et al. (2021) is limited to 3,000 characters. Some of the questions probably came from people with extreme theoretical knowledge. The statement that ‘Foot snares can pose a greater risk of injury to animals than cage traps’ clearly demonstrates little experience in the field. Cage traps are no longer the golden method to capture large felids due to low efficiency, higher costs, and risks of teeth and claw injuries. Araujo et al. (2021) describe several modifications and procedures that reduce the risk of injuries by foot snare traps. All the capture methods were evaluated not only by our researchers but also by Ethics Committees and Brazilian government agencies and were not neglected in this manuscript. Unfortunately, questions that come from theoretical extrapolations with no connection to the field reality can delay the conservation efforts and go against the One Conservation concept described by Pizzutto et al. (2021). Access to threatened species is the best way to generate data that allow a real diagnosis of the species in situ and suggests policies for its conservation. In the case of the jaguar, the greater the number of captures, the greater the chances of making the right decisions, and the greater the number of individual genetics collected and stored in germplasm banks. The isolation of populations and the extremely low number of jaguars in biomes such as the Caatinga and the Atlantic Forest justify the urgency of capturing. Fish broth and/or roar device were used as an attractant in 40 captures. In only one there was any injury to the animal: paw oedema, immediately treated by veterinarians and without compromising its health. The safety of the team is also a concern but taking some precautions such as not entering the area of imminent risk and paying attention to the presence of other animals reduces the chances of accidents to almost zero. Regarding animal welfare, the discussion should be based on the five domains model for animal welfare assessment and monitoring (Mellor et al., 2020), and foot snare traps do not compromise any physical/functional domains. Therefore, they do not promote negative mental experiences, as the rare, mild transient oedema in the paws does not compromise the ability to walk. The injury is much lighter than those that occur due to intraspecific and interspecific conflicts in nature. Furthermore, the anaesthetic protocol produces retrograde amnesia for the pre-anaesthetic period—eliminating negative mental experiences of the foot snare—and anterograde amnesia for the post-anaesthetic period (Gruber & Reed, 1968). Another strategy that reduces animal injuries and distress is frequent remote monitoring—at least every hour—allowing access to the animal within a maximum of 3 hours of capture. Finally, we believe that technical training combined with practical experience allows researchers to develop the intuition inherent in science. None of the authors have any conflicts of interest to declare. The peer review history for this article is available at https://publons.com/publon/10.1111/2041-210X.13706.