Environmental Factors Related to a Semiarid Climate Influence the Freezability of Sperm from Collared Peccaries (Pecari tajacu Linnaeus, 1758).

The influence of environmental factors in a semiarid climate on characteristics of fresh and frozen/thawed sperm collected from collared peccaries (Pecari tajacu) was assessed. Semen from 11 male collared peccaries was collected by electroejaculation during the peaks of the dry and rainy periods while rainfall indices, air temperatures, relative humidity levels, and wind speeds were measured. The number, motility, morphology, osmotic response, and membrane integrity of sperm in the collected ejaculates were assessed. Samples were then frozen in liquid nitrogen, thawed, and reassessed. The rainfall index of the rainy period (73.2 mm) was significantly higher than that of the dry period (13.6 mm) and the relative humidity was significantly higher during the rainy period (74.6%) than it was during the dry period (66.8%). Air temperature and wind speed did not differ between the two periods. Characteristics of sperm in the fresh samples were not affected by environmental parameters. In contrast, computerized analysis revealed that sperm in samples frozen during the rainy period exhibited better post-thaw membrane integrity (28.6 ± 6%), motility (29.5 ± 7.7%), and rapid sperm population (13.7 ± 6.2%) than did sperm in samples frozen during the dry period (23.4 ± 3% membrane integrity, 14.6 ± 4.1% motility, and 4.1 ± 1.2% rapid sperm; p < 0.05). Other characteristics of the frozen/thawed sperm did not differ depending on the period in which they were collected. We demonstrated that environmental parameters did not affect the quality of fresh sperm, but could influence the freezability of sperm collected from collared peccaries raised under a semiarid climate.

Epididymal sperm from Spix's yellow-toothed cavies sperm successfully cryopreserved in Tris extender with 6% glycerol and 20% egg yolk.

As a non-threatened hystricognath rodent species, Spix's yellow-toothed cavies can be used as a model for the development of assisted reproductive techniques for the conservation of closely related species. The objective was to establish a functional protocol for cryopreservation of epididymal sperm from these cavies. Twelve sexually mature males, ∼2 y old and weighing ∼300 g, were euthanized. Sperm were recovered by retrograde flushing of the vas deferens and cauda epididymis with Tris extender. Thereafter, sperm were extended in Tris plus 20% egg yolk, with 3%, 6% or 9% glycerol or dimethyl sulfoxide (DMSO), placed in 0.25 mL straws and cryopreserved in liquid nitrogen. Sperm concentration, motility (using computer-assisted sperm analysis; CASA), plasma membrane integrity, osmotic response, morphology and sperm binding-ability were determined in fresh and frozen-thawed sperm. For most sperm endpoints, glycerol was a more desirable cryoprotectant than DMSO. Data (mean ±â€¯SEM) were similar with use of 3%, 6%, and 9% glycerol (P > 0.05) in osmotic response (40.66 ±â€¯6.3%, 42.5 ±â€¯7.1%, and 39.5 ±â€¯5.0% respectably), and membrane integrity (55.17 ±â€¯5.5%, 68.4 ±â€¯4.1%, and 59.1 ±â€¯4.9% respectably). Among concentrations assessed, the use of 6% glycerol resulted in the greatest (P < 0.05) post-thaw values for total motility (60.9 ±â€¯4.4%), rapid subpopulation motility (27.7 ±â€¯3.1%) and sperm-binding capability (227.0 ±â€¯20.2). In conclusion, epididymal sperm from the Spix's yellow-toothed cavies (G. spixii) are optimally cryopreserved in Tris extender with 6% glycerol and 20% egg yolk.

Estimation, morphometry and ultrastructure of ovarian preantral follicle population in agouti (Dasyprocta leporina) / Morfometria, estimativa e ultraestrutura da população folicular ovariana preantral de cutia (Dasyprocta leporina)

The aim of this study was to characterize the preantral ovarian follicular population in agoutis (D. leporina) by estimating the number of follicles at each developmental category, and also describe the morphometry and the specific features of the follicle and the oocyte by using light and transmission electron microscopy. The length of each ovary was measured using a caliper rule, longitudinally sectioned into two halves and both were immediately fixed to perform the estimation of follicular population and ultrastructural analysis. The mean (±S.E.M.) population of follicular per pair of ovary was estimated at 4419.8±532.26 and 5397.52±574.91 for right and left ovaries, respectively, but no differences were observed between them. The diameters for follicles, oocyte and nuclei were: 18.62±3.40µm, 12.28±2.37µm and 6.10±0.93µm for primordial, 23.75±5.70µm, 14.22±3.00µm and 6.70±1.24µm for primary and 88.55±17.61µm, 52.85±17.56µm and 22.33±17.61µm for secondary follicles, respectively. The most of the follicles found belonged to the primordial category (86.63%), followed by primary (13.01%) and secondary (0.35%) one. Additionally, polyovular follicles were observed in all the animals and they represented 7.51% of the total follicles counted. The ultrastructural analysis showed that the oocyte presented a central and regular nuclei, displaying a homogenous mass. Among the organelles, the mitochondria were the most abundant and the oocyte Golgi apparatus was rarely observed. In conclusion, this work shows for the first time the characterization of the population of preantral follicles in the ovary of Dasyprocta leporina. Those information will be useful for further development and adaptation of biotechniques such as germplasm cryopreservation and in vitro gametes manipulation.(AU)

O objetivo deste trabalho foi caracterizar a população folicular ovariana pré-antral em cutias (D. leporina) estimando o número de folículos em cada categoria de desenvolvimento, e também descrever a morfometria e as características específicas do folículo e oócito usando microscopia de luz e eletrônica de transmissão. O comprimento de cada ovário foi medido utilizando um paquímetro, seccionados longitudinalmente em duas metades e ambos foram imediatamente fixados para realizar a estimativa da população folicular e análise ultraestrutural. A média (±S.E.M.) da população folicular por par de ovário foi estimada em 4419,8±532,26 e 5397,52±574,91 nos ovários direito e esquerdo, respectivamente, mas não foram observadas diferenças entre eles. Os diâmetros dos folículos, oócito e núcleos, respectivamente, foram: 18,62±3,40µm, 12,28±2.37µm e 6,10±0,93µm para primordial, 23,75±5,70µm, 14,22±3,00µm e 6,70±1,24µm para primário e 88,55±17,61µm, 52,85±17,56µm e 22,33±17,61µm de folículos secundários. A maioria dos folículos encontrados pertencia à categoria primordial (86,63%), seguido pelo primário (13,01%) e um secundário (0,35%). Adicionalmente, os folículos poliovulares foram observados em todos os animais e representavam 7,51% do total de folículos contados. A análise ultra-estrutural mostrou que o oócito apresentou núcleos centrais e regulares, exibindo uma massa homogênea. Dentre as organelas, as mitocôndrias foram as mais abundantes e o aparelho de Golgi do oócito foi raramente observado. Em conclusão, este trabalho mostra pela primeira vez a caracterização da população de folículos pré-antrais do ovário da Dasyprocta leporina. Essas informações serão úteis para o desenvolvimento e adaptação de biotécnicas, como a criopreservação de germoplasma e manipulação de gametas in vitro.(AU)

Estrus cycle monitoring of captive collared peccaries (Pecari tajacu) in semiarid conditions / Monitoramento de ciclo estral em catetos (Pecari tajacu) criados em cativeiro em condições semiáridas

Collared peccaries (Peccary tajacu) are among the most hunted species in Latin America due the appreciation of their pelt and meat. In order to optimize breeding management of captive born collared peccaries in semiarid conditions, the objective was to describe and correlate the changes in the ovarian ultrasonographic pattern, hormonal profile, vulvar appearance, and vaginal cytology during the estrus cycle in this species. During 45 days, females (n=4) were subjected each three days to blood collection destined to hormonal dosage by enzyme immunoassay (EIA). In the same occasions, evaluation of external genitalia, ovarian ultrasonography and vaginal cytology were conducted. Results are presented as means and standard deviations. According to hormonal dosage, six estrous cycles were identified as lasting 21.0 ± 5.7 days, being on average 6 days for the estrogenic phase and 15 days for the progesterone phase. Estrogen presented mean peak values of 55.6 ± 20.5 pg/mL. During the luteal phase, the high values for progesterone were 35.3 ± 4.4 ng/mL. The presence of vaginal mucus, a reddish vaginal mucosa and the separation of the vulvar lips were verified in all animals during the estrogenic peak. Through ultrasonography, ovarian follicles measuring 0.2±0.1 cm were visualized during the estrogen peak. Corpora lutea presented hyperechoic regions measuring 0.4±0.2 cm identified during luteal phase. No significant differences (P>0.05) between proportions of vaginal epithelial cells were identified when comparing estrogenic and progesterone phases. In conclusion, female collared peccaries, captive born in semiarid conditions, have an estral cycle that lasts 21.0±5.7 days, with estrous signs characterized by vulvar lips edema and hyperemic vaginal mucosa, coinciding with developed follicles and high estrogen levels.(AU)

Os catetos (Peccary tajacu) estão entre as espécies mais caçadas na América Latina devido a apreciação de seu couro e carne. No intuito de otimizar o manejo produtivo de catetos nascidos em cativeiro sob condições semiáridas, o objetivo foi descrever e correlacionar as modificações verificadas no padrão ultrassonográfico ovariano, o perfil hormonal, a aparência vulvar, e a citologia vaginal durante o ciclo estral nesta espécie. Durante 45 dias, fêmeas (n=4) foram submetidas a coleta de sangue destinado a dosagem hormonal por meio de teste imuno-enzimático (EIA). Na mesma ocasião, foram conduzidas a avaliação da genitália externa, a ultrassonografia ovariana e a citologia vaginal. Os resultados são apresentados com média e desvio padrão De acordo com a dosagem hormonal, foram identificados seis ciclos estrais, com duração 21,0±5,7 dias, sendo em média 6 dias de fase estrogênica e 15 dias de fase progesterônica. O estrógeno apresentou valores médios de pico de 55,6±20,5pg/mL. Durante a fase luteal, os valores mais altos alcançados pela progesterona foram 35,3±4,4ng/mL. A presença de muco vaginal, mucosa vaginal hiperêmica e separação dos lábios vulvares foi identificada em todos os animais durante o pique estrogênico. Por meio da ultrassonografia, folículos ovarianos medindo 0,2±0,1cm foram visualizados durante o pique estrogênico. Corpos lúteos apresentando regiões hiperecóicas medindo 0,4±0,2 cm foram identificados na fase luteal. Nenhuma diferença significativa (P>0,05) entre as proporções de células epiteliais vaginais foram identificadas quando comparadas as fases estrogênica e progesterônica. Em conclusão, fêmeas de cateto, nascidas em cativeiro sob condições semiáridas, apresentam um ciclo estral que dura 21,0±5,7 dias, com sinais de estro caracterizados por edema de lábios vulvares e hiperemia da mucosa vaginal, coincidindo com desenvolvimento de folículos ovarianos e elevados níveis de estrógeno.(AU)