Influência da estação do ano sobre a estrutura testicular em ovinos explorados no sul do Estado do Piauí

Abstract

RESUMO.-Objetivou-se avaliar a influência da estação do ano sobre a estrutura testicular de ovinos SRD. Foram utilizados 10 animais com idade entre dois e três anos. Os testí-culos foram seccionados e fixados em solução de Bouin por 24h. Os fragmentos foram submetidos ao processamento histológico, emblocados em parafina e corados com hematoxilina eosina. Foram avaliadas a proporção volumétrica dos compartimentos testiculares, o diâmetro dos túbulos seminíferos, altura do epitélio seminífero e frequências dos estágios do ciclo do epitélio seminíferos. Os dados foram submetidos à análise de variância a 5% de probabilidade, do programa estatístico SAS 9.0. Os resultados revelaram todos os valores pesquisados sofreram influên-cia da estação do ano. O valor do diâmetro tubular foi de 143,98±17,83 e 170,37±26,64µm, a altura do epitélio seminífero foi de 44,92±9,23 e 50,06±13,61µm e a proporção volumétrica foi de 78,32±13,68 e 80,13±15,14% nos perí-odos seco e chuvoso, respectivamente. A quantificação das células germinativas e de Sertoli mostrou todos os valores foram maiores no período chuvoso quando comparados com o seco. Concluiu-se que a estação do ano interferiu na estrutura testicular, tendo em vista que todos os valores da proporção volumétrica dos componentes testiculares mostraram diferença significativa entre as estações do ano, pois os valores foram mais acentuados no período chuvoso. To evaluate influence of the year season related with the testicular structure of cross bred sheep, the testes of ten 2 to 3-year-old sheep were sectioned and fixed in for 24 hours in bouin's solution. The fragments were subjected to histological processing, embedded in paraffin and stained with hematoxylin-eosin. The volumetric proportion of testicular compartments, the seminiferous tubules, seminiferous epithelial height and frequency of the seminiferous epithelium stages of the cycle were evaluated. Data were subjected to analysis of variance at 5% probability. The results showed that all values studied were influenced by year's season. The tubular diameter was 143.98±17.83 and 170.37±26.64μm, the seminiferous epithelium height was 44.92±9.23 and 50.06±13.61μm, and the testicle parenchyma volume density was 78.32±16.68 and 80.13±15.14% in the dry and rainy periods, respectively. The germ cells and Sertoli cells quantification showed that all values were higher in the rainy season compared with the dry season. It can be concluded that the year season interfered in the testicular structure, given that all values showed significant differences between the seasons, as the values were more pronounced during the rainy season.

Influence of racial crossing on testicular structure and spermatogenesis in sheep Santa Inês and crossbred Santa Inês and Dorper

“…The volume of the interstitial compartment in the seminiferous tubules showed values of 25.88% for crossbred and 25.94% for Santa Ines. Among the components of the interstitial compartment, the connective tissue was the most expressive, presenting almost equal values in both groups, as also found in non-defined breed sheep by Santos et al (2015). In the study performed by these authors, the volume of the interstitial compartment in the dry period of the year was 21.52%, which converges to the results presented.…”

“…It is noteworthy the difference in the tubular diameter between crossbred (173.12 μm) and Santa Inês (185.71 μm), and also the height of the seminiferous epithelium (52.29 and 56.68 μm, respectively), evidencing higher values for Santa Inês. The height of the seminiferous epithelium was higher than that found in Santa Inês (46.67 and 48.26 μm;McManus et al, 2010) and in non-defined breed sheep (44.92 and 50.06 μm; Santos et al, 2015), and lower than those reported by Souza (2003) in Santa Inês (70.88 μm).…”

“…Studies have shown many factors that may influence the spermatogenic process, such as nutrition (Viu et al, 2006), temperature (Marai et al, 2008) and time of the year (rainy or dry; McManus et al, 2010;Santos et al, 2015). Recent studies also showed that the racial factor could lead to differences among the studied breeds (Andreusii et al, 2014).…”

Testicular morphometry as a tool to evaluate the efficiency of immunocastration in lambs

“…The GEH response in the control group (46.71 ± 4.15µm) was similar to that found by Santos et al (2015) , when evaluating the influence of season in mixed-breed sheep (44.92 ± 9.23μm). The reduction of approximately 77% in GEH in the immunized groups in the present study reinforces the effectiveness of the vaccine in blocking the action of GnRH.…”

“…The quantification of testicular histology is a valuable tool for evaluating the sperm capacity of animals under normal, pathological, or experimental conditions ( Castro et al, 1997 ). Sperm kinetics, among other parameters, are important for characterizing testicular activity that occurs inside the seminiferous tubules ( Santos et al, 2015 ). Therefore, the aim of this study was to evaluate the efficiency of immunocastration in lambs by using testicular morphometry.…”