Effects of maternal dietary selenium (Se-enriched yeast) on testis development, testosterone level and testicular steroidogenesis-related gene expression of their male kids in Taihang Black Goats.

To investigate the effects of maternal dietary selenium (Se-enriched yeast) on testis development, testosterone level and steroidogenesis-related gene expression in testis of their male kids, selected pregnant Taihang Black Goats were randomly allotted to four treatment groups. They were fed the basal gestation and lactation diets supplemented with 0 (control), 0.5, 2.0 and 4.0 mg of Se/kg DM. Thirty days after weaning, testes were collected from the kids. After the morphological development status of testis was examined, tissue samples were collected for analyzing testosterone concentration and histological parameters. Testosterone synthesis-related genes were detected using real-time PCR. Localization and quantification of androgen receptor (AR) in testis of goats were determined by immunohistochemical and western blot analysis. The results show that Se supplementation in the diet of dams led to higher (p < 0.05) testicular weight, volume, length, width, transverse and vertical grith of their male kids. Excessive Se (4.0 mg/kg) can inhibit the development of testis by decreasing testicular weight and volume. The density of spermatogenic cells and Leydig cells in the Se treatment groups was significantly (p < 0.05) higher than that in the control. Maternal dietary Se did not affect the thickness of testes, thickness of germinal epithelium and diameter of seminiferous tubule. Se supplemented in the diet of dams improved the testosterone level in testis tissue and serum, and promote the expression of testosterone-related genes. The mRNA expression of StAR, 3ß-HSD and CYP11A1 was decreased with the increasing dietary Se levels of dams. Maternal dietary Se can improve the AR protein abundance in testis of their offspring. AR immunopositive product was detected in Leydig cells, peritubular myoid cells, perivascular smooth muscle cells, primary spermatocytes and spermatids. The expression of AR in spermatogenetic cells is stage specific. This study suggests that maternal dietary Se can influence the testis development and spermatogenesis of their male kids by modulating testosterone synthesis in goats. More attention should be given to the potential role of maternal nutrition in improving reproductive performance of their offspring.

Effects of different levels of dietary selenium on the proliferation of spermatogonial stem cells and antioxidant status in testis of roosters.

The objective of this study was to investigate the different levels of dietary Se (from sodium selenite) on the proliferation of SSCs (spermatogonial stem cells) in testis of roosters. Also, the antioxidant status and Se content in blood plasma and testis were evaluated. A total of eighty 12-week-old Hy-Line Variety white roosters at an averaged body weight of 1.38 ± 0.2 kg were selected and randomly divided into four experimental groups. They were fed with the basal diet (0.044 mgSe/kg DM) supplemented with 0 (control), 0.5, 1.0 or 2.0 mgSe/kg DM (from sodium selenite). After the feeding experiment, blood and testis samples were collected for analysis of the antioxidant status and Se concentration. The testis samples were also used to examine the Thy-1 and ß1-integrin mRNA expression by RT-PCR and detect the population of SSCs by immunofluorescence analysis. The results show that Se concentration in blood and testis of the animals was progressively increased with the increasing Se level in diet. The highest GSH-Px (glutathione peroxidase) activity and lowest MDA content in blood and testis was obtained in the treatment of 0.5mg/kg. RT-PCR analysis showed that mRNA expression of SSCs markers were significantly lower in the control and 1.0mg/kg groups when compared with that in the treatment of 0.5mg/kg. A similar trend was observed in the population of SSCs analyzed by immunofluorescence assay. These data suggest that dietary Se can influence the population of SSCs of roosters during spermatogenesis and that oxidative stress can modulate SSCs behavior through regulating some key factors during spermatogenesis.

Effects of maternal and dietary selenium (Se-enriched yeast) on the expression of Sel P and apoER2 of germ cells of their offspring in goats.

In this experiment the effect of maternal dietary selenium on the expression of Sel P and apoER2 of goat offspring was studied. The experiment was conducted on 119 Taihang Black Goats randomly divided into 4 groups which were fed with a basal diet, supplemented with 0 (control), 0.5, 2 and 4 mg kg(-1) DM Se. Testis samples were collected from young male of each treatment group at the end of the study (30 d after weaning) for mRNA expression using real-time PCR and for protein expression by immunohistochemistry assay. A significant decrease was observed in mRNA expression of Sel P and apoER2 in the testis of the Se-deficient (Group 1) and the Se-excess (Group 4) compared with that in Groups 2 and 3. A similar trend of the protein expression of Sel P and apoER2 was also found. These data indicate that maternal and dietary selenium has an effect on the expression of Sel P and apoER2 in testis of their offspring. In addition, both groups were similar suggesting that the relationship between Sel P and apoER2, and apoER2 is a receptor of Sel P in the seminiferous epithelium to uptake the selenium.

Effect of high-dose nano-selenium and selenium-yeast on feed digestibility, rumen fermentation, and purine derivatives in sheep.

The aim of this study was to evaluate the effect of nano-selenium (NS) and yeast-selenium (YS) supplementation on feed digestibility, rumen fermentation, and urinary purine derivatives in sheep. Six male ruminally cannulated sheep, average 43.32 ± 4.8 kg of BW, were used in a replicated 3 × 3 Latin square experiment. The treatments were control (without NS and YS), NS with 4 g nano-Se (provide 4 mg Se), and YS with 4 g Se-yeast (provide 4 mg Se) per kilogram of diet dry matter (DM), respectively. Experimental periods were 25 days with 15 days of adaptation and 10 days of sampling. Ruminal pH, ammonia N concentration, molar proportion of propionate, and ratio of acetate to propionate were decreased (P < 0.01), and total ruminal VFA concentration was increased with NS and YS supplementation (P < 0.01). In situ ruminal neutral detergent fiber (aNDF) degradation of Leymus chinensis (P < 0.01) and crude protein (CP) of soybean meal (P < 0.01) were significantly improved by Se supplementation. Digestibilities of DM, organic matter, crude protein, ether extract, aNDF, and ADF in the total tract and urinary excretion of purine derivatives were also affected by feeding Se supplementation diets (P < 0.01). Ruminal fermentation was improved by feeding NS, and feed conversion efficiency was also increased compared with YS (P < 0.01). We concluded that nano-Se can be used as a preferentially available selenium source in ruminant nutrition.

Effects of maternal and dietary selenium (Se-enriched yeast) on the expression of p34(cdc2) and CyclinB1 of germ cells of their offspring in goats.

The aim of the study was to evaluate the effect of selenium on the expression of p34(cdc2) and CyclinB1 (two components of MPF regulating cell cycle) of germ cells of their offspring in goats. A herd of 119 Taihang Black Goats, which was randomly divided into 4 treatments, received experimental diet with different Se levels (from Se-enriched yeast) for 174d. The four treatments, fed with a basal diet, were supplemented with 0 (control), 0.5, 2 and 4 mgkg⁻¹ DM Se. Testis samples were collected from the young male goats of each treatment group at the end of the study (30d after weaning) for mRNA expression using real-time PCR and for protein expression by immunohistochemistry assay. Results show that a significant decrease was observed in mRNA expression of p34(cdc2) and CyclinB1 in the testis of Se-deficient (Group 1) and Se-excess (Group 4) animals compared with that in Groups 2 and 3. However, no significant changes were found in mRNA expression of p34(cdc2) between Se-deficient (Group 1) and Se-excess (Group 4). Also the immunohistochemistry assay detected similar results of protein expression of these two genes. These results suggest, that maternal and dietary Se-induced oxidative stress can modulate the mRNA and protein expression of the cell cycle related genes (p34(cdc2) and CyclinB1) in the testis of their offspring. In addition, Se deficiency and Se excess could prevent the completion of the cell cycle.

Effects of maternal and dietary selenium (Se-enriched yeast) on oxidative status in testis and apoptosis of germ cells during spermatogenesis of their offspring in goats.

To investigate the effect of maternal and dietary selenium on antioxidant status in testis and apoptosis of germ cells during spermatogenesis of their offspring, selected Taihang Black Goats (n=119) were randomly allotted to four treatment groups. They were fed the experimental diet with different Se levels (from Se-enriched yeast) for 174 d from 60 d prior to lactation to weaning of kids. The treatments were: (1) Group 1 (control), basal diet without Se supplementation, (2) Group 2, the same basal diet supplemented 0.5mg Se/kg DM, (3) Group 3, the same basal diet supplemented 2mg Se/kg DM and (4) Group 4, the same basal diet supplemented 4 mg Se/kg DM. Thirty days after weaning, testis samples of the young male goats were collected for mRNA expression and analyzing the antioxidant status and Se concentration, as well as the population of apoptotic germ cells by TUNEL assay. The results show that mRNA expression of apoptosis genes (Bcl-2, Bax and Caspase 8) were significantly higher in Groups 1 and 4 than that in Groups 2 and 3. The same trend was observed in the population of apoptotic cells analyzed by TUNEL assay. GSH-Px activity and Se concentration in testis of offspring was progressively increased with the increasing Se level in diet of dams. However, there was no significant difference in GSH-Px activity between Groups 3 and 4. The lowest MDA content was obtained in Group 2 and a significant decrease was observed in Groups 1, 3 and 4. These data suggest that doe maternal and dietary Se could influence antioxidant status in the testis of their offspring and the oxidative stress related to Se from the dam could modulate mRNA expression of apoptosis genes and apoptosis of germ cells during spermatogenesis. It is possible that Se supplementation of the dam's diet during gestation and lactation could be a way to supply the Se necessary for normal development of reproductive function of their offspring.

Effect of elemental nano-selenium on semen quality, glutathione peroxidase activity, and testis ultrastructure in male Boer goats.

The objective of this experiment is to study the effects of novel elemental nano-selenium in the diet on testicular ultrastructure, semen quality and GSH-Px activity in male goats. Forty-two 2-month-old bucks were offered a total mixed ration which had been supplemented with nano-Se (0.3mg/kg Se) or unsupplemented (the control group only received 0.06mg/kg Se-background), for a period of 12 weeks (from weaning to sexual maturity). Results showed that the testicular Se level, semen glutathione peroxidase and ATPase activity increased significantly in the nano-Se supplementation group compared with control (P<0.05). The semen quality (volume, density, motility and pH) was not affected by added Se in diets, however, the sperm abnormality rate of control bucks was significantly higher than Se supplemented bucks (P<0.05). The testes of 5 goats in each group were examined by transmission electron microscopy (TEM), and showed that in Se-deficient bucks the membrane was damaged, and showed the occurrence of abnormalities in the mitochondria of the midpiece of spermatozoa. In conclusion, selenium deficiency resulted in abnormal spermatozoal mitochondria, and supplementation with nano-Se enhanced the testis Se content, testicular and semen GSH-Px activity, protected the membrane system integrity and the tight arrayment of the midpiece of the mitochondria. Further studies are required to research the novel elemental nano-Se with characterization of bioavailability and toxicity in small ruminants.