Selenium supplementation prevents DNA damage in ram spermatozoa

Carla Fredrichsen Moya,Fábio Henrique Fernandes,Marcelo Piagentini,Daisy Maria Fávero Salvadori,Eunice Oba,Danilo Da Cunha Silva

doi:10.1590/0103-8478cr20200102

Carla Fredrichsen Moya, Fábio Henrique Fernandes + Show 4 more

Open Access

https://doi.org/10.1590/0103-8478cr20200102

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Abstract

ABSTRACT: In the present study, we aimed to evaluate the effects of different concentrations of selenium (Se) ovine nutritional supplementation on spermatozoa DNA integrity. Thirty male ovines (age: 10 months) were used. They were fed with hay and ram food in an intensive system, which was divided into stalls (5 m long and 3 m wide) with feeding troughs, and had ad libitum access to food and water. Ovines in group 1 (G1, the negative control) received mineral salt supplementation without Se; ovines in G2 received the same mineral salt mixed with 5 mg Se (as sodium selenite)/kg mineral supplement;ovines in G3 received 10 mg Se/kg mineral supplement; ovines in G4 received 15 mg Se/kg mineral supplement; and ovines in G5 received 20 mg Se/kg mineral supplement. Ovines in all groups remained untreated for 14 days, followed by a treatment period of 56 days. Semen samples were obtained by electroejaculation. The DNA damage in semen samples was evaluated using the comet assay. The experimental design was implemented using a 5 × 5 Latin Square, i.e., five treatments and five experimental periods. The mean differences were compared using Tukey’s test at a significance level of 5%. The control group (G1) showed a high percentage of DNA damage compared to the Se-treated groups (G2-G5). Therefore, Se supplementation could decrease the basal level of DNA damage in sperm cells, suggesting that Se might exert protective effects on sperm DNA.

Highlights

Sheep industry represents an important productive sector of wool for garments, meat, dairy, and leather for human consumption (SCHWAB, 2011)
In reference to the above, the present study aimed to evaluate the effects of different concentrations of selenium (Se) ovine nutritional supplementation on spermatozoa DNA integrity
We selected animals at ten months of age, to ensure that they were sexually mature and to standardize the age of the animals in the groups. This age of the animals corroborates with CHACÓN et al (2019), who reported when analyzing spermatozoa concentration and progressive motility during ram lamb development that the semen quality variables improved from six months until ten months of age, when value stabilization occurred and remained uniform until 12 months old

Summary

Introduction

Sheep industry represents an important productive sector of wool for garments, meat, dairy, and leather for human consumption (SCHWAB, 2011). The ram is mainly responsible for genetically improving the stock, owing to its capacity to mount more than 35 females under natural conditions during a breeding season (MANDIKI et al, 1998). V.51, n.1, with high fertility is important for ovine production (MATOS et al, 1992). In this context, the assessment of sperm DNA integrity is quite relevant, wherein fertile sperms must have a stable DNA capable of decondensation at the appropriate time of fertilization, while maintaining the genetic codification without mutations (AGARWAL & ALLAMANENI, 2005). The investigation of genetic changes in ram sperm is important for ovine herd improvement. We used the comet assay (single-cell gel electrophoresis assay) to evaluate the effects of Se-enriched diets on ram sperm DNA integrity. Comet assay is a shortduration and low-cost technique that can detect single- and double-strand breaks and alkali-labile sites in DNA (KOPPEN et al, 2017)

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