Age-related differences of semen quality, seminal plasma, and spermatozoa antioxidative and oxidative stress variables in bulls during cold and warm periods of the year

Abstract

The aims of this study were to determine the presence and quantities of antioxidative status and oxidative stress (OS) variables in the seminal plasma and spermatozoa of bulls of varying age during cold and warm periods of the year, and to establish the correlation of these variables with semen quality parameters. The study was conducted on two groups each comprising nine Simmental bulls: one group contained younger animals (aged 2 to 4 years) and the second older animals (aged 5 to 10 years). Semen samples were collected using an artificial vagina for biochemical analysis. Seminal plasma and spermatozoa activities of total superoxide dismutase (TSOD), manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (CuZnSOD), catalase (CAT), selenium-dependent glutathione peroxidase, reduced glutathione and concentrations of total protein (TP), thiobarbituric acid reactive substances (TBARS) and protein carbonyl content (PCC) were determined. Several antioxidants in seminal plasma were also determined: total glutathione peroxidase (TGSH-Px), selenium-independent glutathione peroxidase (Non-SeGSH-Px), uric acid, albumins (ALB) and alkaline phosphatase (ALP). Significantly higher spermatozoa motility was observed during the cold v. warm period, and a significantly higher volume and total number of spermatozoa per ejaculate was observed in older than in younger bulls. Significantly higher values of ALP, TP and ALB were found in seminal plasma of older bulls than in younger bulls during the warm period. The seminal plasma of younger bulls showed significantly higher activities of TSOD, MnSOD, CuZnSOD, TGSH-Px and Non-SeGSH-Px. Younger bulls had significantly higher PCC concentration and activity of CAT in seminal plasma than older bulls during the cold period. Significantly higher concentrations of PCC and TBARS, and activities of TSOD, MnSOD and CuZnSOD were established in spermatozoa of the younger than in older bulls during the warm period. It could be concluded that antioxidative and OS variables differ significantly depending on bull age and time of year. Younger bulls were more sensitive to elevated ambient temperatures during the warm period, when the higher enzymatic antioxidative protection in seminal plasma and spermatozoa were insufficient to counteract the intensive oxidative processes in spermatozoa, which eventually resulted in decreased spermatozoa motility. The estimation of antioxidative and OS variables in seminal plasma and spermatozoa may have practical value for the assessment of bull semen quality.

The Effects of Antioxidants Provided with Feed on Certain Quality Parameters of Bull Semen Under Heat Stress Conditions

“…The average activities of SOD signifi cantly differed between groups in S1-5, but not afterwards, which can be explained by high SOD consumption in the neutralisation of free radicals resulting from long-lasting heat stress. This fi nding is in compliance with the results published by Vince et al [42], who detected high activities of SOD in Simmental bulls in summer. Nichi et al [16] proved in bulls of the same breed a higher degree of lipid peroxidation in the semen in the summer period, which means that the organism by means of its antioxidative enzyme system tends to resist to the process and thus prevent the production of semen of lower quality.…”

Classificação Andrológica Por Pontos E Características Andrológicas Na Avaliação Reprodutiva De Touros Da Raça Gir Candidatos Ao Teste De Progênie

“…Vince e colaboradores (17) vão mais além e apontam que fatores intrínsecos como o ambiente, a raça e a idade podem alterar de forma significativa parâmetros andrológicos, como motilidade e concentração espermática. O que corrobora os relatos de Thundathil et al (18) , em que a taxa de fertilidade pode variar em até 20% entre touros classificados como excelentes reprodutores, pois há alterações nos aspectos microscópicos do sêmen.…”

“…A correlação baixa encontrada entre motilidade e defeitos totais define-se por serem variáveis dependentes. A literatura registra que uma alteração na espermatogênese, como um aumento da temperatura ambiente ou corpórea, promove de forma significativa uma alteração na qualidade morfológica das células espermáticas, com interferência na produção e na viabilidade do espermatozoide (17).…”

Role of Uric Acid in Semen

“…For example, a study on cockerels showed that the concentration of uric acid in seminal plasma may be affected by the semen collection method [ 9 ]. In addition, the mean value of seminal urate was found to be higher in younger bulls compared to old ones [ 10 ]. Moreover, uric acid in semen was found to be affected by temperature; its level was found to be higher in cold conditions compared to warm conditions [ 10 ].…”

“…In addition, the mean value of seminal urate was found to be higher in younger bulls compared to old ones [ 10 ]. Moreover, uric acid in semen was found to be affected by temperature; its level was found to be higher in cold conditions compared to warm conditions [ 10 ].…”