000085400 001__ 85400 000085400 005__ 20201117095023.0 000085400 0247_ $$2doi$$a10.1016/j.anireprosci.2018.11.007 000085400 0248_ $$2sideral$$a109744 000085400 037__ $$aART-2019-109744 000085400 041__ $$aeng 000085400 100__ $$aCarvajal-Serna, M. 000085400 245__ $$aChanges in melatonin concentrations in seminal plasma are not correlated with testosterone or antioxidant enzyme activity when rams are located in areas with an equatorial photoperiod 000085400 260__ $$c2019 000085400 5060_ $$aAccess copy available to the general public$$fUnrestricted 000085400 5203_ $$aIn temperate climates, photoperiod and melatonin regulate ram reproduction, modulating hormonal secretions, sperm quality, and seminal plasma composition. Information on the effect of an equatorial photoperiod (12L:12D) on ram reproduction, however, is scarce, and no data on hormonal concentrations and antioxidant enzyme activity in seminal plasma have been reported. Thus, the variation was investigated of melatonin and its relationship with testosterone and antioxidant enzyme activity in the seminal plasma of three sheep breeds in Colombia, when there was a consistent photoperiod during two dry and two rainy seasons per year. Semen was collected once a week from 12 mature rams (four of each breed: Colombian Creole, Hampshire, and Romney Marsh). Seminal plasma was obtained by centrifugation. The concentration of melatonin and testosterone were quantified along with the enzymatic activity of glutathione peroxidase (GPx), glutathione reductase (GRD), and catalase (CAT). Correlation analyses between melatonin and testosterone concentrations or enzymatic activity were also performed. Melatonin concentration was affected by season (P < 0.05) but not breed, with lesser concentrations in the first rainy season. Testosterone concentration, however, was affected by breed and season, with greater concentrations (P < 0.01) in the Hampshire and Romney Marsh rams during the second dry season. Regarding antioxidant enzyme activity, there was only seasonal variation in GPx activity (P < 0.05). When correlation analyses were used for data assessments, there was a negative correlation between melatonin and testosterone concentrations in Hampshire rams. In conclusion, melatonin concentrations in seminal plasma of rams that were located in an area with an equatorial photoperiod was affected by the climatological season but there was no positive correlation with testosterone concentration or antioxidant enzyme activity. 000085400 536__ $$9info:eu-repo/grantAgreement/ES/MINECO-FEDER/AGL2014-57863-R 000085400 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/ 000085400 590__ $$a1.66$$b2019 000085400 591__ $$aAGRICULTURE, DAIRY & ANIMAL SCIENCE$$b22 / 63 = 0.349$$c2019$$dQ2$$eT2 000085400 591__ $$aREPRODUCTIVE BIOLOGY$$b26 / 29 = 0.897$$c2019$$dQ4$$eT3 000085400 592__ $$a0.66$$b2019 000085400 593__ $$aAnimal Science and Zoology$$c2019$$dQ1 000085400 593__ $$aMedicine (miscellaneous)$$c2019$$dQ2 000085400 593__ $$aFood Animals$$c2019$$dQ2 000085400 593__ $$aEndocrinology$$c2019$$dQ3 000085400 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000085400 700__ $$aTorres-Ruda, F. 000085400 700__ $$aCardozo, J.A. 000085400 700__ $$aGrajales-Lombana, H. 000085400 700__ $$0(orcid)0000-0001-9842-6197$$aCebrián-Pérez, J.Á.$$uUniversidad de Zaragoza 000085400 700__ $$0(orcid)0000-0003-1306-8517$$aMuiño-Blanco, T.$$uUniversidad de Zaragoza 000085400 700__ $$0(orcid)0000-0002-2312-6402$$aPérez-Pé, R.$$uUniversidad de Zaragoza 000085400 700__ $$0(orcid)0000-0003-1997-4262$$aCasao, A.$$uUniversidad de Zaragoza 000085400 7102_ $$11002$$2819$$aUniversidad de Zaragoza$$bDpto. Bioq.Biolog.Mol. Celular$$cÁrea Zoología 000085400 7102_ $$11002$$2060$$aUniversidad de Zaragoza$$bDpto. Bioq.Biolog.Mol. Celular$$cÁrea Bioquímica y Biolog.Mole. 000085400 773__ $$g200 (2019), 22-30$$pAnim. reprod. sci.$$tAnimal Reproduction Science$$x0378-4320 000085400 8564_ $$s533820$$uhttps://zaguan.unizar.es/record/85400/files/texto_completo.pdf$$yPostprint 000085400 8564_ $$s224971$$uhttps://zaguan.unizar.es/record/85400/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000085400 909CO $$ooai:zaguan.unizar.es:85400$$particulos$$pdriver 000085400 951__ $$a2020-11-17-09:44:09 000085400 980__ $$aARTICLE