000097127 001__ 97127 000097127 005__ 20220425105234.0 000097127 0247_ $$2doi$$a10.1017/S1751731120001330 000097127 0248_ $$2sideral$$a119643 000097127 037__ $$aART-2020-119643 000097127 041__ $$aeng 000097127 100__ $$0(orcid)0000-0003-2827-3054$$aAbecia, J.A.$$uUniversidad de Zaragoza 000097127 245__ $$aThe continuous presence of ewes in estrus in spring influences testicular volume, testicular echogenicity and testosterone concentration, but not LH pulsatility in rams 000097127 260__ $$c2020 000097127 5060_ $$aAccess copy available to the general public$$fUnrestricted 000097127 5203_ $$aThe continuous presence of active male small ruminants prevents seasonal anestrus in females, but evidence of the same mechanism operating from the females to the males is scarce. This study assessed the effects of the continuous presence of ewes in estrus in spring on ram sexual activity, testicular size and echogenicity, and LH and testosterone concentrations. On 1 March, 20 rams were assigned to two groups (n = 10 each): isolated (ISO) from other sheep, or stimulated (STI) by 12 ewes, which were separated from the rams by an openwork metal barrier, allowing contact between sexes. Each week, four ewes were induced into estrus by intravaginal sponges. Live weight, scrotal circumference, testicular width (TW) and length (TL) were recorded at the beginning and at the end of the experiment, and testicular volume (TV) was calculated; at the same time, testicular ultrasonography and color Doppler scanning were performed. Blood samples (March to May) were collected once per week for testosterone determinations, and at the end of the experiment, blood samples were collected for 6 h at 20-min intervals for LH analysis. Rams were exposed to four estrous ewes in a serving-capacity test. Scrotal circumference, TW and TL were higher in the STI than in the ISO rams (P < 0.05) in May, and TV was higher (P < 0.05) in the STI (391 ± 17 cm3) than in the ISO rams (354 ± 24 cm3). In ISO rams, the number of white pixels was higher (P < 0.01) in May (348 ± 74) than in March (94 ± 21) and differed significantly (P < 0.01) from that of the STI rams in May (160 ± 33). In ISO rams, the number of grey pixels was higher (P < 0.05) in May (107 ± 3) than it was in March (99 ± 1). Stimulated and ISO rams did not differ significantly in mean LH plasma concentrations (0.8 ± 0.5 v. 0.9 ± 0.4 ng/ml), LH pulses (2.1 ± 0.5 v. 2.2 ± 0.2) and amplitude (2.0 ± 0.4 v. 3.2 ± 0.7 ng/ml, respectively). Stimulated rams had significantly higher testosterone concentrations than ISO rams from April to the end of the experiment. Stimulated rams performed more (P < 0.05) mountings with intromission (3.0 ± 0.4) than did ISO rams (1.5 ± 0.5). In conclusion, after 3 months in the continuous presence of ewes in estrus in spring, rams had higher TV and some testicular echogenic parameters were modified than isolated rams. Although exposed rams also had higher levels of testosterone after 2 months in the presence of estrous ewes, their LH pulsatility at the end of the study was not modified. 000097127 536__ $$9info:eu-repo/grantAgreement/ES/MCYT/AGL2017-82118-R 000097127 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/ 000097127 590__ $$a3.24$$b2020 000097127 591__ $$aVETERINARY SCIENCES$$b15 / 146 = 0.103$$c2020$$dQ1$$eT1 000097127 591__ $$aAGRICULTURE, DAIRY & ANIMAL SCIENCE$$b9 / 63 = 0.143$$c2020$$dQ1$$eT1 000097127 592__ $$a0.889$$b2020 000097127 593__ $$aAnimal Science and Zoology$$c2020$$dQ1 000097127 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000097127 700__ $$0(orcid)0000-0003-3929-5064$$aCarvajal-Serna, M.$$uUniversidad de Zaragoza 000097127 700__ $$0(orcid)0000-0003-1997-4262$$aCasao, A.$$uUniversidad de Zaragoza 000097127 700__ $$aPalacios, C. 000097127 700__ $$aPulinas, L. 000097127 700__ $$aKeller, M. 000097127 700__ $$aChemineau, P. 000097127 700__ $$aDelgadillo, J.A. 000097127 7102_ $$11002$$2819$$aUniversidad de Zaragoza$$bDpto. Bioq.Biolog.Mol. Celular$$cÁrea Zoología 000097127 7102_ $$12008$$2700$$aUniversidad de Zaragoza$$bDpto. Produc.Animal Cienc.Ali.$$cÁrea Producción Animal 000097127 773__ $$g14, 12 (2020), 2554-2561$$pAnimal$$tANIMAL$$x1751-7311 000097127 8564_ $$s163906$$uhttps://zaguan.unizar.es/record/97127/files/texto_completo.pdf$$yPostprint 000097127 8564_ $$s26953$$uhttps://zaguan.unizar.es/record/97127/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000097127 909CO $$ooai:zaguan.unizar.es:97127$$particulos$$pdriver 000097127 951__ $$a2022-04-25-10:37:58 000097127 980__ $$aARTICLE