Published in Scientific Works. Series C. Veterinary Medicine, Vol. LXI
Written by Costin BUDICA , Rosalie DOJANA, Laurent OGNEAN, Gabriel COTOR, Nicolae DOJANA
The research was conducted on a breed of adult sow in different physiological states, originated from a northern EU area, during the period of adaptation in a temperate (Romanian) area. The animals were in different physiological status: gilts and sows, estrous, pregnancy or lactation. They were determined the blood plasma levels of main hormones involved in the reproductive function [17-estradiol, progesterone, follicle stimulating hormone (FSH), luteinizing hormone (LH) and melatonin] in the days of the solstices and equinoxes. Plasma levels of 17- estradiol for gilts and sows during the first day of the estrous showed minimal values in March, 20th, increased in June 21st, reaching a maximal values in September, 22nd, and then decreased again. The LH mean values (assayed in the first day of estrous period) were highest during the maximum photophase (June, 21st) and lowest in September, 22nd in gilts, while in sows, the higher levels of plasma LH were found during the day of spring equinox and summer solstice and the lowest levels in September, 22nd (as in gilts). Plasma progesterone of the 25-day-pregnant gilts and sows presented the highest values during the period of maximum scotophase (December, 21st), significantly higher by comparing to the other three analyzed photoperiods. Plasma progesterone of pregnant gilts was lower vs. pregnant sows for every analyzed photoperiod. The maximum amounts of melatonin blood values were found in December 21st, the lowest in June 21st and intermediate values in the two solstices. For all the assayed photoperiods, melatonin contents in midnight samplings were nearer to those taken at midday. Almost every time, the melatonin values in lactant sows were lower vs. in pregnant sows.
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