Changes in Pre and Post Puberty Levels of Progesterone, Estradiol and Ghrelin in Gilts

1 Agricultural Academy, Agricultural Institute, BG-9700 Shumen, Bulgaria
2 Bulgarian Academy of Sciences, Institute of Biology and Immunology of Reproduction, BG-1113 Sof a, Bulgaria


Marchev, Y., M. Chervenkov, V. Mladenova, D. Abadjieva and E. Kistanova, 2017. Changes in pre and post puberty levels of progesterone, estradiol and ghrelin in gilts. Bulg. J. Agric. Sci., 23 (4): 644–647

The onset of puberty in pigs is a physiological process infl uenced by many factors. Some of the most important among them are age, breed, nutrition, technology of breeding, seasons and more. The reproductive system is particularly sensitive to energy reserve and metabolic status of the organism. In recent years it was discovered the role of so-called “metabolic” hormones (leptin and ghrelin) performing interaction between energy reserves and fertility. The purpose of this study was to characterize the changes in pre- and post-puberty levels of progesterone, estradiol and ghrelin in blood sera of gilts from different crossbreeds. An evaluation of the physiological maturity in gilts from LW x L (Large White x Landrace) crossbreed (n=10) and newly developed breed group (developed in the Agricultural Institute – Shumen, Bulgaria) (NBG) (Danube White x Landrace) (n=10), by comparison of the blood serum levels of progesterone, estradiol and ghrelin was carried out. It was established a signifi cantly higher progesterone level (p <0.001) in the blood sera of LWxL gilts at the age of 210 days (3 ng/ml), compared with that of the age of 165 days (0.98 ng/ml). Similar data were obtained in the NBG – 2.68 ng/ml at the age of 220 days and 0.66 ng/ml at the 160 days old gilts. In the LWxL gilts estradiol levels signifi cantly (p <0.001) increase from 113 pg/ml at 165 days of age to 130 pg/ml at 210 day, in NBG gilts the increase was respectively from 77.4 pg/ml at 160 day to 156.8 pg/ml at 220 day. There was a weak negative correlation between ghrelin and progesterone levels in pre pubertal period in both breeds (rp = -0.31 for LW x L and rp. = -0.28 for NBG). However, at the post puberty there was a weak to moderate positive correlation between the two hormones in both breeds (rp = 0.34 for LWxL and rp = 0.42 for NBG). There was no correlation between the levels of estradiol and ghrelin before and after puberty onset in each breed.

Key words: gilts; breed; puberty; progesterone; estradiol; ghrelin
Abbreviations: NBG: newly developed breed group; FSH: follicle stimulating hormone; LH: luteinizing hormone; GnRH: gonadotropin-releasing hormone; ELISA: enzyme linked immunosorbent assay; KNDy: kisspeptin/neurokinin B/dynorphin

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