Immunological castration of male pigs is an attractive alternative to surgical castration used in many countries to reduce the production of the main androgen, androstenone, and skatole, responsible for meat taint. To understand the effect of gonadoliberin (GnRH) vaccination with Improvac on the functional status of Landrace pig testes at the molecular level the role of adipokines was studied. Using western blotting, immunohistochemistry, and enzyme-linked immunosorbent assay, we explored adipokine and leptin signaling and evaluated cholesterol concentrations. In control testis, adiponectin and its receptors were localized to interstitial Leydig cells and spermatogenic cells (especially adiponectin and its receptor 2) while in immunocastrates spermatogenic cells were negative. In control, leptin was exhibited by spermatids and Leydig cells while its receptor only by the later cells. In immunocastrates, leptin immunosignal was not found in spermatogenic cells. In addition, for all studied proteins, the immunosignal was of moderate or weak intensity when compared to the control. Concomitantly, decreased expression of all proteins (p<0.5) was detected. Similarly, in immunocastrates, cholesterol concentrations were increased (p<0.01). In summary, we showed for the first time the coincidence of disturbed adiponectin signaling and leptin signaling together with increased cholesterol concentration and attenuated spermatogenesis as a result of halted androstenone production. Altered GnRH signaling affects the adipokine system in testes of Landrace castrates which may impact further functional changes leading to complete spermatogenesis alteration, as well as lipid homeostasis and fattening perturbances

With the observed in the last years increasing disruption of poultry males’ fertility, there is a need to improve knowledge on the morphology and functioning of the avian reproductive system. A number of molecular and endocrine interrelationships indicate that testicular dysfunction may be one of the reasons for the production of poor semen quality. Because selenium (Se) is known to be an essential element for spermatogenesis, thus the aim of the present study was to determine the effect of Se treatment in ovo on cellular and molecular status (expression of aromatase, estrogen receptors and estrogen level) of testes of chicks. The study was performed on chick embryons exposed to Se at a dose of 0.6 µg/egg. We revealed diverse changes in testis histology after Se-treatment including developmental changes reflected by cell migration or vacuolization of the marginal stroma. We showed for the first time the expression of GPER in the testes of chicks and changes in the expression of aromatase, GPER, ERα and ERβ after treatment with Se. Simultaneously with these, decreased testicular estradiol concentration indicated an altered receptor protein and/or binding by Se only to GPER, ERα that in turn affects hormone concentration and action. Further studies are needed to evaluate other effects of Se supplementation especially of immature birds or mature ones and eggs laying by them per se.