Porker immunocastration against gonadoliberin (GnRH) secretion has been utilized since 2009; however, consumers are still skeptical of it. This is due to not having full information available on the problem of a boar taint, as well as a lack of research on morphological and molecular changes that may occur in the animal reproductive system and other body systems. The present study aimed to explore the functional status of steroidogenic Leydig cells of the testicular interstitial tissue in immunocastrated Polish Landrace pigs. Analyses were performed using Western blot, immunohistochemistry for relaxin (RLN), insulin-like 3 protein (INSL3), pelleted growth factor receptor α (PDGFRα), cytochrome P450scc, 3β- and 17β-hydroxysteroid dehydrogenases (3β-HSD, 17β-HSD), cytochrome P450arom, and 5α-reductase (5α-RED). Immunoassay ELISA was used to measure the androstenone, testosterone, and estradiol levels in the testis and serum of immunocastrates. We revealed disturbances in the distribution and expression of (i) RLN, indicating an inflammatory reaction in the interstitial tissue; (ii) INSL3 and PDGFRα, indicating alterations in the differentiation and function of fetal, perinatal, or adult Leydig cell populations; (iii) P450scc, 3β-HSD, 17β-HSD, P450arom, and 5α-RED, indicating disturbances in the sex steroid hormone production and disturbed functional status of Leydig cells; as well as (iv) decreased levels of androstenone, testosterone, and estradiol in testicular tissue and serum, indicating the dedicated action of Improvac to reduce boar taint at both the hypothalamic–hypophysis–gonadal axis and local level (Leydig cells). In summary, our study provides a significant portion of knowledge on the function of Leydig cells after immunocastration, which is also important for the diagnosis and therapy of testis dysfunction due to GnRH action failure and/or Leydig cell differentiational–functional alterations.

Here, we studied the impact of exposure to short daylight conditions on the expression of senescence marker (p16), membrane androgen receptor (ZIP9) and extracellular signal-regulated kinase (ERK 1/2), as well as cyclic AMP (cAMP) and testosterone levels in the testes of mature bank voles. Animals were assigned to groups based on an analysis of testis diameter, weight, seminiferous tubule diameter and the interstitial tissue area: group 1, not fully regressed (the highest parameters); group 2 (medium parameters); or group 3, regressed (the lowest parameters). Cells positive for p16 were observed only in the seminiferous tubule epithelium. However, in groups 1 and 2, these were mostly cells sloughed into the tubule lumen. In group 3, senescent cells resided in between cells of the seminiferous epithelium. Staining for ZIP9 was found in Sertoli cells. Western blot analysis showed a trend towards a decreased expression of p16 and ZIP9 in the testes of the voles in groups 2 and 3, compared to group 1. In addition, a trend towards an increased expression of ERK, as well as an increase of cAMP and testosterone levels, was revealed in group 2. In the regressed testes, a functional link exists between senescence and androgen levels with implication of ZIP9 and cAMP/ERK signaling pathways.

The length of the distal part of the internal reproductive tract seems to be related to the length and capacity of uterine horns, which is the most important anatomical property influencing litter size in sows. The aim of this study was to evaluate variation in vagina–cervix length (VCL) in gilts and differences in reproductive performance of sows according to VCL. The study was performed in a commercial farm using 221 gilts introduced into the breeding herd. Females were divided into three groups: (S) short (26.0 ± 2.0 cm, n = 36), (M) medium (31.3 ± 1.46 cm; n = 121), and (L) long VCL (36.0 ± 1.4 cm; n = 42) (p < 0.01). Mean live weight of gilts did not differ significantly among groups. Mean first litter size significantly varied between groups S (10.47 ± 3.01) and L (11.98 ± 2.32) (p = 0.0075) and M (10.67 ± 2.98) and L (p = 0.0054), while there was no significant difference between group S and M. Significant advantage (p = 0.023) was noted in the number of litters obtained from sows in groups L (4.69 ± 3.14), M (3.67 ± 2.71), and S (3.36 ± 2.40), and thus in total life production of sows (p = 0.0054), i.e., the number of piglets born alive. To conclude, the differences in vagina–cervix length in gilts during the first service was associated with significant variability in litter size during the first reproductive cycle, giving an advantage to females with longer VCL. Gilts with longer VCL were culled later and gave significantly more litters. Consequently, their lifetime piglet production was greater than gilts with shorter VCL.

Porcine tissue gene expression is highly similar to the expression of homologous genes in humans. Based on this fact, the studies on porcine tissues can be employed to understand human physiology and to predict or treat diseases. Our prior studies clearly showed that there was a regulatory partnership of the peroxisome proliferator-activated receptor (PPAR) and the G-protein coupled membrane estrogen receptor (GPER) that relied upon the tumorigenesis of human and mouse testicular interstitial cells, as well as the PPAR-estrogen related receptor and GPER–xenoestrogen relationships which affected the functional status of immature boar testes. The main objective of this study was to identify the biological processes and signaling pathways governed by PPARα, PPARγ and GPER in the immature testes of seven-day-old boars after pharmacological receptor ligand treatment. Boar testicular tissues were cultured in an organotypic system with the respective PPARα, PPARγ or GPER antagonists. To evaluate the effect of the individual receptor deprivation in testicular tissue on global gene expression, Next Generation Sequencing was performed. Bioinformatic analysis revealed 382 transcripts with altered expression. While tissues treated with PPARα or GPER antagonists showed little significance in the enrichment analysis, the antagonists challenged with the PPARγ antagonist displayed significant alterations in biological processes such as: drug metabolism, adhesion and tubule development. Diverse disruption in the Notch signaling pathway was also observed. The findings of our study proposed that neither PPARα nor GPER, but PPARγ alone seemed to be the main player in the regulation of boar testes functioning during early the postnatal developmental window.