Expression of follicle stimulating and luteinizing hormone receptors in porcine testes after timing the first vaccination for immunocastration

This study aimed to examine the expression of follicle stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in the testes of male fattening pigs based on the timing of the first immunocastration dose. A total of 24 male pigs were randomly assigned to 3 groups: C (n=8) consisted of only intact pigs, T1 (n=8) contained those immunocastrated at 15 and 19 weeks of age, and T2 (n=8) was composed of those immunocastrated at 9 and 19 weeks of age. The expression of FSHR and LHR was evaluated using H-score from immunohistochemistry and protein band intensity from Western blotting. Immunohistochemistry revealed that C pigs exhibited the highest FSHR H-score (82.70±12.20), whereas no significant difference was observed between T1 and T2 (31.61±16.51 vs 36.44±7.77, P > 0.05). The highest LHR H-score was found in C (109.68±3.41), whereas that between T1 and T2 was not different (72.06±5.63 vs 75.71±5.75, P > 0.05). Western blot analysis demonstrated that the highest FSHR protein band intensity occurred in C group (0.66±0.19), while T1 and T2 showed no significant difference (0.29±0.06 vs 0.26±0.10, P > 0.05). LHR protein band intensity was highest in C pigs (0.60±0.38), with no significant difference between T1 and T2 (0.23±0.27 vs 0.17±0.08, P > 0.05). In conclusion, the GnRH vaccine suppressed porcine testicular growth and functions. FSHR and LHR expression did not differ significantly between vaccination protocols.