RESUMEN
The objective of this research was to study the effect of immunocastration on the morphometric characteristics of sex glands in male Swallow-bellied Mangalitsa pigs. The study included 24 animals (13 entire and 11 immunocastrated males). The research focused on the following traits: age at slaughter (days), live weight at slaughter (kg), growth rate (kg day−1), and morphometric testicle traits (volume, cm3; weight, g; length, width, thickness, and circumference, mm). The efficacy of immunocastration was determined based on androstenone and skatole levels in adipose tissue. The group of immunocastrated animals had higher body weight at slaughter (+18.8 kg) due to higher average daily live gain (+87 g). Immunocastration resulted in reduced morphometric measures of testes. The volumes and weight of testes/epididymes were reduced by 28.9-54.4 and 32.1-53.3%, respectively. Testis length and other size-related traits were significantly reduced by 17.4-27.6%. The linear regression effect of live body weight at slaughter within the immunocastrated group on testis measurements was not significant. Within the entire group of males, the increase of live body weight at slaughter by 1 kg had an effect on the increase of volume and weight of testes/epididymes by 0.55-2.24 cm3 and 0.52-2.28 g, respectively. Other size-related testis traits increased by 0.04-0.55 mm for each kg of body weight. Immunocastration also resulted in 79.6% decrease in the weight of accessory sex glands. The present study is the first to demonstrate that immunocastration could be a method of choice for castration of the local fatty pig breed, Mangulica (Swallow-bellied Mangalitsa).(AU)