1. Effect of immunocastration and housing conditions on pig carcass and meat quality traitsMartin Škrlep, Klavdija Poklukar Žnidaršič, Kevin Kress, Milka Vrecl, Gregor Fazarinc, Nina Batorek Lukač, Ulrike Weiler, Volker Stefanski, Marjeta Čandek-Potokar, 2020, original scientific article Abstract: The present study investigated the effects of immunocastration and housing conditions on carcass, meat, and fat quality traits. Immunocastrates (IC, n = 48), entire (EM, n = 48), and surgical castrates (SC, n = 48) male pigs were reared under three different housing conditions. The conditions were standard (n = 36), enriched (n = 36, twice as much space as standard and additional outdoor access), or standard with repeated social mixing (n = 72). Pigs of the IC group were vaccinated at the age of 12 and 22 wk. The animals were slaughtered in four batches, balanced for sex category and housing, at the age of 27 wk reaching 124.7 ± 1.0 kg. Immunocastration led to increased fat deposition (i.e., thicker subcutaneous fat at different anatomical locations, more leaf fat, fatter belly in IC than EM, P < 0.05) but did not affect muscularity traits. As a result, EM exhibited higher and SC lower (P < 0.05) carcass leanness than IC. Fatty acids composition of either subcutaneous or intramuscular fat (IMF) agreed with general adiposity, that is, IC were intermediate between EM and SC exhibiting the lowest and highest fat saturation (P < 0.05), respectively. Compared to SC, EM exhibited higher (P < 0.05) levels of muscle oxidation and collagen content than SC, with IC taking an intermediate position in the case of the level of peroxidation and collagen content, or closer to SC as regards to oxidation of muscle proteins (i.e., carbonyl groups). Meat quality (including marbling score, cooking loss, subjective color redness, and chroma) of IC was similar to EM, and both differed (P < 0.05) from SC. However, IC and SC had less (P < 0.05) tough meat than EM, consistent with protein oxidation. The effect of housing was less evident. Mixing of pigs resulted in lower (P < 0.05) carcass weight and fatness in all sex categories with lower (P < 0.05) oleic and higher (P < 0.05) arachidonic acid in IMF of EM.
Keywords: carcass traits, entire males, housing, immunocastrates, meat quality, surgical castrates
Published in DKUM: 18.12.2024; Views: 0; Downloads: 7
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2. Adipose tissue gene expression of entire male, immunocastrated and surgically castrated pigsKlavdija Poklukar Žnidaršič, Marjeta Čandek-Potokar, Milka Vrecl, Nina Batorek Lukač, Gregor Fazarinc, Kevin Kress, Volker Stefanski, Martin Škrlep, 2021, original scientific article Abstract: Differences in adipose tissue deposition and properties between pig male sex categories, i.e., entire males (EM), immunocastrates (IC) and surgical castrates (SC) are relatively well-characterized, whereas the underlying molecular mechanisms are still not fully understood. To gain knowledge about the genetic regulation of the differences in adipose tissue deposition, two different approaches were used: RNA-sequencing and candidate gene expression by quantitative PCR. A total of 83 differentially expressed genes were identified between EM and IC, 15 between IC and SC and 48 between EM and SC by RNA-sequencing of the subcutaneous adipose tissue. Comparing EM with IC or SC, upregulated genes related to extracellular matrix dynamics and adipogenesis, and downregulated genes involved in the control of lipid and carbohydrate metabolism were detected. Differential gene expression generally indicated high similarity between IC and SC as opposed to EM, except for several heat shock protein genes that were upregulated in EM and IC compared with SC. The candidate gene expression approach showed that genes involved in lipogenesis were downregulated in EM compared with IC pigs, further confirming RNA-sequencing results.
Keywords: pigs, adipose tissue, entire males, immunocastration, surgical castration, RNA-sequencing, expression
Published in DKUM: 10.10.2024; Views: 0; Downloads: 5
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3. Male reproductive organ weight : criteria for detection of androstenone-positive carcasses in immunocastrated and antire male pigsGregor Fazarinc, Nina Batorek Lukač, Martin Škrlep, Klavdija Poklukar Žnidaršič, Alice Broeke, Kevin Kress, Etienne Labussière, Volker Stefanski, Milka Vrecl, Marjeta Čandek-Potokar, 2023, original scientific article Abstract: Immunocastration and rearing of entire males (EMs) are sustainable alternatives to surgical castration. However, these animal carcasses have variable risk of boar taint and should be identified at the slaughter line. We aimed to identify a simple and reliable indicator of androstenone-related boar taint by evaluating pelvic urogenital tract weight as a marker of boar-taint animals at the slaughter line. The pelvic urogenital tract, testes, and accessory sex glands of EMs and immunocastrates (ICs) were collected, dissected, and weighed, before colorimetric measurements of testicular tissue. Additionally, GnRH antibody titers and testosterone, androstenone, and skatole levels were determined. Our results showed that 81.8% of EMs had androstenone levels above the risk threshold (>0.5 µg/g fat; EM/Ahigh subgroup), whereas in ICs, the C/Ahigh subgroup with androstenone >0.5 µg/g fat accounted for only 4.3%. Androstenone levels correlated negatively with GnRH antibody titers and positively with testosterone levels and reproductive organ weights. Identification of ICs with androstenone levels above the threshold (IC/Ahigh subgroup) may be achieved via testes or pelvic urogenital tract weight measurements. However, in EMs, the latter is a more reliable parameter. A principal component analysis based on these variables and hierarchical clustering also distinguished the Ahigh from the Alow subgroup, irrespective of IC/EM. The findings highlight the possible use of pelvic urogenital tract weight along with testes weight as a simple, reliable, and efficient morphometric indicator for identifying androstenone-positive carcasses of different sex categories.
Keywords: boar taint, morphometric indicators, immunocastration, entire males
Published in DKUM: 11.04.2024; Views: 213; Downloads: 15
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4. Immunocastration in adult boars as a model for late-onset hypogonadismNina Batorek Lukač, Kevin Kress, Marjeta Čandek-Potokar, Gregor Fazarinc, Martin Škrlep, Klavdija Poklukar Žnidaršič, Raffael Wesoly, Volker Stefanski, Milka Vrecl, 2022, original scientific article Abstract: Background:
While immunocastration has been studied in male pre-pubertal pigs, data on older, sexually mature animals are limited. To understand the physiological effects of androgen deprivation in the late sexual development phase, we compared mature immunocastrated boars (n = 19; average age = 480 days) to young male immunocastrated pigs (n = 6; average age = 183 days) and young entire males (n = 6; average age = 186 days) as positive and negative controls, respectively.
Objectives:
We hypothesized that the timing of gonadotropin-releasing hormone suppression (early or late sexual development phases) influences the extent of reproductive function inhibition, histological structure of testicular tissue, and expression levels of selected genes related to steroid metabolism.
Materials and methods:
Antibody titer, hormonal status, and histomorphometric analysis of testicular tissue were subjected to principal component analysis followed by hierarchical clustering to evaluate the immunocastration effectiveness in mature boars.
Results:
Hierarchical clustering differentiated mature immunocastrated boars clustered with young immunocastrated pigs from those clustered with entire males. Although all mature immunocastrated boars responded to vaccination, as evidenced by the increased gonadotropin-releasing hormone antibody titers (p < 0.001), decreased serum luteinizing hormone concentrations (p = 0.002), and changes in testicular tissue
vascularization (lighter and less red testicular parenchyma; p ≤ 0.001), the responses were variable. Sharp decreases in testes index (p < 0.001), Leydig cell volume density (p < 0.001), Leydig cell nucleus-to-cytoplasm ratio (p < 0.001), and testosterone concentration (p < 0.001) were observed in mature immunocastrated boars clustered with young immunocastrated pigs compared with those that clustered with entire males. Additionally, mature immunocastrated boars clustered with young immunocastrated pigs showed lower hydroxysteroid 17-beta dehydrogenase 7 expression than entire males (p < 0.05). The young immunocastrated pigs group showed higher folliclestimulating hormone receptors than the entire males and mature immunocastrated boars, lower steroidogenic acute regulatory protein expression levels compared with
entire males, and mature immunocastrated boars clustered with entire males (p < 0.01).
Conclusion:
The two-dose vaccination regime resulted in progressive but variable regression of testicular function in adult (post-pubertal) pigs; however, it was insufficient to induce a complete immunocastration response in all animals.
Keywords: response to immunocastration, pigs, anti-GnRH, morphometry, testicular mRNA expression
Published in DKUM: 16.08.2023; Views: 490; Downloads: 83
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