Effect of Immunocastration on Culled Sows—A Preliminary Study on Reproductive Tract, Carcass Traits, and Meat Quality

Abstract

The Bísaro pig is a Portuguese autochthonous breed greatly appreciated for its meat quality and is mainly reared outdoors. Immunocastration could be a solution to avoid undesirable pregnancies and boar taint in cull sows. The present study tested three immunocastration protocols (with Improvac®) according to their reproductive cycle. The first inoculation was performed two weeks after farrowing (IM1, n = 5), at the beginning of estrus (IM2, n = 5), and one week after the end of estrus (IM3, n = 5), followed by a second administration four weeks apart. A control group (C, n = 5) was also included in the same housing conditions. The sample collection included the reproductive tract for morphometric evaluation, neck fat for the quantification of boar taint compounds, and a portion of the Longissimus thoracis et lumborum for meat quality trait assessment. The reproductive tracts from intact sows (C) were significantly heavier compared to the immunocastrated groups (p < 0.05) (1.403 kg C to 0.508 kg IM1, 0.590 kg IM2, and 0.599 kg IM3), suggesting the regression of the reproductive tract to nonstimulated conditions due to immunization against GnRH. The IM1 group exhibited significantly smaller reproductive tract measurements compared to group C for most of the evaluated segments (p < 0.05). No marked differences were observed in the meat quality traits. Therefore, immunocastration can be used in culling sows to avoid ovarian activity, and it is not detrimental to pork quality traits.

Seasonal Variations on Testicular Morphology, Boar Taint, and Meat Quality Traits in Traditional Outdoor Pig Farming

“…All procedures in this study followed the methodology described previously [ 28 ]. A pH meter WTW 330i (Weilheim, Germany) was used to record carcasses’ pH at 45 min postmortem (pH 45min ), while still in the slaughterhouse line.…”

“…Androstenone (AND) and skatole (SKA) levels in pig fat were quantified using HPLC analysis following the procedures described earlier [ 28 ]. The limits of detection (LoD) of the assays were 16.02 ng/mL and 1.53, respectively, for androstenone and skatole, and the recovery values were 102.84% for androstenone, and 99.72% for skatole.…”

Dependence of the histomorphological structure of m. Longissimus thoracis in fattening pigs from the method of their castration and live weight

“…Зокрема, на думку багатьох дослідників (Bohrer et al, 2014;Xue et al, 2019;Pérez-Ciria et al, 2021), імунокастрація свинок не мала впливу на фізико-хімічні показники їх м'яса. Це було підтверджено звітами (Botelho-Fontela et al, 2023) про відсутність відмінностей у показниках ніжності м'яса між імунокастрованими та некастрованими свинками, що опосередковано вказує на відсутність змін у гістологічних характеристиках м'язів, включаючи розмір м'язового пучка та розмір волокон, оскільки останній, як було показано, впливає на якість м'яса, включаючи ніжність (Bogucka & Kapelański, 2005;Ryu & Kim, 2005).…”