Índices productivos y características de la canal de cerdos Ibéricos inmunocastrados o castrados quirúrgicamente y alimentados con dietas de diferente concentración proteica. Resultados preliminares.

Vaccination against Gonadotropin Releasing Hormone (GnRH) induces antibody production to neutralize GnRH, thus disrupting the hypothalamic-pituitary-gonadal axis (Dunshea et al. 2001). This procedure has been demonstrated to be effective to prevent sexual development and boar taint in male pigs (Batorek et al. 2012) and could be a reliable alternative to surgical castration, which has raised animal welfare concerns, particularly in European countries. Immunocastration can also be an effective strategy to avoid boar taint in production of local pig breeds, usually slaughtered at heavy weights, as for Iberian pig production. Iberian female pigs are also gonadectomized to prevent unwanted oestrus or pregnancies during the finishing period, particularly if it is performed in extensive conditions (Gomez-Fernandez et al. 2013, Martinez-Macipe et al. 2016). Immunocastration may also alter pig performance. Results in the literature indicate that immunocastrated (IC) male pigs exhibit higher performance after the second vaccination compared to surgically castrated (SC) pigs (Millet et al. 2011; Batorek et al. 2012; Dunshea et al. 2013). In addition to animal welfare aspects, this latter observation could be of interest for Iberian and other autochthonous pig breeds, as their capacity for growth and lean tissue deposition rapidly decreases as the animal increases body weight (Nieto et al. 2012). We have previously defined optimal protein-to-energy ratios in the diet for SC Iberian pigs growing from 10 to 150 kg BW (Nieto et al. 2012 & 2013). We hypothesize that protein requirements might be increased in IC compared to SC animals, particularly at earlier stages of growth. Therefore, the purpose of this study is to investigate the effect of immunocastration on Iberian male and female pig performance, protein utilization and carcass traits under three dietary protein concentrations. Results presented are preliminary and comprise a part of a wider study involving additional measurements and individuals.