Effects of pig genotype, immunological castration, and use of ractopamine on growth performance, carcass traits, and pork quality for entire male pigs

Abstract

Entire male (EM) pigs (152; ∼30 kg body weight) were used to examine immunocastration using Improvest and feeding ractopamine on growth performance, carcass and meat quality, and fatty acid composition. Timing for administering second dose of Improvest compared dosing at 4 and 8 wk pre-slaughter. A factorial arrangement evaluated two genotypes [Large Whites and Duroc crossbreds (Durocs)] by five management regimens (EM fed control diet, EM fed ractopamine, second dose Improvest 4 wk pre-slaughter, second dose Improvest 8 wk pre-slaughter, second dose Improvest 4 wk pre-slaughter plus ractopamine). Average daily gain and gain to feed (G:F) were generally greater (P ≤ 0.01) in Durocs. Immunocastration increased (P < 0.01) dry matter intake (DMI); feeding ractopamine decreased (P < 0.02) DMI and increased (P < 0.03) G:F. Immunocastration decreased (P < 0.04) carcass and lean yields; feeding ractopamine increased (P < 0.04) carcass weights, lean yield, muscling, and longissimus shear force while decreasing (P < 0.01) backfats. Immunocastration did not affect loin pH, color, drip loss, and shear force. Timing for second Improvest dose did not affect most growth performance, carcass, and meat quality traits except for greater (P < 0.02) backfats when administering dose 8 wk pre-slaughter. Effects of immunocastration and (or) feeding ractopamine were relatively consistent in both genotypes evaluated.

Influence of Immunocastration on Slaughter Traits and Boar Taint Compounds in Pigs Originating from Three Different Terminal Sire Lines

“…On the other hand, the pH 24 of the IC originating from the TSL A was even lower than the threshold value for “normal” meat (pH 24 > 5.5), as suggested by Forrest [ 67 ]. Contrary to our results, in studies on crossbreds with 25 or 50% of Pietrain genetics [ 58 , 68 ] and different percentages of Duroc in Large White breed [ 57 ], no interaction between male category and genotype was observed for this trait.…”

“…There are not many studies dealing with the interaction between the male category and breed on carcass traits [ 3 ]. As to the diverse differential effect of ST in regard to the pig progeny, the existing literature mainly reports no significant or very limited effect [ 57 , 58 , 59 ]. Contrary to the results of the present study, Škrlep et al (2011) [ 43 ] found no interaction in the experiment with two crossbreds (50% Duroc and 50% Pietrain) and three treatments (IM, IC, EM).…”

The Use of Pork from Entire Male and Immunocastrated Pigs for Meat Products—An Overview with Recommendations

“…The studies with a direct comparison of the male sex category and breed for fat quality traits are, however, scarce and show a limited effect. Park et al [ 42 ], for instance, indicated that the effect of immunocastration on fatty acid composition was relatively consistent in both genotypes (Large White and Duroc crossbreed) evaluated.…”

Precision feeding gestating sows: effects on offspring growth performance and carcass and loin quality at slaughter

“…The remaining four chops were individually vacuum sealed and then aged at ≤4 °C for 2 or 7 d and then frozen at −20 °C until further analysis. The frozen chops were thawed over 24 h at <4 °C and used to determine cooking losses and Warner–Bratzler shear force according to the methods of Park et al (2018) .…”