Effects of Field Pea Diet and Immunocastration in Heavy Pigs on Fresh Pork and Dry-Cured Ham

Abstract

Peas are an alternative to soybeans to supply protein in livestock feeds. Immunocastration avoids surgical castration of male pigs and increases fat deposition in female pigs. This work aimed to assess the effects of pea inclusion on the amount of fat and fatty acid profile of loins and on weight losses of dry-cured hams in different sexes of pigs; in addition, growth performance and feeding behavior in immunocastrated female pigs were evaluated. Two experiments were conducted with crossbred immunocastrated female (IF) and immunocastrated (IM) or surgically castrated (CM) male pigs from Duroc dams sired by Berkshire, which were assigned to one of two diets (soybean vs. pea-based). The effect of castration type on the afore-mentioned variables was evaluated in male pigs, and the growth performance, and feeding behavior in female pigs. The pea-based diet in IF had no effect on average daily gain nor on carcass traits; although, it increased feeding time (p < 0.001) and reduced n-3 polyunsaturated fatty acid (PUFA) content (p < 0.05). In male pigs, the pea-based diet did not change carcass fatness either but reduced the n-3 PUFA levels (p < 0.05). Likewise, IM had lower (p < 0.001) monounsaturated fatty acid (MUFA) and higher (p < 0.05) n-6 PUFA than CM. Diet did not affect dry-cured ham weight losses during the process, while IM showed greater (p < 0.001) losses than CM. Pigs fed a pea-based diet complied with the requirements of cured ham production, while immunocastration in male pigs increased weight losses, partly explained by lower fat content and higher fatty acid unsaturation.