Growth Performance, Meat Quality, and Lipid Oxidation in Pigs’ Fed Diets Containing Grape Pomace

Grape pomace is a winery byproduct that is rich in polyphenols with antioxidant capacity. This study investigated the effect of 0, 5, and 10% inclusion of dehydrated grape pomace (DGP) in finishing pig diets on the growth performance, carcass traits, fatty acid profile, fresh meat quality, and fat stability of a local pig genotype. A total of 36 pigs, 18 barrows, and 18 gilts (83.23 ± 6.03 kg and 132.1 ± 5.6 days old) were allotted in a randomized block design considering the initial weight (block) within sex, with six replicates of each sex per treatment. Including DGP in the diets did not affect daily weight gain or the feed-to-gain ratio; however, daily feed intake increased linearly (p < 0.05) and backfat thickness at the last rib, backfat thickness at the first sacral vertebrae, P2 backfat thickness, fat area, and the percentage of lean meat decreased linearly (p < 0.05) in pigs. The inclusion of DGP in pig diets did not affect the antioxidant potential evaluated by thiobarbituric acid-reactive substances in mini hamburgers or the quality characteristics of fresh meat, except for intramuscular fat (EE). The dietary inclusion of DGP linearly increased (p < 0.05) EE, saturated fatty acids, monounsaturated fatty acids, and Σω-3 and reduced the ω-6:ω-3 ratio in a linear way (p < 0.05) in the loin of pigs. We concluded that it is feasible to include up to 10% of DGP in pig diets without affecting growth performance, but carcass quality may be impaired due to increased adiposity. Furthermore, meat quality can be improved by increasing intramuscular fat and ω-3 fatty acid content, but fat stability is not affected when DGP is included at up to 10% of the diet for 49 days prior to slaughter.