GROWTH PERFORMANCE, CARCASS TRAITS, MEAT QUALITY AND HISTOCHEMICAL CHARACTERISTICS OF MUSCLE FIBERS IN MEXICAN HAIRLESS FINISHING PIGS SUPPLEMENTED WITH ORGANIC COPPER

Background: Pork meat is related to cardiovascular diseases, due to its high content of saturated fatty acids and cholesterol. But it has been shown that dietary supplementation of pigs with organic minerals benefits growth qualities and improves carcass and meat quality characteristics. Objective: The objective was to evaluate the effect of Cu proteinate supplementation of finishing Mexican Hairless pigs (MHP) on growth, carcass characteristics, meat quality and muscle fiber composition. Methodology: Twenty-eight castrated male MHP (62±5.2 kg BW) were randomly assigned to four levels of Cu in the diet (0, 75, 150, and 225 mg kg-1 DM) for 46 d. The DMI, DWG, FC and FE were measured. At the end of fattening, the pigs were slaughtered and the characteristics of the carcass were evaluated. Tissue samples of Longissiumus thoracis (LT) were obtained and muscle fibers, pH, color, temperature and drip loss were evaluated. Results: The DMI was reduced linearly (P≤0.05) as Cu level supplementation increased in the diet. Growth performance was modified quadratically as Cu level supplementation was increased in the diet, as well as the highest DWG and the lowest FC values were found in barrows supplemented with 75 mg Cu kg-1 DM. Pigs supplemented with 75 and 150 mg Cu kg-1 DM had the highest (P≤0.05) CW and LEA compared with the other treatments. BFT and DL decreased linearly (P≤0.05) as Cu supplementation increased in the diet. The Cu supplementation affected (P≤0.05) the color index b and h after 48h. The Cu affected (P≤0.05) the number, composition and relative area of the type I, IIA and BII fibers of the LT. Implications: Organic Cu supplementation in the diet of Mexican Hairless pigs benefits growth efficiency, carcass yield and backfat reduction; however, its effect on content, FA profile, and oxidative stability of IF meat should be analyzed. Conclusions: It is concluded that Cu supplementation effected quadratically the values of Final BW, DWG, CW and LEA, and linearly Cu affected the values of DMI, FC, CCD, BFT, DL, pH, the color index b and h after 48h; treatments with Cu also influenced linearly or quadratically the number, composition and relative area of the type I, IIA and BII fibers of the LT post slaughter muscle metabolism and it may influence the parameters of quality of meat in finishing Mexican Hairless pigs. The production of MHP meat in an intensive fattening system is profitable and can be improved with the inclusion of Cu proteinate in the diet.