The objective of this study was to determine the effect of dietary protein restriction in finishing pigs on the fat content, fatty acid profile, and atherogenic and thrombogenic indices of m. longissimus dorsi. A feeding trial was performed on 45 crossbred [(Polish Landrace x Polish Large White) x Duroc] finishing pigs with an average initial body weight of 65 kg. The animals were divided into experimental groups and were fed finisher diets with different levels of total protein and total lysine: group S-c- standard protein level, O – protein level reduced by 15% relative to the standard level, O+AA – protein level reduced by 15% and supplemented with crystalline lysine to the standard level. The intramuscular fat content, fatty acid profile and health-promoting properties of m. longissimus dorsi were determined. A 15% reduction in total protein levels in diets for finishing pigs insignificantly increased the intramuscular fat content of m. longissimus dorsi, but had no influence on the total concentrations of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). The supplementation of low-protein diets with crystalline lysine decreased the intramuscular fat content of m. longissimus dorsi, decreased the concentrations of margaric-oleic acid (C17:1) and gadoleic acid (C 20:1), and increased α–linolenic acid (C18:3) levels. Meat from pigs fed a low-protein diet supplemented with lysine was characterized by a lower (more desirable) n-6/n-3 PUFA ratio and provide more atherogenic and trombogenic properties.

21.3.2016