Differences in Muscle Lipogenic Gene Expression, Carcass Traits and Fat Deposition among Three Iberian Pig Strains Finished in Two Different Feeding Systems

Abstract

The Iberian pig breed includes several well-differentiated strains. The present study evaluated carcass traits, fat deposition and muscle expression of important lipogenic genes (SCD, ME1, ACACA, FASN, EGR1, ACOX and ACLY) using 65 male pigs of 3 Iberian strains (20 Lampiño, 23 Torbiscal, and 22 Retinto) finished either in a conventional, concentrate-based system (CF) or in montanera (MF), a traditional free-range system with acorn feeding. Torbiscal had the highest ham, Longissimus thoracis and prime cuts yields, and the thinnest subcutaneous adipose tissue (SAT). Retinto had the highest monounsaturated fatty acids (MUFA) and percentage of intramuscular fat (IMF), while Lampiño had the greatest content of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), atherogenic (AI) and thrombogenic (TI) indexes in SAT. Conventionally finished pigs had the highest ham, L. thoracis and prime cuts yields, and SFA. Montanera-finished animals had the highest PUFA and MUFA contents, and the lowest AI, TI and n6/n3 ratio in SAT. In relation to gene expression, Retinto had the greatest SCD, FASN and ACLY levels. Most studied genes were overexpressed in CF pigs. In conclusion, MF pigs had healthier fat than CF pigs, and Retinto had the healthiest fat and the greatest lipogenic trend in muscle, supported by IMF and lipogenic gene expression.

Meat Characteristics, Expression of Myosin Heavy Chain and Metabolism-Related Genes in Thai Native Pigs

“…Our findings indicate that in spite of the similar IMF content in the NT, ST and NE loins, some differences in muscle fatty acids may occur. This observation is in agreement with that of Garrido et al [46], who found differences in the FA composition of Lampiño, Torbiscal and Retinto pigs despite similar IMF contents. The higher PUFA content in the NT loin suggests that it may probably be more susceptible to lipid oxidation compared to the ST and NE loins.…”

“…The AI and TI in the NT loin were lower than those of the NE and ST loins as a result of the decrease in C16:0 and the increase in the total PUFA. Nevertheless, the range of AI and TI observed in this study was in line with those observed in several native pig breeds [41,45,46].…”

“…Regardless of GR, the total content of MUFA, SFA and PUFA in the LT of TNPs ranges from 50 to 53, from 29 to 36 and from 12 to 21%, respectively. A similar trend of FA distribution has been documented in various native pigs [4,45,46]. In pigs, PUFA are obtained from the diet, while MUFA can be supplied from the diet or synthesized de novo [21,47].…”

“…This target was not met in this study, regardless of GR. Likewise, the n-6/n-3 of the LT of native prestice black-pied [52], Ibérico [41], Alentejana [45] and Iberian [30,46] pigs was >4. The AI and TI in the NT loin were lower than those of the NE and ST loins as a result of the decrease in C16:0 and the increase in the total PUFA.…”

Transcriptomic Profiling of Subcutaneous Backfat in Castrated and Intact Alentejano Pigs Finished Outdoors with Commercial and Fiber-Rich Diets

“…The FASN gene encodes the Fatty Acid Synthase, a multi-enzyme protein involved in the de novo synthesis of C16:0 from acetyl-CoA and malonyl-CoA. Additionally, it plays a role in the synthesis of long-chain SFAs [ 59 , 60 ]. Previous studies have investigated the relationship between higher expression of FASN and an increased risk of obesity due to the accumulation of triacylglycerols in humans [ 61 ].…”