Genotype and dietary inclusion of omega-3 fatty acids and fiber influence metabolism of subcutaneous adipose tissue and systemic metabolic outcomes in growing pigs

Adipose tissue properties are considered as determinants of meat quality, but also play roles in animal robustness. From 33 kg to 116 kg on average, a total of 60 Duroc (D) or Pietrain (P) crossbred female pigs were individually fed either a conventional (C) or an experimental (R) feeding strategy with a diet rich in omega 3 fatty acids and crude fibers (n = 15 pigs per group). The D pigs had a lower feed efficiency and a higher proportion of subcutaneous adipose tissue (SCAT) at slaughter than P pigs (P < 0.01). SCAT in D pigs had lower levels of polyunsaturated fatty acids (PUFA; P < 0.001) and higher levels of peroxidized lipids (P < 0.05) than SCAT in P pigs. In plasma, reactive oxygen metabolites to total antioxidant capacity was higher (P < 0.01) in D pigs than in P pigs. Compared to C, feeding the R diet resulted in a marked decrease in the n-6:n-3 PUFA ratio in SCAT, which was even more pronounced in D pigs than in P pigs (P < 0.05). The R feeding strategy increased beta-hydroxyacyl-coenzyme A dehydrogenase activity (P < 0.05) acting in fatty acid oxidation, and SCAT susceptibility to peroxidation. This also led to a reduction in plasma phospholipid concentrations and oxidative stress in the D pigs (P < 0.05). Thus, the nutritional value of fat products for humans and the systemic metabolic outcomes for pigs could be improved with an appropriate feeding strategy.