Correlations between fat depot traits and fatty acid composition in abdominal subcutaneous adipose tissue and longissimus muscle: results from a White Duroc x Erhualian intercross [F.sub.2] population

The aim of this study was to quantify the partial correlation coefficients ([r.sub.p]) between fat depot traits (FDT) and the fatty acid composition of abdominal subcutaneous adipose tissue and LM intramuscular fat in 639 [F.sub.2] pigs derived from a White Duroc x Chinese Erhualian cross. Fat depot traits are classified into 2 groups: 1 is adipose tissues (abdominal subcutaneous adipose tissue weight, mesenteric adipose tissue weight, perirenal adipose tissue weight, and backfat thickness at 4 locations); the other is LM [intramuscular fat content (IMF) and marbling score]. Correlations of FDT within classification groups were markedly greater (P < 0.001) than those observed between the 2 groups ([r.sub.p] = 0.62 vs. 0.26), indicating variability in fat content of muscle is relatively independent of amount of carcass fat. In general, fatter pigs had greater (P < 0.05) proportions of SFA and MUFA, and less PUFA, than leaner pigs. However, the relationships of individual fatty acids with FDT varied. We found that the amounts of some fatty acids regarded as neutral (e.g., stearic acid) or beneficial (e.g., palmitoleic acid and linolenic acid) for human health were associated with smaller amount of adipose tissues, or merely with greater IMF (P < 0.05). Therefore, we conclude that increasing the proportions of these neutral or healthy fatty acids can be achieved without reducing the IMF of LM, which is positively related to eating quality. Key words: abdominal subcutaneous adipose tissue, correlation, fat depot trait, fatty acid composition, longissimus muscle, pig doi: 10.2527/jas.2009-2602