Jm. Eggert et al., Effects of conjugated linoleic acid on the belly firmness and fatty acid composition of genetically lean pigs, J ANIM SCI, 79(11), 2001, pp. 2866-2872
A study of the effects of conjugated linoleic acid (CLA) on the belly firmn
ess and fatty acid composition of genetically lean pigs was conducted. From
75 to 120 kg live weight, 30 gilts were allowed ad libitum access to a cor
n-soybean meal diet supplemented with either 1% CLA oil (CLA-60) or 1% sunf
lower oil (SFO) or were fed the sunflower oil-supplemented diet restricted
to the amount consumed by pigs fed the CLA-60 diet (RSFO). Conjugated linol
eic acid oil consists of 60% positional and geometric isomers of CLA. Pigs
fed SFO exhibited higher average daily gains (0.98 vs 0.80 kg/d, P < 0.01)
than RSFO-fed pigs, but there were no effects of dietary treatment on feed
intake or feed efficiency. Dietary treatment did not affect (P > 0.05) back
fat thickness or longissimus muscle area. Bellies of gilts fed CLA-60 were
subjectively evaluated to be firmer (2.91 vs 2.43 or 2.07 +/- 0.13, P < 0.0
1) than those of SFO- or RSFO-fed gilts, respectively. The longissimus musc
le of gilts fed CLA-60 contained more saturated fatty acids (39.77 vs 36.04
or 36.73 +/- 0.74%, P < 0.001) and less unsaturated fatty acids (60.23 vs
63.96 or 63.27 +/- 0.74%, P < 0.001) than that of gilts fed SFO or RSFO, re
spectively. The belly fat of gilts fed CLA-60 contained more saturated fatt
y acids (44.45 vs 37.50 or 36.60 +/- 0.46%, P < 0.001.) and less unsaturate
d fatty acids (54.78 vs 61.75 or 62.47 +/- 0.46%, P < 0.001), resulting in
lower iodine values (57.69 vs 66.37 or 65.62 +/- 0.91, P < 0.001) than that
of gilts fed SFO or RSFO, respectively. Gilts fed CLA-60 accumulated more
CIA in the longissimus muscle (0.55 vs 0.09 or 0.09 +/- 0.03%, P < 0.01) an
d belly fat (1.56 vs 0.13 or 0.13 +/- 0.15%, P < 0.001) than did gilts fed
SFO or RSFO, respectively. Dietary treatment did not affect (P > 0.05) 24-h
pH, drip loss or subjective quality evaluations of the longissimus muscle.
The effect of supplemental CLA to improve belly firmness is of practical s
ignificance and may provide a nutritional solution to carcass fat and belly
firmness problems, thereby enhancing the overall value of extremely lean c
arcasses.