Influence of a conjugated linoleic acid mixture on growth, organ weights, carcass traits and meat quality in growing pigs

Grain soybean meal diets, either with 2% of a conjugated linoleic acid (CLA) preparation or with 2% rapeseed oil (control), were tested in 2 x 40 pigs, Pietrain x (Landrace x Large White), each group with 20 female in the live weight range 23.5-117.0 kg and 20 male-castrated pigs in the live weight range 23.5-110.6 kg. The CLA-content of the preparation amounted to 54.0% cis/trans + trans/cis, 8.7% cis/cis and 32.7% trans/trans isomers. Daily weight gain, feed intake and feed : gain ratio were not influenced by the diets tested. The carcass lean increased significantly from 57.2% of the control group to 58.7% in the CLA group (p < 0.05). The male-castrated showed a stronger CLA effect than the female pigs not only was the carcass lean significantly increased by 2%, but backfat thickness was significantly decreased by 2.8 mm, i.e. minus 11% (as compared with barrows of the control). The meat of CLA-fed pigs had a higher conductivity. A CLA effect on further meat quality characteristics (pH 45 min post-mortem, impedance, colour criteria, intramuscular fat, drip loss, frying loss, shear force, sensory attributes) could not be detected. There were some significant correlations between the meat quality attributes.