EFFECTS OF CONJUGATED LINOLEIC ACID SUPPLEMENTATION ON PERFORMANCES, CARCASS QUALITY AND FATTY ACID COMPOSITION IN MEAT OF FINISHING PIGS

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid with conjugated double bonds. Conjugated linoleic acids have been reported to have a wide range of health beneficial effects, including anticarcinogenic, antiatherogenic, antidiabetic and immune stimulatory. The objective of this study was to elucidate the effects of CLA on performance, carcass quality and fatty acid composition of meat from finishing pigs. Forty eight crossbred finishing pigs [Duroc x (Landrace x Large White)] (24 gilts and 24 barrows), weighing 60 kg were used. The experimental design was a 3 x 2 factorial arrangement, with the level of CLA supplementation (0%, 0.5%, and 1.0% in diet) as the first factor and sex of pigs (gilts and barrows) as the second factor. Feed consumption was recorded weekly, while body weight was recorded fortnightly. Carcass composition was determined by slaughtering 24 pigs (12 gilts and 12 barrows). CLA supplementation did not affect (P > 0.05) average daily gain (ADG), average daily feed intake (ADFI) and Gain: Feed, however gilts showed higher (P < 0.01) ADG and Gain: Feed than those of barrows. There was no interaction between CLA and sex in ADG, ADFI and Gain: Feed. In addition, CLA supplementation did not affect (P > 0.05) backfat thickness (first rib, tenth rib, last rib and last lumbar), loin eye area and lean percentage. Firmness, marbling, color (L*, a* and b* value) and chemical composition (protein, moisture and ash contents) of ham and loin were not influenced by CLA supplementation. However, CLA supplementation showed lower percentage of lipid in ham (P < 0.05) and in loin (P < 0.01) than that of the unsupplemented control. CLA supplementation showed higher total saturated fatty acid (SFA) percentage (especially C12: 0, C14: 0, C16: 0 in ham and C12: 0, C14: 0, C16: 0, C18: 0 in loin) and SFA: UFA ratio. However, CLA supplementation showed lower unsaturated fatty acid (UFA) percentage especially monounsaturated fatty acid (MUFA) percentage (C18: 1n9c in ham and C18: 1n9c, C18: 2n9c, C20: 3n6 and C20: 4n6 in loin). Poly-unsaturated fatty acid (PUFA) percentage in ham and loin were not influenced by CLA supplementation. However, barrows showed higher C18: 2n6c, C18: 3n3, C20: 3n6, C20: 4n6 and PUFA than those of gilts, whereas gilts showed higher C10: 0 than that of barrows in loin. Accumulation of CLA (cis 9-tran 11 and tran 10-cis 12) in ham and loin was increased with supplemental CLA. There were no interactions between CLA and sex in all parameters. The present study clearly showed that CLA supplementation reduced fat content in meat, reduced UFA and MUFA but increased SFA and CLA in meat lipid.