Effect of breed and diet on subcutaneous beef fat fatty acid indices for enzyme activities and nutritional interest

ZARLENGA, M.; LATIMORI, N.; SANCHO, A.M.; PIGHIN, D.G.; GARCÍA, P.T.

Ghent

Congreso; 57th International Congress of Meat Science and Technology-ICoMST; 2011

The effects of breed and diet on several indices of fatty acids involved in MUFA metabolism in subcutaneous fat for 54 Hereford (H), Bradford 1/4 (B 1/4), Bradford 3/8 (B3/8) and Bradford 1/2 (B1/2) steers under three production systems, pasture exclusive (P), pasture and 0.7% corn grain (P+0.7%), and feedlot (F) were determined. Samples of subcutaneous fat were taken at the height of the 11-13 rib and stored at -20‹C until analysis. Lipids were extracted using the method of Folch et al. (1). The fatty acid methyl esters (FAME) were analyzed on a Chrompack 900 gas chromatograph with a 100 m CP-Sil 88 capillary column. The indices for the activities of ƒ¢-9 desaturases as well as the elongase activity were estimated by the ratios of the products of the reaction to the substrates of the reaction. Treatments were compared by analysis of variance using the GML procedure (SAS 8.0 SAS Institute, Inc., Cary, NC). Mean values were compared using the TukeyLs test. The ratio MUFA/SFA was affected by diet and breed. F had higher MUFA/SFA ratios than P and P+0.7% and was higher in B1/2, B1/4 and B3/8 compared with H. The ratio 16:1/16:0 was only affected by breed. H was lower than the other breeds. The ratio 18:1/18:0 was only affected by diet. H presented the lowest values. 18:2/18:3 ratio was lower in P compared to F and higher in H and B3/8 compared to B1/2 and B3/8. The CLA concentrations were lower in F and in B3/8.et al. (1). The fatty acid methyl esters (FAME) were analyzed on a Chrompack 900 gas chromatograph with a 100 m CP-Sil 88 capillary column. The indices for the activities of ƒ¢-9 desaturases as well as the elongase activity were estimated by the ratios of the products of the reaction to the substrates of the reaction. Treatments were compared by analysis of variance using the GML procedure (SAS 8.0 SAS Institute, Inc., Cary, NC). Mean values were compared using the TukeyLs test. The ratio MUFA/SFA was affected by diet and breed. F had higher MUFA/SFA ratios than P and P+0.7% and was higher in B1/2, B1/4 and B3/8 compared with H. The ratio 16:1/16:0 was only affected by breed. H was lower than the other breeds. The ratio 18:1/18:0 was only affected by diet. H presented the lowest values. 18:2/18:3 ratio was lower in P compared to F and higher in H and B3/8 compared to B1/2 and B3/8. The CLA concentrations were lower in F and in B3/8.ƒ¢-9 desaturases as well as the elongase activity were estimated by the ratios of the products of the reaction to the substrates of the reaction. Treatments were compared by analysis of variance using the GML procedure (SAS 8.0 SAS Institute, Inc., Cary, NC). Mean values were compared using the TukeyLs test. The ratio MUFA/SFA was affected by diet and breed. F had higher MUFA/SFA ratios than P and P+0.7% and was higher in B1/2, B1/4 and B3/8 compared with H. The ratio 16:1/16:0 was only affected by breed. H was lower than the other breeds. The ratio 18:1/18:0 was only affected by diet. H presented the lowest values. 18:2/18:3 ratio was lower in P compared to F and higher in H and B3/8 compared to B1/2 and B3/8. The CLA concentrations were lower in F and in B3/8.