Effect of diet on the deposition of n-3 fatty acids, conjugated linoleic and C18:1trans fatty acid isomers in muscle lipids of German Holstein bulls.
This study examined the effects of feeding diets rich in either n-3 or n-6 polyunsaturated fatty acids (PUFA) on the fatty acid composition of longissimus muscle in beef bulls. Thirty-three German Holstein bulls were randomly allocated to either an indoor concentrate system or periods of pasture feeding (160 days) followed by a finishing period on a concentrate containing linseed to enhance the contents of n-3 PUFA and conjugated linoleic acids (CLA) in beef muscle. The relative proportion and concentration (mg/100 g fresh muscle) of n-3 fatty acids in the phospholipid and triglyceride fractions were significantly increased (p < or = 0.05) in muscle lipids of pasture-fed bulls. The pasture feeding affected the distribution of individual CLA isomers in the muscle lipids. The proportion of the most prominent isomer, CLA cis-9,trans-11, was decreased from 73.5 to 65.0% of total CLA in bulls fed on concentrate as compared to pasture. The second most abundant CLA isomers were CLA trans-7,cis-9 and CLA trans-11,cis-13 in bulls fed on concentrate and pasture, respectively. Diet had no effect on the concentration of C18:1 trans-11. In contrast, the concentration of the C18:1 trans-13/14, trans-15, and trans-16 isomers in the muscle lipids was up to two times higher in pasture-fed as compared to concentrate-fed bulls. Pasture feeding enhanced the concentration of n-3 fatty acids, but the diet had no effect on the concentration of CLA cis-9,trans-11.
Department of Muscle Biology and Growth, Research Institute for Biology of Farm Animals, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany.
Dirk
D
Dannenberger
Gerd
G
Nuernberg
Nigel
N
Scollan
Wiebke
W
Schabbel
Hans
H
Steinhart
Klaus
K
Ender
Karin
K
Nuernberg
D000818:Animals; D002417:Cattle; D004032:Diet; D005227:Fatty Acids / Q000032:analysis; D015525:Fatty Acids, Omega-3 / Q000032:analysis*; D044243:Linoleic Acids, Conjugated / Q000032:analysis*; D008055:Lipids / Q000032:analysis; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry*; D010743:Phospholipids / Q000032:analysis; D044242:Trans Fatty Acids / Q000032:analysis*; D014280:Triglycerides / Q000032:analysis
D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D044243:Linoleic Acids, Conjugated; D008055:Lipids; D010743:Phospholipids; D044242:Trans Fatty Acids; D014280:Triglycerides