TY - JOUR
T1 - The fatty acid composition of muscle and adipose tissue of steers offered unwilted or wilted grass silage supplemented with sunflower oil and fishoil
AU - Noci, F.
AU - Monahan, F. J.
AU - Scollan, N. D.
AU - Moloney, Aidan P.
PY - 2007/3
Y1 - 2007/3
N2 - The effects of the type of grass silage and dietary inclusion of fish oil (FO) on the fatty acid profile of bovine intramuscular and subcutaneous adipose tissue were investigated. Eighty Friesian steers were assigned (n 10) to unwilted or wilted silage, and to one of four rations which contained, per kg, 80 g of sunflower oil and either 0, 10, 20 or 40 g of FO replacing lard. Animals were slaughtered after 108 d and the fatty acid profile of the neutral, polar and total lipid fractions of the M. longissimus dorsi, and the total lipid fraction of the subcutaneous adipose tissue were determined. Wilting of grass prior to ensiling increased the concentration of conjugated linoleic acid (CLA) in intramuscular total lipid (P<0.01), but did not affect the n-6:n-3 PUFA ratio. Increasing FO supply linearly increased (P<0.05) the concentration of the cis-9,trans-11 and trans-10,cis-12 isomers of CLA and trans-11 18: 1 predominantly in the neutral lipid fraction of intramuscular total lipid, and linearly decreased the n-6:n-3 PUFA ratio. Wilting of grass prior to ensiling increased the concentration of CLA in subcutaneous adipose tissue (P<0.001), while increasing FO supply linearly increased the concentration of cis-9,trans-11 CLA. From a human nutrition perspective, increasing the level of FO in the ration or wilting of grass prior to ensiling appear to modify the fatty acid composition of beef muscle favourably. However, the health implications of associated increases in trans fatty acids remain to be elucidated.
AB - The effects of the type of grass silage and dietary inclusion of fish oil (FO) on the fatty acid profile of bovine intramuscular and subcutaneous adipose tissue were investigated. Eighty Friesian steers were assigned (n 10) to unwilted or wilted silage, and to one of four rations which contained, per kg, 80 g of sunflower oil and either 0, 10, 20 or 40 g of FO replacing lard. Animals were slaughtered after 108 d and the fatty acid profile of the neutral, polar and total lipid fractions of the M. longissimus dorsi, and the total lipid fraction of the subcutaneous adipose tissue were determined. Wilting of grass prior to ensiling increased the concentration of conjugated linoleic acid (CLA) in intramuscular total lipid (P<0.01), but did not affect the n-6:n-3 PUFA ratio. Increasing FO supply linearly increased (P<0.05) the concentration of the cis-9,trans-11 and trans-10,cis-12 isomers of CLA and trans-11 18: 1 predominantly in the neutral lipid fraction of intramuscular total lipid, and linearly decreased the n-6:n-3 PUFA ratio. Wilting of grass prior to ensiling increased the concentration of CLA in subcutaneous adipose tissue (P<0.001), while increasing FO supply linearly increased the concentration of cis-9,trans-11 CLA. From a human nutrition perspective, increasing the level of FO in the ration or wilting of grass prior to ensiling appear to modify the fatty acid composition of beef muscle favourably. However, the health implications of associated increases in trans fatty acids remain to be elucidated.
KW - Conjugated linoleic acid
KW - Fish oil
KW - PUFA
KW - Wilted silage
UR - http://www.scopus.com/inward/record.url?scp=34047253928&partnerID=8YFLogxK
U2 - 10.1017/S0007114507381361
DO - 10.1017/S0007114507381361
M3 - Article
C2 - 17313712
AN - SCOPUS:34047253928
SN - 0007-1145
VL - 97
SP - 502
EP - 513
JO - British Journal of Nutrition
JF - British Journal of Nutrition
IS - 3
ER -