Double-muscling character influences the trans-18:1 and conjugated linoleic acid profile in concentrate-fed yearling bulls
Noelia Aldai a*
, Michael E. R. Dugan a , Manuel Juárez a
, Koldo Osoro b a
Agriculture & Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail,
Lacombe, AB, Canada T4L 1W1; b Servicio Regional de Investigación y Desarrollo
Agroalimentario (SERIDA), Área de Sistemas de Producción Animal, Consejería de
Medio Ambiente y Desarrollo Rural, Principado de Asturias, 33300 Villaviciosa,
Asturias, Spain
*Corresponding author:
Tel: (+1) 403 7828569; Fax: (+1) 403 7826120; email: noelia.aldai@agr.gc.ca
; noeliaaldai@hotmail.com
Target journal: MEAT SCIENCE

ABSTRACT
To examine the extent of the effect of muscular hypertrophy character in “Asturiana de los Valles” northern-Spanish breed produced under intensive conditions on trans -18:1 and conjugated linoleic acid (CLA) profile, backfat and muscle tissues of 75 yearling bulls were studied (double-muscled, mh/mh , n=24; heterozygous, mh/+ , n=26; normal,
+/+ , n=25). Total trans -18:1 contents were of 10.98%-15.07% in backfat and 8.64%-
9.46% in muscle, and the major isomer was 10 t -18:1. 11 t -18:1 was not the second major isomer in all genotypes studied and 13 t /14 t -18:1 content was similar to 11 t -18:1 in double-muscled and normal but not in heterozygous animals as these had significantly higher 11 t -18:1 content ( P <0.001). Total CLA contents were of 0.71-0.85% in backfat and 0.32-0.40% in muscle. Highest total CLA content was measured in heterozygous, intermediate in normal and lowest in double-muscled animals ( P <0.05). Heterozygous animals had significantly higher contents of 9 c ,11 t - ( P <0.01), 11 t ,13 c - ( P <0.01) and
9 c ,11 c -18:2 ( P <0.05) isomers and presented significantly higher contents of the sum of
9 c ,11 t -/11 t ,13 c -/11 t ,13 t -18:2 known as grass-feeding-related isomers.
Key Words: Asturiana de los Valles, beef, double muscling, conjugated linoleic acid, trans fatty acids.