|Neel, James - Jim|
Submitted to: American Society of Animal Science
Publication Type: Proceedings
Publication Acceptance Date: 6/30/2005
Publication Date: 7/24/2005
Citation: Guay, J., Fontenot, J., Swecker, W., Neel, J.P., Herbein, J., Clapham, W.M., Scaglia, G., Abaye, A. 2005. Fatty acid composition of diets, metabolism and deposition in edible tissue of pasture- and feedlot-finished cattle. #620, J. Anim. Sci., Vol. 83, Suppl. 1, p. 370.
Technical Abstract: A finishing study was conducted to determine the fatty acid (FA) composition of feeds and to evaluate FA metabolism in beef cattle. Twelve steers were finished on a high-concentrate diet in feedlot (individually fed) and 12 on pasture (initial BW = 302.9 ± 89.3 kg). The pasture treatment consisted of three replications. The high-concentrate diet consisted of cracked corn, corn silage, soybean meal, and mineral supplement. Subcutaneous adipose tissue biopsy samples were obtained initially, and on d 28, 84, and 140. Pasture forage and composited feedlot diet ingredient samples were collected every 14 d. Adipose tissue data were analyzed as a completely randomized design using the PROC MIXED procedure. The average FA composition of the high-concentrate diet consisted primarily of linoleic acid (16.17 to 28.0 mg/g DM, or 55.17 to 58.17 % of total FA). The FA composition of pasture forage samples consisted primarily of linolenic acid (9.81 to 47.71 mg/g DM, or 56.38 to 76.98 % of total FA). The conjugated linoleic acid (CLA) content of adipose tissue decreased (P < 0.05) in high-concentrate-fed steers and increased (P < 0.05) in pasture-finished steers. The pasture-finished steers had higher (P < 0.05) amounts of CLA in adipose tissue on d 24 (12.91 vs. 5.2 mg/g tissue), d 84 (10.50 vs. 2.11 mg/g tissue), and d 140 (10.01 vs. 2.12 mg/g tissue), than the high-concentrate finished steers. The pasture-finished steers had higher (P < 0.05) amounts of linolenic acid (an omega-3 FA) in adipose tissue on d 28 (6.82 vs. 2.77 mg/g tissue), d 84 (5.15 vs. 2.8 mg/g tissue), and d 140 (5.81 vs. 2.57 mg/g tissue), than the high-concentrate finished steers. An increase of CLA and omega-3 FA in beef products may be beneficial to consumer health.