Opportunities and Implications of Pasture‐Based Lamb Fattening to Enhance the Long‐Chain Fatty Acid Composition in Meat

Abstract

Health-conscious consumers following dietary fat recommendations require meat that is low in saturated fat with preferably high levels of long-chain omega-3 fatty acids. This review summarizes the influence of dietary lipids from red meat on human health and examines the potential to enhance lipid composition through pasture-feeding. The role of fatty acids in plant and ruminant metabolism is discussed to highlight the complexity of ruminal digestion when trying to enhance fatty acids in meat. Generally, ruminants that consume pasture diets have been shown to produce a more desirable fatty acid composition than those fed grain and offer potential to be further enhanced by using specific plant species. Elevated polyunsaturated fat content in meat, however, tends to increase susceptibility to oxidation, which influences other meat quality characteristics including shelf-life and color. The use of specific plant species may mitigate these negative effects due to vitamin E or other antioxidants in these plants, which protect polyunsaturated fats from oxidation. When assessing the potential of plants as a natural dietary fat source, consideration must be given to environmental influences on plant fatty acid composition to ensure consistent production of meat products with high nutritive value under a range of management practices. This review also explores the potential impact of climate change on plant fatty acid composition, and the potential implications of this for meat quality.

Effects of dietary fat sources on the intramuscular and subcutaneous adipose tissue fatty acid composition, and consumer acceptability of lamb

“…Similarly, Raes et al . and Howes et al . reported that linseed used as a feed ingredient in concentrate or grass‐based diets led to an increase in the muscle concentration of n‐3 PUFA in ruminants.…”

“…In ruminants, dietary PUFA undergoes biohydrogenation to SFA, which explains the inefficient deposition of PUFA in the muscle . However, the intermediates of ruminal biohydrogenation of C18:2n‐6 – rumenic acid, an isomer of conjugated linoleic acid (CLA c9,t11‐ C18:2), and trans‐vaccenic acid ( t11 ‐C18:1) – are of human health importance: t11 ‐C18:1 can either be converted to C18:0 through ruminal biohydrogenation or to CLA by the Δ 9 ‐desaturase enzyme . The effect of diet on the muscle proportion of CLA c9,t11‐ C18:2 indicated that BPR had a higher proportion than C ( P = 0.05; supplementary Table S1), which may be explained by the higher concentration of C18:2 in the BPR diet (Table ).…”

Framework for life cycle assessment of livestock production systems to account for the nutritional quality of final products

“…(2006) and Howes, Bekhit, Burritt, and Campbell (2015) further explored nutritional strategies to enhance long chain PUFA in beef. Specifically, Scollan et al.…”

“…Motivated by health‐conscious consumers, Howes et al. (2015) reviewed current literature to identify opportunities to enhance long chain PUFA in lamb fattening systems. Notably, the authors considered how specific cultivars of herbs and legumes might affect fatty acid profiles; Ådnøy et al.…”

“…Howes et al. (2015) hypothesized that such increases to PUFA could result from a decrease in biohydrogenation caused by endogenous plant factors of a diverse sward. Factors contributing to reduced biohydrogenation were separately reviewed by Lee (2014) and Buccioni, Decandia, Minieri, Molle, and Cabiddu (2012); as an example, red clover ( Trifolium pratense ) facilitates the flow of PUFA to the duodenum and then deposition into meat and milk, through the action of the enzyme system polyphenol oxidase in the rumen.…”