Manipulation of Omega‐3 PUFAs in Lamb: Phenotypic and Genotypic Views

Abstract

A number of studies have shown that dietary omega-6 and omega-3 long-chain fatty acids can be incorporated into muscle tissue of ruminants despite the biohydrogenation of dietary fatty acids in the rumen. The main focus of this review is on eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) fatty acids because health authorities around the world consider the sum of these fatty acids as the basis of classifying a food as a source or good source of omega-3 polyunsaturated fatty acids (PUFAs). A high proportion of polyunsaturated fatty acids are hydrogenated in the rumen, leading to a higher concentration of 18:0, but some escapes the rumen to be absorbed intact by the small intestine. Feeding strategies for ruminants have been successfully applied to increase the absorption of PUFAs in the small intestine and therefore to increase the levels of PUFAs in muscle tissue. Protected fats and algae are strong candidates to improve the nutritional value of red meat in ruminants in terms of health-claimable omega-3 fatty acids. Efforts to understand the genetic basis of fatty acid metabolism have been underway. The knowledge of the main genes which control the output of omega-3 fatty acids is still lacking, but gene expression studies have helped to explain the deposition of these acids in muscle, liver, and subcutaneous fat.

Supplementation effects of seleno-compounds, carnosic acid, and fish oil onconcentrations of fatty acids, tocopherols, cholesterol, and amino acids in the livers of lambs

“…In fact, in vivo studies involving dietary FO documented that EPA and DHA are biohydrogenated, although to a lesser extent than usually observed for LA or αLNA (26). However, DHA deposition is strictly metabolically regulated and cannot be substantially influenced by diet.…”

Addition of an extract of lucerne (Medicago sativa L.) to cattle diets – Effects on fatty acid profile, meat quality and eating quality of the M. longissimus muscle

“…Concentrate diets have been found to increase the expression of SCD relative to forage-based diets (Daniel, et al, 2004;Hiller, 2014), where SCD desaturates stearic acid (18:0) to form 18:1cis-9 (see review, Alvarenga, Chen, Furusho-Garcia, Perez, & Hopkins, 2015). In the present study, the ratio of 18:0/18:1 in muscle was similar for steaks from cattle fed either S-CC or GS, however the ratio of 18:1 trans-11/CLA cis-9, trans-11 was significantly lower for S-CC steaks versus GS steaks (0.19 vs 0.23 for S-CC and GS respectively, P = 0.011), which may indicate greater conversion of 18:1 trans-11 to CLA cis-9, trans-11, possibly via higher SCD activity in the muscle of S-CC animals.…”

The Effect of Extensive Feeding Systems on Growth Rate, Carcass Traits, and Meat Quality of Finishing Lambs

“…The C18:2 cis9 trans11 isomer, in particular, may decrease fat accumulation, modulate the immune response, and decrease the inflammatory response (Pariza and others ; Paim and others ). A way to increase the concentration of these important fatty acids in lamb products is through diet manipulation (Ponnampalam ; Dannenberger and others ; Tsiplakou and others ; Ponnampalam and others ; Alvarenga and others ; Sun and others ). Many studies have evaluated the fatty acid concentration of meat from lambs fed different pasture types, with or without supplementation, compared with meat of lambs fed under indoor systems using concentrate diets, and the results are summarized in Table .…”