Legume finishing provides beef with positive human dietary fatty acid ratios and consumer preference comparable with grain-finished beef1

Abstract

Consumer liking, proximate composition, pH, Warner-Bratzler shear force, fatty acid composition, and volatile compounds were determined from the LM (longissimus thoracis) of cattle ( = 6 per diet) finished on conventional feedlot (USUGrain), legume, and grass forage diets. Forage diets included a condensed tannin-containing perennial legume, birdsfoot trefoil (; USUBFT), and a grass, meadow brome ( Rehmann; USUGrass). Moreover, representative retail forage (USDA Certified Organic Grass-fed [OrgGrass]) and conventional beef (USDA Choice, Grain-fed; ChGrain) were investigated ( = 6 per retail type). The ChGrain had the greatest ( < 0.05) intramuscular fat (IMF) percentage followed by USUGrain, the IMF percentage of which was greater ( < 0.05) than that of USUGrass and OrgGrass. The IMF content of USUBFT was similar ( > 0.05) to that of both USUGrain and USUGrass. Both grain-finished beef treatments were rated greater ( < 0.05) for flavor, tenderness, fattiness, juiciness, and overall liking compared with USUGrass and OrgGrass. Consumer liking of USUBFT beef tenderness, fattiness, and overall liking were comparable ( > 0.05) with that of USUGrain and ChGrain. Flavor liking was rated greatest ( < 0.05) for USUGrain and ChGrain, and that of USUBFT was intermediate ( > 0.05) to those of ChGrain, USUGrass, and OrgGrass. Cumulative SFA and MUFA concentrations were greatest ( < 0.05) in ChGrain and USUGrain, whereas USUGrass and OrgGrass had lower ( < 0.05) concentrations. Concentrations of cumulative SFA and MUFA in USUBFT were intermediate and similar ( > 0.05) to those of USUGrain and USUGrass. Each forage-finished beef treatment, USUGrass, OrgGrass, and USUBFT, had lower ( < 0.001) ratios of -6:-3 fatty acids. Hexanal was the most numerically abundant volatile compound. The concentration of hexanal increased with increasing concentrations of total PUFA. Among all the lipid degradation products (aldehydes, alcohols, furans, carboxylic acids, and ketones) measured in this study, there was an overall trend toward greater quantities in grain-finished products, lower quantities in USUGrass and OrgGrass, and intermediate quantities in USUBFT. This trend was in agreement with IMF content, fatty acid concentrations, and sensory attributes. These results suggest an opportunity for a birdsfoot trefoil finishing program, which results in beef comparable in sensory quality with grain-finished beef but with reduced -6 and SFA, similar to grass-finished beef.

Diet and Genetics Influence Beef Cattle Performance and Meat Quality Characteristics

“…In a four-month study where steers grazed on tall fescue only, or combined with red clover or alfalfa, there was no effect of pasture on meat FA content [152]. Similarly, rib eye rolls from steers finished on tall fescue and meadow brome or birdsfoot trefoil for four months had similar marbling scores, n-6-n3 ratios and total SFA, MUFA and PUFA, but EPA was higher in birdsfoot trefoil finished steers [166]. The effect of pasture type on FA composition was reported in a 90-day study where lambs with access to shrubs produced meat with higher percentage of ALA, n-3, n-6, total PUFA and lower MUFA and n-6:n-3 ratio than those on grass only, but total SFA was similar [167].…”

Seasonal differences exist in the polyunsaturated fatty acid, mineral and antioxidant content of U.S. grass-finished beef

“…Carbon # Overall (n = 512) Fall (n = 202) Spring (n = 310) P-value 1 cattle finished on birdsfoot trefoil, a perennial legume, have increased ALA and DPA compared to that finished solely on grass [2]. Because of the survey-based nature of this study, information on diets fed to the cattle is limited, and based only on self-reported data from the producer.…”

“…Grass-finished beef refers to products from cattle raised solely on pasture forages without grain supplementation. Research suggests that GFB is generally higher in certain nutrients beneficial to human health and meets growing consumer preferences in meat production systems [2]. Importantly, GFB is richer in vitamins and minerals and lower in total fat than conventional grain-finished beef.…”

Consumer sensory evaluation and chemical composition of beef gluteus medius and triceps brachii steaks from cattle finished on forage or concentrate diets

“…All cattle production and harvest procedures are described in detail by Chail et al (2016). In brief, 18…”

“…Forage-finished beef is generally lower in fat content and has lower ratios of n-6:n-3 fatty acids (<4.0), which may reduce incidence of cardiovascular disease (Simopoulos, 2004). Recently, forage finishing with a perennial legume, birdsfoot trefoil, was revealed to produce rib eye steaks with favorable fatty acid ratios while also having palatability comparable to that of grain-finished beef (Chail et al, 2016). However, it is unclear how a forage-finishing diet may impact muscles beyond the generally very palatable longissimus thoracis of the rib eye.…”