The effects of including sprouted barley in the diets of angus finishing steers on meat quality, sensory analysis, and meat metabolome

Abstract

Improving sustainability of agricultural production has been at the forefront of research in recent years due to external factors, such as drought and urbanization. Producers are interested in exploring new practices to remain viable. One practice being researched is vertical farming systems (VFS) to produce feed. These VFS control temperature, water, light, and sprout cereal grains that can be fed whole to livestock, but to date, little research has been completed on feeding sprouted grains to livestock. This study utilized growing Angus steers (n = 60) that were stratified by weight (385 kg ± 10.3) into two different diet groups, control (CON, n = 30) or sprouted barley (SB, n = 30). The CON diet was a traditional finishing ration for the region (rolled barley, corn silage, and alfalfa), while SB was fed a ration with 20% dry matter (DM) sprouted barley. All animals were fed out of Vytelle® units to assess individual intake. At harvest, one loin from each animal was obtained for meat quality analysis. Meat quality was assessed using PROC MIXED in SAS, with day as a repeated measure to evaluate main effects of diet on color. Sensory data were analyzed using a paired two-way t-test. Welch's t-test was employed for meat metabolome analysis, while feed metabolome data was evaluated using an ANOVA. Color (L*, a*, and b*) nor three meat quality markers (cooking loss, drip loss, Warner-Bratzler Shear Force) were impacted by diet (P ≥ 0.19). Deoxymyoglobin (DMb) content was not affected by diet (P = 0.18), but metmyoglobin (MMb) was (P = 0.05) and oxymyoglobin (OMb) tended (P = 0.08) to be different. MMb increased over time for both diets, but CON generally had increased MMb compared to SB. Changes in OMb are explained by both CON and SB decreasing over the seven-day period with SB generally having more OMb compared to CON throughout. A consumer acceptance panel revealed SB and CON to not be different (P ≥ 0.11) in terms of liking for overall acceptance, aroma, flavor, tenderness, nor juiciness. Despite 71 out of 85 phytochemical metabolites being different in the feeds (P < 0.05) with 28 being elevated in the SB feed at 20% DM, only two out of 23 phytochemical metabolites differed (P < 0.05) in meat samples. The inclusion of sprouted barley at 20% DM in the diets of finishing Angus steers had no significant impact on meat quality, nor many aspects of sensory analysis.

Keywords: beef cattle; meat quality; phytochemicals; sprouted barley; vertical agriculture.

Figure 1.

Scores plot showing feed metabolic separation between the control total mixed ration (CON) (red), sprouted barley total mixed ration (SB) (green), and barley sprout feed (SPB) (blue). Each feed type shows a distinct metabolic profile, but it is apparent that the CON TMR and SPB feed are more different from each other than the SB TMR, which is a combination of the control and barley sprout sample.

Figure 2.

Random Forest plot of feed metabolites differentiating compounds between the control total mixed ration (CON), sprouted barley total mixed ration (SB), and barley sprout feed (SPB). Greater mean decreases in accuracy values indicate key metabolites, such as pyrogallol, trimethyl apigenin, and epicatechin and catechin, as significant metabolites that distinguish between samples. Red denotes high expression, and blue denotes low expression across group, while yellow denotes intermediate expression.

Figure 3.

The heatmap shows distinct clustering of feed metabolites within samples and highlights the unique characteristics of specific feed types with red indicating high expression and blue indicating low expression under each respective feed type. Feed types include the control total mixed ration (CON) (red), sprouted barley total mixed ration (SB) (green), and barley sprout feed (SPB) (blue).

Figure 4.

Scores plot showing meat metabolic separation between the control total mixed ration (CON; n = 30) (red), sprouted barley total mixed ration (SB; n = 30) (green). The homogeneity and overlap in the plot indicate only subtle differences were observed between groups.

Figure 5.

Random forest plot of meat metabolites differentiating cattle between the control total mixed ration (CON; n = 30) (red) and sprouted barley total mixed ration (SB; n = 30) (green). Greater mean decrease accuracy values indicate key metabolites, such as Hippuric Acid and 2-Hydroxyisocaproic Acid, as significant markers of the sprout diet’s metabolic impact. Red denotes high expression, and blue denotes low expression across groups.

Figure 6.

Heatmap of meat metabolite abundance in cattle fed the control total mixed ration (CON; n = 30) (red) or sprouted barley total mixed ration (SB; n = 30) (green), with red indicating high expression and blue indicating low expression. It shows no differences (P > 0.05) in metabolic profiles between the barley sprout and control groups, as indicated by the lack of distinct clustering or pattern separation.