Influence of Level of Flaxseed Addition and Time Fed Flaxseed on Carcass Characteristics, Sensory Panel Evaluation, and Fatty Acid Content of Fresh Beef

T.D. Maddock¹, V.L. Anderson², P.T. Berg¹, R.J. Maddock³, M.J. Marchello¹

¹NDSU Animal and Range Sciences Dept, ²NDSU Carrington Research Extension Center, and

³SDSU Animal And Range Sciences Dept.

Ninety crossbred steers were randomly divided into six treatment groups and finished to determine if differing levels of flaxseed addition and time fed flaxseed would affect carcass composition, sensory panel evaluations, and/or fatty acid profiles in fresh beef, specifically alpha-linolenic (18:3, n-3), and an omega-3 fatty acid associated with flax. Treatments included corn as a control diet, barley as a basal diet, and 3% or 6% flaxseed addition to the barley diet for the last 28 or 56 days of the feeding period. Once cattle were visually determined to be finished they were shipped to a commercial slaughter facility for harvest. No differences (P < 0.05) were found between treatments for 12^th rib fat thickness, REA, or marbling. Flaxseed addition did increase marbling score when compared to the basal barley diet (P = 0.03). Beef IMPS # 180 boneless strip loins were removed from the carcass and used for sensory panel evaluation and fatty acid profiles. Sensory evaluation of tenderness was lower (P < 0.05) in steers fed 6% flaxseed vs. those fed 3 percent flaxseed. Sensory evaluation of juiciness was higher (P = 0.02) for corn than all other treatments, but no differences (P > 0.05) were found among treatments that included barley. Flavor was not affected by flaxseed addition (P < 0.45). Flaxseed inclusion in the barley diet increased (P <0.01) alpha-linolenic fatty acid content. Six percent inclusion had higher (P = 0.04) alpha-linolenic fatty acid content than 3%, and steers fed flaxseed 56 d had higher (P < 0.01) alpha-linolenic fatty acid content than those steers fed 28 d. Flaxseed addition did not change other measured fatty acid content (P > 0.10). The inclusion of flaxseed into barley diets for finishing beef steers increased alpha-linolenic fatty acid content without significantly affecting flavor or measured carcass quality traits.

Keywords: Flaxseed, Omega-3, Carcass, Beef

Table 1. Effects of corn or barley and flaxseed addition on sensory characteristics of beef.

	Treatment
Item	Corn	Bly	3% 28d	6% 28d	3% 56d	6% 56d	SE	P
Tend	5.68^c	5.60^bc	5.78^c	4.92^a	5.50^bc	5.24^ab	0.16	<0.01
Juic	5.76^b	5.45^ab	5.36^a	5.24^a	5.14^a	5.28^a	0.14	0.02
Flavor	5.36	5.44	5.30	5.20	5.52	5.30	0.12	0.45

^a,b,c Least squares means within row lacking a common superscript differ (P < 0.05). Higher score is reflective of more desirable sensory response.

Table 2. P-values for contrasts of corn or barley and flaxseed addition on sensory characteristics of beef.

Item	Corn vs. Barley^a	Barley Vs Flax^a	28d vs. 56d^a	3% vs. 6%^a	Interaction^a
Tenderness	0.71	0.16	0.90	<0.01	0.05
Juiciness	0.11	0.20	0.48	0.96	0.34
Flavor	0.63	0.41	0.17	0.17	0.58

^a Contrasts are corn diet vs. barley diet, barley diet vs. all diets including flax, diets that included flax fed for 28 d vs. diets that included flax fed 56 d, diets that included 3 percent flax vs. diets that included 6 percent flax, and the interaction of days fed flax (28 or 56) and the level of flax included (3% or 6%).

Table 3. Effects of corn or barley and flaxseed addition on carcass characteristics of beef.

	Treatments
Item	Corn	Bly	3% 28d	6% 28d	3% 56d	6% 56d	SE	P
Carcass WT	764.1	747.1	756.6	761.0	754.0	758.1	9.7	0.87
PYG	2.9	2.9	3.0	3.0	3.0	3.0	0.1	0.93
REA	12.6	12.9	13.2	13.1	12.7	12.6	0.3	0.70
KPH	1.9	1.8	1.8	1.7	1.9	1.9	0.1	0.73
12^th Rib Fat	0.38	0.38	0.41	0.40	0.39	0.40	0.03	0.93
YG	2.7	2.5	2.5	2.6	2.7	2.7	0.1	0.77
MARB	366	315	363	381	359	337	19	0.17
Dress P	60.2	60.6	60.9	60.5	60.4	60.3	0.4	0.92
L	33.2	32.8	32.0	32.9	32.5	33.5	0.4	0.15
A	16.4	16.1	15.7	16.2	16.4	16.2	0.3	0.42
B	3.5	3.5	3.3	3.3	3.3	3.3	0.1	0.64

Table 4. P-values for contrasts of corn or barley and flaxseed addition on carcass characteristics of beef.

Item	Corn vs. Barley^a	Barley Vs Flax^a	28d vs. 56d^a	3% vs. 6%^a	Interaction^a
Carcass WT	0.22	0.34	0.78	0.66	0.98
PYG	0.99	0.41	0.72	0.89	0.79
REA	0.45	0.85	0.14	0.79	0.90
KPH	0.58	0.83	0.17	0.93	0.45
12^th Rib Fat	0.99	0.41	0.72	0.89	0.79
YG	0.30	0.38	0.26	0.78	0.90
MARB	0.06	0.03	0.20	0.91	0.30
Dress P	0.54	0.85	0.43	0.57	0.79
L	0.41	0.91	0.18	0.03	0.94
A	0.35	0.93	0.22	0.67	0.17
B	0.80	0.11	0.95	0.88	0.81

^a Contrasts are corn diet vs. barley diet, barley diet vs. all diets including flax, diets that included flax fed for 28 d vs. diets that included flax fed 56 d, diets that included 3 percent flax vs. diets that included 6 percent flax, and the interaction of days fed flax (28 or 56) and the level of flax included (3% or 6%).

Table 5. Effects of corn or barley and flaxseed addition on fatty acid content of beef

	Treatments
Item	Corn	Bly	3% 28d	6% 28d	3% 56d	6% 56d	SE	P
12:0	2.78	2.68	2.74