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United States Department of Agriculture

Agricultural Research Service

Research Project: RANGELAND AND LIVESTOCK RESOURCE MANAGEMENT Title: The effect of flaxseed supplementation on growth, carcass characteristics, fatty acid profile, retail shelf life, and sensory characteristics of beef from steers finished on grasslands of the northern Great Plains

Authors
item Kronberg, Scott
item Scholljegerdes, Eric
item Lepper, Ashley -
item Berg, Eric -

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 1, 2011
Publication Date: September 1, 2011
Citation: Kronberg, S.L., Scholljegerdes, E.J., Lepper, A.N., Berg, E.P. 2011. The effect of flaxseed supplementation on growth, carcass characteristics, fatty acid profile, retail shelf life, and sensory characteristics of beef from steers finished on grasslands of the northern Great Plains. Journal of Animal Science. 89:2892-2903.

Interpretive Summary: A trial was conducted to determine if steers that were grown and finished while grazing grasses would have a more healthful fatty acid profile in their muscle, grow faster, have different carcass characteristics, and if steaks from these steers would have improved tenderness and altered sensory panel ratings if they were supplemented with a flaxseed daily for 85 days. Eighteen yearling Angus steers with an average weight of 880 lbs. at the beginning of trial were randomly divided into three groups of six steers each. Treatment 1 steers (FLAX) received a daily supplement of ground flaxseed (0.20% of body weight) while Treatment 2 steers (CSBM) received a daily supplement of ground corn and soybean meal (0.28% of body weight) that had levels of CP and DE that were similar to the supplement for FLAX steers. Control steers (CONT) were not supplemented. Treatments were given to each individual steer in side-by-side stalls, and were fed from mid-August until November 7th, 2007 the day before they were harvested. All steers grazed growing forage beginning in early-May through the first week of November. Growth rates, carcass characteristics, tenderness and sensory attributes of ribeye steaks, and fatty acid profiles of the steaks were determined by standard techniques. Growth rates of the FLAX steers was 25% greater than that of the CONT steers, but similar to that of the CSBM steers. There were no differences in the carcass characteristics of the three groups of steers, and no differences in tenderness or sensory attributes except for a very slight off flavor detected in steaks from FLAX and CONT steers. The omega-3 fatty acids a-linolenic acid and eicosapentaenoic acid (EPA) were 62 and 22% higher, respectively, in beef from FLAX compared to CONT steers. Compared to the other two groups, the ratio of omega-6 to omega-3 fatty acids was lower in beef from the FLAX steers. The results indicate that the growth rate of yearling Angus steers grazing growing grasses on the northern Great Plains may be increased and the fatty acid profile of their steaks may be made more healthful by supplementing them daily with small amounts of ground flaxseed.

Technical Abstract: A trial was conducted to determine if steers that were grown and finished while grazing grasses would have a more healthful fatty acid profile in their muscle, grow faster, have different carcass characteristics, and if steaks from these steers would have improved tenderness and altered sensory panel ratings if they were supplemented with a flaxseed daily for 85 d. Eighteen yearling Angus steers weighing 399 kg (+/- 21) at the beginning of trial were randomly divided into three groups. Treatment 1 steers (FLAX; n = 6) received a daily supplement of ground flaxseed (0.20% of body weight) while Treatment 2 steers (CSBM; n = 6) received a daily supplement of ground corn and soybean meal (0.28% of body weight) that had levels of CP and DE that were similar to the supplement for FLAX steers. Control steers (CONT; n = 6) were not supplemented. Treatments were given to each individual steer in side-by-side stalls, and were fed from mid-August until November 7th, 2007 the day before they were harvested. All steers grazed growing forage beginning in early-May through the first week of November. Growth rates, carcass characteristics, tenderness and sensory attributes of ribeye steaks, and fatty acid profiles of the steaks were determined by standard techniques. Growth rates of FLAX was 25% greater (P < 0.01) than that of the CONT steers, but similar (P = 0.45) to that of the CSBM steers. There were no differences (P > 0.14) in the carcass characteristics of the three groups of steers, and no differences (P > 0.24) in tenderness or sensory attributes except for a very slight off flavor detected in steaks from FLAX and CONT steers (P = 0.06). The n-3 fatty acids a-linolenic acid and eicosapentaenoic acid (EPA) were 62 and 22% higher, respectively, in beef from FLAX compared to CONT steers (P < 0.0001). Compared to the other two groups, the ratio of n-6 to n-3 fatty acids was lower (P < 0.0001) in beef from the FLAX steers. The results indicate that the growth rate of yearling Angus steers grazing growing grasses on the northern Great Plains may be increased and the fatty acid profile of their steaks may be made more healthful by supplementing them daily with small amounts of ground flaxseed.

Last Modified: 10/31/2014