049 Inclusion of Post-Extraction Algal Residue in Finishing Rations of Beef Steers: Trained Sensory Panel Ratings for Strip Steaks

Microalgae's viability as a biofuel is partially dependent on development of a market for its co-product, post-extraction algal reside (PEAR). The protein rich co-product, PEAR, is being considered as a nutrient source for cattle. To investigate the impact of PEAR inclusion in finishing rations on beef flavor, 18 Angus × Hereford steers (initial BW = 549 ± 38.8 kg) were assigned randomly to one of three treatments designed to replace OM in the diet: PEAR hand-mixed into the diet at 1.0 kg OM/d (PEAR), 1.0 kg OM/d glucose infused ruminally (GR) or 1.0 kg OM/d glucose infused abomasally (GA). Basal diets consisted of dry rolled corn (42.3%), ground milo (18.0%), cottonseed hulls (13.5%), grass hay (10.0%), molasses (6.7%), cottonseed meal (5.4%), vitamin/mineral premix (2.3%), urea (0.9%), and limestone (0.9%). Treatments were applied for the last 35 d prior to harvest. Forty-eight h post-harvest, strip steaks were collected from each carcass, individually vacuum packaged, aged for 14 d, and frozen until analysis. An expert-trained sensory panel was conducted over 3 consecutive d. Data were analyzed using the MIXED procedure of SAS. The fixed effect in the model was treatment and panel day was included as a random effect. Least-squares means were calculated and all pairwise comparisons were evaluated. Of the flavors and aromas present in PEAR-fed beef, there was a treatment difference in fat-like flavor (P = 0.02); PEAR strip steaks were not different from either GA or GR (P > 0.10), but GA and GR were different in fat-like flavor (P < 0.01). Additionally, overall sweet (flavor and aromatics) was different among treatments (P = 0.05); only PEAR steaks were higher in overall sweet flavor and aromatics than GA (0.58 vs. 0.30; P < 0.02). Sweet flavor also differed among treatments (P < 0.01); steaks from PEAR supplemented steers were sweeter than GA (P < 0.01) and GR (P < 0.02). Provision of PEAR in finishing rations of beef steers, compared to glucose infusion, did not result in significant or numeric differences in beef identification, brown/roasted, bloody/serumy, metallic, umami, sour, salty, bitter, or burnt flavor attributes (P≥ 0.13). There were no off-flavors detected in strip steaks from inclusion of 1.0 kg OM/d PEAR compared to glucose infusion. Therefore, this PEAR preparation can be included in a finishing ration at up to 10% without negatively impacting beef flavor and aroma.