AbstractsMedical & Health Science

Effects of feeding cattle calcium hydroxide treated corn stover during backgrounding on carcass characteristics and beef quality

by Christina Fehrman

Institution: University of Minnesota
Year: 2016
Keywords: Alkaline; Backgrounding; Beef; Corn Stover; Meat Quality; Processed Meat
Posted: 02/05/2017
Record ID: 2113542
Full text PDF: http://hdl.handle.net/11299/182149


Sixty-seven purebred Angus steers (initial mean BW 197 kg.) were used to evaluate the effects of calcium hydroxide treated corn stover in backgrounding diets and a common finishing phase. Steers were randomly assigned to 1 of 4 dietary treatments: untreated corn stover (CON), corn stover treated with 50% DM water (H2O); 50% DM, water and calcium hydroxide treated corn stover (Ca(OH)2); grazing on a turnip cover crop (CC) for 29 days before adapted to ad libitum alfalfa haylage diet fed in feed bunks for remaining 20 d of backgrounding. Steers were fed individually using a Calan system for 49 days. All diets were formulated on a dry matter (DM) basis to contain 30% corn stover, 15% alfalfa haylage, 25% dried distillers grains with solubles, 25% dry rolled corn, and 5% supplement containing monensin. Upon completion of dietary treatments, steers were fed a common feedlot diet for 240 days. Steers were then harvested at a commercial abattoir, and carcass characteristics were recorded 48 hours postmortem. Strip loins and shoulder clods (IMPS180 and #114) from the right side of the carcass were collected. All primals were transported to the University of Minnesota Meat Laboratory for further evaluation. Strip loins were fabricated into 2.54 cm steaks at 96 hours postmortem. Strip loin steaks were used to evaluate vacuum purge, cook loss, and Warner-Bratzler shear force (WBSF), color scores, as well as consumer acceptability. Shoulder clods were processed to ground beef for evaluation of subjective and objective color scores as well as Thiobarbituric Acid Reactive Substances (TBARS). Portions of ground beef were then processed into bologna to be evaluated for objective and subjective color as well as consumer acceptability. Dietary treatment had no effect on carcass characteristics including hot carcass weight (HCW) (P = 0.694), ribeye area (REA) (P = 0.259), 12th rib backfat (P = 0.780), marbling score (P = 0.845), USDA Yield Grade (P = 0.890), and USDA Quality Grade (P = 0.877). Although purge loss (P = 0.884) and cook loss (P = 0.149) were not affected by treatment, WBSF values were lower for CC than CON (1.6 v 2.23kg respectively; P = 0.001). Lean color scores for fresh steaks were affected by dietary treatment (P = .004). On day 5, CC (5.34) was less bright cherry red than CON (5.66; P = .017) and H2O (5.76; P = .001). On day 7, CC (4.92) was less bright cherry red than CON (5.22; P = .032) and H2O (5.29; P = .007). Overall desirability scores for fresh steaks differed (P = .011) among dietary treatments with H2O being more desirable than CC on day 5 (5.35 v 4.93; P = .023) and Ca(OH)2 was more desirable than CC on day 6 (5.36 v 4.98; P = .047). Discoloration scores for fresh steaks varied among treatments (P = .003). On day 5, CC (10.02) was more discolored than H2O (10.30; P = .019) and Ca(OH)2 (10.32; P = .016). On day 6, steaks from CC were more discolored than H2O steaks (9.27 v 9.57; P = .013). Day 7 fresh steak discoloration scores shows that CC (9.13) was more discolored than CON (9.42; P = .027),…