Progress 05/10/02 to 09/30/07
Outputs
OUTPUTS: The overall objective of this research was to determine factors that affect the amount of intramuscular fat and the impact of intramuscular fat on consumer perception of palatability. To compare different methods of palatability measurements, steaks from two USDA quality grades were evaluated by a trained sensory panel, consumer sensory panel and Warner-Bratzler shear force (WBSF). When all muscles were considered, correlations were generally significant across all three groups, however when muscles were considered individually, few significant correlations were found. Five muscles from the beef wholesale chuck were then evaluated by 138 consumers. Differences in palatability ratings due to quality grade were found for three muscles in which USDA Choice was rated higher for tenderness and juiciness when compared to USDA Select. Tenderness, juiciness, and flavor ratings were correlated with overall like and with price. Two trials were conducted to determine the effect of feeding flax to cattle. Yearling beef heifers were fed diets that included either no flax, or 8% whole flax, rolled flax or ground flax. Steaks were tested for WBSF measurement, sensory panel evaluation and fatty acid analysis. Feeding either whole or processed 8% flax to feedlot heifers increased USDA yield grade and tended to increase marbling score. Feeding 8% flax increased the level of n-3 fatty acids in fresh beef. In order to determine if including flax in creep feed would affect carcass composition, cow-calf pairs were assigned to one of four treatments: no creep feed, 0%, 12.5%, or 25% flax creep feed. Calves fed flax had lower marbling scores than those fed 0%; however, calves fed 25% flax had greater marbling scores than those fed 12.5 %. Field pea inclusion in feedlot diets of steers was investigated in two studies to measure effects on carcass quality, marbling growth, and palatability of steaks. Field peas replacing corn and soybean meal at levels of 0, 10, 20, and 30% in the diets of steer calves produced no differences for WBSF, sensory panel tenderness, juiciness, or flavor. A second study using finishing beef heifers fed 0, 10, 20 and 30 % field peas found no treatment differences for USDA quality grade or yield grade. Increasing levels of dietary field peas quadratically decreased WBSF. Sensory panel analysis indicated a linear increase in tenderness ratings with addition of peas, a tendency for greater juiciness ratings and no differences in flavor or off flavor. To determine factors affecting fat in pork , 45 pigs representing two genetic lines and two sex classes (barrows and gilts) were assigned to either a control diet or treatment diet containing 4.5g ractopamine per day for two weeks prior to slaughter. Marbling was found to be affected by production traits and location of chops within the loin. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Flax or field peas in diets for cattle may have the potential to improve meat quality. For several beef muscles, marbling was an important determination of palatability. Several factors, including sex class, genetic line, and finishing diet can affect marbling and palatability of fresh pork.
Publications
- No publications reported this period
|
Progress 01/01/06 to 12/31/06
Outputs
Field pea inclusion in feedlot diets of steers was investigated in two studies to measure effects on carcass quality, marbling growth, and palatability of steaks. Study one used one hundred forty-four steer calves blocked by BW (433 kg) and allotted to 24 pens with six pens assigned to each treatment based on weight block. The basal diet contained 80% dry rolled corn, 5% alfalfa/grass hay, 5% pressed beet pulp, 5% concentrated separator byproduct, and 5% supplement (DM basis). Field peas replaced corn and soybean meal at 0, 10, 20, and 30% of the diet DM. Steers were fed for 70 to 98 d and transported to a commercial slaughter facility. Longissimus muscle samples were vacuum packaged, aged for 14d at 4 C, cut into 2.54-cm thick steaks, and frozen. One steak from each carcass was evaluated for Warner-Bratzler shear force (WBSF). A second steak from each carcass was evaluated by a trained taste panel for tenderness, juiciness, and flavor intensity using a scale of 1 to 8
(1 = extremely tough, dry, and bland; 8 = extremely tender, juicy, and intense beef flavor.) No differences were measured for WBSF (3.76; P = 0.12), sensory panel tenderness (5.80; P = 0.53), juiciness (5.43; P = 0.81), or flavor (5.65; P = 0.58). The second study used finishing beef heifers to determine the effects of increasing levels of field peas in feedlot diets on performance, carcass quality, and sensory evaluation of steaks. One hundred eighteen heifers were blocked by BW (initial BW = 420 kg) in a randomized complete block design and allotted to 16 pens (four pens per treatment). Treatments were 0, 10, 20, and 30% dry rolled field peas (DM basis) replacing corn and canola meal in corn-based finishing diets. Heifers were fed for 74 d and transported to a commercial slaughter facility.A 7-cm (approximate) portion of longissimus muscle was removed caudally from 12th rib location on the left side of each carcass. Longissimus muscle samples were vacuum packaged, aged for 14 d at 4
C, cut into 2.54 cm thick steaks, and frozen. One steak from each carcass was evaluated for Warner-Bratzler shear force (WBSF). A second steak from each carcass was evaluated by a trained taste panel for tenderness, juiciness, and flavor intensity using a scale of 1 to 8 (1 = extremely tough, dry, and bland; 8 = extremely tender, juicy, and intense beef flavor), and off-flavor intensity (1 = no off flavors; 4 = intense off flavors). No treatment differences were observed for DMI, ADG, G:F, USDA quality grade or yield grade (P > 0.13). Increasing level of dietary field peas quadratically decreased (P = 0.001) WBSF (4.30; 3.63; 3.68; 3.71 kg for 0, 10, 20, and 30% peas, respectively). Sensory panel analysis indicated a linear increase in tenderness ratings (P = 0.002) with addition of peas (4.56; 5.14; 5.28; 5.34 for 0, 10, 20, and 30% peas, respectively). Sensory panel ratings indicated a tendency for greater juiciness ratings (P = 0.14) and no differences in flavor (P = 0.21) or off
flavor (P = 0.32). The conflicting results of these two studies have indicated the need for more research in this area.
Impacts
The use of alternative crops, such as filed peas will allow traditional feed crops, such as corn, to be used for other applications (ethanol). In addition, filed peas in cattle diets may improve meat quality.
Publications
- Slinden, E.L., G.P. Lardy, M.L. Bauer, V.L. Anderson, R.J. Maddock, K.R. Maddock Carlin. 2007. Effects of field pea inclusion in high grain diets for beef steers on beef tenderness, postmortem proteolysis and calpastatin activity. J.Anim. Sci. 85 (Suppl. 2)
- Maddock Carlin, K.R., G.P. Lardy, R.J. Maddock, B. Ilse, V.L. Anderson. 2006. Field pea inclusion in high grain diets for beef heifers improves beef tenderness without altering performance. J. Anim. Sci 84 (Suppl.1): 36.
|
Progress 01/01/05 to 12/31/05
Outputs
In order to determine if including flax in creep feed would affect nursing calf performance, subsequent feedlot performance, and ensuing carcass composition, ninety-six cow-calf (steer) pairs (663 plus/minus 9 kg initial cow BW; 168 plus/minus 1 kg initial calf BW) were stratified by cow age and steer weight, and allotted to one of 12 pastures (8 pairs per pasture). Pastures were assigned randomly to one of four treatments (DM basis): 1) no creep feed (CON); 2) 0% flax creep feed (55% wheat middlings, 39.5% soy hulls, 4.2% molasses, 1.3% limestone; CRP); 3) low flax creep feed (12.5% flax, 26.0% wheat middlings, 56.0% soy hulls, 4.2% molasses, 1.3% limestone; LOW); or 4) high flax creep feed (25.0% flax, 69.5% soy hulls, 4.2% molasses, 1.3% dicalcium phosphate; HIGH). All creep fed calves were offered CRP ad libitum for the initial 21 d to acclimate calves to feeders and diets. Treatment diets were offered ad libitum for 37 d prior to weaning. Calves were then
co-mingled and fed a corn and corn-silage-based backgrounding diet for 98 d after which they were fed a corn-based finishing diet for 143 d. Once cattle were appraised to have an average of 1 cm of external fat, cattle were transported to an abattoir, harvested, chilled for 24 h, and carcass data were collected. Loin samples (longissimus lumborum; approx. 1000 g) were removed from the left side of each carcass, transported to the South Dakota State University meat laboratory, vacuum packaged and aged at 4 C for 14 d after which 2.54-cm-thick steaks were cooked and Warner-Bratzler shear force was measured. There was no difference in creep feed intake between control and flax creep feeds (P = 0.26) or due to flax level (P = 0.14). Creep-fed calves had greater pre-weaning ADG (P = 0.05) than CON calves. Backgrounding ADG was not affected (P = 0.34) by creep feed; however, creep-fed calves tended (P = 0.11) to have greater finishing ADG. Flax addition had no effect on backgrounding ADG (P
= 0.36) or finishing ADG (P = 0.71) compared to CRP-fed calves. Creep-fed calves had greater HCW (P = 0.05) and lower marbling scores (P = 0.08) than CON. Calves fed flax had lower marbling scores (P = 0.06) than those fed CRP; however, calves fed HIGH had greater marbling scores (P = 0.08) than those fed LOW. Including flax in nursing steer creep feed for the last 37 d prior to weaning did not affect nursing calf or post-weaning performance, but may decrease marbling scores.
Impacts
Flax can be included at 12.5% or 25% (DM basis) in creep feed without adversely affecting feed intake, but including flax in nursing calf creep feed does not improve cow or calf performance. Flax did not alter most carcass traits with the exception of marbling, which was lower in calves offered flax than those offered the control creep diet. Additionally, there was an effect of level noted for marbling, with 25% flax creep fed calves having greater marbling scores than those offered 12.5%. There appears to be no adverse effects of including flax in nursing calf creep feed. Therefore, the addition of flax to diest may improve meat quality and increase the demand for flax as a feedstuff.
Publications
- Maddock, T.D., B. Kreft, R. J. Maddock, V. L. Anderson, G. P. Lardy. 2006. The effect of including flax in beef creep feed on performance and subsequent carcass characteristics. JAVA. 5(156-160).
|
Progress 01/01/04 to 12/31/04
Outputs
To determine relationships among different methods of palatability measurements, steaks from seven beef chuck and rib muscles and two USDA quality grades were evaluated by a trained sensory panel, a consumer sensory panel, and Warner-Bratzler shear force. Ten USDA Choice and ten USDA Select boneless boxed beef subprimals were used to obtain each muscle. When all muscles were considered, correlations were generally significant for palatability across consumer ratings, trained ratings, and shear force; however, when muscles were considered individually, few significant correlations were found. Spearman rank correlations also were used to evaluate correlations among evaluations of palatability. Spearman rank correlations found more significant relationships for palatability traits than Pearson correlations coefficients; however, within specific muscles, some correlations were found to not be significant. These results indicate care must be taken when trying to
extrapolate shear force and trained panel ratings to predict consumer ratings of muscles from the chuck and brisket. A study was conducted to determine if feeding flax and the type of flax processing affected growth performance and carcass traits, especially intramuscular fat content and composition. In the study, 128 yearling beef heifers were blocked by weight and assigned randomly to feedlot diets that included no flax (CON), whole flax (WHL), rolled flax or ground flax. Heifers were fed a growing ration for 56 d after which they were transitioned to a finishing ration. Flax was fed at 8% of diet DM. All diets provided 0.5 mg melengestrol acetate, 2000 IU vitamin E, and 232 mg monensin daily. Cattle were harvested by block following 96, 97, and 124 (two blocks) days on feed. At 24 h postmortem, carcass data were collected and a portion of the loin was removed and two steaks were removed from each loin for Warner-Bratzler shear force measurement and sensory panel evaluation. In
addition, approximately 100 g of muscle was collected for fatty acid analysis. Flax (control vs whole, rolled, and ground) did not affect DMI (P = 0.79), 12th rib fat (P = 0.32), or LMA (P = 0.23). Flax increased ADG (P = 0.006) and gain efficiency (P = 0.006). Flax also increased (P = 0.01) USDA yield grade. Processing (rolled and ground flax vs whole flax) increased ADG (P = 0.05) and gain efficiency (P = 0.08). Flax tended (P = 0.14) to increase marbling score. Processing increased calculated NEm (P = 0.003) and NEg (P = 0.003). Muscle from heifers fed flax had greater phospholipid 18:3n-3 (P < 0.001), 20:5n-3 (P < 0.001), 22:5n-3 (P < 0.001), and 22:6n-3 (P = 0.02) fractions and greater neutral lipid 18:3n-3 (P < 0.001). Feeding 8% (DM) flax to feedlot heifers increased gain and efficiency and processing flax increases available energy and resulted in increased efficiency of growth. Feeding 8% (DM) flax can increase the level of n-3 fatty acids in fresh beef.
Impacts
Marbling is an excellent indicator of eating satisfaction of fresh meat. Several factors, including sex class, genetic line, and finishing diet can affect marbling of fresh pork. Pork producers interested in producing high-quality pork could change selection and production practices to improve the amount of marbling. For several beef muscles, marbling was an important determination of palatability. Selecting higher quality grades for muscles to be used as steaks may be important.
Publications
- No publications reported this period
|
Progress 01/01/03 to 12/31/03
Outputs
Two experiments evaluating marbling (intramuscular fat content) were conducted. Forty-five pigs representing two genetic lines and two sex classes (barrows and gilts) were randomly assigned to either a control diet or treatment diet containing 4.5g Paylean per d for two weeks prior to slaughter. Three chops (2.5 cm thick) representing the cranial end (C1), the middle portion (C2) and the caudal end (C3) were taken from each loin. On day 6 marbling differed by sex class with chops from gilts having lower marbling scores (P lt 0.05) than chops from barrows. In addition on day 18 marbling was affected by sex class with gilts having less marbling (P lt 0.05). Marbling was also affected by genotype with genetic line 2 pigs having less marbling (P lt 0.05), and by the finishing diet x genotype interaction where genetic line 1 pigs fed the treatment diet were had more marbling (P lt 0.05) than all other finishing diet x genotype combinations. Day 19 evaluations were similar
to day 6 with regards to day 18 marbling characteristics. On day 19 marbling was also affected by finishing diet with pigs fed the treatment diet having more marbling (P lt 0.05) than pigs fed the control diet. In conclusion, quality attributes of enhanced case-ready pork loin chops were significantly affected by production traits and location of chops within the loin. Experiment two evaluated the importance of intramuscular fat on the palatability traits of various beef muscles. One hundred thirty-eight consumers evaluated steaks from five muscles from the beef wholesale chuck, including: the complexus (CP), infraspinatus (IF), serratus ventralis (SV), supraspinatus (SS), and triceps brachii (TB); one muscle from the beef wholesale brisket: the deep pectoral (DP); and one muscle from the beef wholesale rib: the longissimus thoracis (LT). Ten USDA Choice and ten USDA Select boneless boxed beef subprimals were used for each muscle. Subprimals were aged 14 d from box date, frozen, and
cut into 2.5-cm-thick steaks. Differences in palatability ratings due to quality grade were found for several muscles; USDA Choice SV and SS were rated higher (P lt 0.05) for overall like, tenderness, and juiciness than USDA Select. For the IF USDA Choice was rated higher (P lt 0.05) for tenderness and juiciness. The USDA Choice TB was rated higher (P lt 0.05) for juiciness and the USDA Choice DP was rated higher for overall like than their USDA Select counterparts. Tenderness, juiciness, and flavor ratings were correlated with overall like ratings (r equals 0.84, 0.77, 0.76, respectively) and with price (r equals 0.73, 0.70, 0.68, respectively).
Impacts
Marbling is an excellent indicator of eating satisfaction of fresh meat. Several factors, including sex class, genetic line, and finishing diet can affect marbling of fresh pork. Pork producers interested in producing high-quality pork could change selection and production practices to improve the amount of marbling. For several beef muscles, marbling was an important determination of palatability. Selecting higher quality grades for muscles to be used as steaks may be important.
Publications
- Kukowski, A. C., R. J. Maddock, and D. M. Wulf. 2004. Evaluating consumer acceptability of various muscles from the beef chuck and rib. J. Anim. Sci. 82: 521-525
- Kukowski, A. C., R. J. Maddock, S. W. Fausti, G. L. Taylor, and D. M. Wulf. 2003. Evaluating consumer acceptability and willingness to pay for various beef chuck muscles. Proc. 56th Annu. Rec. Meat Conf., University of Missouri. p. 119.
- Searls, G. A., R. J. Maddock, D. M. Wulf, C. P. Allison, M. E. Doumit, T. W. Hothaus, and R. C. Johnson. 2003. Quality attributes of enhanced case-ready pork loin chops. Proc. 56th Annu. Rec. Meat Conf., University of Missouri. p. 123.
|
|