Browsing by Subject "Beef -- Quality"
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Item Carcass composition, cholesterol content and palatability traits of Chianina and British crossbred beef(Texas Tech University, 1986-05) Wheeler, Tommy LNot availableItem Effects of Sel-Plex (organic selenium) and vitamin E on performance, immune response, and beef cut shelf life of feedlot steers(Texas Tech University, 2002-08) Clyburn, Bradley ScottSeveral experiments were designed to evaluate the differences of vitamin E level and selenium source on animal performance, selenium plasma concentrations, carcass characteristics, beef retail display, sensory characteristics, colostrum and milk components, and immunity in ruminants. Steers receiving Se yeast responded with an improvement in performance during the first 56 d, however, neither Se source nor vitamin E level affected performance over the entire 103 d experiment. Carcass quality measurements were similar among all treatments, however cattle supplemented with inorganic selenium and a moderate level of vitamin E responded with an increased loin-eye area. Lean muscle lightness of steaks aged 7, 14, and 35 d was improved with 50% less vitamin E when Se yeast was added to the diet. Steaks from steers fed no supplemental dietary Se or vitamin E, for all aging treatments, showed no difference in lean muscle lightness difference from the organic Se treatments with 125 lU and 500 lU of vitamin E nor the inorganic Se treatments at 35 d of aging. Neither selenium source nor vitamin E level influenced Warner Bratzler shear values. Selenium enriched yeast resulted in a greater Se colostrum concentration compared to inorganic Se and the control treatments, however, no differences were observed in milk Se concentration among treatments. Selenium yeast resulted in a greater colostrum Se concentration compared to inorganic Se and the control treatments, however, no differences were observed in milk Se concentration among treatments. Selenium source did not affect milk fat percentage between treatments. However, ewes supplemented with dietary inorganic Se showed a reduced colostrum (0 h) protein percentage compared to the control and the Se yeast treatments. Selenium source did not significantly affect milk lactose percentage among treatments. Additionally, non-fat solids percentage was reduced for all treatments after 6 h of lactation. Selenium source or supplementation had no affect on somatic cell count between treatments. Neither Se source nor supplementation affected ewe or lamb plasma Se or immunogloblin levels.Item Improving palatability of beef and hot processed pork loins(Texas Tech University, 1986-08) Harmon, Celia JeanNot availableItem Methods to improve the quality and consistency of beef(Texas Tech University, 2000-05) Hilton, Gretchen GayleThe need to improve the quality and consistency of beef has been a concern of researchers, producers, packers, retailers, and restaurateurs for decades. As consumers strive to find a convenient, healthy, affordable, palatable food sources, the beef industry has fallen behind. Beefs lack of consistency, convenience, and the health concerns associated with eating beef have resulted in lost market share to other protein sources. The beef industry needs to identify means of providing consumers with high quality, convenient products. This dissertation evaluates methods to improve the quality and consistency of beef First, a study was conducted to determine if a guaranteed tender beef steak could be successfully offered to consumers in retail stores. This study utilized a new technology, middle meat electrical stimulation, to improve tenderness and also evaluated six different cattle breed types. Electrical stimulation did not improve tenderness (P > .05). However, electrical stimulation did improve (P < .05) marbling score, quality grade, and lean color. No palatability differences (P > .05) were found between breed types. Moreover, 99% of the steaks had Warner-Bratzler shear (WBS) values less than 4.5 kg. Thus, providing consumers with a guaranteed tender beef steak can be accomplished. A second study was conducted to utilize objective color measurements to identify tough beef carcasses from others. This study used CIE L*, a* and b* color measurements determined from the previous experience to determine if specific objective color measurements could be used to identify carcasses that produced tough steaks. Carcasses were selected that had L*, a* and b* values below 32.5, 20.5 and 20.5. A higher proportion of these carcasses (P < .05), 73.7%, had WBS values greater than 4.5 kg. Therefore, identifying a portion of the carcasses that produce tough steaks using objective color measurements can be accomplished efficiently and effectively. Both projects provided results that can be utilized by the beef industry to improve the quality and consistency of beef that is sold to consumers.Item Muscle calcium modulation using vitamin D to improve beef tenderness(Texas Tech University, 2001-05) Montgomery, Jayden LloydThe effect of supplemental vitamin D3 (VITD) doses during the last 8 d of feeding and biological type of cattle on feedlot performance, VITD residues, meat tenderness, and muscle calcium homeostasis was studied. Supplementing cattle with 5 million lU/steer daily of VITD negatively affect average daily gain and feed intake, but feeding 1 or .5 million lU/steer daily did not negatively impact feedlot performance data. All the treatments studied improved meat tenderness. Sensory panel scores and Warner-Bratzler shear force indicated that the longissimus and semimembranosus muscles were the most responsible to VITD improving tenderness by as much as 21%. Tissue VITD residues in the liver, kidney, and muscle were increased by supplementing steers with VITD. Cooking samples seemed to reduce treatment effects on residues. Supplementing steers with VITD also increased the calcium content of meat and activated ì-calpain, thereby increasing myofibrillar proteolysis and degradation of troponin T. Therefore, vitamin D supplementation of beef cattle can improve meat tenderness and presumably improves the marketability of beef by decreasing the variation in beef tenderness and accelerating postmortem tenderization. The effect of VITD supplementation on muscle mineral metabolism also was investigated. The VITD treatments seemed to increase the binding of calcium near the Zline and to myofibril proteins. Moreover, VITD supplementation and postmortem aging increased the concentration of Ca2+and P in the cytosol of longissimus muscle. Several cell culture experiments were devised to try and explain the role of vitamin D in muscle cell protein synthesis and degradation. Treatment of myotubes with l.25-dihydroxyvitamin D3 decreased cellular protein synthesis and increased cellular protein degradation. The expression of calpastatin, m-calpain, calbindin, and the calcium-sensing receptor also were decreased by treatment in myotubes. Therefore, the affects of VITD treatment on cellular degradation might be attributable to regulation of calpastatin, ì-calpain, and m-calpain expression. Therefore vitamin D3 is an important regulator of calcium homeostasis and proteolysis in muscle. Feeding vitamin D3 at .5 million lU daily for 8 d to steers can improve beef tenderness and possibly the marketability of beefItem Palatability, chemical composition, and retail caselife of steaks from feedlot cattle fed ractopamine(Texas Tech University, 1990-05) Dietzel, Christine Jan JorgensonNot availableItem The evaluation of seven microsatellite markers and real time ultrasound information as tools for selecting animals for improved carcass characteristics and beef tenderness(Texas Tech University, 2002-12) Barham, Brett LeeThis study evaluated seven published bovine microsatellite markers selected from the USDA-MARC database for their usefulness as a selection tool for beef tenderness. Data from steers from ten different sire breeds were sorted into the top (upper tail, n = 25) and bottom (lower tall, n = 25) steers for average daily gain, marbling score, rib eye area, and Warner-Bratzler shear force (WBS) following a 14 d aging treatment. The resulting 200 animals were genotyped by a commercial laboratory (Celera AgGen, Davis, CA) for microsatellite markers BMC1501 (Leptin), BMC9001 (Nebulin), BMS 1678 (Thyroglobulin), BY5 (Myostatin), URB011 (Calpain), CAST (Calpastatin), and BM2394 (WBS). For all but one marker, additional alleles were discovered in the study. Additionally, analysis revealed that several markers had significant effects on some carcass and tenderness traits. These results imply that it may be possible to select for unique alleles to help Improve beef tenderness. Moreover, the study analyzed the Impact of growth Implants, sire breed and sire on carcass value and profitability. Implanted animals showed an increased carcass value of over $40 per head over non-Implanted animals. There was a range of sire EPD's for carcass value of $67 (-$37 to $30) from all sires in the study, indicating that sire selection can be a very important aspect of profitability in a retained ownership program. The decision to retain ownership is often a financial risk, therefore it is important to consider all management options that have a potential to maximize profit. Realized profit from retaining ownership was higher for animals implanted (P < 0.05). Non-implanted animals had a negative LS means for realized profit (-$27 per animal), while both SS and SR implant treatments had positive realized profit ($32 and $15 per head, respectively). The study also evaluated a new real time ultrasound software package to determine accuracy of prediction of carcass traits and tenderness. Pearson correlation coefficients between carcass fat thickness and ultrasound fat thickness was highly correlated (r = 0.81). Similarly, Spearman's correlation coefficient was also highly correlated for ultrasound fat thickness and carcass fat thickness (r = 0.84). Analysis of variance results indicated that ultrasound fat thickness measurements accounted for a significant amount of carcass fat thickness variation (R^= 0.65, P< 0.0001). Pearson correlation coefficients between average percent chemical fat and marbling score with ultrasound percent intramuscular fat was 0.519 and 0.600, respectively. Pearson correlation coefficient between the carcass ribeye area and ultrasound ribeye area was insignificant at 0.063 (P = 0.6132) as was the Spearman's correlation coefficient (r = 0.086; P = 0.4938). Analysis of variance between ultrasound ribeye area revealed that it failed to account for a significant amount of variation in carcass ribeye measurements (R^ = 0.004, P = 0.613). Results indicated that the software does not accurately predict ribeye area. The unique aspect of the software utilized in the study is the ability to predict tendemess. However, the data revealed an Insignificant correlation between ultrasound tenderness score and WBS or any sensory panel tenderness ratings. Additionally, analysis of variance failed to detect an association between ultrasound tenderness scores and WBS and sensory panel scores.Item Valuing fed cattle carcass characteristics(Texas Tech University, 2002-12) Ward, Jason KyleNot available