Browsing by Author "Woerner, Dale R. (TTU)"
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Item Changes in the Flavor Profile of Ground Beef Resulting from the Application of Antimicrobial Interventions(2022) Hernandez-Sintharakao, Michael J.; Swenson, Joanna K.; Nair, Mahesh N.; Geornaras, Ifigenia; Engle, Terry E.; Belk, Keith E.; Woerner, Dale R. (TTU)The objective of this study was to characterize flavor, fatty acid composition, and volatile compounds of beef treated with common antimicrobial interventions in beef processing facilities. The effect of 3 prechilling antimicrobial interventions (4.5% lactic acid [LA]; 400 ppm peroxyacetic acid acidified to pH 1.2 with a sulfuric acid and sodium sulfate blend [aPAA]; or untreated control [CON]) and 4 postchilling treatments (CON; LA; aPAA; or a 2.5% solution of a commercial blend of lactic and citric acid [LAC]) were analyzed. Briskets (n = 30/treatment) were treated before and after chilling using a custom-built pilot-sized spray cabinet, ground twice, and formed into patties. Cooked patties were analyzed by a trained sensory panel, and a subset of raw samples (n = 6) were analyzed for fatty acid composition and volatile compounds. Samples treated with LA before and after chilling were more intense in sourness than the CON (P <0.05). Fatty acid analysis showed no differences (P >0.05) due to the use of chemical interventions. Only postchilling treatments had an effect on volatile compounds. The relative abundances of pentanal and pentanol were greater (P <0.05) in LA-treated postchilling intervention samples than CON and LAC, hexanoic acid was greater (P <0.05) in aPAA than CON and LAC, and acetic acid was greater (P <0.05) in aPAA than LAC. Overall, these results demonstrated that LA pre-and postchilling antimicrobial interventions only impact the sourness of ground beef but did not affect the fatty acid composition, while postchilling antimicrobial treatments had a minimal impact on volatile compounds.Item Characterization of the Microbial Resistome in Conventional and “Raised Without Antibiotics” Beef and Dairy Production Systems(2019) Rovira, Pablo; McAllister, Tim; Lakin, Steven M.; Cook, Shaun R.; Doster, Enrique; Noyes, Noelle R.; Weinroth, Maggie D.; Yang, Xiang; Parker, Jennifer K.; Boucher, Christina; Booker, Calvin W.; Woerner, Dale R. (TTU); Belk, Keith E.; Morley, Paul S.Metagenomic investigations have the potential to provide unprecedented insights into microbial ecologies, such as those relating to antimicrobial resistance (AMR). We characterized the microbial resistome in livestock operations raising cattle conventionally (CONV) or without antibiotic exposures (RWA) using shotgun metagenomics. Samples of feces, wastewater from catchment basins, and soil where wastewater was applied were collected from CONV and RWA feedlot and dairy farms. After DNA extraction and sequencing, shotgun metagenomic reads were aligned to reference databases for identification of bacteria (Kraken) and antibiotic resistance genes (ARGs) accessions (MEGARes). Differences in microbial resistomes were found across farms with different production practices (CONV vs. RWA), types of cattle (beef vs. dairy), and types of sample (feces vs. wastewater vs. soil). Feces had the greatest number of ARGs per sample (mean = 118 and 79 in CONV and RWA, respectively), with tetracycline efflux pumps, macrolide phosphotransferases, and aminoglycoside nucleotidyltransferases mechanisms of resistance more abundant in CONV than in RWA feces. Tetracycline and macrolide–lincosamide–streptogramin classes of resistance were more abundant in feedlot cattle than in dairy cow feces, whereas the β-lactam class was more abundant in dairy cow feces. Lack of congruence between ARGs and microbial communities (procrustes analysis) suggested that other factors (e.g., location of farms, cattle source, management practices, diet, horizontal ARGs transfer, and co-selection of resistance), in addition to antimicrobial use, could have impacted resistome profiles. For that reason, we could not establish a cause–effect relationship between antimicrobial use and AMR, although ARGs in feces and effluents were associated with drug classes used to treat animals according to farms’ records (tetracyclines and macrolides in feedlots, β-lactams in dairies), whereas ARGs in soil were dominated by multidrug resistance. Characterization of the “resistance potential” of animal-derived and environmental samples is the first step toward incorporating metagenomic approaches into AMR surveillance in agricultural systems. Further research is needed to assess the public-health risk associated with different microbial resistomes.Item Crossbreeding beef sires to dairy cows: Cow, feedlot, and carcass performance(2022) Foraker, Blake A. (TTU); Ballou, Michael A. (TTU); Woerner, Dale R. (TTU)Genetic and reproductive advancements in the dairy industry, volatile milk markets, and beef packer restrictions on dairy carcasses have increased the popularity of crossbreeding beef sires to dairy cows in the United States. This observational study aimed to understand performance of dairy cows bred to beef sires and feedlot and carcass performance of crossbred beef × dairy cattle. For dairy cow performance, archived records from two dairies representing two successive lactations were evaluated in cows (Dairy A: n = 72/group; Dairy B: n = 456/group) representing 1) All Dairy, where previous sire type of conception was Holstein for both lactations, or 2) Beef on Dairy, where previous sire type of conception was Holstein for the preceding lactation and a beef breed for the subsequent lactation. For feedlot performance, closeout data from pens (n = 26/cattle type) of beef and beef × dairy steers and heifers were evaluated. For carcass performance, individual carcass data were compared between conventional beef (n = 966), beef × dairy (n = 518), and Holstein (n = 935) steers sampled across a variety of processing facilities, harvest lots, and geographical regions. Cow lactation performance was minimally impacted by sire type of previous conception. Cows conceived to beef sires exhibited a 2 to 3 d greater (P < 0.01) gestation length than cows conceived to Holstein sires. Beef × dairy cattle were not largely different in weight gain at the feedlot but exhibited 1-unit lesser (P < 0.01) dressing percentage than beef cattle. Beef × dairy carcasses possessed 18% lesser (P < 0.05) 12th rib fat thickness than beef cattle and 5% greater (P< 0.05) ribeye area than dairy cattle. Additionally, beef cattle produced nearly double (P < 0.05) the percentage of yield grade 4 carcasses produced by beef × dairy and Holstein cattle.Item Descriptive Sensory Attributes and Volatile Flavor Compounds of Plant-Based Meat Alternatives and Ground Beef(2023) Hernandez, Manuel Sebastian (TTU); Woerner, Dale R. (TTU); Brooks, J. Chance (TTU); Legako, Jerrad F. (TTU)The objective of this study was to characterize descriptive sensory attributes and volatile compounds among ground beef (GB) and plant-based meat alternatives (PBMA). The Beyond Burger, Impossible Burger, a third brand of PBMA, regular GB, and lean GB were collected from local and national chain grocery stores. Patties were formed and cooked on an enamel-lined cast iron skillet to an internal temperature of 71 °C. A trained descriptive sensory panel evaluated patties for 17 flavor attributes and 4 texture attributes. Volatile compounds were extracted using solid phase microextraction and analyzed via gas chromatography-mass spectrometry. Distinct differences in sensory and volatile profiles were elucidated (p < 0.05). PBMA possessed decreased beef flavor intensity and increased umami, nutty, smokey-charcoal, and musty/earthy flavor compared to GB. Sensory differences corresponded with pyrazine, furan, ketone, alcohol, and aldehyde concentration differences between products. These data support the conclusion that ground beef and PBMA possess different flavor and texture characteristics. Furthermore, the flavor of PBMA varied among available retail brands.Item Effects of feedlot bunk management and bulk density of steam-flaked corn on growth performance, carcass characteristics, and liver score of finishing beef steers fed high-concentrate diets without by-products or tylosin phosphate(2021) Smock, Taylor M. (TTU); Woerner, Dale R. (TTU); Petry, Amy L. (TTU); Manahan, Jeff L. (TTU); Helmuth, Cory L. (TTU); Coppin, Carley M. (TTU); Hales, Kristin E. (TTU)Objective: Our objective was to evaluate effects of bunk management strategy and bulk density of steam-flaked corn (SFC) on growth performance, carcass characteristics, and incidence and severity of liver abscesses in finishing beef steers fed diets without tylosin phosphate. Materials and Methods: Beef steers (n = 192; initial BW = 332 ± 8.1 kg) were used in a randomized complete block design comprised of 12 BW blocks and 12 pen replications per treatment. A 2 × 2 factorial arrangement of treatments was used: (1) slick-bunk management + 335 g/L SFC-based diets (SFC); (2) modified ad libitum bunk management + 335 g/L SFC; (3) slick-bunk management + 425 g/L SFC; (4) modified ad libitum bunk management + 425 g/L SFC. Results and Discussion: Bunk management strategy did not affect growth performance, carcass characteristics, or liver abscess score (P ≥ 0.10). The ADG of steers fed 425 g/L SFC was greater (P = 0.05) from d 35 to 105 than those fed 335 g/L SFC; however, overall ADG was not different (P = 0.36). The DMI of steers fed 425 g/L SFC was greater at each interim period (P ≤ 0.05) and overall (P ≤ 0.01) than those fed 335 g/L SFC. Gain-to-feed (G:F) of steers fed 425 g/L SFC tended (P = 0.10) to be lesser from d 0 to 35 but was not different overall (P = 0.12). Steers fed 425 g/L SFC tended to have greater backfat and calculated empty body fat percentage (P ≤ 0.07) than those fed 335 g/L SFC and greater calculated YG (P = 0.05). Steers fed 425 g/L SFC had 43.5% fewer (P = 0.04) liver abscesses than those fed 335 g/L SFC, but liver abscess severity did not differ (P ≥ 0.12). Implications and Applications: Bunk management did not affect growth performance, carcass characteristics, or development of liver abscesses. Steers fed 425 g/L SFC-based diets had greater DMI and 43.5% fewer liver abscesses than those fed 335 g/L SFC-based diets with similar overall G:F, but carcasses were fatter. Greater bulk density of SFC may be a useful management strategy and a viable antimicrobial alternative to decrease liver abscesses.Item Effects of physical activity and feed and water restriction at reimplanting time on feed intake patterns, growth performance, and carcass characteristics of finishing beef steers(2022) Helmuth, Cory L. (TTU); Woerner, Dale R. (TTU); Ballou, Michael A. (TTU); Manahan, Jeff L. (TTU); Coppin, Carley M. (TTU); Long, Nathan S. (TTU); Hoffman, Ashley A. (TTU); Young, James Daniel (TTU); Smock, Taylor M. (TTU); Hales, Kristin E. (TTU)In the feedlot, there can be a decrease in dry matter intake (DMI) associated with reimplanting cattle that negatively affects growth performance. This study was conducted to determine the mechanisms causing a decrease in DMI after reimplanting and identify a strategy to mitigate the decrease. Crossbred steers (n=200; 10 pens/treatment; initial bodyweight [BW]=386±4.9 kg) were used in a randomized complete block design experiment. Cattle were implanted with Revalor-IS on day 0. Treatments included a Revalor-200 implant on day 90 before feeding with the following management practices imposed: 1) steers were returned to their home pen immediately after reimplant (PCON); 2) steers were placed in pens and restricted from feed and water for 4 h (RES); 3) steers were walked an additional 805 m after reimplant and then returned home (LOC); 4) steers were restricted from feed and water for 4 h and walked an additional 805 m (RES+LOC); 5) steers were given an oral bolus of Megasphaera elsdenii (Lactipro; MS Biotec, Wamego, KS) and were restricted from feed and water for 4 h, and then walked an additional 805 m (LACT). One hundred steers were given an ear tag to record minutes of activity (ESense Flex Tags, Allflex Livestock Intelligence, Madison, WI). As a percentage of BW, DMI was 5% greater (P=0.01) from reimplant to end for PCON vs. RES, LOC, and RES+LOC treatments. Likewise, as a percentage of BW, DMI was 6.6% greater (P=0.03) from reimplant to end and 4.0% greater (P=0.05) overall for the PCON treatment vs. the LOC treatment. Overall, DMI as a percentage of BW was 3.3% greater (P=0.02) for PCON vs. RES, LOC, and RES+LOC treatments. There was an increase in G:F from reimplant to end (P=0.05) for RES+LOC vs. the LACT treatment. From these data, we conclude that restricting cattle from feed and water for 4 h after reimplanting did not alter subsequent DMI. Increasing locomotion had the greatest negative effect on DMI and growth performance. Management strategies to decrease locomotion associated with reimplanting would be beneficial to DMI and overall growth performance of finishing beef steers.Item Effects of Saccharomyces cerevisiae CNCM I-1077 and calcium clinoptilolite zeolite compared with tylosin phosphate and negative control on health, performance, carcass outcomes, and liver abscesses of dairy-beef cross feedlot cattle*(2024) Theurer, Miles E.; Woerner, Dale R. (TTU); Johnson, Bradley J. (TTU); Wilson, Reese (TTU); Sarturi, Jhones O. (TTU); Amachawadi, Raghavendra G.; Nagaraja, T. G.; Simpson, Jim; Fox, J. Trent; Adams, Paige; Karges, Kip K.Objective: Our objective was to evaluate the effects of in-feed, non-antibiotic alternatives (Saccharomyces cerevisiae CNCM I-1077 and calcium clinoptilolite zeolite) on health, growth performance, carcass characteristics, and liver abscesses in dairy-beef cross composites in a commercial feedlot. Materials and Methods: Dairy-beef, intact heifers (n = 2,088; average BW = 334.8 kg) were assigned to 1 of 3 treatment groups: (1) Negative control (no feed-grade antimicrobials for control of liver abscesses; NC); (2) Saccharomyces cerevisiae CNCM I-1077 (0.5 g/heifer per day to provide 1 × 1010 cfu/heifer per day) and calcium clinoptilolite zeolite (replacing flaked corn at 1.2% on a DM basis; LB), or (3) tylosin phosphate (targeted at a rate of 68 mg/heifer per day; TY). Heifers averaged 228 d on feed at harvest. Individual carcass outcomes and liver scores were captured at harvest. Results and Discussion: Heifers in the TY treatment had reduced DMI, increased G:F, and reduced cost of gain compared with the other treatments. Carcass characteristics were not affected by treatments. Heifers offered LB tended to have fewer total liver abscesses compared with the TY group, whereas NC was intermediate. Implications and Applications: Feedlot performance improved for dairy-beef heifers offered tylosin; however, TY had the greatest percentage of liver abscesses compared with NC. Feeding the combination of Saccharomyces cerevisiae CNCM I-1077 and calcium clinoptilolite as a non-antimicrobial alternative for the mitigation of liver abscesses in dairy-beef females seems to be promising strategy; however, growth performance outcomes may be reduced compared with tylosin.Item Efficacy of Common Antimicrobial Interventions at and above Regulatory Allowable Pick-Up Levels on Pathogen Reduction(2023) Blandon, Sabrina E. (TTU); Vargas, David A. (TTU); Casas, Diego E. (TTU); Sarasty, Oscar (TTU); Woerner, Dale R. (TTU); Echeverry, Alejandro (TTU); Miller, Markus F. (TTU); Carpio, Carlos E. (TTU); Sanchez-Plata, Marcos X. (TTU); Legako, Jerrad F. (TTU)The objective of this study was to evaluate the food safety efficacy of common antimicrobial interventions at and above required uptake levels for processing aids on the reduction of Shiga-toxin producing E. coli (STEC) and Salmonella spp. through spray and dip applications. Beef trim was inoculated with specific isolates of STEC or Salmonella strains. Trim was intervened with peracetic or lactic acid through spray or dip application. Meat rinses were serially diluted and plated following the drop dilution method; an enumerable range of 2–30 colonies was used to report results before log transformation. The combination of all treatments exhibits an average reduction rate of 0.16 LogCFU/g for STEC and Salmonella spp., suggesting that for every 1% increase in uptake there is an increase of 0.16 LogCFU/g of reduction rate. There is a statistical significance in the reduction rate of Shiga-toxin producing Escherichia coli in relation to the uptake percentage (p < 0.01). The addition of explanatory variables increases the R2 of the regression for STEC, where all the additional explanatory variables are statistically significant for reduction (p < 0.01). The addition of explanatory variables increases the R2 of the regression for Salmonella spp., but only trim type is statistically significant for reduction rate (p < 0.01). An increase in uptake percentages showed a significant increase in reduction rate of pathogens on beef trimmings.Item Evaluation of Beef Steak Flavor Development in Vacuum Rollstock Packaging Under Two Lighting Sources(2022) Barker, Samantha N. (TTU); Legako, Jerrad F. (TTU); Brooks, J. Chance (TTU); Woerner, Dale R. (TTU)The objective of this study was to determine the influence of lighting type and display duration on flavor development in multiple beef muscles. Paired beef top sirloin butts, strip loins, and tenderloins were collected from USDA Low Choice carcasses (Small00 to Small100 marbling score, n = 16). Subprimals were wet aged in the absence of light for 7 d postmortem at 0°C to 4°C before being fabricated into 2.5-cm steaks representing the Gluteus medius, Longissimus lum-borum (LL), and Psoas major. Steaks were packaged individually in vacuum rollstock packaging and assigned to either light-emitting diode (LED) or fluorescent (FLUR) display cases for a display period of 0, 2, 6, or 10 d. All steaks were assigned to either trained descriptive panel analysis (n = 384) or volatile compound analysis (n = 384) and cooked to a medium degree of doneness (71°C). Two-way interactions occurred between lighting type and display duration, showing increased tenderness sooner during display for LED steaks, and lower umami intensity in FLUR steaks after 10 d (P < 0.001). Lighting and muscle type showed more tender LL and Psoas major steaks in LED lighting (P ≤ 0.001). Lighting and display duration interactions also showed increased concentrations of 2,3-butanedione under FLUR light and ethyl benzene under LED display (P ≤ 0.043), whereas lighting and muscle type showed greater concentrations of alcohols and carboxylic acids in LL steaks under LED lighting (P ≤ 0.046). Furthermore, discriminant function analyses were per-formed, suggesting that the most successful retail display period was within 2 to 6 d, with no difference between lighting types (P = 0.212). Overall, these data reveal little differentiation between lighting types, implying that newer LED lighting does not detrimentally influence beef quality when vacuum packaging is utilized.Item Flavor Development of Individually VacuumPackaged Beef Steaks During Extended Wet Aging(2023) Barker, Samantha N. (TTU); Brooks, J. Chance (TTU); Bachler, Jordan T. (TTU); Woerner, Dale R. (TTU); Legako, Jerrad F. (TTU)The objective of the study was to determine the effect of extended aging on the flavor development of various muscles, individually stored in vacuum rollstock packaging. Strip loins, paired tenderloins, and top sirloin butts (n = 48) from USDA Low Choice carcasses (Small00 to Small100 marbling score, n = 16). Subprimals were wet-aged in the absence of light for 28 d postmortem before fabrication into 2.54 cm steaks representing the longissimus lumborum (LL), psoas major (PM), and gluteus medius (GM). Steaks were individually packaged in vacuum rollstock packaging and assigned to an additional aging time of 28, 35, 42, 49, or 56 d. Cut steaks (n = 240/test) were designated to trained descriptive panel analysis or volatile compound analysis. No interactions occurred for trained sensory analysis, but a main effect of days of age (P ≤ 0.033) showed the greatest effect on negatively associated attributes, including liver-like, oxidized, fishy, bitter, and sour, after 42 d of aging. A main effect of muscle type also occurred (P ≤ 0.040) for flavor attributes, in which GM and PM samples scored higher in off-flavor attributes compared with LL samples, including flavors such as liver-like, oxidized, and sour. An interaction between muscle type and days of age occurred for 2-pentyl-furan (P = 0.021). One compound— 3 hydroxy-2 butanone—was affected by muscle type (P = 0.009). However, most compounds were affected by days of age (P ≤ 0.046), in which compounds related to off-flavors increased in concentrations the most after 49 d. Additionally, discriminant function analyses were performed, suggesting the most effective aging time for individual steaks to be under 49 d when considering loadings for volatile compounds and flavor attributes corresponding with days of age. Overall, these data suggest individual packaging of GM, LL, and PM muscles is most optimal for up to 42 or 49 d of age without a large impact from the presence of off-flavors, thus providing food service establishments the opportunity to individually package beef steaks for an extended period while maintaining consumer satisfaction through optimal flavor.Item Identification of blood-based biomarkers for detection of liver abscesses in beef × dairy heifers(2024) Wilson, Reese A. (TTU); Johnson, Bradley J. (TTU); Sarturi, Jhones O. (TTU); Crossland, Whitney L. (TTU); Hales, Kristin E. (TTU); Rathmann, Ryan J. (TTU); Bratcher, Christy L. (TTU); Theurer, Miles E.; Amachawadi, Raghavendra G.; Nagaraja, T. G.; Speidel, Scott E.; Enns, R. Mark; Thomas, Milton G.; Foraker, Blake A.; Cleveland, Matthew A.; Woerner, Dale R. (TTU)Objective: The objective was to determine the effects of liver abscesses on complete blood counts (CBC) and liver function and to identify blood-based biomarkers for detection of liver abscesses in feedlot cattle. Materials and Methods: Blood samples were collected on a subset of beef × dairy crossbred heifers with and without liver abscesses (n = 94; n = 113, respectively). From these blood samples, CBC and serum chemistry analytes related to liver health (alkaline phosphatase, gamma glutamyl transferase, bile acids, total bilirubin, and cholesterol) were analyzed to characterize animal health and model for liver abscesses. Abscess presence was predicted using logistic regression models and machine learning algorithms, with individual heifer serving as the experimental unit. Results and Discussion: In a binary system (abscessed or not), heifers with liver abscesses had lower concentrations of lymphocyte (LYM) and total white blood cell (WBC) concentrations but elevated platelet-to-LYM ratio. Serum chemistry measures were not affected by abscess presence or liver score (severity). In univariate, predictive modeling of CBC measures, only total WBC concentration was accurate (65.85%) at predicting liver abscess presence; however, this was not deemed an acceptable biomarker due to its poor specificity (54.79%). Using total WBC, basophils, red blood cells, and procalcitonin as variables to predict liver abscess condition, the Logit- Boost model produced the greatest accuracy (80.65%) and specificity (85.71%). An accurate blood test that allows for the detection of liver abscesses during the finishing phase may allow for therapeutic management or alternative marketing of cattle; however, the marginal accuracy demonstrated in this study combined with the impracticality and cost of analyzing a blood sample may not be feasible. Regardless, the most explanatory CBC variables in cattle with abscessed livers were suggestive of an immune response. Implications and Applications: Liver condition influenced the CBC of beef × dairy heifers but not serum chemistry. Multivariate predictive models showed potential for predicting liver abscess condition based on CBC. The results of this study warrant further investigation for biomarkers of the liver abscess condition. An antemortem indicator for liver abscesses could prove useful for making management decisions and in research applications, particularly in evaluating interventions.Item Influence of Aging Temperature and Duration on Flavor and Tenderness Development of Vacuum-Packaged Beef Longissimus(2023) Hernandez, M. Sebastian (TTU); Woerner, Dale R. (TTU); Brooks, J. Chance (TTU); Wheeler, Tommy L.; Legako, Jerrad F. (TTU)The objective of this study was to investigate the influence of beef wet-aging temperature and duration on beef palatability. Paired beef strip loins were obtained from USDA Choice carcasses (n = 60) at a commercial processing facility. Paired strip loins were assigned to a storage temperature (−2°C, 0°C, or 4°C). Strip loins were portioned into half loins and further assigned to an aging duration (14, 28, 42, or 56 d). Loins were aged in commercial upright refrigerators. After aging, loins were fabricated into 2.54-cm steaks and assigned to either volatile compound analysis, descriptive sensory analysis, or consumer sensory analysis. Data were analyzed as a split-plot in which carcass served as the whole plot and loin portion served as the subplot. An alpha of P < 0.05 was used. For descriptive sensory analysis, an interaction was observed for beef identity, bloody/serumy, fat-like, liver-like, bitter, sour, and musty/earthy (P < 0.05). Loins aged for 56 d at 4°C were the most intense for liver-like, sour, and musty/earthy notes compared with all other treatments (P < 0.05). An interaction was observed for consumer juiciness, tenderness, and overall liking (P < 0.05). Steaks from loins aged for 14 d at −2°C were rated the least for juiciness, tenderness, and overall liking (P < 0.05). Ethanol, acetic acid, 1-penten-3-ol, and 2-methylbutanal were each greatest in loins aged for 56 d (P < 0.05). Aging at 4°C yielded the greatest concentrations of ethanol and heptanoic acid (P < 0.05). Off-flavor development increased during extended aging but was dependent on storage temperature. Extended aging (>28 d) conducted at colder temperatures did not negatively influence palatability. Aging for 14 d at −2°C was detrimental to consumer liking. It may be concluded that both aging temperature and duration should be considered when seeking to optimize beef palatability.Item Metaphylactic antimicrobial effects on occurrences of antimicrobial resistance in Salmonella enterica, Escherichia coli and Enterococcus spp. measured longitudinally from feedlot arrival to harvest in high-risk beef cattle(2022) Long, Nathan S. (TTU); Wells, James E.; Berry, Elaine D.; Legako, Jerrad F. (TTU); Woerner, Dale R. (TTU); Loneragan, Guy H.; Broadway, Paul R.; Carroll, Jeff A.; Sanchez, Nicole C.Burdick; Fernando, Samodha C.; Bacon, Carley M. (TTU); Helmuth, Cory L. (TTU); Smock, Taylor M. (TTU); Manahan, Jeff L. (TTU); Hoffman, Ashley A. (TTU); Hales, Kristin E. (TTU)Aims: Our objective was to determine how injectable antimicrobials affected populations of Salmonella enterica, Escherichia coli and Enterococcus spp. in feedlot cattle. Methods and Results: Two arrival date blocks of high-risk crossbred beef cattle (n = 249; mean BW = 244 kg) were randomly assigned one of four antimicrobial treatments administered on day 0: sterile saline control (CON), tulathromycin (TUL), ceftiofur (CEF) or florfenicol (FLR). Faecal samples were collected on days 0, 28, 56, 112, 182 and study end (day 252 for block 1 and day 242 for block 2). Hide swabs and subiliac lymph nodes were collected the day before and the day of harvest. Samples were cultured for antimicrobial-resistant Salmonella, Escherichia coli and Enterococcus spp. The effect of treatment varied by day across all targeted bacterial populations (p ≤ 0.01) except total E. coli. Total E. coli counts were greatest on days 112, 182 and study end (p ≤ 0.01). Tulathromycin resulted in greater counts and prevalence of Salmonella from faeces than CON at study end (p ≤ 0.01). Tulathromycin and CEF yielded greater Salmonella hide prevalence and greater counts of 128ERYR E. coli at study end than CON (p ≤ 0.01). No faecal Salmonella resistant to tetracyclines or third-generation cephalosporins were detected. Ceftiofur was associated with greater counts of 8ERYR Enterococcus spp. at study end (p ≤ 0.03). By the day before harvest, antimicrobial use did not increase prevalence or counts for all other bacterial populations compared with CON (p ≥ 0.13). Conclusions: Antimicrobial resistance (AMR) in feedlot cattle is not caused solely by using a metaphylactic antimicrobial on arrival, but more likely a multitude of environmental and management factors.Item Microbial growth study on pork loins as influenced by the application of different antimicrobials(2021) Vargas, David A. (TTU); Miller, Markus F. (TTU); Woerner, Dale R. (TTU); Echeverry, Alejandro (TTU)The use of antimicrobials in the pork industry is critical in order to ensure food safety and, at the same time, extend shelf life. The objective of the study was to determine the impact of antimicrobials on indicator bacteria on pork loins under long, dark, refrigerated storage conditions. Fresh boneless pork loins (n = 36) were split in five sections and treated with antimicrobials: Water (WAT), Bovibrom 225 ppm (BB225), Bovibrom 500 ppm (BB500), Fit Fresh 3 ppm (FF3), or Washing Solution 750 ppm (WS750). Sections were stored for 1, 14, 28, and 42 days at 2–4◦C. Mesophilic and psychrotrophic aerobic bacteria (APC-M, APC-P), lactic acid bacteria (LAB-M), coliforms, and Escherichia coli were enumerated before intervention, after intervention, and at each storage time. All bacterial enumeration data were converted into log10 for statistical analysis, and the Kruskal–Wallis test was used to find statistical differences (p < 0.05). Initial counts did not differ between treatments, while, after treatment interventions, treatment WS750 did not effectively reduce counts for APC-M, APC-P, and coliforms (p < 0.01). BB500, FF3, and WS750 performed better at inhibiting the growth of indicator bacteria when compared with water until 14 days of dark storage.Item Prediction of Tenderness, Juiciness, and Flavor Profile of 2 Beef Muscles with Different Aging Times Using Rapid Evaporative Ionization Mass Spectrometry (REIMS)(2023) Hernandez-Sintharakao, Michael J.; Sarchet, Chandler J. (TTU); Prenni, Jessica E.; Woerner, Dale R. (TTU); Zhai, Chaoyu; Nair, Mahesh N.Rapid evaporative ionization mass spectrometry (REIMS) is a novel technique that provides rapid chemical information on biological tissues and has the potential to predict beef quality attributes in real time. This study aims to assess the ability of analysis by REIMS coupled with chemometric modeling to predict the quality attributes of wet-aged beef at the grading time. USDA Select and upper two-thirds Choice (n = 42, N = 84) striploins (longissimus lumborum [LL]) and tenderloins (psoas major [PM]) were collected 36 h postmortem from a commercial beef abattoir. The LL and PM were cut into portions and aged for 3, 14, and 28 d. Aged samples were analyzed for slice shear force, Warner-Bratzler shear force (WBS), and trained sensory panels (tenderness, juiciness, and flavor attributes), and results were used to categorize both LL and PM into binary classes. Additionally, slivers of the longissimus dorsi muscle between the 12th and 13th rib were collected during grading (36 h postmortem) and analyzed using REIMS. The REIMS data were used to build predictive models for tenderness, juiciness, and flavor classes for the 3 aging periods and 2 muscles. Prediction accuracies of all models were higher than classifying the samples by chance (P < 0.05), except WBS of 3 d aging model (P > 0.05). However, model accuracies were not too high, which could be due to overlaps between classes, small sample sizes, and unbalanced data, which could negatively affect predictive models. Results demonstrated that the chemical finger-prints obtained with REIMS could potentially sort carcasses by flavor, juiciness, and tenderness in real time. However, the full realization of this approach will require an increased sample size and the development of a sampling method that allows improved separation between sensory classes.Item The effects of a nutritional packet (live yeast, vitamins C and B1, and electrolytes) offered to steers in a calf-fed system on growth performance, nutrient digestion, feeding behavior, carcass characteristics, and ruminal variables(2023) Rush, Camron J. (TTU); Sarturi, Jhones O. (TTU); Huerta-Leidenz, Nelson O. (TTU); Woerner, Dale R. (TTU); Crossland, Whitney L. (TTU); Henry, Darren D.; Silva, Kaliu G.S. (TTU); Lopez, Alejandra M. (TTU)Effects of a nutritional packet strategically offered to calf-fed system steers on growth performance, nutrient digestibility, feeding behavior, ruminal variables, and carcass characteristics were evaluated. Angus crossbred steer-calves (N=60; body weight [BW]=234±4 kg) were used in a randomized complete block design (block=BW) and stratified into two treatments: 1) control; and 2) 30 g/steer-daily (dry matter [DM] basis) of a nutritional packet containing (steer-daily basis): Live yeast (Saccharomyces cerevisiae; 1.7×1010 CFU), vitamin C (Ascorbic acid, 162 mg), vitamin B1 (thiamin hydrochloride, 400 mg), sodium chloride (2.4 g), and potassium chloride (2.4 g). Animals were offered (electronic feed-bunks [SmartFeed, C-Lock Inc., Rapid City, SD]), a steam-flaked corn-based finishing diet to ad libitum (individual intake), once daily for 233 d. Treatments were offered during the first and last 60 days on feed (DOF). The GLIMMIX procedure of SAS was used, with steer as the experimental unit, treatment and phase (for feeding behavior and digestibility) as fixed effects, and BW-block as a random effect. Steers offered the nutritional packet had 14% less (P<0.01) intake and 18% greater (P=0.01) feed efficiency during the initial 30 DOF. Intake (days 0 to 233) was 6% greater (P=0.02) for steers offered the nutritional packet, while BW gain was not different (P≥0.44). Greater (P=0.02) dressing percent (61.1% vs. 62%) for steers offered the packet was observed, while other carcass variables were not different (P≥0.33). Digestibility of DM, organic matter, and fiber were greater (P<0.01) for steers offered the packet. Steers offered the packet spent 13% less time eating during the first 60 DOF, while during the last 60 DOF a 14% greater meal frequency and 12.3% smaller mean meal size (treatment×phase interaction, P<0.02) were observed. Steers offered the packet had a reduced (P≤0.01) mean meal duration during both phases. Regardless of treatment, a decreased rumination (P≤0.03) and chewing (P≤0.01) activities were observed for the last 60 DOF compared to the first 60 DOF. Ruminal papillae area was 30% greater (P=0.02) and the total volatile fatty acid (VFA) tended (P=0.09) to be greater for steers offered the nutritional packet. The nutritional packet offered to calf-fed steers improved feed efficiency during the initial 30 d after arrival, while inducing superior overall intake, nutrient digestibility, dressing percentage, ruminal papillae area, and total ruminal VFA.