No description available.

No description available.

Numerous outbreaks of foodborne illness have been attributed to non-intact beef (e.g., tenderized, marinated, and enhanced) products contaminated with Escherichia coli O157:H7. Organic acids are commonly utilized in the beef industry as antimicrobial interventions, which must be validated to eliminate or reduce E. coli O157:H7 to an undetectable level. Rifampicin-resistant Biotype I E. coli O157:H7 surrogate microorganisms (ATCC BAA-1427, BAA-1428, and BAA-1430) were applied as a cocktail (7.8 log10 CFU/ml) to three beef products (boneless strip loins, top sirloin butts, and bottom sirloin flaps) prior to treatment with an antimicrobial intervention (2.5% Beefxide or 2.9% lactic acid). Products were then subjected to a single or multiple pass tenderization and/or marination process. Beefxide and lactic acid treatments resulted in statistically significant log reductions of the microorganisms (P < 0.05) on the surfaces for all three products. Surrogate microorganisms were recovered from interior samples of all three products after mechanical tenderization. Additionally, surrogate concentrations recovered from flap surface and internal samples taken post-tumbling and marination were statistically similar (P < 0.05). These data indicate that tenderization and marination processes can transfer microorganisms into the interior of whole-muscle cuts, and suggest Beefxide and lactic acid may be similar in their efficacy as an antimicrobial applied as an intervention in the production of non-intact beef products.

The unprecedented beef export growth observed in Paraguay during recent years generated a new marketing environment in its livestock sector. While changes in beef marketed along the supply chain are well-known, no efforts have been undertaken to assess welfare changes of each economic agent of the Paraguayan Beef Supply Chain. Demand and supply systems are estimated for the fattening, slaughter and beef retail markets. A vertical multi-market approach accounting for the linkages among the three markets is used to measure welfare changes of all economic agents in the new marketing environment. The results suggest that consumers and slaughterhouses are worse off, feeder and calf producers are better off and overall society is better off.

Previously, ADH1Cc.-64T>C was shown to have an association with intramuscular fat (IMF) in the longissimus thoracis (LT) muscle when vitamin A was limited in finishing rations of beef steers. The purpose of the current study was to determine the optimum vitamin A supplementation level, in combination with ADH1C genotype, to increase IMF of the LT muscle. Forty-five TT, 45 CT and 27 CC cross-bred steers, black in colour, were backgrounded on a commercial ration containing 3360 IU vitamin A/kg DM. During finishing the steers were randomly assigned to one of three vitamin A treatments at 25, 50 and 75% of the NRC recommendation of 2200 IU/kg DM. Treatments were administered via an oral bolus. Carcass quality was evaluated and a sample from the LT muscle was collected for analysis of IMF. A treatment x genotype interaction (P=0.04) was observed for IMF; TT steers on the 75% treatment had higher IMF relative to CT and CC steers on the same treatment. Intramuscular fat was also higher for TT steers on the 75% treatment in comparison to TT steers on the 25% treatment. Eighty-four percent of the steers graded Canada AAA. Western blot analysis showed that TT steers had higher (P=0.02) ADH1C levels in hepatic tissue. Previously, TT steers had increased IMF when fed limited vitamin A. In the current study the lack of variation between treatments and genotypes at the lower vitamin A treatment levels was likely due to the majority of the steers grading Canada AAA (USDA Choice). However, the western blot data supports that TT steers are expected to have higher IMF deposition, due to an increase production of ADH1C.

The unprecedented beef export growth observed in Paraguay during recent years generated a new marketing environment in its livestock sector. While changes in beef marketed along the supply chain are well-known, no efforts have been undertaken to assess welfare changes of each economic agent of the Paraguayan Beef Supply Chain. Demand and supply systems are estimated for the fattening, slaughter and beef retail markets. A vertical multi-market approach accounting for the linkages among the three markets is used to measure welfare changes of all economic agents in the new marketing environment. The results suggest that consumers and slaughterhouses are worse off, feeder and calf producers are better off and overall society is better off.

No description available.

The objective of this study was to identify critical parameters of application for selected harvest and fabrication intervention strategies used to control Escherichia coli O157:H7 and Salmonella. Paired, boneless, beef strip loin (n=120, IMPS 180) were selected at a commercial cow harvest facility, transported to the Food Microbiology Laboratory, Texas A&M University, and inoculated with nonpathogenic, rifampicin-resistant E. coli organisms (ATCC #1427, 1428, 1430) to simulate harvest floor contamination. The beef strip loins were inoculated hot (~30°C) and then subjected to one of three chemical treatments (L-lactic acid, peroxyacetic acid, and acidified sodium chlorite) including subset variations for concentration and pH. Lactic acid was applied warm (~53°C) and at room temperature (~25°C), whereas the peroxyacetic acid, and acidified sodium chlorite were applied at room temperature (~25°C). Lactic acid was applied at concentrations of 2.5% and 5% using different water sources (tap and distilled), and at a common pH of ~2.2 using different water sources (tap and distilled). Peroxyacetic acid was applied at concentrations of 210 ppm and 150 ppm, and acidified sodium chlorite was applied at concentrations of 500 ppm and 1200 ppm. Half of the strip loins received the chemical interventions prior to chilling or “hot” (~25°C), whereas the other half received the interventions after a chilling for ~24 h at ~2°C. When applied to hot strip loins, only the 2.5% and 5% lactic acid treatments resulted in a greater than 1 log reduction, but for chilled strip loins all treatments achieved greater than a 1 log reduction. When tap water was used to prepare the intervention, there was a difference between reductions for hot (0.68 CFU/cm2) and chilled (2.02 CFU/cm2) product, but there were no differences between hot and chilled for distilled water. Also, there were no differences in reductions between using tap and distilled water for hot products or for chilled products. The pH of the meat surface was lowest for the 5.0% lactic acid (3.07) and highest for the 150 ppm peroxyacetic acid (6.07). These data support the significance of conducting in-plant validation studies utilizing the specific parameters used in the plant.

Graduation date: 1956

Graduation date: 1959