Progress Report on Iowa State University Burroughs Endowment Activities

Faculty in the Department of Animal Science initiated soliciting of funds in 1987 to establish a permanent endowment to recognize the distinguished career and major contributions of Dr. Wise Burroughs, a distinguished professor in animal science at Iowa State University. The endowment was established in the Iowa State University Foundation in 1991. The purpose of the fund is to support research and graduate education in the areas of fundamental factors regulating growth in food-producing animals, with emphasis on ruminants; to enhance growth of animals with the goal of improving the competitive position of ruminants as food-producing animals; and to develop innovative approaches to ruminant nutrition and/or growth enhancement as a means to improve desirability of meat produced by food animals. Dr. Burroughs’ research resulted in important and significant developments in technology for modern production systems for beef cattle. He was widely known for his ability to communicate complex ideas and research results for use by those involved in the animal industry. The current Burroughs Team has established three research projects: 1) Ghrelin--How does ghrelin affect blood and body composition in rats?; 2) Use of 25- hydroxyvitamin D3 to improve tenderness of beef; 3) Redesigning beef cattle to have a more healthful fatty acid composition.

Effect of MGA on Performance, Sexual Behavior, Carcass Quality and Tenderness in Mixed-Sex Pens of Cattle

The effect of MGA in mixed pens of steers and heifers was evaluated over a three-year period at the ISU Armstrong Research Farm near Lewis, Iowa. Two pens of approximately 40 head were fed diets with or without MGA in each of three replications. Estrus and riding activity was monitored using the Heat Watchâ system. At slaughter, in addition to routine carcass data collection, a rib sample was collected from each carcass for tenderness evaluation. There was no effect on dry matter intake due to MGA treatment. Mixed-sex pens that were fed MGA were 4% more efficient than controls. MGA-fed steers gained similarly to control steers. MGA fed heifers gained 8% faster than control heifers. MGA highly reduced measures of estrus and riding activity throughout the feeding period. MGA feeding improved marbling and tenderness measured in both steers and heifers. These data suggest that MGA has potential to improve performance, quality grade and tenderness in mixed pens of steers and heifers.

Comparison of Round and Square Cores in the Determination of Beef Tenderness by Warner- Bratzler and Instron

Seven rib-eye rolls, lip on (112A), were each cut into eight 2.54 centimeter thick steaks starting from the blade end. Steaks were randomly assigned to one of four treatment groups; 1) round versus square cores using Instron [inst1], 2) round versus square cores using Warner- Bratzler [inst2], 3) Instron versus Warner-Bratzler using round cores [rdsq1], and 4) Instron versus Warner- Bratzler using square cores [rdsq2]. Subsequently, steaks from each group were broiled in a General Electric industrial broiler grill to an internal temperature of 63 §C. Steaks were held overnight at 2 §C. Two steaks from each rib were placed into each instrument/core treatment group. Steaks were then divided into three sections identified as: a) lateral, b) medial, and c) central. Three 1.27 centimeter cores from each section were taken from each steak for a total of nine cores per steak and sheared once through the center. The results indicated that there was a significant difference ( p> .05) between round and square cores for both Warner- Bratzler and Instron. In all mean groups tested, square cores had higher shear values than did round cores. There was no indication of differences between instruments, and no significant interactions between instruments and core types.

Effects of Feeding Calcium Salts of Conjugated Linoleic Acid (CLA) to Finishing Steers

Thirty crossbred steers were randomly assigned to three treatment groups and fed corn-based finishing diets (88% concentrate) containing 0, 1.0 or 2.5% conjugated linoleic acid (CLA) for an average of 130 days. Steers fed 2.5% CLA consumed less feed and had lower daily gains than control steers. Carcass weights tended to be reduced, and marbling scores were decreased by feeding 2.5% CLA. There were no significant effects of feeding CLA on dressing percentages, yield grades and backfat measurements. The rounds from each animal were physically separated into tissue components. Rounds from steers fed CLA contained a higher percentage of lean tissue and a lower percentage of fat. Feeding CLA increased concentrations of CLA in lipids from fat and lean in rib steaks and rounds. Increasing CLA in beef had no effects on shelf life, tenderness, juiciness, flavor or flavor intensity of rib steaks. Although results indicated that feeding calcium salts of CLA to beef steers decreased performance, concentrations of CLA in tissues could be increased offering the availability of a leaner, more healthful meat product.

Occurrence and Genetic Characteristics of Third-Generation Cephalosporin-Resistant Escherichia coli in Swiss Retail Meat

Prevalence and genetic relatedness were determined for third-generation cephalosporin-resistant Escherichia coli (3GC-R-Ec) detected in Swiss beef, veal, pork, and poultry retail meat. Samples from meat-packing plants (MPPs) processing 70% of the slaughtered animals in Switzerland were purchased at different intervals between April and June 2013 and analyzed. Sixty-nine 3GC-R-Ec isolates were obtained and characterized by microarray, PCR/DNA sequencing, Multi Locus Sequence Typing (MLST), and plasmid replicon typing. Plasmids of selected strains were transformed by electroporation into E. coli TOP10 cells and analyzed by plasmid MLST. The prevalence of 3GC-R-Ec was 73.3% in chicken and 2% in beef meat. No 3GC-R-Ec were found in pork and veal. Overall, the blaCTX-M-1 (79.4%), blaCMY-2 (17.6%), blaCMY-4 (1.5%), and blaSHV-12 (1.5%) β-lactamase genes were detected, as well as other genes conferring resistance to chloramphenicol (cmlA1-like), sulfonamides (sul), tetracycline (tet), and trimethoprim (dfrA). The 3GC-R-Ec from chicken meat often harbored virulence genes associated with avian pathogens. Plasmid incompatibility (Inc) groups IncI1, IncFIB, IncFII, and IncB/O were the most frequent. A high rate of clonality (e.g., ST1304, ST38, and ST93) among isolates from the same MPPs suggests that strains persist at the plant and spread to meat at the carcass-processing stage. Additionally, the presence of the blaCTX-M-1 gene on an IncI1 plasmid sequence type 3 (IncI1/pST3) in genetically diverse strains indicates interstrain spread of an epidemic plasmid. The blaCMY-2 and blaCMY-4 genes were located on IncB/O plasmids. This study represents the first comprehensive assessment of 3GC-R-Ec in meat in Switzerland. It demonstrates the need for monitoring contaminants and for the adaptation of the Hazard Analysis and Critical Control Point concept to avoid the spread of multidrug-resistant bacteria through the food chain.

Role of milk and meat products as vehicles for antibiotic-resistant bacteria

This subject is reviewed under the following headings: Microbial contamination of raw meat and raw milk; Antibiotic resistance of food-borne pathogens; Antibiotic resistance of commensal and potentially pathogenic bacteria as a new threat in food microbiology; Antibiotic-resistant staphylococci in fermented meat and [in] milk products; Antibiotic-resistant Enterococcus sp. in fermented meat and [in] milk products; Enterococci in farm animals and meat; Enterococci in fermented food; Molecular characterization of resistance of food-borne enterococci; and Further ecological and epidemiological considerations of resistant live bacteria in food. It is concluded that further research is needed, particularly into the possible transfer of the resistance of bacteria consumed in meat or milk products to the indigenous bacteria of the human consumer.

Aus der Geschichte der Juden in Hessen am Anfang des 19. Jahrhunderts : Gutachten des Staatsministers Du Bos Du Thil über "die Verbesserung des bürgerlichen Zustandes der Juden"

hrsg. u. erläutert von J. Lebermann

Bos indicus introgression into (peri-)alpine cattle breeds - evidence from the analysis of bovine whey protein variants.

The major bovine whey proteins, α-lactalbumin (α-LA) and β-lactoglobulin (β-LG), exhibit breed-specific genetic variation. The aim of this study was to identify possible new protein variants and determine the distribution of variants across a variety of 18 taurine and indicine cattle breeds applying a DNA-based sequencing approach. To this end, the open reading frames of the respective genes (LALBA and LGB) were sequenced in 476 animals. Within the LALBA gene, a previously unknown synonymous and a previously undesignated non-synonymous nucleotide exchange were identified. Furthermore, two known α-LA variants (A and B) and four known β-LG variants (A, B, C and W) were determined. The occurrence of typical indicine variants in some taurine cattle breeds, such as Suisse Eringer, German Hinterwälder and Hungarian Grey Steppe, further supports the hypothesis of ancient Bos indicus introgression into (peri-)alpine cattle breeds.

Antibiotic resistance and phylogenetic characterization of Acinetobacter baumannii strains isolated from commercial raw meat in Switzerland.

The spread of antibiotic-resistant bacteria through food has become a major public health concern because some important human pathogens may be transferred via the food chain. Acinetobacter baumannii is one of the most life-threatening gram-negative pathogens; multidrug-resistant (MDR) clones of A. baumannii are spreading worldwide, causing outbreaks in hospitals. However, the role of raw meat as a reservoir of A. baumannii remains unexplored. In this study, we describe for the first time the antibiotic susceptibility and fingerprint (repetitive extragenic palindromic PCR [rep-PCR] profile and sequence types [STs]) of A. baumannii strains found in raw meat retailed in Switzerland. Our results indicate that A. baumannii was present in 62 (25.0%) of 248 (CI 95%: 19.7 to 30.9%) meat samples analyzed between November 2012 and May 2013, with those derived from poultry being the most contaminated (48.0% [CI 95%: 37.8 to 58.3%]). Thirty-nine strains were further tested for antibiotic susceptibility and clonality. Strains were frequently not susceptible (intermediate and/or resistant) to third- and fourth-generation cephalosporins for human use (i.e., ceftriaxone [65%], cefotaxime [32%], ceftazidime [5%], and cefepime [2.5%]). Resistance to piperacillin-tazobactam, ciprofloxacin, colistin, and tetracycline was sporadically observed (2.5, 2.5, 5, and 5%, respectively), whereas resistance to carbapenems was not found. The strains were genetically very diverse from each other and belonged to 29 different STs, forming 12 singletons and 6 clonal complexes (CCs), of which 3 were new (CC277, CC360, and CC347). RepPCR analysis further distinguished some strains of the same ST. Moreover, some A. baumannii strains from meat belonged to the clonal complexes CC32 and CC79, similar to the MDR isolates responsible for human infections. In conclusion, our findings suggest that raw meat represents a reservoir of MDR A. baumannii and may serve as a vector for the spread of these pathogens into both community and hospital settings.

Exposure assessment of extended-spectrum beta-lactamases/AmpC beta-lactamases-producing Escherichia coli in meat in Denmark

INTRODUCTION Extended-spectrum beta-lactamases (ESBL) and AmpC beta-lactamases (AmpC) are of concern for veterinary and public health because of their ability to cause treatment failure due to antimicrobial resistance in Enterobacteriaceae. The main objective was to assess the relative contribution (RC) of different types of meat to the exposure of consumers to ESBL/AmpC and their potential importance for human infections in Denmark. MATERIAL AND METHODS The prevalence of each genotype of ESBL/AmpC-producing E. coli in imported and nationally produced broiler meat, pork and beef was weighted by the meat consumption patterns. Data originated from the Danish surveillance program for antibiotic use and antibiotic resistance (DANMAP) from 2009 to 2011. DANMAP also provided data about human ESBL/AmpC cases in 2011, which were used to assess a possible genotype overlap. Uncertainty about the occurrence of ESBL/AmpC-producing E. coli in meat was assessed by inspecting beta distributions given the available data of the genotypes in each type of meat. RESULTS AND DISCUSSION Broiler meat represented the largest part (83.8%) of the estimated ESBL/AmpC-contaminated pool of meat compared to pork (12.5%) and beef (3.7%). CMY-2 was the genotype with the highest RC to human exposure (58.3%). However, this genotype is rarely found in human infections in Denmark. CONCLUSION The overlap between ESBL/AmpC genotypes in meat and human E. coli infections was limited. This suggests that meat might constitute a less important source of ESBL/AmpC exposure to humans in Denmark than previously thought - maybe because the use of cephalosporins is restricted in cattle and banned in poultry and pigs. Nonetheless, more detailed surveillance data are required to determine the contribution of meat compared to other sources, such as travelling, pets, water resources, community and hospitals in the pursuit of a full source attribution model.

Zur Kenntnis von Aphelenchus ormerodis Ritzema Bos.

Von Dr. Kati Marcinowski

Fritillaria sieana : aus dem kilikischen Taurus

AR