Bacterial culture and susceptibility of samples taken from septic foot lesions of adult beef cattle.

BACKGROUND: Lameness is an economically important and common disease of cattle, and foot disease is the most common cause of lameness in cattle. Limited data is available regarding lameness in cow-calf operations. OBJECTIVES: Describe the bacteria most commonly isolated from septic lesions of the feet of adult beef cattle and the antimicrobial susceptibility patterns of the isolated bacteria. ANIMALS: Fifty-four adult cattle from cow-calf operations and diagnosed with a sole abscess or distal interphalangeal joint sepsis were enrolled. METHODS: Prospective observational study. Abscess fluid from a convenience sample of clinical cases was cultured. Isolated bacteria were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry or 16s rRNA gene sequencing. Antimicrobial susceptibility profiling was performed on isolates when a bacterial species was identified from ≥5 samples. RESULTS: Fifty of the 54 samples were polymicrobial. Trueperella pyogenes (22/54), Streptococcus uberis (16/54), and Bacteroides pyogenes (14/54) were the most commonly isolated bacteria. Eighty-one of 96 tested isolates were resistant to at least 1 antimicrobial; multidrug resistance was identified in 37/96 isolates. Oxytetracycline (50/96), tylosin (40/96), and florfenicol (37/96) resistance was commonly identified. Resistance to ceftiofur (5/96) was rare. CONCLUSIONS AND CLINICAL IMPORTANCE: Septic processes of the foot in these adult beef cattle frequently were polymicrobial. Most of the isolated bacteria were resistant to at least 1 antimicrobial with over one-third being multidrug resistant. Although simple sole abscesses do not require antimicrobial treatment, deep septic processes of the foot often are treated with antimicrobials. Culture and susceptibility of deep septic lesions may guide judicious antimicrobial usage.

Effects of spring- versus fall-calving on perinatal nutrient availability and neonatal vigor in beef cattle.

To determine the effect of calving season on perinatal nutrient availability and neonatal beef calf vigor, data were collected from 4 spring- (average calving date: February 14; n = 203 total) and 4 fall- (average calving date: September 20; n = 179 total) calving experiments. Time to stand was determined as minutes from birth to standing for 5 s. After birth, calf weight and size (length, heart and abdominal girth, and cannon circumference) were recorded. Jugular blood samples and rectal temperatures were obtained at 0, 6, 12, and 24 h postnatally in 6 experiments and at 48 h postnatally in Exp. 2 to 8. Data were analyzed with fixed effects of season (single point) or season, hour, and their interaction (over time, using repeated measures). Experiment was a random effect; calf sex was included when P ≤ 0.25. Within calving season, correlations were determined between calf size, vigor, and 48-h serum total protein. Fall-born calves tended to have lighter (P = 0.09) birth weight and faster (P = 0.05) time to stand than spring-born calves. Season did not affect (P ≥ 0.18) gestation length, other calf size measures, or 48-h serum total protein. Fall-born calves had greater (P ≤ 0.003) rectal temperature at 0, 24, and 48 h postnatal. Spring-born calves had greater (P ≤ 0.009) circulating glucose at 0 h, serum non-esterified fatty acids at 0 and 6 h, and plasma triglycerides at 0, 6, 12, and 48 h. Fall-born calves had greater (P ≤ 0.03) sodium from 6 to 48 h and magnesium from 0 to 24 h of age. Phosphorus was greater (P ≤ 0.02) at 6 and 12 h of age in spring-born calves. Spring-born calves had greater (P ≤ 0.04) aspartate aminotransferase at 12 and 24 h and creatine kinase at 0 and 12 h of age. Fall-born calves had greater (P ≤ 0.03) albumin, calcium, and chloride, had lower (P ≤ 0.03) bicarbonate and direct bilirubin, and tended to have greater (P = 0.10) anion gap (all main effects of calving season). Calf birth weight had a weak positive relationship (P ≤ 0.03) with 48-h serum total protein and time to stand in fall-born, but not spring-born, calves. Overall, fetal growth was restricted and neonatal dehydration was increased by warm conditions for fall-born calves, but vigor and metabolism were negatively affected by cold conditions in spring-born calves. These data suggest that calving season influences perinatal nutrient availability, which may impact the transition of beef calves to postnatal life.

Fundamentals of Systems Thinking.

A system is a set of interconnected elements that are organized in such a way to achieve a purpose. Structure and feedback are fundamental properties of all systems and determine system behavior-whether successful or failed. Systems thinking is a methodology used to create structural explanations for why things are happening so we are in a better position to identify long-term strategies that will fundamentally improve system performance. This article addresses the origins of systems thinking and briefly describes a methodology that has been used primarily in business management but has application in veterinary medicine as well.

Setting the stage for long-term reproductive health.

This article discusses some of the aspects of heifer development that contribute to long-term health and productivity, such as disease prevention and control. Nutrition is also an important component of long-term health, and body condition score is discussed as a way to determine whether the nutrient demands of heifers are being met.

Incorporating reproductive management of beef heifers into a veterinary practice.

Veterinarians play an important role in reproductive management of dairy herds across the United States; however, in many cases, their involvement in reproductive management of beef herds has been limited. The reasons for this vary; however, there are ways for veterinarians to become more actively involved in reproductive management of US beef herds. Veterinarians can have an impact on producers' profits by implementing their skills and knowledge to beef heifer development programs. This article provides an overview of the services veterinarians can provide to beef cattle producers that pertain to reproductive management of replacement beef heifers.