27 research outputs found
Effect of feeding mixed microbial culture fortified with trace minerals on ruminal fermentation, nutrient digestibility, nitrogen and trace mineral balance in Sheep
Yeast cell wall supplementation alters aspects of the physiological and acute phase responses of crossbred heifers to an endotoxin challenge
Effects of different levels of lespedeza and supplementation with monensin, coconut oil, or soybean oil on ruminal methane emission by mature Boer goat wethers after different lengths of feeding
Evaluation of a method to predict negative feedstuff associative effects in meat goats consuming diets with different forage sources and levels of concentrate
Effect of mass medication with antibiotics at feedlot entry on the health and growth rate of cattle destined for the Australian domestic market
Comparison of antemortem antimicrobial treatment regimens to antimicrobial susceptibility patterns of postmortem lung isolates from feedlot cattle with bronchopneumonia
A retrospective study was performed to compare the treatment regimens in feedlot cattle that died with bovine respiratory disease (BRD) to the antimicrobial susceptibility patterns of the microorganisms isolated from lungs. Forty-three cattle submitted by the Willard Sparks Beef Research Center (WSBRC) to the Oklahoma Animal Disease Diagnostic Laboratory for postmortem examination during 2007 had bronchopneumonia (acute = 16, subacute = 5, or chronic = 22). Lungs from cattle were cultured aerobically (40 cattle) and for Mycoplasma spp. (34 cattle). Susceptibility panels were performed. At least 1 BRD pathogen (Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, Mycoplasma bovis, or Arcanobacterium pyogenes) was isolated from 39 cattle, and 77% (30/39) had multiple organisms recovered. Mycoplasmal infections were common (25/34) and a major component of mixed infections (24/25). The majority (60%) of the M. haemolytica, P. multocida, and H. somni isolates were resistant to tetracycline. Most of the H. somni isolates (67%) were susceptible to tilmicosin (Ti), enrofloxacin (En), ceftiofur (Ce), and florfenicol, despite extensive treatment with Ti, En, and Ce (75% of isolates were from cattle that received each antimicrobial once). Most of the M. haemolytica (65%) and P. multocida (79%) isolates were susceptible to En and Ce, despite antemortem treatment of cattle with these antimicrobials. Hence, the current study reports a discrepancy between the antemortem treatment of clinical BRD and the susceptibility patterns of the bacteria isolated from lungs postmortem. Based on these findings, factors other than antimicrobial resistance are playing a role in the death of feedlot cattle with BRD