Biochemical Engineering Symposium Proceedings (June 4, 1971)

This report presents the proceedings of the Biochemical Engineering Symposium held at Kansas State University, June 4, 1971. Since most of the papers will be published elsewhere, only very brief papers are included here. Moreover, several of the projects are still in progress at this time. Request for additional information on projects conducted at the University of Nebraska should be directed to Dr. Peter J. Reilly and for Kansas State University to Dr. L. E. Erickson. ContentsChao, Chih-Cheng, University of Nebraska, "Symbiotic Growth of Actobacter suboxydans and Saccharomyces carlsbergensis in a Chemostat" S.Y. Chiu, Kansas State University, "Model Identification in Mixed Populations Using Continuous Culture Data" Shinji Goto, University of Nebraska, "Symbiotic Growth of Bacteria and Blue Green Algae in a Chemostat" I.C. Kao, Kansas State University, "ATP as a Parameter of Mixed Culture Interaction" Indravadan R. Kothari, University of Nebraska, "Growth of Single Cells of Schizocaccharomyces pombe under Nutrient Limitation" G.C.Y. Chu, Kansas State University, "Experimental Optimization of Biological Waste Treatment Processes" Mark Young, University of Nebraska, "Aerobic Fermentation of Paunch Liquor" P.S. Shah, Kansas State University, "Optimal Control of Growth Processes"

The Costs and Predictive Factors of Bovine Respiratory Disease in Standardized Steer Tests

A retrospective study of 2,146 feedlot cattle in 17 feedlot tests from 1988 to 1997 was conducted to determine the impact of bovine respiratory disease (BRD) on veterinary treatment costs, average daily gain, carcass traits, mortality, and net profit. Morbidity caused by BRD was 20.6%. The average cost to treat each case of BRD was $12.39. Mortality rate of calves diagnosed and treated for BRD was 5.9% vs. .35% for those not diagnosed with BRD. Average daily gain differed between treated and non-treated steers during the first 28 days on feed but did not differ from 28 days to harvest. Net profit was $57.48 lower for treated steers. Eighty-two percent of this difference was due to a combination of mortality and treatment costs. Eighteen percent of the net profit difference was due to improved performance and carcass value of the non-treated steers. Data from 496 steers and heifers in nine feedlot tests were used to determine the effects of age, weaning, and use of modified live virus or killed vaccines prior to the test to predict BRD. Younger calves, non-weaned calves, and calves vaccinated with killed vaccines prior to the test had higher BRD morbidity than those that were older, weaned, or vaccinated with modified live virus vaccines, respectively. Treatment regimes that precluded relapse resulting in re-treatment prevented reduced performance and loss of carcass value. Using modified live virus vaccines and weaning calves 30 days prior to shipment reduced the incidence of BRD.