Escherichia coli endotoxin as a stressor in the domestic fowl.

During 24 h after the injection of fowls (aged eight to 11 weeks) with Escherichia coli endotoxin (1 to 3 mg/kg) isolated from a pathogenic strain (O78) there were changes in the ascorbate content of the adrenal gland and increases in the plasma free fatty acid levels, indicating that the toxin behaves as a mild stressor.     

Factors associated with mortality in feedlot cattle: the Bruce County Beef Cattle Project.

The design of and the analysis of data from the Bruch County Beef Cattle Project, particularity the field study, are presented and discussed. A major value of the study may lie in its ability to relate laboratory findings to events in the field. The factor most strongly related to mortality was ration, with cattle on hay based rations having a much lower mortality on average than cattle on corn based rations. In general, management activities associated with growing cattle (as opposed to fattening) over the first winter were sparing for mortality. Groups of cattle given prophylactic vaccines or drugs within two days of arrival tended to experience higher mortality (not statistically higher) than those cattle not receiving those measures, or cattle groups recieving the same prophylactics more than 48 hours after arrival. However, these results require validation in the remaining years of the study. Fibrinous pneumonia was the most frequent diagnosis in the calves on postmortem examination.     

Evalution of an Epidural Intracranial Pressure Monitoring System in Cats

The accuracy of an inexpensive, easily implantable, epidural intracranial pressure (ICP) monitoring system was assessed in six normal cats by comparing measurements from this system to those obtained with a fiberoptic intraparenchymal monitoring system. The epidural monitoring system consisted of a three-way stopcock and saline-filled extension tubing, connected to a standard blood pressure transducer. Each cat was placed under halothane anesthesia and mechanically ventilated. Both an epidural and a fiberoptic intraparenchymal monitoring device were placed in the left cranium of each cat; correct placement was verified by computed tomography. Mean ICP values were simultaneously recorded from both monitoring devices. After obtaining baseline ICP measurements, the ICP was manipulated via ventilation, jugular compression, and pharmacologic agents. Arterial blood pressure levels, arterial blood gas values, end-tidal carbon dioxide levels, and end-tidal halothane levels were recorded throughout the study. Cerebral perfusion pressure was calculated for each level of ICP. Repeated measures analysis of variance method was used to compare mean ICP values between the two monitoring systems. No significant differences in ICP values obtained from the two systems were found (p>0.05) at any level of ICP. The results of this study show that the epidural monitoring system is a reliable alternative to the fiberoptic intraparenchymal ICP monitoring system in normal cats. The accuracy of the epidural monitoring system in pathologic states needs to be investigated.     

Sucrose avoidance by American robins (Turdus migratorius): Implications for control of bird damage in fruit crops

Altering the relative sugar content in fruit is a potential alternative to chemical, aural and visual repellents to control bird damage to cultivated fruit crops. Some frugivorous birds, such as the American robin (Turdus migratorius), lack the digestive enzyme sucrase, and therefore cannot digest sucrose. It was predicted that robins would avoid consumption of foods that contain sucrose. When offered sweetened agar cubes that contained glucose, fructose, sucrose, or a hexose mixture, total consumption was significantly lower and faecal sugar concentration higher in the sucrose tests. In tests involving two sugars, mean total consumption was reduced when sucrose was eaten. Development of high-sucrose fruits warrants further investigation as a means to mitigate bird damage to certain fruit crops.