Prevalence of enterotoxigenic Escherichia coli in calves in Scotland and northern England

Eighty-eight of 1529 (5.7 per cent) Escherichia coli isolates from diarrhoeic and clinically normal calves in Scotland and northern England were found to possess the K99 pilus antigen (K99+). There was complete correlation between possession of K99 antigen, heat stable enterotoxin production and ability to dilate intestinal loops. The diagnosis of calf enterotoxigenic E coli infections may therefore be based on the detection of K99 antigen alone. Enterotoxigenic E coli was isolated from 23 of 306 (7.5 per cent) diarrhoeic calves from eight of 70 (11.4 per cent) farms and was not isolated from clinically normal calves. Infected calves were between one and three days old. A survey by an enzyme-linked immunosorbent assay found 3.0 per cent and 3.9 per cent of sera from calves and cows respectively to contain antibodies to K99 antigen. The prevalence of other enteropathogenic organisms in calf faeces is also discussed.     

Inhibition of two acetylcholinesterases by the 4-nitrophenyl esters of methyl-, ethyl-, and isopropyl(phenyl)phosphinic acid

The inhibition of eel acetylcholinesterase and bovine erythrocyte acetylcholinesterase by the 4-nitrophenyl esters of methyl-, ethyl-, and isopropyl(phenyl)phosphinic acid (MPP, EPP, and IPP, respectively) was investigated at pH 6.90 in 0.067 M phosphate buffer (25.0°C) using stopped-flow instrumentation and automated data processing. Our evaluation of the dissociation constant, K_d, the unimolecular bonding rate constant, k₂, and the bimolecular reaction constant, k_i, are the first reported values for these constants for a homologous series of this class of organophosphorus compounds. The largest k₁ value (29,428 M^?1 sec^?1) was observed for the reaction of eel acetylcholinesterase with 4-nitrophenyl methyl(phenyl)phosphinate. The smallest k_i value (9.6 M^?1 sec^?1) was observed for the reaction of bovine erythrocyte acetylcholinesterase with 4-nitrophenyl isopropyl(phenyl)phosphinate.     

Incidence of clinical mastitis in Danish dairy cattle and screening for non-reporting in a passively collected national surveillance system

Dairy herds from three counties in Denmark (n=2144) were monitored for a 1-year period to measure the incidence rate (incidence-density) of clinical mastitis. Two different screening methods were evaluated to remove herds from the database for which the herdsman and veterinarian were suspected of under-reporting the mastitis cases which had occurred. One method was based upon agreement between clinical mastitis reports and measures of somatic cell counts of >1 million cells per ml. A second method was based upon agreement between cases reported through the regular disease-reporting system and cases reported on a management questionnaire. Depending upon the method of calculation and screening method used, rates of clinical mastitis varied between 36 and 48 cases per 100 cow-years at risk. The exclusion of herds because of documented non-reporting behavior (screening) resulted in a preponderance of herds with zero or very low incidence of mastitis being removed from the database. Following screening, the frequency distribution of herd mastitis incidence rates became decidedly more symmetrically and normally distributed.     

Two cases of planned relaparotomy for severe peritonitis secondary to gastrointestinal pathology

Planned relaparotomy is a technique in which two or more surgeries are planned before or during the initial surgery. Two dogs underwent planned relaparotomy for severe peritonitis secondary to gastric ulceration and linear foreign body. Both dogs had good outcomes, and unnecessary procedures that would likely have led to increased morbidity were avoided. This technique may be useful in avoiding unnecessary procedures as well as providing for better stabilization of the animal.     

A preliminary report on a mechanical crawfish harvesting unit

The commercial crawfish industry in Louisiana is rapidly expanding. Because current harvesting methods are labor intensive and expensive, an automated mechanical harvester was developed.

The automated harvester is based on high density trapping with frequent trap movements. A linear move irrigator, which is adapted to large areas, was used as a chassis. Movement of the harvester was controlled automatically. The machine lowered traps for a preset trapping time, lifted and emptied the traps and moved a programmed distance before resetting the traps.

In a comparison test, the machine equaled or exceeded the efficiency of standard trapping methods. Little mechanical difficulty was experienced with the harvester.