Epidemiology of Haemophilus somnus infection in dairy cattle in Quebec.

Serological studies on Haemophilus somnus infection were carried out on 1795 cattle from 231 dairy herds in the province of Quebec. An epidemiological investigation was done in each of the dairy operations. Seroreactivity rate and mean log2 titer for all the sera were 55.4% and 4.1620 respectively. Cattle from eastern regions of Quebec demonstrated the lowest prevalence of H. somnus agglutinins. The percentage of seroreactor animals was 60.3 in herds of 100 cattle or more in comparison to 53.2 in herds of smaller size. About 75% of the animals from 16 herds in which one or more cattle showed nervous manifestations of undetermined origin over a one year period had antibodies to H. somnus. Herds in which respiratory diseases occurred had 59.6% seroreactor animals and herds in which weak calf syndrome was diagnosed over a one year period had 61.4% seroreactor animals. In 87 herds located within 20 km of feedlots, 61.8% of the sera had titers and the mean log2 titer was 4.4813.     

Efficiency of food utilization by pregnant and lactating sows. 2. The influence of isocaloric diets with different protein levels on pregnancy and lactation

The efficiency of utilization of feed energy as digestible, metabolizable and net energy is similar in pregnant and lactating sows irrespective of the stage of these physiological conditions. This efficiency with the value of about 71% resembles the one found in the growing and fattening pigs, which enables us to use, for this category of animals, the same system offered evaluation and of the energy requirements based on fat nutritive units. The maintenance energy requirement expressed in ME varies from 467 kJ/kg 0.75 in pregnant sows to 512 kJ/kg 0.75 in lactating sows, for the suckling piglets having intermediary value of 498 kJ/kg 0.75. The efficiency of utilization of diets protein for maintenance and for synthesis is also similar for these categories of pigs, varying from 71% in lactating sows to 75-76% in pregnant sows. In suckling piglets we had recorded an efficiency of DCP utilization which varies parabolically with size of the ingesta and therefore with that of weight gain. The DCP maintenance requirement expressed in g N dig./kg 0.75 varies within narrow limits between 0.345 g N in suckling piglets 0.380 g N in pregnant sows; In lactating sows we have detected an intermediary value of 0.355 g N. Based on these experimental data and also using recent experimental results obtained by Schiemann and Beyer (1984) regarding the energy and N content of the foetuses, of the organs of reproductions and of milk, we could calculate the energy and protein requirements. These requirements when compared with the values used in our country show us higher values of energy in pregnant and lactating sows and lower values of protein for the same categories, including the piglets, where we have also found lower values for the energy too.     

Haemophilus somnus: a comparison among three serological tests and a serological survey in beef and dairy cattle.

Serological tests for the detection of antibodies against Haemophilus somnus were carried out in herds of beef and dairy cattle using three different techniques: agglutination, complement fixation and counterimmunoelectrophoresis. The agglutination test appeared to detect more seroreactors than the complement fixation and counterimmunoelectrophoresis tests. Results of the three tests indicated that there were more positive reactors in beef cattle and dairy cattle from infected herds than in dairy cattle from clinically normal herds.     

Aortic valvular dysplasia in a dog

A case of aortic valve dysplasia in a 6 year old male cocker spaniel is described. The dog was presented to the veterinarian because of strong dyspnea and frequent coughing. Clinical examination, EKG, radiographs and angiocardiography all pointed towards a tentative diagnosis of aortic insufficiency. Four months after the first appointment the dog was presented again with congestive heart failure, neural symptoms and strong abdominal pain. Electrocardiography and concentrations of LDH and CK were typical of myocardial infarction. Autopsy revealed a narrowing of the aortic valves in combination with a subaortic stenosis and several infarctions localized in the left ventricle as well as a recent infarction in the left kidney.     

Therapy trials with enrofloxacin (Baytril) in a laying hen flock with Salmonella pullorum infections

The course of a disease due to Salmonella pullorum in laying chickens is described. The experimental application of enrofloxacin (Baytril) at a dosage of 100 mg/l drinking water for 10 days resulted in a stop of the mortality rate, increment of egg production and reduction of Salmonella excretion. A recurrence of the disease was observed in the fifth week following the end of treatment with high mortality and decreasing egg laying. The treatment lead to a short-dated success but a permanent elimination of the germ from the flock was not achieved.