Growth in broiler chickens after the regulation of sex differentiation using tamoxifen

We studied the influence of an embryonal application of antiestrogen tamoxifen on gonad differentiation and sex dimorphism during the growth of Slovgal chickens. A single application of 500 micrograms tamoxifen to the incubated eggs before the onset of gonad differentiation induced in pullets the growth of the right gonad, which usually develops only in cockerels. Comparing the size of both gonads it is clear that the above dose of antiestrogen had the 22.31% masculinizing effect. Morphological changes observed just after hatching correlated with the testosterone concentration in plasma. The pullets masculinized by tamoxifen had a significantly higher level of male hormone. The changes in sex differentiation were reflected in the altered growth of pullet bodies. With respect to the higher growth rate and more effective feed conversion, their growth can be appreciated as masculinized. The higher body weight at the end of seven-week fattening (4.25% in comparison with the control group of pullets) was due to the higher trunk weight. The growth was stimulated by tamoxifen application also in cockerels (5.57% increase in body weight) but it was not accompanied by any changes in feed conversion.     

Coxiella burnetii and Chlamydia psittaci infection in dogs]

The prevalence of Coxiella burnetii and Chlamydia psittaci antibodies was investigated in 530 dog specimens divided into six groups, i. e. A = private watch dogs, B1 = service dogs from Bratislava, B2 = service dogs from other localities of Slovakia and Moravia, C = watch dogs from farms, I = household dogs, T = stray dogs. The dogs demonstrated the higher seropositivity to C. burnetii (11.7%) than to Ch. psittaci (5.5%). The highest percentage of antibodies to C. burnetii was found in stray dogs (23.7%), less prevalence of antibodies was observed in the animals in group C (13.6%), almost the same positivity was proved in the dogs of group B1 and B2 (10.5 and 10.6%). The highest positivity to Ch. psittaci was demonstrated in the dogs of group A (8.7%), less in group B2 (6.6%) and the least number in group B1 (1.9%). The stray dogs occupied the intermediate position in this data (Tab. I). Ninety four localities were tested, from which 38 were seropositive. Neither acute coxiellosis nor chlamydiosis were proved in any animals examined. Ninety per cent of dogs were found healthy, but 10% of dogs demonstrated hepatopathia and gastroenteritis. Two of them (category A and I) were seropositive to C. burnetii (titer 1:8 to 1:16) and one to Ch. psittaci (titer 1:16). Both C. burnetii and Ch. psittaci attack dogs parallely with the agents of other zoonoses, of which the most common is Toxoplasma gondii (Tab. II). Several dogs demonstrated seropositivity to three up to five zoonotic agents (Tab. III).     

Radioimmunologic determination of the mycotoxin ochratoxin A--a new diagnostic method in Czechoslovakia

A new radioimmunological method was developed for the determination of the mycotoxin ochratoxin A. The specific antibodies used in this method had been prepared by the immunization of rabbits by means of administration of ochratoxin A conjugate with bovine serum albumin. Their effective affinity constant was Ka = 5.1 X 10(-9) l. Mol-1. The substance used as radioligand was 125I-ochratoxin with a high specific radioactivity (Czechoslovak patent PV 6136, 1986). The average sensitivity of determination (ED 85%) was 10 to 15 picograms per 0.1 ml of sample. The range of the calibration curve was mostly from 5 to 360 picograms.     

Rapid detection of Aujeszky's disease (pseudorabies) virus infection of pigs by direct filter hybridisation of nasal and tonsillar specimens

A direct filter hybridisation method has been developed to diagnose acute Aujeszky's disease in live pigs. The advantages of the method are easy, fast sample processing; no DNA-purification is needed, and the hybridisation itself is simplified. The direct filter hybridisation method has been tested on pseudorabies virus infected cultured cells, experimentally infected pigs and on specimens from an outbreak of Aujeszky's disease. Virus isolation and filter hybridisation gave comparable results, indicating that the direct filter hybridisation method is a good tool for rapid diagnosis. It is independent of cell culture facilities and the disease can be diagnosed in live animals within 15 hours.     

Phage typing coagulase-positive staphylococci from rooks and gulls

Phage typing was performed on 86 strains of Staphylococcus aureus and 25 strains of Staphylococcus intermedius from rooks and gulls with human, bovine, chicken and canine phages. Eighty per cent of the S aureus strains and 64 per cent of the S intermedius strains were typable. The S aureus biotype D strains of rook origin were specifically lysed at routine test dilution (RTD) by chicken phages from groups I or I + IV, by human phages belonging to groups I and M, and partly by canine phage 58. The other rook and gull S aureus strains did not show characteristic phage patterns. The S intermedius strains isolated from both species of birds could be typed only with canine phages and this correlated with their classification into biotypes. All the biotype 1 strains tested but only two of 12 biotype 2 strains were lysed with canine phages at RTD.     

Hemoconcentration in calves and its relation to the hematologic, protein, mineral and electrolyte profile

The dynamics of hematological, protein, mineral and electrolytic profile was examined clinically in nine calves when the hemoconcentration was induced experimentally. The hemoconcentration occurred after diarrhea caused by the per os application of 12 g saccharose per one kg of live weight. The hemoconcentration culminated six hours after application. The calves where the hemoconcentration did not exceed the critical value were included in the first group, and the calves with the extreme hemoconcentration values in the other group. In the first group (with the increasing hemoconcentration degree), a statistically significant increase was found in the values of hematocrit, erythrocytes, hemoglobin, total protein in blood serum and total immunoglobins and a statistically insignificant increase in the levels of leucocytes, inorganic phosphorus, serum calcium and sodium. Serum potassium and magnesium showed the inverse dynamics, i. e. the decrease. In the second group (with the extreme hemoconcentration), hyperkalemia and slight hypermagnesemia were identified, while the other parameters showed deviations similar to those observed in the first group. After the rehydration of animals by a preparation without any influence on the studied parameters, the hemoconcentration and the parameters under study stabilized, while in the second group the hemoconcentration was increasing even during the rehydration and the levels of serum potassium and magnesium showed different tendencies. As follows from the results, in the calves suffering from scours accompanied by hemoconcentration the correction of the parameters of metabolic profile is necessary.