Effect of starting body fat content and genotype of laying hens on the changes in their live weight, body fat content, egg production and egg composition during the first egg-laying period.

A total 120 laying hens (60 TETRA BLANCA white egg layers and 60 TETRA SL brown egg layers) were selected from 250 TETRA BLANCA and 250 TETRA SL pullets based on their predicted body fat content by means of computed tomography (CT) at 16 weeks of age. Three groups of pullets were chosen for the investigation with the highest (n = 20), lowest (n = 20) and average (n = 20) body fat content. Changes in the live weight, body fat content, egg production and egg composition of the chosen animals were recorded at 32, 52 and 72 weeks of age. Based on the results, it was established that differences in starting body fat content of the hens remained the same during the experimental period. The differences between the two extreme groups were statistically significant at each age. The starting body fat content of the hens affected the rate of egg production, i.e. hens with high starting body fat content produced 11-14 eggs fewer than the hens with a low or average body fat content but had no effect on the composition of the eggs. Genotype affected almost all of the examined traits: TETRA BLANCA hens had lower live weight and higher body fat content during the experimental period and produced fewer eggs with lower albumen and higher yolk, dry matter and crude fat content than the TETRA SL hens.

Comparison of changes in production and egg composition in relation to in vivo estimates of body weight and composition of brown and white egg layers during the first egg-laying period.

1. The aim of this study was to compare the changes in the production and in the body and egg composition of 45 TETRA SL brown egg layers and 45 TETRA BLANCA white egg layers during the first egg-laying period. 2. Changes in the body composition of the hens were followed in vivo by means of computed tomography (CT) four-weekly, between 20 and 72 weeks of age. The measurements covered the whole body of the hens using overlapping 10 mm slice thicknesses on a Siemens Somatom Emotion 6 multislice CT scanner. 3. The yolk, albumen and shell ratio of the eggs, produced on the days of the CT measurements by the hens, were determined and their composition was analysed chemically. 4. The body fat content of the hens increased continuously until 44 weeks of age and plateaued thereafter in both genotypes. However, the body fat content of the white egg layers was always higher than that of the brown egg layers. 5. The yolk ratio and the dry matter and crude fat content of the eggs of white egg layers were higher than the brown egg layers throughout the experiment. 6. Moderate correlations were observed in both genotypes between the body fat content of the hens and egg yolk ratio of their eggs.

Antiarrhythmic activity of oximethers.

More than sixty 2-substituted-cycloalkanone-oxim-/2-hydroxy-3-dialkylamino/- propylethers were investigated on aconitine induced ventricular arrhythmia model in rats. According to the structure-activity relationships cyclohexanes containing diisopropylamine in the basic group were the most effective derivatives. Based on the highest per os activity and lowest toxicity EGIS-3966 (ED50 values 1.21 mg/kg iv. and 27.3 mg/kg per os) was selected for further development.

Substituted cycloalkanol ethers of psychostimulant activity: studies on quantitative structure-activity relationships.

Quantitative relationships between chemical structures and locomotor activities of 20 substituted cycloalcanol basic ethers have been investigated using Hansch- and Free-Wilson methods. The Hansch-type regression analysis performed on 10 compounds having different cycloalkyl-rings revealed the highly significant role of the hydrophobic characteristics on the activity tested. The QSAR-study of 20 cycloalcanol-ethers according to Free and Wilson gave a significant equation with good statistical indices. On the basis of the results the compounds under study appear not to exert their activity through interaction with receptor raising strict sterical and electrical requirements.

Stereochemistry and enantiomeric purity of a novel anxiolytic agent, deramciclane fumarate.

The synthesis, stereostructure, and enantiomeric separation by chromatography of a new, chiral anxiolytic agent, deramciclane fumarate (2, (-)-[1R,2S,4R]-2-(2-dimethylaminoethoxy)-2-phenyl-1,7, 7-trimethylbicyclo[2.2.1]heptane fumarate, EGIS-3886), is described. The optical antipode and the racemate of compound 2 were also prepared. The structure was determined by single crystal X-ray diffraction analysis. The enantiomeric separation was accomplished by HPLC on Chiralcel OD (250 x 4.6 mm; 10 microm) and hexane-ethanol (99.5:0.5) as mobile phase at room temperature. The enantiomeric purity of the synthesized drug substance proved to be very high (>99. 9%). Some statements published earlier on the stereostructure of deramciclane fumarate are critically discussed.