Dynamics of urea concentration in cockerels during the 1st month of life]

The concentration of urea in the blood serum of 190 cockerels (The Primant commercial hybrid) was determined by means of diacetylmonoxim (Homolka, 1971). Uremia reached values from 0 to 23.20 +/- 5.29 mg per 100 ml. A high individual variability of uremia was found.     

Synchronization of estrus in heifers using Chlorsuperlutin (CSL) vaginal tampons]

A pilot experiment with heifer heat synchronization with chlorsuperlutin-soked intravaginal tampons was conducted with 254 heifers in six herds in the North Moravian region. The rubber-foam tampons, cylindrical in shape (diameter 70 mm, height 70-90 mm), were introduced into the cranial part of the vagina, using an applicator and a vaginal speculum. Sixteen days after introduction, the tampons were removed by pulling the silon thread with which the tampons were cross-stitched. The heifers were inseminated on the second to fifth day after the removal of the tampons. The average performance in the application of the tampons was 38.5 tampons per hour, and in their removal 20.7 tampons per hour. The retention rate of the tampons was 97.6%; out of this, 79.8% of the tampons were pulled out by the silon thread. The signs of heat were good, 87.9% of the heifers could be inseminated intrauterinally. All the heifers with retained tampons were inseminated. The conception rate after the first insemination was 32.7%, after the second insemination 56.4%, and after two inseminations 68.1%. Out of the synchronized heifers, 8.1% were culled for slaughter. The drawbacks of this treatment include the low conception rate of the synchronized heifers, a high requirement for repeated insemination in the synchronized oestrus, and, consequently, a high sperm consumption.     

Migration of protoplasmic droplets and phagocytosis of damaged sperm during their passage through the efferent ducts in boars and bulls

Seventeen gonad pairs of boars and ten gonad pairs of bulls were examined to evaluate the migration of protoplasmic droplets and the phagocytosis of defective spermatozoa. The material for a microscopic investigation of secretions was collected from two sites in the testis and from seven sites in the epididymis. The greatest motion of protoplasmic droplets was recorded in the caput epididymidis, although the migration of droplets from the proximal section of the connective part of the flagellum towards the distal parts could also be observed as far as in the cauda epididymidis in both animals. A proximally located droplet still occurred in the cauda epididymidis in 4.5% of the spermatozoa of boars and in 1.9% of those of bulls. Absent mitochondrial spirals or swollen connective parts were observed in the imprints of testicular tissue in almost 50% of the spermatozoa whereas in the secretion of efferent ducts they were observed only in 0.3% of bull spermatozoa and about 3% of boar spermatozoa. No such defects were recorded in the epididymis head and tail in either of the two species. The marked reduction in the number of defective spermatozoa without mitochondrial spirals in the secretion of efferent ducts and after passage through the caput epididymidis testifies to the phagocytic ability of the epithelium of this part of efferent ducts.     

Use of the colonizing preparation Amylastin in the stimulation of rumen-type digestion in young ruminants

In experiments with calves during the milk-nutrition period we tested the use of the colonisation preparation Amylastim, containing a bacterial strain of Streptococcus bovis AO 24/85, as a factor speeding up the development of the rumen microflora. We gave the preparation to the animals for a period of four weeks and studied its influence on the microflora adherent to the epithelium of the rumen wall. We ascertained a significant increase in the number of Streptococcus bovis germs (P less than 0.001) as well as of alpha-amylase activity (P less than 0.05). When giving the preparation Amylastim to calves in large-scale production conditions we ascertained a positive effect on the health condition, total losses being lower.     

Morphologic and cytochemical study of Sertoli cell nuclei in ruminants]

Nuclei and nucleoli were examined at an ultrastructural level in the testicular tissue of bulls and rams. In the two species there occurs a morphologically interesting so called multivesicular nuclear body; the interpretation of its function is not quite clear. The tissue was processed by a routine electron microscope technique and than a cytochemical demonstration of several types of proteins was used. Acidic argyrophilic proteins were demonstrated by a silver-staining technique, basic lysine-rich proteins by means of ethanolic PTA, and ribonucleoproteins (RNP) by the method of Bernhard's regressive preferential staining. Multivesicular nuclear bodies in bull Sertoli's cells are composed of a greater number of membrane bound vesicles with granules on the outer surface (Fig. 1). The results of cytochemistry reactions show that the granules contain acidic argyrophilic proteins (Fig. 3) and RNP (Fig. 7). The intervesicular material is an analogy of the dense fibrillar component of normal nucleoli of somatic cells. This component contains the three types of investigated proteins (Figs. 2, 3, 5, 7). In the nuclear bodies of ram Sertoli's cells the number of vesicles is much lower, the fibrillar component is prevailing, in form of clusters and striae of filamentous material around the vesicles. The cytochemistry reactions proved that this material contains acidic argyrophilic proteins (Fig. 4) and basic PTA positive (Fig. 6) proteins. The presence of acidic and basic regulatory proteins in the fibrillar component of multivesicular nuclear bodies indicates the active synthesis of RNA occurring in this material. It is therefore possible to consider this special type of nuclear bodies as a full equivalent of nucleoli of somatic cells as to the function.     

Use of mass spectrometry in the chemical analysis of organophosporus compounds]

The authors studied the possibility of using mass spectrometry in the chemical analysis of the biologically highly active organophosphorus compounds. The results show that methylthiophosphorous acid O-ethyl-S-(2-dimethylaminoethyl) ester has the most complex mass spectrum of all the substances under study. In the spectrum characteristic fragments were detected, having m/e values of 42, 44, 58, 71 and 72 [corresponding to the presence of the (CH3)2NCH2CH2-group], and 81, 95, 97, 105 and 125 which are characteristic of the phosphoester group. Mass spectrometric analysis, performed in this study, proved that the MS method is suitable for a qualitative analysis of biologically highly active organophosphorus compounds such as methylthiophosphorous acid O-ethyl-S-(2-dimethylaminoethyl) ester.     

Ultrastructural study of the hypothalamic region after administration of aurothioglucose in mice]

Aurothioglucose dose of 1 mg g-1 1. w. was applied intraperitoneally to experimental female mice. After 24 hours the animals were decapitated and samples for ultrastructural examination were immediately taken from the region of the hypothalamic ventromedial nucleus. The following findings were obtained from the study of 243 electronograms of 8 experimental animals: 1. dense round particles 0.034 to 0.016 mu in size, representing the gold of aurothioglucose; 2. parenchymatous dystrophy of the mitochondria; 3. peeling off of the individual layers of myelin sheath and the granularity of these layers corresponding to the disintegration of nerve fibres.