Prenatal and postnatal development of Sertoli cells in rams

The morphological picture of Sertoli cells was studied in view of development. The testicular tissue of rams was studied from the 80th to the 140th day of intrauterine development and the testes of ram-lambs were studied from the 1st to the 40th day from birth; further, the testes were studied in adult rams. The development and differentiation of Sertoli cell precursors were examined, including their change into differentiated mature Sertoli cells. The electron-microscopic picture of these cells was described with special emphasis on those morphological changes in cells which are closely related with their functional activity during the development of the testes. The findings obtained so far in this field are incomplete and concern mainly laboratory animals and man. The results of the study extend the theoretical knowledge in the fields of histology, embryology, physiology, endocrinology and andrology. At the same time, they may serve as starting material for the study of the control of spermatogenesis under experimental conditions.     

Supplementation of swine feed rations with zeolite during cage rearing

The effect of the addition of zeolite to pig feed ration was studied in the cage rearing system under production conditions. Zeolite was mixed in the COS I and COS II feed mixtures directly in the feed plant, the mixing ratio being 100 kg feed mixture + 5 kg zeolite. The feed mixture was administered in granular form ad libitum. The test group had 648 weanlings and the control group 674 weanlings; the piglets, kept in two-story cages in four sections, were arranged so that the test group could be a mirror-like reflection of the control group. The trial lasted 45 days. The piglets given the fortified feed ration had daily weight gains higher by 0.017 kg and feed consumption lower by 0.234 kg per 1 kg of gain, as compared with the control animals. The costs of the feed ration required for producing a kilogram of gain were 8.55 Cz. crowns in the zeolite group and 9.422 crowns in the control group.     

The effect of LH releasing hormone on testosterone levels in the blood of boars with sexual dysfunctions]

The levels were assessed of testosterone in the blood plasma before and 90 minutes after i.v. application of 1 mg of synthetic LH-releasing hormone to 57 boars with disorders of sexual functions and to 43 boars without sexual dysfunctions. The group of animals with sexual disorders included boars with inferior ejaculate quality and low fertility (24 animals) and cases with disturbed sexual potency (33 boars). In animals with the studied changes of sexual functions, compared with boars without sexual dysfunctions, no statistically significant difference was found in the basal concentration of testosterone in the blood. LH-releasing hormone application increased significantly the testosterone levels in the group of boars without sexual disorders by 99.5% on an average and in the whole group of animals with changes in sexual functions approximately by only 65.8%. At the same time in the subgroup of inferior ejaculate quality and low fertility the post-application increase of testicular incretion reached 60.4% and in potency disorders 61.6% and was statistically insignificant in the latter. On the basis of these findings it was derived that in boars with reproduction deviations there existed a decreased incretion reserve of the system hypophysis - testicle and the involvement of this factor in the formation of the studied sexual disorders is assumed. The obtained results are discussed in view of the earlier findings about the incretion reserve of the testicles in boars with changes in sexual functions.     

Internal parasites in calves and heifers in a central rearing barn

In the specialised rearing house for young cattle of all age groups the occurrence of endoparasites was followed. In the age group of 21 to 90 days, 56% of calves aged about 30 days eliminated oocysts of coccidia. On the whole, 49.3% of calves were infested by coccidia, 3% by enterohelminths. 90.3% of calves aged from three to six months were parasitised by coccidia, 7.4% by enterohelminths. Young cattle, aged from 6 to 12 months, were parasitised in 94.6% by coccidia and in 14.1% by enterohelminths. 86.6% of pregnant heifers at the age of 14 to 19 months had coccidia, 7.7% enterohelminths. The total farm capacity was about 950 animals. Throughout the year the number of examined animals amounted to 1,195, out of this number 958 animals, i. e. 80.2%, were infested by coccidia, 55.6% of animals by the species Eimeria bovis, 47.0% by E. zuernii, 43.3% by E. auburnensis, 39.4% by E. ellipsoidalis, 25.2% by E. cylindrica, 13.6% by E. subspherica, 3.1% by E. bukidnonensis, 1.7% by Isospora spp., 0.4% by E. brasiliensis, 0.08% by E. pellita. Enterohelminths were observed only in 96 animals, i. e. in 8.03%. Trichocephalus was found in 3.9% of animals, Cooperia in 2.4%, Ostertagia in 0.6%, Chabertia in 0.4%, Nematodirus in 0.3%, Capillaria in 0.2%, Oesophagostomum in 0.2%, Bunostomum in 0.1% and Trichostrongylus in 0.1%. The highest elimination of oocysts of coccidia was observed in August, January and February, of eggs of enterohelminths from August to October. In all age groups the most frequent was the occurrence of pathogenic species of coccidia.     

The passage of nitrogenous compounds through the wall of perfused sheep rumen (author's transl)]

Experiments were performed by the method of the extracorporeal perfusion of sheep rumen lasting 150 minutes. After 60 minutes of perfusion, 20 g of enzymatic casein hydrolyzate were applied to the rumen. Ammonia, urea, and total nitrogen were determined in the samples of perfusate, and ammonia and pH were determined in the rumen content. Considerable amounts of ammonia accumulated in the perfusate in the course of the experiment. At the end of perfusion, the concentration of NH3-N reached an average value of up to 12 mg per 100 ml. The level of urea in the perfusate decreased only in the first phase of perfusion (before the application of casein hydrolyzate to the rumen) and remained unchanged in the subsequent phase. It is assumed that part of urea-N from the perfusate after urea hydrolysis, taking place already in the rumen wall, returned to the perfusate in the form of ammonia. In the first phase of perfusion the passage of nitrogen from the blood into the rumen took place, in the second phase its absorption from the rumen into the blood was observed. The urea-N ratio from the passage of total nitrogen into the rumen ranged between 4.63% and 13.84%, but the concentration of total nitrogen in the perfusate decreased by 7-15% and that of urea nitrogen by 37-42%. It follows from the results that a major part of endogenous nitrogen passing from perfusate to the rumen was represented by proteins and/or their peptidic splits.     

Isolation of Chlamydia psittaci and Moraxella bovis from infectious keratoconjunctivitis in lambs

Out of 189 lambs in the flock, 25 animals suffered from bilateral or unilateral conjunctivitis, or keratoconjunctivitis. By serological examination (RVK), positive levels of antibodies to the group-specific antigen of Chl. psittaci were found in three out of six lambs examined by laboratory methods. Bacteriological examination of eye smears of six lambs showed in four cases the infection by microorganisms of Moraxella bovis. Smears from the conjunctivas of these lambs were after preparation instilled in the yolk sacs of six to seven days old chicken embryos. One strain of Chlamydia psittaci was isolated from the same material as Moraxella bovis.     

Determination of zearalenone in grains using high pressure liquid chromatography

The determination of zearalenone content in cereals (maize, wheat and barley) was performed by means of liquid chromatography using the Czechoslovak-made apparatus. This method enables to determine this mycotoxin up to the concentration of 8 micrograms per 1 kg of grain with the accuracy exceeding +/- 9%.     

Ascorbic acid levels in the bronchopneumonia of calves]

The level of ascorbic acid in the blood plasma of 59 calves was determined. The age of the calves ranged between two and three months and the samples of blood were collected in January. The first group of calves included 30 animals displaying no clinical symptoms of disease: the average ascorbic acid level was 0.50 +/- 0.18 mg per 100 ml. In the second group, consisting of 19 calves, the blood of the animals was collected three weeks after the termination of the acute stage of bronchopneumonia; the average value of ascorbic acid was 0.30 +/- 0.14 mg per 100 ml. The lowest average value of ascorbic acid was obtained in the calves at an acute stage of bronchopneumonia, reaching 0.18 +/- 0.11 mg per 100 ml. The differences of results between groups I and II and between groups I and III were found to be statistically significant. A conspicuous drop of ascorbic acid level was ascertained in calves suffering from bronchopneumonia-this problem needs deeper scrutiny, owing to the fact that bronchopneumonia is responsible for considerable economic losses in large-capacity calf houses.     

Changes in biochemical indicators in the blood and organs of pigs fed dried grape press cake]

In two experiments the effect of feeding dried crushed white and red grape press cake replacing 10--20% of the complex feed mixture A1 and SOL, was studied on the 21 biochemical indicators of blood serum, plasma, suprarenal glands, liver and tissue of fattened pigs. Changes indicating unsuitability of this non-traditional feed were not observed. During feeding red grape press cake, the young pigs of 35kg body weight had a lower concentration of glucose in blood serum, in comparison with the control. The temporary increase of calcium level and decrease of inorganic phosphorus in these animals was accompanied by a lower activity of alkaline phosphatase. White and red grape press cake affected positively the vitamin E level in blood serum. In the muscles of the experimental slaughter pigs protein proportion was increased and fat proportion was decreased.