Thyroxine and progesterone levels in cows and heifers after administration of Oestrophan (Spofa) in the luteal phase of the cycle

Thyroxine and progesterone levels were studied in cows and heifers in the luteal stage of the cycle after the application of the synthetic analogue of prostaglandine of group F2 alpha: Oestrophan Spofa. The preparation was administered at a rate of 0.5 mg in 2 ml per animal. The thyroxine and progesterone levels were determined radioimmunologically. The administration of Oestrophan led to a reduction in the progesterone level from the initial value of 17.33 +/- 2.73 nmol/l of serum to 7.69 +/- 1.17 nmol/l of serum an hour after the application, followed by slow decrease below the value 1.59 +/- 0.22 nmol/l of serum at the 24th hour. The initial levels of thyroxine with the average values of 122.11 +/- 23.41 nmol/l of serum were comparatively high. An hour from application of the preparation, a significant decrease to the average levels of 88.14 +/- 16.26 nmol/l of serum (P less than 0.05) was recorded with a significant negative correlation. The correlation coefficient r = -83316, P less than 0.01. The thyroxine level decreases to the values of 24.20 +/- 9.26 nmol/l of serum and 24.12 +/- 6.68 nmol/l of serum, P less than 0.01, at the 52nd to 56th hour, i. e. at the time when the pre-ovulation peak of oestrogens can be expected. A statistically significant correlation--even despite the fact that a highly significant decline in thyroxine and progesterone had been observed--was recorded in none of the cases in the subsequent period of study, except the first hour. It can be assumed from the results that the thyroid hormones are among the links acting at more levels of the regulatory biological circuit responsible for the physiological course of ovulation and reproduction process.     

Amino acid production in the isolated and perfused rumen wall of sheep

The metabolism of amino acids and urea in an isolated perfused wall of sheep rumen was studied by the method of organ perfusion, using 3 kinds of perfusate. In experiments with semisynthetic perfusate containing urea (SPurea) the levels of lysine, valine, glutamic acid and alanine increased at a simultaneous decrease of levels of leucine, arginine, aspartic acid, threonine and methionine. In perfusions with the semisynthetic medium without urea (SP) the levels of lysine, valine, phenylalanine, isoleucine, glutamic acid, glycine and alanine increased, the level of threonine dropped. In perfusions with whole autologous blood (KP) the levels of valine, glutamic acid and alanine increased, the level of arginine decreased. The level of urea decreased sharply at using SPurea and KP, however, the equal cumulation of ammonia (200-400 mumol x 1(-1)) was found in all three types of perfusate after 2-hr perfusion. Moreover, in experiments with SP a low level of urea was found already after 5-min. of perfusion. The results of the experiments suggest that the rumen wall is capable of producing amino acids also without the contents of rumen, and that independently on the presence or absence of urea as a nitrogen source.     

The incidence of flukes of the genus Paramphistomum in Czechoslovakia

An effort was made to evaluate objectively all findings on the variability of fluke of the family Paramphistomatidae and to give a clear survey on the species occurring in this country in order to be able to control it successfully in the case of widespread occurrence of paramphistomatosis or its intermediate hosts. The individual fluke species have specific intermediate hosts and a correct determination can make preventive measurements easier. Three species of rumen fluke live parasitically in the CSSR: Paramphistomum cervi, P. ichikawai and P. daubneyi. Findings indicated as P. scotiae (and/or Liorchis scotiae) from Slovakia should be evaluated as P. cervi. Also P. leydeni is identical with the species P. cervi. All three species live parasitically on game. Domestic ruminants are parasitized by P. cervi and P. ichikawai. P. cervi is the most widespread species in this territory and also in the whole Central Europe. P. daubney is very rare in this territory; it was found only in moufflon.     

Improvement of the method for propagation,larval and postlarval rearing of the wels (Silurus glanis L.)

Using the old method of spawning it is impossible to produce wels larvae in quantities sufficient for a special fry farm economically. Because of this, a large-scale intensive method had to be developed, similar to those for other species which are propagated in hatcheries. A method for storing breeders was elaborated which included sewing their mouths shut and consequently eliminating injuries. Pituitary treatment — practised by others before — was applied, and disadvantages of the method (such as the development of furuncles) eliminated. A method for taking sperm from males with the help of a special syphon was developed.To avoid losses, larvae were reared in basins until they reached the size of 2–2.5 cm. Using this method considerable quantities of fry were produced in our hatchery.     

A rapid determination of cholesterol in egg yolks using the Bio-La-Test

A technique of direct one-stage determination of the total cholesterol content in egg yolk is proposed. Yolk samples are treated by dilution into a form suitable for a diagnostic application of the Bio-La-Test Cholesterol (manufacturer Lachema, n.e., Brno, CSSR), designed for the determination of cholesterol in blood serum. The procedure of applying the bio-assay was partly modified. Modification of the Bio-La-Test for egg yolk provides results with a methodical error of 1.5%. The time needed for sample preparation and the analysis itself does not exceed 40 minutes. It was found out by checking the proposed analytical procedure that in the egg yolk of the Hisex laying hybrid the content of cholesterol fluctuated from 1.14 to 1.41 weight percent during the laying period.     

The effect of stress on blood levels of vitamin A and E in piglets

In five trials with 99 suckling or weaned piglets, the effects of the increased adrenocortical function, caused by cold, weaning from the sow or fasting or by stimulation with exogenous adrenocorticotrophic hormone (ACTH) were studied as exerted on vitamin A and vitamin E concentrations in the blood serum. Three hours after an exposure of three-day and four-day piglets to the temperature of 8-12 degrees C, a small drop of the concentrations of both vitamins occurred. In four-week weanling piglets a decrease in vitamin E concentration was observed in two days, the trend being slight in vitamin A concentration. At the same time some sibs were left fasting, which considerably reduced the concentrations of both vitamins. The situation was similar in two hours after ACTH administration to suckling piglets, however the difference was insignificant in vitamin E concentrations. In seventeen hours elapsing from two administrations of the adrenocorticotrophic hormone (ACTH) when the increased secretion of corticosteroids was fading out, only the vitamin A concentration in suckling piglets was found to drop. The response in weanling piglets was negligible. The suppressive effects of stress on vitamin A concentrations were usually observed when the levels of circulating corticosteroids were high or in the period immediately following this status. The changes in nutrition after early weaning exert large negative effects on vitamin E concentrations in the blood serum. The differences in the response of the organism to the two vitamins may be due to various types of transport mechanisms in the blood circulation. The specific effects of stress factors are mentioned.