Campylobacter jejuni and its incidence in meat packaged under warm conditions

The problem of survival of Campylobacter jejuni was studied in artificially contaminated butchered meat packed in warm condition. Apart from the presence of Campylobacter jejuni, the total number of microorganisms and the shelf life of the meat were studied. With plain packing, Campylobacter jejuni survived six to seven days and the shelf life of the meat was about a week. In vacuum-packed meat Campylobacter jejuni was isolated for ten to eleven days and sensory changes occurred after ten to fourteen days. In meat packed in protective atmosphere Campylobacter jejuni was able to survive for ten to thirteen days and the meat kept its sensory properties for a fortnight or longer. There were no differences in the survival of Campylobacter jejuni in pork and beef, nor were there any substantial differences in the microorganism survival in PSE, DFD meat and in intact meat.     

Spectrophotometric method for differentiation of cardiac and hepatic lactate dehydrogenase activities in dogs

To differentiate the origin of high total lactate dehydrogenase (LD) activity in canine sera, a spectrophotometric method based on the preferential inhibition of cardiac LD isoenzymes by pyruvate was performed. Comparison with the electrophoretic separation of LD isoenzyme activities and determination of the hydroxybutyrate dehydrogenase-to-LD ratio indicated that the method proposed gave a better discrimination between cardiac and hepatic LD activities than did the other tests.     

The use of dried grape press cake in pig fattening]

In dried grape press cake the content of crude nutrients and ash, overall sugar, amino acids, alpha-tocopherol and gross energy was determined. In biological experiments with pigs (total of 109 animals) 10% of mixture A1 or SOL was replaced by the same amount of dried crushed grape press cake, without affecting negatively the weight gains and consumption of mixtures per unit of weight gain. Nutritional effects of grape press cake are a subject of discussion and comprise three factors: higher content of enrgy (fat and sugars) in mixtures containing press cake, anti-oxidation effect of press cake and the effect of tocopherols on the metabolism of basic nutrients.     

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.