The effect of animal fat and vegetable oil supplementation of feeds of different energy concentration upon the digestibility of nutrients and some blood parameters in rabbits

The effect of mixed animal fat and sunflower oil supplementation (5%) of a feed of medium (12.02 MJ DE/kg) and low (8.54 MJ DE/kg) energy concentration upon the digestibility of nutrients and on some blood parameters was investigated. The ether-extractable content of feed and faecal samples was determined by diethyl ether extraction (after Soxhlet) and the total (true) fat level was measured by the method of Stoldt (1952), viz. petroleum ether extraction of samples pretreated with 4 N HCl. In the majority of cases the voluntary feed intake decreased after the addition of animal fat or vegetable oil. Mixed animal fat supplementation significantly (by 5 and 11 units) improved the digestibility of the ether extract if added to either of the basal diets. The digestibility of crude fibre and N-free extract increased only in the case of the basal diet of low energy concentration (by 4 and 7 units, respectively). Sunflower oil addition produced changes of the same tendency (9, 9, 28 and 5 units). The digestibility of the crude protein was practically not altered by either supplementation. The total fat content of feed and faecal samples proved to be higher than that of the ether extract, on an average by 27 and 100%, respectively. Consequently, the digestibility coefficients of the total fat are by 10 units lower than those of the ether extract. The DE concentrations, calculated by means of the digestible ether extract or the total fat content, differed significantly only between the basal diets. The addition of mixed animal fat to either of the basal diets increased the blood concentration of total lipids (by 18 and 32%, respectively), while that of sunflower oil did not cause such an alteration. Neither fat nor oil supplementation had an effect on the cholesterol level of the blood plasma. Both the animal fat and the vegetable oil surplus modified the fatty acid composition of blood lipids. It was characteristic of each treatment that the proportion of polyunsaturated fatty acids increased.     

Experimental control of the process of lead absorption and deposition in domestic ducks

A trial was conducted with 40 domestic ducks of the White Pekin breed at the age of 40 days: thirty pieces of lead shot were introduced as a single dose in the gizzard. The process of lead resorption and deposition was found not to be significantly influenced by the therapeutic treatments nor changes in the composition of feed. A week after the administration of shot a significant increase was recorded in the content of lead to 4.32 mg in liver, to 11.36 mg in kidney and to 1.15 mg in muscle (the respective values for the control animals were 0.07, 0.11 and 0.06 mg per kg). At the end of the trial after three weeks of treatment and administration of experimental diets, no significant differences were recorded in lead content in liver, kidney and muscle between the untreated and treated ducks nor ducks fed experimental diets.     

Allele distributions of two novel SNPs within the sheep Cyp19 gene

Oestrogen is an important regulator of reproduction and growth. The key enzyme of oestrogen biosynthesis, aromatase cytochrome P450, is encoded by the Cyp19 gene. In order to generate genetic markers for the sheep Cyp19 gene, two novel single nucleotide polymorphisms (SNPs), one located in promoter 2 (P2), the other one in intron 9 (I9), were identified by a comparative sequencing approach. The allele distributions of both SNPs were investigated by means of Polymerase chain reaction‐restriction fragment length polymorphism analysis (PCR‐RFLP) in five economically relevant sheep breeds (British Milk Sheep, Carranzana, Latxa Black Face, Latxa White Face, Merino) and three ancient Hungarian breeds kept as gene reserves (Cikta, Racka, Tsigai). In British Milk Sheep, only the intronic SNP was present whereas in Merino, Cikta, Racka, Tsigai, Carranzana, Latxa Black Face and Latxa White Face, both SNPs could be found. This indicates that the newly identified SNPs can be used as markers for the Cyp19 locus in various sheep breeds.     

A REVIEW OF NONCONVENTIONAL ULTRASOUND TECHNIQUES AND CONTRAST-ENHANCED ULTRASONOGRAPHY OF NONCARDIAC CANINE DISORDERS

Modern ultrasound contrast media are gas-containing stabilized microbubbles that remain intact in the circulating blood for several minutes after intravenous injection and increase the intensity of the backscattered ultrasound. When the microbubbles disappear from the blood, they can be detected in the parenchyma of the liver and the spleen for about 30 more minutes (late liver- and spleen-specific phase). The insonated microbubbles produce second harmonic ultrasound frequencies, whose detection requires nonconventional ultrasound modalities such as pulsed inversion imaging. Nonconventional ultrasound techniques can also be used without microbubbles because second harmonics can be generated by ultrasound in tissues as well. The physical principles and advantages of nonconventional ultrasound techniques are described. The circulating microbubbles can be used not only to enhance weak Doppler signals, but also to perform dynamic contrast studies. Contrast-enhanced dynamic ultrasound studies--similar to contrast-enhanced CT and MRI examinations--have been used in humans to characterize lesions noninvasively (i.e., without biopsies) found during conventional ultrasound examinations. To map the distribution of contrast medium in a nodule or in an organ, specific scanning techniques such as stimulated acoustic emission have been developed. Stimulated acoustic emission occurs when high acoustic pressure ultrasonic waves disrupt the stationary or slowly moving microbubbles. This results in the release of a large amount of harmonic ultrasound frequencies. When the stimulated acoustic emission technique is used for dynamic studies, scanning must be interrupted several times to allow the microvasculature of the lesion to refill with microbubbles (interval delay imaging). The contrast patterns of malignant and benign hepatic nodules in humans have been the most intensively studied. Another type of dynamic study in humans measures the transit time of the contrast medium; that is, how fast the peripherally injected microbubbles reach the hepatic veins. Hepatic cirrhosis can be differentiated from other diffuse parenchymal liver diseases by a shorter transit time. Introducing nonconventional ultrasound techniques and ultrasound contrast media in veterinary diagnostic imaging may have potential value; however, intensive research should be carried out before ultrasound contrast agents can routinely be used in clinical practice.     

The effect of ionizing radiation on structural changes in the energy nutrients in animal feed

For the purpose of testing the effect of ionizing radiation, feeds for dogs (meat feed mixture VETACAN and loose feed mixture VETAVIT) irradiated by 60Co radioisotope at the dose of 25 kGy/kg were studied for 60 days. It has been found out that the total volume of energetic and non-energetic nutrients is not changed. Qualitative structure, however, displays a significant, on the average 35% disintegration of essential amino acids, decrease of proteins and increase of free ammonic bases. A significant oxidation effect of radiation is exerted on the decomposition of fats with a release of free fatty acids from glycerol bond in a process similar to rancidification (from 13.3-37.10 mg/g in meat mixture, from 103.1-103.04-135.04 mg/g in loose mixture). A certain disintegration of nutrients, only within the limits of significance, occurred also in the saccharide proportion of the loose feed mixture (acidity of water extract 348.8-403.99-436.60 mg/100 g). It has been proved that radiosterilization reliably secures microbiological and mycological sanitation of feeds and causes no sensory changes noticeable by human senses. It follows from the results that ionizing radiation has a pronounced antimicrobial and antimycotic effectiveness. However, it causes significant structural changes of energetic nutrients in the feeds of animal as well as of vegetable origin.     

The effect of feeds treated with ionizing irradiation on biochemical indicators of the nutritional value of energy nutrients

The influence of feedstuffs treated with ionizing radiation on the nutrition of dogs was tested in four groups of animals. Two groups were administered for 90 days a ration, the main part of which (VETACAN meat feed mixture and VETAVIT loose feed mixture) was irradiated with radioisotope Co 60 of the intensity of 25 kGy/kg, in other two groups of dogs the nonirradiated ration was used for the same time period. The control groups of dogs were put together for these two diets. The laboratory examination of irradiated feedstuffs confirmed their complete microbiological and mycological intactness. However, the irradiation brought about a significant 35% degradation of essential amino acids with an increase of ammonia nitrogen, destructive changes in the lipid component of feedstuffs and a partial decomposition of the saccharide part of the VETAVIT feed mixture, expressed by the acidity of water extract. The sensory evaluation of irradiated feedstuffs did not show any perceptible alterations. The haematological examination of the blood of animals, which had been administered irradiated feed rations, demonstrated a significant negative influence on the blood picture. The biochemical examination of the blood serum and plasma revealed that total proteins of experimental dogs dropped and the creatinine level was also significantly decreased. Neither was the level of carbohydrate nutrition nor the energy saturation affected by irradiation. The glucose levels in the blood serum of dogs fluctuated within the range of physiological reference values. The growth of free ammoniacal bases of feedstuffs, evoked by ionizing radiation, conditioned obviously the level of actual pH of blood in dogs as determined in this study. The destruction of lipoid fraction in the feedstuffs induced a decrease in the activity of lipophile retinol and thus the biological value of feeds was impaired. The biochemical examination of ALT, AST and ALP enzyme activity did not show any increased activity of parenchyma, in particular of liver cell. A decisive role of the biological quality of feed ration for utilization of some minerals was demonstrated by a significant decrease of the magnesium level in animals administered irradiated feed rations without any biological supplementation. On the contrary, the potassium, calcium and phosphorus levels did not reflect this dietary difference between the groups.     

Sarcocystosis in slaughterhouse sheep

The occurrence of sarcocystosis was studied in the sheep produced in the vicinity of Brno and killed in the slaughterhouse. Adspection, the homogenization method and the digestion method were used for the detection of muscular cysts. Antibodies to sarcocystosis were determined in the blood serum by the indirect fluorescence method. The total number of sheep examined was 157; sarcocysts were detected in the muscle of 102 sheep (64.9%). The highest incidence was recorded in ewes: 60 ewes (80%) out of 75 were positive. Out of the 157 blood serum samples examined by the indirect fluorescence method, antibodies were found in 105 samples (66.9%). The antibody response was 77.3% in ewes, 63.4% in lambs and 46.6% in rams. The highest titres (640-10 240) were obtained in 16 lambs and 26 ewes.     

Morphologic changes in the ovary and histologic changes in the tertiary ovarian follicles in ewes after prolonged irradiation during anestrus

The changes in volume, weight and the histomorphological changes of the tertiary follicles of ewes were studied after protracted irradiation with 4.8 Gy in the anoestrous period by the morphometric and qualitative histological methods. The trial was performed in May with 21 ewes of the Slovak Merino breed, divided into three groups. The first group (five ewes) was control. The second and third groups (each containing eight ewes) were exposed to gamma-rays for five days, the total dose being 4.8 Gy. Within ten days after the treatment, all the irradiated and control ewes were given Ampicillin Spofa per os at a dose of 250 mg per head/day and Roboran Spofa at a dose of 10 g per head/day. The animals were killed by bleeding on the fifth day of irradiation and on the tenth day after the end of the treatment. After killing, the volume and weight of the ovaries were determined and a common histological method was used to cut these ovaries into 7 microns slices in series 70 microns apart. The slices were stained with haematoxylin-eosine and were evaluated by means of light microscopy. After irradiation the weight of the ovaries was found to decrease significantly; however, ovary volume remained unchanged. The atretic and non-atretic tertiary follicles were subjected to qualitative histological differentiation after Marion et al. (1968) and the number of non-atretic follicles was found to have decreased significantly in the irradiated ewes. The late type of atresia contributes most significantly to an increase in the proportion of atretic tertiary follicles. The administration of vitamins after irradiation reduced the occurrence of atretic changes.     

The effect of milk cultures on the survival of salmonellae in milk

The influence was investigated of yoghurt and cream cultures on salmonella survival in milk. Salmonella-contaminated milk was blended with yoghurt culture and kept for three hours at the temperature of 43 degrees C; the mixture with cream culture was kept for 20 hours at the temperature of 22 degrees C. The samples were then stored at a room temperature and at the temperature of 4 degrees C. The two milk cultures exerted inhibitory effects on salmonellae within the range of 92.5 to 99.8%. The inhibitory effects depended on the activity of the culture (expressed by titration acidity), storage time and temperature and on the starting concentration of salmonellae.