[Experimentally induced aflatoxicosis in broilers]. / Eksperimentalno vuzproizvedena aflatoksikoza pri broileri.

Aflatoxicosis was induced under experimental conditions in two groups of broiler birds fed in the course of the entire fattening period upon feed, containing 0,250 and 0,600 ppm aflatoxin. Dependable changes were established in the investigated haematological and biochemical indices. There was a drop of the body weight and an increase in the feed to gain ratio. Pathologic changes were recorded in the liver.

[Toxicity and nutritive action of Pharmakhim's sodium monensin in weaned lambs]. / Toksichnost i nutritivno seistvie na monenzin-natrii "Farmakhim" pri shileta.

Tested was the monensin-Na Pharmakhim preparation (commercial formula Monensin-100, a 10 per cent premix of monensin-sodium) with weaned lambs with regard to toxicity, tolerance, nutritive action, distribution, and residual amounts in the body as well as with special reference to its effect on meat quality. It was found that doses of 15 mg/kg body mass were well tolerated, with no changes in both behaviour and appetite. The minimum lethal dose was 30 mg/kg b. m. Medicated feed, containing Monensin-100 at rates 10, 20, and 30 ppm, offered to the animals in the course of 90 days produced a positive effect after the 30th day, acting best in conc. of 30 ppm. In the amounts referred to Monensin-100 negligibly stimulated the process of hemopoiesis; more substantial was the improvement of the carbohydrate metabolism, raising the amount of blood sugar (better at the rate of 30 ppm). Histologic investigations of parenchymal organs of the animals treated with nutrient amounts of the preparation revealed no degenerative changes. Neither was there any negative effect on the tested organoleptic, physico-chemical, and microbiological indices of the meat obtained following the use of Monensin-100 in the concentrations referred to. The withdrawal time at slaughtering weaned lambs that had been offered Monensin-100 with the feed in the course of 90 days with regard to the concentrations cited above was shown to be at least 48 hours.

[Histogenesis of granulation tissue in wound healing by second intention in horses and cattle]. / Khistogenez na granulatsionnata tukan pri zarastvashti po vtorichen nachin rani na kone i goveda.

An experiment in comparative developmental aspect was carried out with 5 horses and 5 cattle having a total of 60 skin and muscular wounds. Light microscopic studies on hematoxylin-eosin stained preparations revealed that the dystrophic changes in the underlying tissues were more strongly manifested in horses. This had to be taken into consideration in the surgical treatment of wounds with this animal species. The basic differences comprised the better manifested leukocytic reaction in horses and the more strongly expressed processes of growth and differentiation on the part of the connective tissue after the tenth day of wounding in cattle. The definitive formation of granular tissue in horses took place in shorter terms than in cattle. In the fully developed new tissue in horses three different layers were found: leukocytic, vascular-fibroblastic, and a maturing one, while in cattle the layers found were four: fibrous tissue, heterophilic-leukocytic, vascular-fibroblastic, and a maturing one.

[Effect of ochratoxin on the health status of broilers]. / Vliianie na okhratoksina vurkhu zdravoslovnoto sustoianie na pileta broileri.

An experiment was carried out with 7-day-old broiler birds to assess the effect of ochratoxin A on their health. A standard feed mixture, containing 4 mg/kg ochratoxin A in pure substance, was offered to the birds in the course of 21 days. No severe clinical symptoms and death cases were observed during the experimental period. However, both the growth and the development of the birds were arrested along with an increase in the relative weight of the kidneys and changes in their morphology--vascular disturbances and dystrophy more strongly manifested in the kidneys and to a weaker extent seen in the bursa of Fabricius, the thymus, and other organs.

[Toxicological and pharmacokinetic research on lincomycin hydrochloride in broiler chickens and layer hens]. / Toksikologichni i farmakokinetichni prouchvaniia na linkomitsinov khidrokhlorid pri pileta broileri i kokoshki.

Tested was the activity of linkomycin hydrochloride at the rate of 820 IU/mg. The LD50 of the preparation was found to exceed 12.0 g/kg body mass at intracrop application to broiler birds. When offered with the drinking water or the feed in amounts that were 3 to 5 times higher than the therapeutic ones for broilers in the course of 45 days it did not cause mortality nor induced changes in the white and red blood cell counts, in the total protein, and in the levels of urea, blood sugar, AlT, and AcT. Neither were there any structural changes in the internal organs. Upon the single intracrop treatment of broilers with linkomycin at 50 and 100 mg/kg most of the amount introduced was established in the blood serum at the second hour and up to the 6th and 8th hour, respectively. Studies on the effect of age on the serum concentrations at this route of introduction revealed that the preparation was absorbed at higher rates in the broilers than in the layers, while with the persistence of the levels there were no essential differences. At the single oral administration with broilers in amounts of 100 mg/kg linkomycin was chiefly retained in the kidneys, liver, and lungs as well in the content of the small and large intestines. At intracrop application to layers in doses of 100 mg/kg in the course of 7 days the antibiotic was excreted with the eggs at the time of treatment and in the course of 4 days later in bacteriostatic concentrations of 0.6-5.9 micrograms/cm3.

[Toxicological research on a protein-vitamin B12 concentrate in broiler chicks]. / Toksikologichni prouchvaniia vurkhu beltuchno-vitaminen kontsentrat-B12 pri pileta broileri.

Studied were the acute and the subchronic toxicity, and the total tolerance of birds with regard to the Bulgarian protein-vitamin concentrate B12 (PVC-B12) with manifested activity of 230 mg per kilogram. With single introduction into the crop at rates of up to 20 g/kg PVC-B12 had no unfavourable effect on the health of birds. The same applied to its manifold use over a period of 10 days when given with the feed in amounts that exceeded ten and twenty times the recommended prophylactic and stimulating doses. As feed supplement at rates of 4 and 12 g/100 kg in the course of 56 days the preparation did not induce changes in the appetite, behaviour, general condition, clinical and biochemical composition of the blood, and structural organization and development of the viscera.

[Preclinical research on Pharmachim's ronidazole]. / Predklinichni izsledvaniia na ronidazol "Farmakhim".

Ronidazol-Pharmachim (RPh) in the form of 10 per cent water-soluble powder was studied in terms of resistance to various values of pH of the surrounding medium, acute toxicity, the species-specific tolerance of various mammals of it, its subchronic toxicity and residual amounts with pigs. The preparation was found to be stable in water solutions (pH 5.0 to 9.0) in the course of at least 96 hours, and in n HCl--for more than a month. At oral administration LD50 of RPh was 34000 mg (2982 divided by 3876) per kg for albino rats weighing 150-200 g. At intraperitoneal injection in the form of pure substance LD50 was 1500 mg (1320 divided by 1690) per kg. With pigs at single oral application at the rates of 20, 60, and 180 mg/kg (= 20-30 times the ED50) RPh was tolerated with no changes in the behaviour and appetite. When used with the drinking water at rates of 60, 180, and 300 ppm in the course of 30 days there was no unfavourable effect on the gain and the blood picture and no injury of the structure of viscera of pigs. In concentrations of 180 ppm it was shown to stimulate the growth of pigs. The withdrawal time with pigs given RPh with the drinking water was at least 72 hours after the preparation was offered last.

[Pathomorphology of stachybotryotoxicosis in calves during the nursing period]. / Vurkhu patomorfologiiata na stakhibotriotoksikoza pri teleta prez mlechniia period.

An enzootic of stachybotryotoxicosis was established on a dairy farm in 35-46-day-old calves due to the use of straw contaminated with Stachybotrys alternans. Studied were the epizootiology, the clinical picture, and chiefly the morphology of the disease. A characteristic clinical feature was the edema in the intermandibular space. Morphologically, there were numerous hemorrhages in the subcutaneous tissue, skeletal muscles, abomasal and intestinal mucosa, kidney cortex, and urinary bladder as well as ulcerous and erosive colitis, edematized mesenterial lymph nodes and occasionally catarrhal and necrotic stomatitis, icterus, and perirenal edema. Contrary to the gross lesion picture known there were no changes in the rumen, reticulum, and omasum which were not sufficiently developed during that period. Histologically, there were degenerative nephrosis, focal hemorrhagic glomerulonephritis (occasionally coupled with bacterial embolization and dystrophic calcification of the kidneys), granular degeneration of the liver and heart, hemorrhages and edema of the lungs, and edema, hyperemia, and thrombi in the brain.

[Pathomorphology of acute furazolidone poisoning in calves]. / Vurkhu patomorfologiiata na akutno otraviane s furazolidon pri teleta.

Studied was the morphologic picture in a total of 13 calves spontaneously intoxicated with furazolidon following its overrating and use once and severalfold as a therapeutic means against infectious enteritis. There were hemorrhages in the subcutaneous tissue and the muscles, kidneys, abomasum, spleen, and heart as well as liver dystrophia and hyperemia and edema of the leptomeninges and the brain cortex. Histologically, there were hyperemia, strong and diffuse pericellular and perivascular edema of the cerebrum and the cerebellum with degenerative changes in the Purkinje layer, fatty degeneration and biliary thrombi in the liver, hemorrhages and activation of the endothelial cells and glomeruli of the kidneys, hyperemia and fatty infiltration of the myocardium, and hemorrhages in the spleen.

[Quality of meat from lambs fattened on feed mixtures with added bacterial protein]. / Kachestvo na mesoto ot agneta, ugoiavani s furazhni smeski s dobavka na bakterialen protein.

Physico-chemical, microbiologic, and histologic investigations were carried out with meat and parenchymal organs of lambs offered feed mixtures with a supplement of bacterial protein on methanol basis in fattening the animals up to 35 kilograms. The addition of 5 per cent bacterial protein which replaced in terms of protein equivalent 60 per cent of the sunflower oil meal and totally the amount of urea in the mixtures had no negative effect on the physical and chemical composition of the meat and its biologic value. Histologically, no degenerative changes in the skeletal muscles and parenchymal organs were found. There was hypofunction of the thyroid gland in the test lambs. No pathogenic and occasionally pathogenic organisms were found in the sampled meat and organs.

[Species-specific toxicity of arprinocid in mammals and birds]. / Niakoi prouchvaniia vurkhu vidovospetsifichnata toksichnost na arprinotsid pri bozainitsi i ptitsi.

Studied was the species-specific tolerance and the subchronic toxicity of the arprinocid coccidiostatic (9-/2-chloro-6-fluorophenylmethyl/9H-pirineamine) in the form of a 12% premix with trade mark Arpocox, Merk Sharp and Dohme Research Laboratories. It was found that at single oral application arprinocid led to the intoxication of broiler birds at 50 mg/kg, turkey poults-at up to 18 mg/kg, ducklings--up to 18 mg/kg, goslings--up to 6 mg/kg, calves--up to 10 mg/kg, lambs--up to 60 mg/kg, pigs--up to 30 mg/kg. The lethal dose for chickens was over 100 mg/kg, turkeys and duckling--30 mg/kg, and goslings--18 mg/kg. Arprinocid given with the feed to chicken broilers in conc. 60 ppm for 30 days did not lead to side effects. In conc. of 120 and especially 180 ppm there was retardation of growth with birds and inhibition of hemopoiesis. With pigs the preparation in conc. 60 to 180 ppm given with the feed had no effect on the growth and consumption of feeds; in 120 ppm and especially in 180 ppm it inhibited the hemo- and erythropoiesis. With chickens and pigs arprinocid in 180 ppm did not cause degenerative and inflammatory changes in the liver, kidneys, heart, spleen, testes, ovaria, adrenals, thyroid, and skeletal muscles.

[Toxicological studies of a combination of technical tylosin phosphate with bentonite (farmazin TB)]. / Toksikologichni prouchvaniia vurkhu komibnatsiia na tekhnicheski tilozinov fosfat s bentonit (farmazin TB).

Studied were both the acute and subchronic toxicity of technical tylosine phosphate (TP), produced at the Research Chemical and Pharmaceutical Institute, Sofia, used in combination with bentonite, known as Pharmasine TB. Pharmasine TB was practically untoxic for albino mice and birds at oral application. Neither toxic nor lethal effects were observed after giving it once, twice, and three times at a 2-hour interval at rates of 5 and 10 g per kg body mass. Calves and pigs also showed very good tolerance for the preparation at oral application. At prolonged application via the feed (30 days) in amounts of 0.5, 1.5, and 2.5 per cent (equal to 100, resp., 300 and 500 ppm with regard to tylosine in active matter) Pharmasine TB was shown to stimulate the weight gain on the basis of the better utilization of feed, having no unfavourable effect on the appetite, behaviour, clinical and biochemical composition of blood, and the morphologic structure of the viscera in pigs. Used in the same way with birds at the rates of 3, 5, and 10 per cent (equal to 450, resp., 750 and 1500 ppm with regard to tylosine in active matter) for a time period of 60 days the preparation did not lead to deviations in terms of the most clinical and morphological indices, however, it inhibited the weight gain by 3.2 to 8.1 per cent. According to the authors, this was due incomplete biologic value of the medicated feeds and their improper utilization because of the introduction of rather greater amounts of bentonite with Pharmasine TB.

[Toxicological evaluation of "Farmakhim" thiabendazole in mammals and birds]. / Toksikologichni prouchvaniia na tiabendazol "Farmakhim" pri bozainitsi i ptitsi.

Studied were the acute toxicity (albino mice and rats, chicken broilers), species specific tolerance (lambs, sheep, goats, pigs, calves, chicks, chickens), and subchronic toxicity (albino rats, pigs, pulets) of tiabendazole Pharmachim (TP). It was found that LD50 of TP at the oral application to albino mice, weighing 18-20 g was 2.7 g (2.14 divided by 3.40) per kg for albino rats weighing 120-200 g it proved technically undeterminable. For broilers at one month it was 4.0 g (2.54 divided by 6.28) per kg. LD50 of TP of the firm Merck Sharp and Dome for albino mice was 2.9 g (2.28 divided by 3.68), and for broilers -- 5.0 g (4.31 divided by 5.8) per kg. The lethal dose for lambs was 400 mg/kg, for sheep -- 800 mg/kg, for goats -- 500 mg/kg, and for calves -- 500 mg/kg. When treated with amounts of 450 and 850 mg/kg pigs vomited. The same was true of drugs when offered the preparation at the rate of 300 mg/Kg chicks and chickens tolerated amounts of 500 mg/kg. TP was well tolerated by pigs, rats, and pullets when given with the feed for 30 days in 0.1 per cent conc.; in 0.4% conc. (pigs), 0.5% (albino rats), 0.3% (pullets), and 1% (albino rats and pullets) led to the arrest of growth and rise of transaminases and urea in the blood serum (rats and pigs) and the adverse effect of the red blood picture (rats, pigs, and pullets). Histologically, there were vascular troubles and granular degeneration that predominated in the kidneys, and were more slightly expressed in the remaining parenchymal organs.

[Doxycycline hydrochloride administered in the drinking water to poultry]. / Doksitsiklinov khidrokhlorid, prilozhim s vodata za piene pri ptitsi.

Investigated were the acute toxicity, serum concentrations, and residual amounts of doxycycline in broiler chickens. It was found that the LD50 of doxycycline when applied via the crop to week-old broiler birds was 2500 mg/kg mass. The amount of 0.005 g/kg mass given orally to birds led to serum concentrations that on the eighteenth hour were found to drop up to subtherapeutic ones. When applied with the drinking water at the rate of 0.02 to 0.04 g l or kg feed it was well absorbed as early as the first hours. In such case the drug maintained therapeutic concentrations that were higher in the internal organs than those in the serum. The residual amounts of doxicycline hydrochloride when it was applied at 0.04 g/l of water or kg feed were found up to 48 h hour by the method of agar diffusion, using Bac. subtilis L2 as a test organism. The withdrawal time should amount to 72 hours.

[Bulgarian potassium-calcium zeolite in the prophylaxis of digestive tract disorders in calves]. / Bulgarskiiat kalievo-kaltsiev zeolit kato profilaktichno sredstvo sreshchu khranosmilalatelnite razstroistva pri teleta.

Scientific and economic trials were carried out to test the prophylactic effect of Bulgarian K-Ca zeolite products in the prevention of digestive troubles in calves, corresponding to the State Standard production branch requirements of 33675789-79, and to 0.00-0.01 mm (France). When applied at the rate of 2 per cent constituent of the daily milk ration from the first to the fifteenth day after calving it was found to produce a good prophylactic effect against digestive disturbances. It was also found that there was enhancement of the general resistance in calves. This resulted in lower morbidity and mortality rates, and shortening the period of illness in calves that received zeolite. By the end of the experimental period there was a definite rise of the blood albumins, the sum total of the gamma-globulins, the hemoglobin value, and the absolute values of granulocytes and lymphocytes.

[Toxicity of "Farmakhim" tetramisole in laboratory and farm animals]. / Prouchvaniia vurkhu toksichnostta na tetramizol "Farmakhim" pri laboratorni i selskostopanski zhivotni.

Tetramisole produced by ICI, England, and Tetramisole Pharmachim, Bulgaria, were comparatively studied in terms of their acute and subchronic toxicity, and the local and general tolerance and antinematode activity. No differences were found in their acute toxicity (LD50) for albino mice at oral, subcutaneous, and venous application, the index of resorption being 6.3. The same was true so far as the tolerance in calves, sheep, goats, and pigs was concerned. Orally at the rate of 45 mg/kg in sheep and over 30/kg with calves (3, resp., 2 times as high as the therapeutic dose) tetramisole produced nervous and locomotor excitement, tremor, salivation, higher respiration and pulse rate, frequent urination and defecation. Following the tenfold oral administration at intervals, of 3 days at rates of 15 and 45 mg/kg tetramisole Pharmachim did not affect unfavourably the appetite, behaviour, general status, and the clinical and biochemical composition of the blood as well as the structural pattern of the viscera in sheep. Tetramisole Pharmachim was shown to be well tolerated with regard to the conjunctivae at concentrations of up to 5 per cent, the subcutaneous tissues and muscles at conc. of up to 3 per cent, and mucous membranes of the stomach and intestines at conc. of up to 10 per cent.

[Clinical, morphological and biochemical changes in lambs caused by Fusarium toxins]. / Klinichni, morfologichni i biokhimichni promeni pri shileta, predizvikani ot toksini na Fusarium.

Studied was the effect of toxic trichotecenes and the F-2 toxin on the health status and the morphologic and biochemical changes in the blood on weaned lambs. It was shown that there was a drop of the hemoglobin content, rise of the leucocyte count, and decrease in the amount of the total proteins along with an increase in the activity of glutamate-oxalacetate and glutamate-pyruvate transaminases, alkaline phosphatase, and lactate-dehydrogenase. The morphologic changes appeared confined to the rumen, lymph nodes of the forestomach, duodenal mucosa, liver, and kidneys.

[Clinical, morphological and biochemical changes in pigs caused by the toxic metabolites of Fusarium tricinctum]. / Klinichni, morfologichni i biokhimichni promeni pri praseta, predizvikani ot toksichni metaboliti na Fusarium trichinatum.

Experiments were carried out with pigs in the course of 30 days with the use of dietary mixtures containing 10 and 20 per cent cultures of Fusarium tricinctum in rice. The treated animals showed higher sensitivity to trichotecenes. These moulds metabolites raised the activity of the serum glutamate oxaloacetate and glutamate-pyruvate transaminases, aldolase, lactate dehydrogenases, alkaline phosphatase, lipid level, and leukocyte count but lowered the amount of total protein and that of hemoglobin. The morphologic lesions seemed confined mainly to the stomach, intestines, and kidneys.

[Histological changes in the liver of Benkovska breed geese during the fattening period]. / Vurkhu khistologichnite promeni v cherniia drob na benkovskata guska prez perioda na ugoiavaneto.

Studies were carried out to follow up the histologic changes taking place in the liver of Benkovska breed geese during different periods of fattening. A correlation was established between the period of fattening and the severity of the liver lesions. During the preparatory period there was in the hepatocytes focal fatty infiltration, and by the 5th-10th day of the forced fattening diffuse fatty infiltration and fatty and granular degeneration were seen. On the 15th-20th day of the fattening period predominating in the dystrophic hepatocytes were the medium-sized fatty vacuoles, and on the 28th day - the larger vacuoles, which corresponds to Ist quality in terms of weight and macroscopic picture. The enrichment of the liver with fats was accompanied by lymphocytic and pseudoeosinophilic leukocyte infiltration of the interstitium.