[Incidence of anemia in newborn calves]. / Prouchvaniia vurkhu razprostranenieto na anemiiata pri novorodenite teleta.

The indices of the red and white blood picture were studied in a total of 788 calves, aged up to 30 days, 541 out of which were born in the winter-spring months, and 253 of which were born on the same farms in the summer-autumn months, originating from 17 dairy farms of 6 regions of the country. It was found that the calves born on industrial cattle-breeding farms were comparatively often affected with anemia, showing lower hemoglobin level, hematocrit values, and erythrocyte count along with hypoferremia. More widely occurring was the anemia in calves during the winter-spring period as well as in twin calves and calves of cows that gave birth for the first time. Simmenthals and Simmenthal crosses were shown to suffer more often from anemia than the calves of the Bulgarian Brown and Black-and-white breeds and their crosses. There were no sexual differences with regard to the hematologic indices. The percent of day-old diseased calves was comparatively high.

[Experiments to obtain and use an allergen for the diagnosis of leukemia in animals]. / Opiti za poluchavane i prilozhenie na alergen za diagnostika na levkozata po zhivotnite.

The tested allergen was obtained from a stable cell line FLK which produces leukosis virus type "C" for diagnostics of animal leukosis (cattle, sheep, pigs). It was found that the allergen is strictly specific and induces hypersensitivity of delayed type which is recorded best on the 24th h of injection. The most suitable site to inject the allergen proved to be the tail fold for cattle and sheep and the dorsal part of the ear--for pigs in dose of 0.2 cc. The allergen reaction correlates to a considerable degree with the serologic one (AGDS) but it does not detect all serologic reagents. It detects much larger percent of susceptible animal compared with the hematologic method. Data obtained give grounds to assume that the allergen reaction may be used for quick herd diagnostics of leukosis.

[Study and identification of the respiratory syncytial virus isolated from a leukemic cow]. / Prouchvanie i identifitsirane na respiratorno-sintsitialen virus, izoliran ot levkemichno bolna krava.

A virus was isolated from the lymph nodes of a cow. By its cultural, physical, chemical, and biologic properties it proved identical with the standard bovine respiratory syncytial virus. It multiplied well in cell cultures of calf kidney at pH 7--7.5. Introduced in 20-day-old guinea pigs the virus caused anorexia, bristling up of hairs, stunting, and occasionally death. The inoculated guinea pigs developed pneumonia of a proliferative type with Langhans' giant cells. The interrlationship between the isolated virus and the standard oncorna virus, type C, is discussed.

[Changes in the serum proteins of cattle with leukemia]. / Prouchvaniia vurkhu izmeneniiata na serumnite proteini pri bolni ot levkoza goveda.

Studied was the content of total protein and the protein fraction ratio in the blood serum of 14 normal and 58 leukosis-affected cattle. It was found that in the initial phase of leukosis there were no essential changes in the serum proteins. In animals with a more advanced course of the disease (up to 25000 leukocytes per ml, with 65-85 per cent lymphocytes) no drop of the albumins and rise of the alpha-globulins and gamma-globulins were observed, however, there were cases presenting comparatively high lymphocytosis (up to 23000 lymphocytes) without changes in the serum proteins. In animals with well manifested tumoral changes there were almost invariably a strong drop of the albumins (up to 15-20 per cent) and a rise of the alpha1-globulins (up to 15 per cent), alpha2-globulins (up to 18 per cent), and gamma-globulins (up to 51 per cent).

[Changes in the calcium phosphorus and magnesium content in the blood serum of cows during calving]. / Promeni v sudurzhanieto na kaltsii, fosfor i magnezii v kruvniia serum na kravi po vreme na otelvaneto.

A total of 447 cows were investigated during the dry period, the period following calving, and the period of intense lactation, once each time, and other 55 cows were subjected to systemic periodical examinations in the last month prior to calving and up to the tenth day after it. It was found that the content of serum calcium and inorganic phosphorus dropped in the first days following calving in most of the animals. In about 30% of the cows calcium and inorganic phosphorus dropped as low as the lower physiologic threshold. The blood serum magnesium likewise dropped after calving, however, in the greater part of the investigated animals it remained within the normal range. The alkaline phosphatase activity became slightly weaker in the first days after calving, but in some of the cows the level of the alkaline phosphatase was lower in the period post partum.

[Study of disorders in calcium and phosphorus metabolism in the intensive fattening of young cattle]. / Prouchvane smushteniiata v kaltsievo-fosforniia obmen pri intenzivno ugoiavane na mladi goveda

Studied were mass disease outbreaks on eight farms in calves intensively fed concentrate mixtures that were rich in phosphorus compounds. Clinically, there were selling and deformations of the joints with pains. The tarsal and carpal joints were chiefly involved. Kyphosis of the backbone, spastic paresis of the posterior part of the body as well as tetaniform spasms in the initial stage of the disease were also observed. Morphologically, the diseased animals manifested erosions and thinning of the joint cartilage, tearing of the Achilles tendon, and increased amounts of the joint fluid. The histologic study revealed edema of the cartilage cells, disorders in the structure of the hyalin cartilage, formation of cavities, and broadening of the lumen of the Haversian canals. In most cases the blood serum presented hyperphosphatemia (up to 15.67 mg% inorganic P) and relative or absolute hypocalcemia (up to 4.47 mg% Ca). On the farm both hypocalcemia and hypophosphatemia were observed. Good prophylactic results were obtained through correct Ca:P ratios in the diet that contained calcium additives as well as by the injection of vitamin D solutions, etc. It is believed that these cases should be referred to a distinctive form of rickets of a characteristic clinical course' the inadequate Ca:P ratios in the rations playing the main etiologic role. Subsidiary causes are probably vitamin D deficiency, restricted movement of the animals, and mechanical traumata caused by the animal's own bodyweight.