[Genetic polymorphism of alkaline phosphatase and the resistance to Marek's disease virus]. / Genetichen polimorfizum na alkalnata fosfataza i ustoichivost na virusa na bolestta na Marek.

Experiments were carried out with a total of 222 birds of the 5-A, 6-E, Ya-73, LL, and LS lines of the White Leghorn breed to find whether or not there existed any correlation between the alkaline phosphatase allels and the resistance to Marek's disease. The polymorphism of alkaline phosphatase was evaluated in the blood plasma of birds through horizontal electrophoresis in starch gel after G a hn e [3]. The resistance of the five egg laying lines of birds was found to be associated with the Akps allel, and their susceptibility - with the AkpF allel. No mortality with the homozygous gene type SS was established in the investigated lines except for a birds of the LL line. It was found that there existed full agreement of the results from the studies on broiler and laying lines concerning the exclusive resistance of birds of Akp SS gene type. This made it reasonable to believe that the indirect selection by resistance to the Marek's disease virus through the use of the Akps allel as a genetic marker was promising.

[Changes in the polymorphism of the blood serum alkaline phosphatase in chickens undergoing subacute lindane treatment]. / Promeni v polimorfizma na alkalnata fosfataza v kruvna plazma na kokoshki pri subakutno tretirane s lindan.

Investigated were a total of 123 birds of the White Leghorn breed and 50 birds of the White Plymouth Rock breed. Preliminary studies were carried out on the LD50 amount of lindane (151 mg/kg body mass) with 6 groups of chickens. The birds were divided into 4 subgroups for each breed. The first subgroup was a control one and was not given lindane, and the remaining subgroups were offered the following amounts of lindane in the course of 5 successive days: II - 1/20 LD50 (7.6 mg/kg daily); III - 1/10 LD50 (15.1 mg/kg); and IV - 1/5 LD50 (30.2 mg/kg). Each single one of the test birds was treated individually by means of a rubber tube and a syringe with a pure substance of lindane dissolved in oil. The polymorphism of alkaline phosphatase in the blood plasms of chickens was determined through horizontal electrophoresis in starch gel after the method of Gahne [14]. It was found that at subacute treatment of the birds a drop off was observed of the S1 fraction, and, as a result, the frequence of the homozygotic alkaline-phosphatase phenotypes FF and SS rose, while that of FS1 and SS1 dropped. Subacute treatment with part of the birds led to the appearance of an additional fraction F1, which accompanied the SS, SS1, and SS2 phenotypes only. The changes that took place as a result of the subacute treatment were only phenotypic ones as the F1 and S1 fractions had no hereditary character.

[Resistance of different breeds of laying poultry to Marek's disease virus]. / Ustoichivost na razlichni linii ptitsi iaitsenosno napravlenie kum virusa na bolestta na Marek.

Investigated were a total of 447 two-day-old chicks of lines 5-A, ia-73' ll and lS of the Leghorn breed divided into 2 groups: controls--99 males and females, and test ones--348 infected at the age of 2 days via intraabdominal injection with 0.4 cm3 heparinized blood each, containing 5000 PFU per dose of the Marek's disease virus (CT-1 isolate). Both linear and sexual variations were found in the resistance of the birds. Most resistant proved to be the 5-A chicks of both sexes, and most susceptible--those of the lS line. No essential differences were observed in the response of the initial lines of broiler birds and the lines of laying birds raised in this country at the intraabdominal infection with the same virus. It was established that the birds of lines 5-A and 6-E of the Canadian Leghorn breed were close in terms of resistance with the birds of lines 66 and 77 of the Cornish breed, while those of the Leghorn lines ll and lS were resembling by resistance the birds of lines 88 and 89 of the White Plymouth Rock broilers which were more susceptible to Marek's disease. It is stated that the cockerels and poults of the ia-73 synthetic line, newly developed in this country, show essentially varying resistance most probably associated with insufficient consolidation.

[Phagocytic activity and antibody formation in relation to the resistance of poultry to fowl typhoid-pullorum disease]. / Fagotsitna aktivnost i antitialoobrazuvane vuv vruzka s ustoichivostta na ptitsite kum tif-puloroza.

Vulchanov's method (1954) was employed to study the phagocytic activity, and the classic method with the agglutination test served to follow up the production of antibodies. Some breed-associated differences were observed in the phagocytic activity and the normal serologic antibody titer prior to the infection with Salmonella pullorum and Salmonella gallinarum. Highest were the indices with the Leghorn breed, followed by the Cornish and Plymouth Rock breeds. Certain breed differences were also established between the size of changes taking place in the phagocytic activity following the infection of birds with Salmonella pullorum and Salmonella gallinarum. These indices were least changed with the Leghorn breed, more with Cornish, and most Plymouth Rock. There was a correlation between phagocytic activity and the average serologic titer. Higher indices of phagocytosis corresponded to higher average antibody titers.

[Poultry resistance to typhoid-pullorum disease by sex and breed]. / Ustoichivost na ptitsite kum tif-puloroza spored pola i porodata.

Studied was the resistance of a total of 1729 birds of the Leghorn, Cornish, and White Plymouth Rock breeds with regard to typhoid and pullorum disease after the oral infection with strain 2348 of Salmonella pullorum and strain 2307 of Salmonella gallinarum. In accordance with the manifested clinical picture and the results of the bacteriologic investigations all birds were divided into three groups--unaffected, survived, and died. There existed breed- and sex-associated variations in the resistance, resp., the susceptibility of birds to both strains of Salmonellae. Highest was the resistance of the Leghorn birds, followed by those of the Cornish breed. Most susceptible proved the birds of the White Plymouth Rock breed. The cocks seemed to be more resistant than the hens. Besides, there was a trend in the females in transferring resistance to both strains, which was common in al birds.

[Serum protein spectrum in chickens with different degrees of resistance to Salm. gallinarum, and the relation between globulin levels and antibody formation]. / Serumen beltuchen spektr vuv vruzka s ustoichivostta na ptitsite kum Salm. gallinarum i zavisimost mezhdu nivoto na globulinite i antitialoobrazuvaneto.

An experiment was carried out with 231 chickens of the Leghorn breed, 177--of the Cornish breed, and 532--of the White Plymouth Rock breed. In order to check the resistance of the birds to typhoid all of them were infected orally at the age of 2.5 months with an 18-hour broth culture of Salmonella gallinarum. Depending on the clinical course of the disease and the results of the bacteriologic investigations the birds were divided into three groups: A--chickens that did not develop the infection; B--survivors; and C--birds that died. The total protein in the serum was determined by the classical method of Kingsley, the protein spectrum--through electrophoresis in agar by the microexpress method of Wieme, and the antibody production--by the classical serum agglutination test. Differences were established in the level of the total globulins as well as in that of alfa, beta, and gamma globulins and the albumins and total protein in dependence on the resistance of chickens to Salmonella gallinarum. These changes were more slightly expressed in the birds that did not develop the disease, and were more strongly expressed in those that died. There were also breed-associated differences as to the deviations of the protein spectrum indices in relation to the resistance to typhoid. A correlation was also established between the level of globulins and the antibody production.

[Relationship between the genetic polymorphism of alkaline phosphatase and the resistance of broiler poultry to Marek's disease virus]. / Zavisimost mezhdu genetichniia polimorfizum na alkalnata fosfataza i ustoichivostta na ptitsite broilerno napravlenie kum virusa na bolestta na Marek.

Studied was the polymorphism of alkaline phosphatase in blood plasma samples taken from 507 poulets and cocks of lines 66 and 77 of the Cornish breed, and lines 88 and 99 of the White Plymouth Rock breed. The birds were divided into three groups to test their resistance to Marek's disease: (1) controls, (2) infected with the virus of Marek's disease with 3 subgroups--resistant birds, slightly susceptible ones, and strongly susceptible ones, and (3) contacts, with two subgroups--survivals and birds that died. The blood plasma alkaline phosphatase was determined through horizontal electrophoresis on a starch gel, employing the method of Gahne. It was found that the alkaline phosphatase genetype FF frequency was lower with lines 66 and 77 than with line 88 and especially with line 99 of the White Plymouth Rock breed which proved most susceptible to the virus of Marek's disease. In the homozygotic alkaline phosphatase genetype SS none of the investigated lines showed any mortality. The resistance of broiler birds to Marek's disease was governed by the Akps allele, while the susceptibility was governed by the Akpf one. The former could be used as a genetic marker in the selection of initial lines of broiler birds by resistance, and the latter could be used as a marker in the selection by susceptibility.

[Breed, line and sex differences of phagocytic activity in relation to broiler poultry resistance to Marek's disease virus]. / Porodni, lineini i polovi razliki na fagotsitnata aktivnost vuv vruzka s ustoichivostta na ptitsite broilerno napravlenie kum virusa na bolestta na Marek.

The phagocytic activity was studied of 421 poulets and cocks of lines 66 and 77 of the Cornish breed, and lines 88 and 99 of the White Plymouth rock breed. Breed and linear differences were noticed in the changes of the phagocytic activity (phagocytic number and phagocytic index) with birds infected with the virus of Marek's disease. The rise of the phagocytic activity with lines 66 and 77 was slighter as compared with that of the White Plymouth Rock lines 88 and 99. Strongest were the changes in the phagocytic activity with birds that were strongly susceptible to Marek's disease, and slight est--with birds that were resistant to the disease. A trend of a better expressed phagocytic activity was noticed with the cocks of all investigated lines.

[Genetic polymorphism of poultry blood serum esterases in relation to resistance to bacterial infections]. / Geneticheskii polimorfizm ésteraz syvorotki krovi ptits v sviazi s rezistentnost'iu k bakterial'nym infektsiiam.

The experiments were carried out on White Leghorn, White Rock and Cornish chickens during the 1974--1975 season. The aim of the investigation was to study polymorphism of blood esterases in chickens in relation to their resistance to Salmonella pullorum and S. gallinarum. The data obtained indicate the following: 1) an additional, inheritant alyesterase fraction (A1) Appears in blood serum of resistant chickens after their contamination with Salmonella; 2) most chickens, which are resistant to Salmonella, have heterozygous genotype for blood serum cholinesterase.