[Seasonal dynamics and the prevention of the meningoencephalitic form of listeriosis in lambs].

The seasonal dynamics of the meningoencephalitic form of listeriosis in lambs was followed up. The peak values in the disease course were found to be in the months of February and March. It is likely that outbreaks coincide with the start in feeding the lambs with roughage.

[Immunoprophylaxis of listeriosis in sheep with a killed vaccine].

Experiments were carried out with 20 young ewes, 20 rabbits, 20 guinea pigs, and 10000 sheep and lambs, using a killed vaccine of Listeria 1 and 4c with heat under the protection of antidenaturation agents. Bacteriologic, histologic, and histochemical investigations and lung macrophage cultures were used to establish the changes in untreated, vaccinated, and challenged vaccinated animals. Listeria organisms from the challenged animals were isolated in sporadic cases from the barin and viscera, while from untreated and infected animals such organisms were isolated during the entire period of investigation.

[Causes of death in chicks in the 1st days after hatching].

Scientific and productional experiments and complex investigations were carried out on breeding eggs, chick embryos, newly hatched birds, and ecologic habitats of two broiler dressing combines. It was found that the basic reasons for the morbidity and mortality of chicks in the first days following hatching were: the eggs chosen for hatching were of a lower biologic value due to deficient feeding (1); the veterinary, sanitary, and hygiene requirements with regard to the production, shipping, storing, and hatching of breeding eggs were overlooked (2); the little birds were offered feed mixtures of low value, along with admission of other drawback in their feeding (3); during the first days of raising the birds were kept at lower temperatures and lower relative humidity on the premises.

[Effect of levamisole on the formation of agglutinins against salmonellosis in weaned lambs].

In order to follow up the effect of levamizol on the titer of agglutinins a killed vaccine of Salmonella abortus ovis; S. enteritidis, and S. typhimurium strains was used under protection of antidenaturating agents (80 per cent sac charose) and levamizol ICI at the rate of 10 mg per kg body mass.

[Bacterial contamination, clinical and pathohistological findings in the sex organs of cows following parturition].

Studied were a total of 119 cows of the Bulgatian Brown breed in different physiologic status at various numbers of days following parturition. Thirty-seven of the animals showed puerperal endometritis, while the remaining showed a normal course during puerperium. Uterine secretion and biopsic material for bacteriologic and histologic investigation were taken from all cows.