[Evaluation of the immune state of poultry against Newcastle virus via various serological reactions]. / Otsenka imunnoto sustoianie na ptitsi sreshtu niukiasulskiia virus chrez razlichni serologichni reaktsii.

Studied were 336 sera of vaccinated and challenged chickens, 76 egg extracts, and 36 birds following challenge for the presence of serum antibodies against the Newcastle disease virus, using the hemagglutination-inhibition reaction, the agar gel diffusion precipitation reaction, and the virus-neutralizing test. The values of the antihemagglutinins, precipitins, and virus-neutralizing antibodies were investigated in relation to the immunobiologic resistance of birds to a velogenic Newcastle disease virus. A correlation was found between the antihemagglutinins and the neutralizing antibodies in broilers, aged 30-60 days, treated with an aerosol vaccine La Sota, and in henlayers treated muscularly with the Komarov vaccine. The presence of antihemagglutinin titers of 1:40 and higher values or positive neutralizing indices in the investigated birds were able to provide immunobiologic protection in challenging with a velogenic virus. Precipitins were detected in the blood sera of the challenged birds, which made reasonable their use as a sign pointing to the passage of a velogenic virus through the birds. The lower number of cases with positive precipitin reactions in the vaccinated birds speaks against using objectively this index for the evaluation of the immunologic status.

[Determination of the effect of clinoptilolit on the BOD (biochemical oxygen demand) of the waste waters from pig farms]. / Opredeliane vliianieto na klinoptilolita vurkhu BPK (biokhimichna potrebnost ot kislorod) na otpaduchna voda ot svineferma.

The passage of sedimented refuse water from pig-breeding farms through a clinoptilolit filtre of a grain size of 1.0 up to 0.5 mm leads to a decrease in BNO5 (the biochemical need of water) of such water by about 21 per cent. This is of interest to the purification of wastage waters associated with the everyday life as well as of refuse waters linked with animal-breeding activity, with special reference to keeping waters clean.

[Effect of zeolite mineral clinoptilolith on nitogen concentration in bird droppings]. / Vliianie na zeolitoviia mineral klinoptilolit vurkhu sudurzhanieto na azot v oborskiia tor.

The addition of certain amounts of the zeolite mineral klinoptilolith to freshly obtained bird feces led to the retention of nitrogen--up to 14 per cent and more--as compared with feces without zeolite in storage. The addition of the mineral produced also a deodorizing effect in neutralizing the offensive smelling accompanying the putrefaction process.