EFFECT OF HENS IMMUNIZATION AGAINST EGG-LAYING REDUCTION SYNDROME-76 ON VETERINARY AND SANITARY CHARACTERISTICS OF MARKETABLE EGGS
The aim of the study was to assess the effect of immunization of chickens with Avivak-SSYA-76 vaccine on the veterinary and sanitary characteristics of commodity eggs received from them. During the experiment it was found that after vaccination against SSN-76, the egg production of the hens of the experimental group increased by 3.68%, while on average 0.9 eggs were obtained from one immunized laying hen more than from chicken of the control group. The average weight of eggs obtained from immunized birds was 4.3 g more, and their shells were 0.023 mm thicker than eggs laid by hens of the control group. The yolk and egg protein indices, which characterize the dry matter content in the egg and the protein quality, were also higher for egg products from vaccinated chickens than for non-immunized birds. The increase in poultry egg production and the improvement of the marketability of egg products obtained from birds after immunization against SSN-76 is associated with a positive effect of the biological product on the immune system and the general physiological state of the bird and, as a consequence, on its egg productivity. Bacterial contamination of eggs obtained from poultry immunized against SSN-76 was almost 25% lower than that of analogous products demolished by hens of the control group, which is the result of increased immunity of productive birds after the Avivak-SSN-76 vaccine and a decrease in the probability of endogenous contamination of eggs with microflora.