APPLICATION OF SOME PROBIOTIC MICROORGANISMS FOR IMPROVEMENT POULTRY IMMUNITY AGAINST VIRAL INFECTION

Abstract

Poultry farming is one of the most important food industries, chain, production is the field of poultry farming. The International Office of Epidemiology has organized the viral diseases that affect poultry during the breeding period into a set of lists according to the extent of their seriousness and put in list (A) a group of viruses, namely, the influenza virus, the Newcastle virus and the Gumboro virus, according to the severity of these diseases, the speed of their spread and their impact on poultry.The focus of our study was on the Gumboro virus as amodel. There are many other additives that are added to the poultry diet. They are used as alternatives to anti-growth stimulants (antibiotics) and chemicals, which are added with the aim of improving growth, strengthening immunity and protecting poultry from infection with various infections. Besides, many studies have proven that Lactic acid bacteria such as Lactobacillus, which improve the growth of poultry and maintain the beneficial microorganisms present within the digestive system and compete with harmful pathogenic bacteria.In addition, other studies have shown that poultry immunity is significantly improved by addition yeast products and probiotic cultures to the diet. It also stimulates the GALT immune system in poultry through a special mechanism called toll-like receptor (TLR), regulating immune responses, stimulating T-cells and stimulating T-cells and epithelial cells. On the other hand, the Gumboro virus causes an immune disease that affects young chickens of 3 to 6 weeks of age, which leads to a high death rate and thus a loss and deficiency in poultry production.This virus causes damage to the lymphatic tissues, especially the tissues of the bursa gland, and it is one of the members of the genus of poultry viruses belonging to the Birnaviridae family. At the present time, there is no specific treatment for birds infected with this virus, except for the vaccines used, which are expensive and used only by companies and poultry factories. There are different strategies to prevent poultry virus replication or reduce its acute effects on young birds. In this study, the effect of probiotics will be identified in improving poultry immunity against viral infection. Based on all of the above and in this study:the following steps were performance , A group of virus-specific strains were isolated from samples of dead poultry suspected of being infected with the virus by injecting them into the fertilized egg embryo for adaptation. In order, the Giza governorate strain 10-6.7, the BeniSuef governorate 10-8.3, the Fayoum governorate 10-9.7, and the Qalyubia governorate 10-6.5, and all the strains gave a positive result with the Ikhtarloni immunoassay. Then the virus was identified by PCR technique and accordingly all strains gave bands at 620 bp.A comparison with the control sample, which did not show any bands, and then the pathological ability was tested to choose the most virulent strains for application in the study, and it was concluded that the third strain (Fayoum strain) is the most virulent of them, vvIBDV and the rest of the classical virulent IBDV strains (cvIBDV). This was achieved by following up on the death rate, the number of dead birds, and the average weight of all birds after being injected with the isolated strains. The third strain gave the largest death rate of 100%.