CONTROL OF MICROBIAL POLLUTION IN FEED-STUFFS OF ANIMAL ORIGIN AS AFFECTED BY SOME ENVIRONMENTAL FACTORS

Abstract

Feedstuffs of animal origin (meat & bone meal and fish meal) used as supplements in poultry diets were subjected to microbiological analysis to determine their contamination with pathogenic bacteria (Salmonella, Staphylococcus aureus, E. coli, Klebsiella and Shigella) as well as their total bacterial and fungal load. The effect of some environmental conditions (storage temperature and moisture content) on total bacterial and fungal densities was periodically evaluated during a period extended to 30 days. Chemical components (protein, fat, ash and fiber content) of meat & bone meal and fish meal as affected by environmental factors were also determined. In an experiment, trials were paid to eliminate samonellosis from chicks fed on a diet contaminated with S. typhimurium which cause high mortality percentages ilffi.Ongst the infected chicks. Application of competitive exclusion technique (CE) in chicks infected with S. typhimurium (by oral inoculation with anaerobic culture isolated from• the caecal contents of adult chickens and(or) given 2.5% lactose in drinking water) was investigated. Densities of Salmonella in cloaca and caeca, mortality of treated birds, pH, VFAs, lactic acid of caecal contents were estimated periodically. Growth performance and blood analysis of treated birds as affected by CE treatments were also evaluated.

Results show that both of Staph. aureus and Salmonella are present in fish meal, and meat & bone meal. Storage temperature and moisture content play an. important role on increasing microbial load ofboth feedstuffs under investigation. In contrast, chemical analysis showed no variation under different storage temperatures or moisture contents. Using CE technique (anaerobic culture + lactose, 2.5%) appreciably reduced salmonellosis in chicks infected with S. .typhimurium