Abstract:
Salmonella remains a persistent public health concern both in the developed and developing countries.
Several reports on the prevalence of Salmonella in food, food production environment and human cases
have been found both in developing and developed countries. A randomized controlled field trial
based on parallel group design was conducted from January, 2018 to July, 2018 with the
objectives to investigate the preventive effect of supplementing Effective Microbial (EM) in diet
of beef cattle in reducing the presence and burden of Salmonella in their lymph nodes. The
treatment group exposed to feed supplemented by EM and non- exposed (Control) groups was
established. The Chercher Oda-Bultum Farmers Union beef Farm was used for the study
purpose. The animals were slaughtered after follow up periods of 90, 100 and 115 days at
Haremaya University abattoir. Lymphnode samples was collected from which mesenteric LN (n
= 130), Subiliac LN (n = 130) and total (n = 260). Isolation and enumeration of Salmonella were
conducted. Prevalence and load determination analyzed in laboratory total significant reduction
(53.00%) relative and (37.00%) absolute risk reduction among control and treatment group
(P=0.000) were observed. The significant shift in concentration of Salmonella in LNs (MLN and
SLNs) due to the influence of supplementation EM (P = 0.000) age in MLN (P = 0.00) and body
condition (P=0.025) in SLN, duration of treatment for both have significant interaction
(P=0.000). Using EM in the diet of beef cattle is effective in reducing risk of Salmonella in both
prevalence and burden. Further study in different agro ecology, season, breed, production system
should be conducted. Using animal model to investigate the interaction of EM, Salmonella and
bovine immune system will also be important
