In this study,Wong et al. (2014) took six day old bacteria-free chicks
and artificially inoculated them with 10 Log10 CFU/ml of S. Typhimurium
and 12 Log10 PFU/ml of bacteriophage 1 h after bacteria
inoculation. Although a single dose was given, in contrast to multiple
doses, it was administered before S. Typhimurium had colonized
the gut. After 6 h, S. Typhimurium concentrations were just
below 3 Log10 CFU/ml and the bacteria were undetected after 24 h.
Both studies suggested that the bacteriophage concentration
should be higher than that of the bacteria to have significant
pathogenic reductions in-vivo, and bacteriophages should be given
prior to pathogenic exposure in order to sustain that reduction over
time. This finding was corroborated by Waseh et al. (2010) in a
study where two day old pathogen-free chicks were inoculated
with bacteriophage 1 h after inoculation with 7 Log10 CFU of Salmonella.
Two subsequent phage doses resulted in 100-fold decrease
of Salmonella after four days. Many studies involving bacteriophage
administration in live chickens are carried out using oral gavage in a
highly controlled environment, an approach that is not representative
of delivery methods likely to be used under commercial
conditions where factors such as gut bacterial concentration and
bacteriophage uptake are not as easily controlled.