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Use of Competitive Exclusion (Protexin) to Reduce Salmonella
Date:
2005
Location:
Depart. of Pathobiology, College of Veterinary Medicine, Auburn University
Department of
Poultry, College of Agriculture, Auburn University
Objective
of Trial:
To test the
effect of Protexin as a Competitive Exclusion product against Salmonella typhimurium in experimentally
infected broilers. Formulation:
Protexin
(multi-strain) Total Viable Count 2 x 108 CFU/g Base: Dextrose Monohydrate
Dosage
and Administration:
| Treatment Grp
| Treatment Grp | Treatment Grp | Treatment Grp | Treatment Grp | Treatment
| 1
| 2
| 3
| 4
| 5
| No of birds
| 16
| 16
| 16
| 16
| 16
| Protexin
| DOH
Day 1 - 3
(1g/litre water)
| -
| Day 1 - 3
(1g/litre water)
| -
| -
| Salmonella-specific
bacteriophage |
| Day 4 - 6
Day 18 -20
| Day 4 - 6
Day 9 -10
|
|
| Salmonella typhimurium
|
| Day 7
| Day 7
| Day 7
| Day 7
|
Procedure:
Protexin and Salmonella-specific
bacteriophages were administered to birds according to the dosage and
administration detailed in the table above.
The challenge pathogen, Salmonella
typhimurium, was orally inoculated at a concentration of 4x105 CFU/bird on day
7 of age according to the dosage and administration detailed in the table
above.
Daily live weight was measured for all
birds in all groups from the Day of Hatch (DOH) until Day 18. Birds were either
euthanized on day 18 or day 21. Necropsy was preformed and samples of ileal
contents, ileal wall, caeca and pool of spleen and liver analysed for quantitative
bacteriology. Parameter
| Day
| Results
| Significance
| Live weight
| Throughout
| Groups 1, 2, 3 and 5 than Group 4
| No significant difference but indicated a protective effect of the treatments on birds experimentally infected with Salmonella typhimurium. | | Live weight | Day 7
| Group 4
| Reduction in weight post challenge (Day 7) and maintenance of a mean lower live weight throughout the experimental period.
| | Live weight | Day 18
| Group 4 (157g) less mean weight than Group 2 (181g)
| P < 0.05
| | Live weight | Day 18
| Group 1 (17g), Group 3 (169g) higher mean weight than Group 2 (157g)
| No significant difference but indicated a protective effect of the treatments on birds experimentally infected with Salmonella typhimurium. | Ileum
| Day 11
| Group 1 and 3 less Salmonella typhimurium than Group 4
| P < 0.05
| Ileum
| Day 11
| Group 2 less Salmonella typhimurium than Group 4 | No significant difference but indicated a protective effect of the treatments on birds experimentally infected with Salmonella typhimurium. | Ileum
| Day 21
| Group 1 and 3 less Salmonella typhimurium than Group 4 | P < 0.05 | Cseca
| Day 11
| Group 1 and 3 10-fold less Salmonella typhimurium than Group 4 | P < 0.05 | Caeca
| Day 11
| Group 2 less Salmonella typhimurium than Group 4 | P < 0.05 | Caeca
| Day 21
| Group 1 and 3 less Salmonella typhimurium than Group 4 | P < 0.05 | Spleen/liver pools
| Day 11
| Group 1, 2 and 3 less Salmonella typhimurium than Group 4 | No significant difference but indicated a protective effect of the treatments on birds experimentally infected with Salmonella typhimurium. | Spleen/liver pools
| Day 21
| Group 1, 2 and 3 less Salmonella typhimurium than Group 4 | No significant difference but indicated a protective effect of the treatments on birds experimentally infected with Salmonella typhimurium. |
Conclusion:
Results indicate a protective effect of
Protexin as a Competitive Exclusion product against Salmonella typhimurium
colonisation in experimentally infected broilers.
ToroA,
H., PriceA, S.B., McKeeB, S., HoerrA, F.J., KrehlingA, J., PerdueA, M. and BauermeisterB, L. (2005). Use of
Bacteriophages in Combination with Competitive Exclusion to Reduce Salmonella
from Infected Chickens. Avian Diseases. 49: 118-124.
ADepartment
of Pathobiology, College of Veterinary Medicine, Auburn University.
BDepartment
of Poultry, College of Agriculture, Auburn University.
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