Diet Change in Broilers Can Reduce Salmonella Challenge08 May 2014
Following a Salmonella Typhimurium challenge in chicks, dietary supplementation with the amino acid, arginine and vitamin E improved immune response although the concentration of the bacteria in the birds' caeca were unaffected, according to new research from the US.
Two experiments published in Poultry Science evaluated the effects of arginine, vitamin E and mannanoligosaccharide (MOS) on the immune response and clearance of Salmonella in broiler chickens, reported X. Liu of Texas A&M Univeristy and co-authors there and at USDA-ARS, Southern Plains Agricultural Research Center and Mississippi State University.
In each experiment, day-old chicks (n=160) were randomly distributed into four groups:
- antibiotic-free diet (negative control, CTL−)
- antibiotic-supplemented diet (positive control, CTL+)
- antibiotic free-diet plus arginine and vitamin E (AVE), or
- antibiotic-free diet plus arginine, vitamin E and MOS (AVM).
Birds were orally challenged with 106 colony-forming units (cfu) of a novobiocyn and nalidixic acid-resistant Salmonella enterica serovar Typhimurium strain on day 7 (experiment 1) or day 3 (experiment 2).
Heterophil- (HOB) and monocyte- (MOB) oxidative burst and lymphocyte proliferation (LPR), antibody titres and Salmonella content in the caeca were measured at several intervals post-infection (PI).
In experiment 1, both AVM and AVE decreased HOB compared with the controls five and nine days post-infection but increased LPR nine days post-infection.
In the same experiment, birds fed the AVE diet had higher MOB than birds fed CTL+ or the AVM diet at seven days post-infection, whereas nine days post-infection, birds fed the AVM diet had the highest MOB.
In experiment 2, birds fed the AVE diet had higher MOB, HOB and LPR than birds in the other treatments seven and 14 days post-infection, except on day 7 post-infection, when MOB was not different among treatments.
Birds fed the AVM diet had the highest IgA antibody titre and a higher IgM antibody titre than the CTL+ birds.
In experiment 1, Salmonella Typhimurium content in the caeca was lower in birds fed the AVM diet than those fed the CTL− diet three days post-infection. However, later on, (10 and 17 days post-infection), and in experiment 2 (at seven 14, and 21 days post-infection), Salmonella Typhimurium concentrations were not different among treatments.
Liu and co-authors concluded that arginine and vitamin E improved immune response after a Salmonella Typhimurium challenge in young chicks. Although they did not reduce Salmonella Typhimurium concentrations in the caeca, they may improve bacterial resistance against other pathogens in commercial growing conditions.
Liu X., J.A. Byrd, M. Farnell and C.A. Ruiz-Feria. 2014. Arginine and vitamin E improve the immune response after a Salmonella challenge in broiler chicks. Poultry Science. 93:882-890. doi: 10.3382/ps.2013-03723
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