MICROBIAL INTERACTIONS AND INTERVENTIONS TO REDUCE TRANSMISSION OF FOODBORNE PATHOGENS THROUGH POULTRY
Location: Food and Feed Safety Research
Title: Dietary lactose and its effects on the disease necrotic enteritis
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 3, 2007
Publication Date: August 1, 2007
Citation: McReynolds, J.L., Byrd II, J.A., Genovese, K.J., Poole, T.L., Duke, S.E., Farnell, M.B., Nisbet, D.J. 2007. Dietary lactose and its effect on the disease condition of necrotic enteritis. Poultry Science. 86:1656-1661.
Interpretive Summary: In the commercial poultry industry, diseases of the gastrointestinal tract can cause serious health and economic effects. One of these diseases is necrotic enteritis (NE). This disease is known to be caused by the bacterium Clostridium perfringens, however the cause of the disease is poorly understood. Lactose has been shown to have beneficial impacts on the gastrointestinal microflora. The objective of the present investigation was to evaluate the microbial ecology and clinical signs associated with NE in the gastrointestinal system of birds being fed dietary lactose. Birds fed low concentrations of dietary lactose had decreased clinical signs of NE. Because of the low cost of lactose and the potential benefits both on animal health and enteropathogen control, lactose may offer a cost effective means to decrease the impact of NE on commercial poultry production.
Clostridium perfringens (CP) is the etiologic agent of Necrotic enteritis (NE) and is ubiquitous in nature. The incidence of NE has increased in poultry flocks that have stopped using antibiotic growth promoters. The mechanisms of colonization of CP and the factors involved in onset of NE are not fully understood. Previously, our laboratory has demonstrated that lactose could potentially reduce Salmonella and CP in ceca of poultry. In the present investigation, we hypothesized that dietary lactose would reduce the clinical signs of NE and could be used as an alternative to antibiotics. In Exp. 1, day-of-hatch broilers were fed either a non-lactose control diet, a diet with 2.5% lactose, or a diet with 4.5% lactose throughout the experiment. Birds were administered CP (10**7 cfu/mL) daily via oral gavage for three consecutive days starting on d 17. When evaluating the intestinal lesions associated with NE, birds fed 2.5% lactose had significantly lower (P < 0.05) lesion scores (0.70 ± .52) compared to the control (1.55 ± .52) or the 4.5% lactose (1.60 ± .52) fed groups. Microbial population analysis suggest that lactose did not affect bacterial populations during the 21d evaluation. In a replicate experiment the overall lesion scores, were significantly (P > 0.05) reduced in birds fed 2.5% lactose compared to the birds fed the control diet with mean lesion scores of 1.10 ± .73 and 1.80 ± .73 respectively. These experiments suggest that lactose could be used as a potential alternative to growth promoting antibiotics to help control this costly disease.