Effects of Electron-Beam Irradiation of the Diet on Microbial Population, Intestinal Morphology, Ileal Digestibility and Performance of Broilers

Document Type: Research Article


1 Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran

2 Radiation Applications Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, Karaj, Iran


A total of 300 one-day old male broilers (Cobb 500) were randomly divided into four treatment groups. The groups comprised of 15 birds each, and were defined by diet and the birds in each group were fed 0 (control), 3, 5, or 7 kGy electron-beam irradiated diets. A total of 5 replicates were performed. The chemical composition of the diet was not affected by irradiation.Irradiation doses of 5 and 7 kGy completely eliminated microbial load in diets (P<0.05) and decreased the total aerobic and coliform counts in ileum and cecum at increasing rate at 14, 28 and 42 days of age (L: P<0.001; Q: P<0.0001). Total coliforms of the ileum decreased with the increased irradiation dose at 21 and 42 days of age (Q: P<0.0001). Lactobacillus counts improved with increased EBI dose, except for lactobacillus in cecum at 42 days of age. There was a linear increase in villus height (duodenum, jejunum, and ileum) with higher irradiation doses at 21 and 42 days of age. Additionally, a linear increase and a decrease in villus height:crypt depth were observed in the jejunum at 21 and 42 days of age, respectively (P<0.05). The villus height:crypt depth of duodenum and jejunum followed a linear increasing rate (Q: P<0.001) with the increased irradiation dose. Feed intake, mortality (all periods), body weight gain, and feed conversion ratio were similar between treatments at 1-14 and 14-28 days of age. Body weight gain, however, increased at a rising rate (Q: P<0.001), and feed conversion ratio decreased at a diminishing rate (Q: P<0.01) with higher irradiation doses during 28-42 and 1-42 days of age. The ileal digestibility of dry matter, organic matter, ether extracts, gross energy, and apparent metabolizable energy increased with the irradiation dose (Q: P<0.001). Our results indicated that electron-beam diet irradiation reduces microbial coliform counts and supports lactic acid producers in the gastrointestinal tract. Moreover, the ileal digestibility of nutrients, body weight gain, and feed conversion ratio improve with irradiation.


Al-Masri M.R. (2003).Changes in apparent metabolizable energy and digestive tract of broiler chickens fed diets containing irradiated meat-bone meal. Radiat. Phys. Chem. 67, 73-77.
Ananthaswamy H.N., Vakil U.K. and Sreenivasan A. (1970). Susceptibility to amylolysis of gamma irradiated wheat. J. Food Sci. 35, 792-794.
AOAC. (2000). Official Methods of Analysis. 15th Ed. Association of Official Analytical Chemists, Inc., Washington D.C., USA.
Barrow P.A. (1992). Probiotics for chicken. Pp. 255-257 in Probiotics: The Scientific Basis. F. Fuller Ed.  Chapman and Hall, London, UK.
Campbell G.L., Classen H.L., Reichert R.D.andCampbell L.D. (1983). Improvement of the nutritive value of rye for broiler chickens by gamma irradiation-induced viscosity reduction. Br. Poult. Sci. 24, 205-212.
Derouchey J.M., Tokach M.D., Nelssen R.D., Goodband S.S., Dritz J.S., Woodworth J.C., Webster M.J. and James B.W. (2003). Effects of blood meal pH and irradiation on nursery pig performance. J. Anim. Sci. 81, 1013-1022.
Diehl J.F. and Scherz H. (1975). Estimation of radiolytic products as a basis for evaluation the wholesomeness of irradiated foods. J. Appl. Radiat. Isot. 26, 499-507.
Elias P.S. and CohenA.J. (1977). Radiation Chemistry of Major Food Components: its Relevance to the Assessment of the Wholesomeness of Irradiated Foods.Amsterdam; New York : Elsevier Scientific Pub. Co.
Engberg R.M., Hedeman M.S. and Jensen B.B. (2002). The influence of grinding and pelleting of feed on the microbial composition and activity in the digestive tract of broiler chickens. Br. Poult. Sci. 43, 569-579.
Engberg R.M., Hedemann M.S., Steenfeldt S. and Jensen B. (2004). Influence of whole wheat and xylanase on broiler performance and microbial composition and activity in the digestive tract. Poult. Sci. 83, 925-938.
Farag M.D.E.H. (1989). Radiation deactivation of antinutritional factors: trypsin inhibitor and hemagglutinin in soybeans. Egyptian J. Rad. Sci. Appl. 6, 207-215.
Farag M.D.E.H. (1998). The nutritive value for chicks of full-fat soybeans irradiated at up to 60 kGy. Anim. Feed. Sci. Technol. 73, 319-328.
Ghazy M.A. (1990). Effect of gamma-irradiation on some antinutritional factors in kidney bean (Phaseolus vulgaris) seeds. Minia J. Agric. Res. Dev. 12, 1965-1980.
Gong J., Forster R.J., Yu H., Chambers J.R., Wheatcroft R., Sabour P.M. and Chen S. (2002).Molecular analysis of bacterial populations in the ileum of broiler chickens and comparison with bacteria in the cecum. FEMS. Microbiol. Ecol. 41, 171-179.
Hubener K., Vahjen W. and Simon O. (2002). Bacterial responses to different dietary cereal types and xylanase supplementation in the intestine of broiler chicken. Arch. Anim. Nutr. 56, 167-187.
Iji P.A., Saki A. and Tivey D.R. (2001). Body and intestinal growth of broiler chicks on a commercial starter diet. 1. Intestinal weight and mucosal development. Br. Poult. Sci. 42, 505-513.
Ismail F.A. and Osman A.Z. (1976). Improvement in digestibility of broad bean (Vicia faba) by gamma-irradiation. Istp. Radiat. Res. 8, 17-22.
Jay J.M., Loessner M.J. and Golden D.A. (2005). Modern Food Microbiology 7th Ed. New York, NY, USA.
Kim H.J., Feng H., Kushad M.M. and Fan X. (2006). Effects of ultrasound, irradiation and acidic electrolyzed water on germination of alfalfa and broccoli seeds and Escherichia coli O157:H7. J. Food Sci. 71, 168-173.
Kluth H. and Rodehutscord M. (2010). Effect of the duration of prefeeding on amino acid digestibility of wheat distillers dried grains with solubles in broiler chicken. Poult. Sci. 89, 681-687.
Knarreborg A., Simon R., Engberg M., Jensen B.B. and Tannock G.W. (2002).Effects of dietary fat source and subtherapeutic levels of antibiotic on the bacterial community in the ileum of broiler chickens at various ages.Appl. Environ. Microb.68, 5918-5924.
Lacroix M., Amiot J. and Brisson G.J. (1983). Hydrolysis and ultrafiltration treatment to improve the nutritive value of rapeseed proteins. J. Food Sci. 48, 1644-1645.
Lee M.H., Lee M.K. and Kwon J.H. (1998). Sterilizing effect of electron beam on ginseng powders. Korean J. Food Sci. Technol. 30, 1362-2366.
Louise M.F., Paul E.C. and Alistair S.G. (2006). The effect of electron beam irradiation, combined with acetic acid, on the survival and recovery of Escherichia coli and Lactobacillus curvatus. Int. J. Food Microbiol. 35, 259-265.
Mani V.andChandra P. (2003).Effect of feeding soybean on nutrient intake, digestibility and N-balance in goats. SmallRumin. Res. 48, 77-81.
Molins R.A. (2001). Food Irradiation Principles and Applications. John Wiley and Sons Inc., Publication, New York. USA. ISBN 0–471-35634–4.
NRC. (1994). Nutrient Requirements of Poultry, 9th Rev. Ed. National Academy Press, Washington, DC.
Nene S.P., Vakil U.K. and Sreenivasan A. (1975). Effect of gamma radiation on red gram (Cajanus cajan) proteins. J. Food Sci. 40, 815-819.
Nieto-Sandoval J.M., Almela L., Fernandez-Lopez J. and Munoz J.A. (2000). Effect of electron beam irradiation on color and microbial bioburden of red paprika. J. Food Prot. 63, 633-637.
Rodriguez O., Castell-Perez M.E., Ekpanyaskun N., Moreira R.G. and Castillo A. (2006). Surrogates of validation of electron beam irradiation of foods. Int. J. Food Microbiol. 110, 117-122.
Saeman J.F., Millett M.A. and Lawton E.J. (1952). Effect of high energy cathode rays on cellulose. Indust. Engin. Chem. 44, 2848-2852.
Sandev S. and Karaivanov I. (1977).The composition and digestibility of irradiated roughage treatment with gamma irradiation.Tierernahr. Fuetterung. 10, 238-242.
SAS Institute. (2004). SAS®/STAT Software, Release 9.2. SAS Institute, Inc., Cary, NC.
Satin M. (1996). Food Irradiation. Pp. 1-25 in Food Irradiation: a Guidebook. 2nd Ed. Technomic Publishing Company, Inc., Lancaster, PA.
Shakouri M.D., Iji P.A., Mikkelsen L.L. and Cowieson A.J. (2009). Intestinal function and gut microflora of broiler chickens as influenced by cereal grains and microbial enzyme supplementation. J. Anim. Physiol. Anim. Nutr. 93, 647-658.
Short F.J., Gorton P., Wiseman J. and Boorman K.N. (1996).Determination of titanium dioxide added as an inert marker in chicken digestibility studies. Anim. Feed Sci. Technol. 59, 215-221.
Siddhuraju P., Makkarb H.P.S. and Beckera K. (2002). The effect of ionising radiation on antinutritional factors and the nutritional value of plant materials with reference to human and animal food. Food Chem. 78, 187-205.
Williams B.A., Verstegen M.W.A. and Tamminga S. (2001). Fermentation in the large intestine of single-stomached animals and its relationship to animal health. Nutr. Res. Rev. 14, 207-227.
Witkamp M. (1963). Microbial populations of leaf litter in relation to environmental conditions and decomposition. J. Anim. Ecol. 44, 370-377.
Xu Z.R., Hu C.H., Xia M.S., Zhan X.A. and Wang M.Q. (2003). Effects of dietary fructo oligosaccharide on digestive enzyme activities, intestinal microflora and morphology of male broilers. Poult. Sci. 82, 1030-1036.
Zeb A., Bibi N., Shah A.B., Chaudry M.A., Asif A.R., Jan M. and Meulen U.T. (2002).Nutritional value of rapeseed meal for broiler chicks as influenced by gamma irradiation treatments. Nucleus. 39, 119-125.