Skip to main content Accessibility help
×
×
Home

Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review

  • U. Gadde (a1), W. H. Kim (a1), S. T. Oh (a1) and Hyun S. Lillehoj (a1)

Abstract

With the increase in regulations regarding the use of antibiotic growth promoters and the rise in consumer demand for poultry products from ‘Raised Without Antibiotics’ or ‘No Antibiotics Ever’ flocks, the quest for alternative products or approaches has intensified in recent years. A great deal of research has focused on the development of antibiotic alternatives to maintain or improve poultry health and performance. This review describes the potential for the various alternatives available to increase animal productivity and help poultry perform to their genetic potential under existing commercial conditions. The classes of alternatives described include probiotics, prebiotics, synbiotics, organic acids, enzymes, phytogenics, antimicrobial peptides, hyperimmune egg antibodies, bacteriophages, clay, and metals. A brief description of the mechanism of action, efficacy, and advantages and disadvantages of their uses are also presented. Though the beneficial effects of many of the alternatives developed have been well demonstrated, the general consensus is that these products lack consistency and the results vary greatly from farm to farm. Furthermore, their mode of action needs to be better defined. Optimal combinations of various alternatives coupled with good management and husbandry practices will be the key to maximize performance and maintain animal productivity, while we move forward with the ultimate goal of reducing antibiotic use in the animal industry.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review
      Available formats
      ×

Copyright

Corresponding author

*Corresponding author. E-mail: hyun.lillehoj@ars.usda.gov

Footnotes

Hide All

Oak Ridge Institute for Science and Education (ORISE) Research Fellow at the Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, USDA, Beltsville, MD 20705, USA.

Footnotes

References

Hide All
Adeola, O and Cowieson, AJ (2011). Opportunities and challenges in using exogenous enzymes to improve non-ruminant animal production. Journal of Animal Science 89: 31893218.
Adil, S, Banday, T, Bhat, GA, Mir, MS and Rehman, M (2010). Effect of dietary supplementation of organic acids on performance, intestinal histomorphology, and serum biochemistry of broiler chicken. Veterinary Medicine International 2010: 479485.
Adil, S, Banday, T, Bhat, GA, Salahuddin, M, Raquib, M and Shanaz, S (2011). Response of broiler chicken to dietary supplementation of organic acids. Journal of Central European Agriculture 12: 498508.
Ahmed, ST, Islam, MM, Mun, HS, Sim, HJ, Kim, YJ and Yang, CJ (2014). Effects of Bacillus amyloliquefaciens as a probiotic strain on growth performance, cecal microflora, and fecal noxious gas emissions of broiler chickens. Poultry Science 93: 19631971.
Alçiçek, A, Bozkurt, M and Çabuk, M (2004). The effect of a mixture of herbal essential oils, an organic acid or a probiotic on broiler performance. South African Journal of Animal Science 34: 217222.
Alimohamadi, K, Taherpour, K, Ghasemi, HA and Fatahnia, F (2014). Comparative effects of using black seed (Nigella sativa), cumin seed (Cuminum cyminum), probiotic or prebiotic on growth performance, blood hematology and serum biochemistry of broiler chicks. Journal of Animal Physiology and Animal Nutrition 98: 538546.
Alzueta, C, Rodríguez, ML, Ortiz, LT, Rebolé, A and Treviño, J (2010). Effects of inulin on growth performance, nutrient digestibility and metabolisable energy in broiler chickens. British Poultry Science 51: 393398.
Alloui, MN, Szczurek, W and Świątkiewicz, S (2013). The usefulness of prebiotics and probiotics in modern poultry nutrition: a review. Annals of Animal Science 13: 1732.
Amad, AA, Männer, K, Wendler, KR, Neumann, K and Zentek, J (2011). Effects of a phytogenic feed additive on growth performance and ileal nutrient digestibility in broiler chickens. Poultry Science 90: 28112816.
Amerah, AM, Péron, A, Zaefarian, F and Ravindran, V (2011). Influence of whole wheat inclusion and a blend of essential oils on the performance, nutrient utilisation, digestive tract development and ileal microbiota profile of broiler chickens. British Poultry Science 52: 124132.
Ani, AO, Ogbu, CC and Iloh, EA (2014). Response of broiler chicks to diets containing graded levels of clay. Journal of Animal and Plant Sciences 24: 3034.
Apata, DF (2008). Growth performance, nutrient digestibility and immune response of broiler chicks fed diets supplemented with a culture of Lactobacillus bulgaricus . Journal of the Science of Food and Agriculture 88: 12531258.
Applegate, TJ, Klose, V, Steiner, T, Ganner, A and Schatzmayr, G (2010). Probiotics and phytogenics for poultry: myth or reality? Journal of Applied Poultry Research 19: 194210.
Arias, VJ and Koutsos, EA (2006). Effects of copper source and level on intestinal physiology and growth of broiler chickens. Poultry Science 85: 9991007.
Ashayerizadeh, A, Dabiri, N, Ashayerizadeh, O, Mirzadeh, KH, Roshanfekr, H and Mamooee, M (2009). Effect of dietary antibiotic, probiotic and prebiotic as growth promoters, on growth performance, carcass characteristics and hematological indices of broiler chickens. Pakistan Journal of Biological Sciences 12: 5257.
Attia, YA, Qota, EM, Zeweil, HS, Bovera, F, Abd Al-Hamid, AE and Sahledom, MD (2012). Effect of different dietary concentrations of inorganic and organic copper on growth performance and lipid metabolism of White Pekin male ducks. British Poultry Science 53: 7788.
Atteh, JO, Onagbesan, OM, Tona, K, Decuypere, E, Geuns, JMC and Buyse, J (2008). Evaluation of supplementary stevia (Stevia rebaudiana, bertoni) leaves and stevioside in broiler diets: effects on feed intake, nutrient metabolism, blood parameters and growth performance. Journal of Animal Physiology and Animal Nutrition 92: 640649.
Awad, WA, Ghareeb, K, Abdel-Raheem, S and Böhm, J (2009). Effects of dietary inclusion of probiotic and synbiotic on growth performance, organ weights, and intestinal histomorphology of broiler chickens. Poultry Science 88: 4955.
Bai, SP, Wu, AM, Ding, XM, Lei, Y, Bai, J, Zhang, KY and Chio, JS (2013). Effects of probiotic-supplemented diets on growth performance and intestinal immune characteristics of broiler chickens. Poultry Science 92: 663670.
Banday, MT, Adil, S, Khan, AA and Untoo, M (2015). A study of efficacy of fumaric acid supplementation in diet of broiler chicken. International Journal of Poultry Science 14: 589594.
Bao, H, She, R, Liu, T, Zhang, Y, Peng, KS, Luo, D, Yue, Z, Ding, Y, Hu, Y, Liu, W and Zhai, L (2009). Effects of pig antibacterial peptides on growth performance and intestine mucosal immune of broiler chickens. Poultry Science 88: 291297.
Basmacioğlu, H, Tokuşoğlu, Ö and Ergül, M (2004). The effect of oregano and rosemary essential oils or alpha-tocopheryl acetate on performance and lipid oxidation of meat enriched with n-3 PUFA's in broilers. South African Journal of Animal Science 34: 197210.
Baurhoo, B, Phillip, L and Ruiz-Feria, CA (2007). Effects of purified lignin and mannan oligosaccharides on intestinal integrity and microbial populations in the ceca and litter of broiler chickens. Poultry Science 86: 10701078.
Bedford, M (2000). Removal of antibiotic growth promoters from poultry diets: implications and strategies to minimise subsequent problems. World's Poultry Science Journal 56: 347365.
Bedford, MR and Cowieson, AJ (2012). Exogenous enzymes and their effects on intestinal microbiology. Animal Feed Science and Technology 173: 7685.
Bedford, MR and Schulze, H (1998). Exogenous enzymes for pigs and poultry. Nutrition Research Reviews 11: 91114.
Benites, V, Gilharry, R, Gernat, AG and Murillo, JG (2008). Effect of dietary mannan oligosaccharide from Bio-Mos or SAF-Mannan on live performance of broiler chickens. Journal of Applied Poultry Research 17: 471475.
Biggs, P and Parsons, CM (2008). The effects of several organic acids on growth performance, nutrient digestibilities, and cecal microbial populations in young chicks. Poultry Science 87: 25812589.
Blajman, JE, Frizzo, LS, Zbrun, MV, Astesana, DM, Fusari, ML, Soto, LP, Rosmini, MR and Signorini, ML (2014). Probiotics and broiler growth performance: a meta-analysis of randomized controlled trials. British Poultry Science 55: 483494.
Boroojeni, F, Vahjen, W, Mader, A, Knorr, F, Ruhnke, I, Röhe, I, Hafeez, A, Villodre, C, Männer, K and Zentek, J (2014). The effects of different thermal treatments and organic acid levels in feed on microbial composition and activity in gastrointestinal tract of broilers. Poultry Science 93: 14401452.
Bozkurt, M, Küçükyilmaz, K, Çatli, AU and Çinar, M (2008). Growth performance and slaughter characteristics of broiler chickens fed with antibiotic, mannan oligosaccharide and dextran oligosaccharide supplemented diets. International Journal of Poultry Science 7: 969977.
Brainer, MMA, Menten, JFM, Vale, MM and Morais, SCD (2003). Cupric citrate as growth promoter for broiler chickens in different rearing stages. Scientia Agricola 60: 441445.
Bravo, D and Ionescu, C (2008). Meta-analysis of the effect of a mixture of carvacrol, cinnamaldehyde and capsicum oleoresin in broilers. Poultry Science 87 (suppl. 1): 75.
Bravo, D, Pirgozliev, V and Rose, SP (2014). A mixture of carvacrol, cinnamaldehyde, and capsicum oleoresin improves energy utilization and growth performance of broiler chickens fed maize-based diet. Journal of Animal Science 92: 15311536.
Brenes, A, Viveros, A, Goñi, I, Centeno, C, Sáyago-Ayerdy, SG, Arija, I and Saura-Calixto, F (2008). Effect of grape pomace concentrate and vitamin E on digestibility of polyphenols and antioxidant activity in chickens. Poultry Science 87: 307316.
Brennan, KM, Graugnard, DE, Xiao, R, Spry, ML, Pierce, JL, Lumpkins, B and Mathis, GF (2013). Comparison of gene expression profiles of the jejunum of broilers supplemented with a yeast cell wall-derived mannan oligosaccharide versus bacitracin methylene disalicylate. British Poultry Science 54: 238246.
Brown, M (2011). Modes of action of probiotics: recent developments. Journal of Animal and Veterinary Advances 10: 18951900.
Burrell, AL, Dozier, WA III, Davis, AJ, Compton, MM, Freeman, ME, Vendrell, PF and Ward, TL (2004). Responses of broilers to dietary zinc concentrations and sources in relation to environmental implications. British Poultry Science 45: 255263.
Çabuk, M, Bozkurt, M, Alçiçek, A, Akbaş, Y and Küçükyilmaz, K (2006). Effect of a herbal essential oil mixture on growth and internal organ weight of broilers from young and old breeder flocks. South African Journal of Animal Science 36: 135141.
Cao, FL, Zhang, XH, Yu, WW, Zhao, LG and Wang, T (2012). Effect of feeding fermented Ginkgo biloba leaves on growth performance, meat quality, and lipid metabolism in broilers. Poultry Science 91: 12101221.
Calik, A and Ergün, A (2015). Effect of lactulose supplementation on growth performance, intestinal histomorphology, cecal microbial population, and short-chain fatty acid composition of broiler chickens. Poultry Science 94: 21732182.
Castanon, JIR (2007). History of the use of antibiotic as growth promoters in European poultry feeds. Poultry Science 86: 24662471.
Cavazzoni, V, Adami, A and Castrovilli, C (1998). Performance of broiler chickens supplemented with Bacillus coagulans as probiotic. British Poultry Science 39: 526529.
Chalghoumi, R, Belgacem, A, Trabelsi, I, Bouatour, Y and Bergaoui, R (2013). Effect of dietary supplementation with probiotic or essential oils on growth performance of broiler chickens. International Journal of Poultry Science 12: 538544.
Chamorro, S, Viveros, A, Centeno, C, Romero, C, Arija, I and Brenes, A (2013). Effects of dietary grape seed extract on growth performance, amino acid digestibility and plasma lipids and mineral content in broiler chicks. Animal 7: 555561.
Cheng, G, Hao, H, Xie, S, Wang, X, dai, M, Huang, L and Yuan, Z (2014). Antibiotic alternatives: the substitution of antibiotics in animal husbandry? Frontiers in Microbiology 5: 217.
Chiang, SH and Hsieh, WM (1995). Effect of direct fed microorganisms on broiler growth performance and litter ammonia level. Asian-Australasian Journal of Animal Sciences 8: 159162.
Chichlowski, J, Croom, J, McBride, BW, Havenstein, GB and Koci, MD (2007). Metabolic and physiological impact of probioitcs or Direct-Fed-Microbials on poultry: a brief review of current knowledge. International Journal of Poultry Science 6: 694704.
Cho, JH and Kim, IH (2014). Effects of lactulose supplementation on performance, blood profiles, excreta microbial shedding of Lactobacillus and Escherichia coli, relative organ weight and excreta noxious gas contents in broilers. Journal of Animal Physiology and Animal Nutrition 98: 424430.
Cho, I, Yamanishi, S, Cox, L, Methé, BA, Zavadil, J, Li, K, Gao, Z, Mahana, D, Raju, K, Teitler, I, Li, H, Alekseyenko, AV and Blaser, MJ (2012). Antibiotics in early life alter the murine colonic microbiome and adiposity. Nature 488: 621626.
Choct, M (2001). Alternatives to in-feed antibiotics in monogastric animal industry. American Soybean Association Technical Bulletin 30: 16.
Choct, M (2006). Enzymes for the feed industry: past, present and future. Worlds's Poultry Science Journal 62: 515.
Choct, M (2009). Managing gut health through nutrition. British Poultry Science 50: 915.
Choi, SC, Ingale, SL, Kim, JS, Park, YK, Kwon, IK and Chae, BJ (2013). An antimicrobial peptide-A3: effects on growth performance, nutrient retention, intestinal and faecal microflora and intestinal morphology of broilers. British Poultry Science 54: 738746.
Chowdhury, R, Islam, KMS, Khan, MJ, Karim, MR, Haque, MN, Khatun, M and Pesti, GM (2009). Effect of citric acid, avilamycin, and their combination on the performance, tibia ash, and immune status of broilers. Poultry Science 88: 16161622.
Ciorba, MA (2012). A Gastroenterologist's guide to probiotics. Clinical Gastroenterology and Hepatology 10: 960968.
Cleveland, J, Montville, TJ, Nes, IF and Chikindas, ML (2001). Bacteriocins: safe, natural antimicrobials for food preservation. International Journal of Food Microbiology 71: 120.
Cook, ME (2001). Method of using anti-phospholipase A2 antibodies to enhance growth or improve feed efficiency. US Patent 6,213,930 B1.
Cook, ME (2002). Method of using anti-phospholipase A2 antibodies to enhance growth or improve feed efficiency. US Patent 6,383,485.
Cook, ME (2004). Antibodies: alternatives to antibiotics in improving growth and feed efficiency. Journal of Applied Poultry Research 13: 106119.
Corrigan, A, Horgan, K, Clipson, N and Murphy, RA (2011). Effect of dietary supplementation with a Saccharomyces cerevisiae mannan oligosaccharide on the bacterial community structure of broiler cecal contents. Applied and Environmental Microbiology 77: 66536662.
Cosby, DE, Cox, NA, Harrison, MA, Wilson, JL, Buhr, RJ and Fedorka-Cray, PJ (2015). Salmonella and antimicrobial resistance in broilers: a review. Journal of Applied Poultry Research 24: 408426.
Cotter, PD, Hill, C and Ross, RP (2005). Bacteriocins: developing innate immunity for food. Nature Reviews Microbiology 3: 777788.
Cox, CM and Dalloul, RA (2015). Immunomodulatory role of probiotics in poultry and potential in ovo application. Beneficial Microbes 6: 4552.
Cox, LM, Yamanishi, S, Sohn, J, Alekseyenko, AV, Leung, JM, Cho, I, Kim, SG, Li, H, Gao, Z, Mahana, D, Rodriguez, JGZ, Rogers, AB, Robine, N, Loke, P and Blaser, JM (2014). Altering the intestinal microbiota during a critical developmental window has lasting metabolic consequences. Cell 158: 705721.
Cromwell, GL (1991). Antimicrobial agents. In: Miller, ER, Ullrey, DE and Lewis, AJ (eds) Swine Nutrition. Stoneham: Butterworth-Heinemann, pp. 297314.
Czerwiński, J, Højberg, O, Smulikowska, S, Engberg, RM and Mieczkowska, A (2010). Influence of dietary peas and organic acids and probiotic supplementation on performance and caecal microbial ecology of broiler chickens. British Poultry Science 51: 258269.
Dahiya, JP, Wilkie, DC, Van Kessel, AG and Drew, MD (2006). Potential strategies for controlling necrotic enteritis in broiler chickens in post-antibiotic era. Animal Feed Science and Technology 129: 6088.
d'Herelle, F (1917). Sur un microbe invisible antagonists des bacilles dysenteriques. Comptes rendus de l'Académie des Sciences 165: 373375.
Dibner, JJ and Buttin, P (2002). Use of organic acids as a model to study the impact of gut microflora on nutrition and metabolism. Journal of Applied Poultry Research 11: 453463.
Dibner, JJ and Richards, JD (2005). Antibiotic growth promoters in agriculture: history and mode of action. Poultry Science 84: 634643.
Dumonceaux, TJ, Hill, JE, Hemmingsen, SM and Van Kessel, AG (2006). Characterization of intestinal microbiota and response to dietary virginiamycin supplementation in the broiler chicken. Applied and Environmental Microbiology 72: 28152823.
Durrani, FR, Sultan, A, Ahmed, S, Chand, N, Khattak, FM and Durrani, Z (2007). Efficacy of aniseed extract as immune stimulant and growth promoter in broiler chicks. Pakistan Journal of Biological Sciences 10: 37183721.
Edens, FW (2003). An alternative for antibiotic use in poultry: probiotics. Revista Brasileria de Ciência Avícola 5: 7597.
Endtz, HP, Mouton, RP, van der Reyden, T, Ruijs, GJ, Biever, M and van Klingeren, B (1990). Fluoroquinolone resistance in Campylobacter spp. isolated from human stools and poultry products. Lancet 335: 787.
Engberg, RM, Hedemann, MS and Jensen, BB (2002). The influence of grinding and pelleting of feed on the microbial composition and activity in the digestive tract of broiler chickens. British Poultry Science 43: 569579.
El-Abasy, M, Motobu, M, Shimura, K, Na, KJ, Kang, CB, Koge, K, Onodera, T and Hirota, Y (2002). Immunostimulating and growth-promoting effects of Sugar Cane Extract (SCE) in chickens. Journal of Veterinary Medical Science 64: 10611063.
Ewing, HP, Pesti, GM, Bakalli, RI and Menten, JFM (1998). Studies on the feeding of cupric sulfate pentahydrate, cupric citrate, and copper oxychloride to broiler chickens. Poultry Science 77: 445448.
FAO/WHO (2001). Health and nutritional properties of probiotics in food including powder milk with live lactic acid bacteria. Report of a Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food including Powder Milk with Live Lactic Acid Bacteria; FAO/WHO: Córdoba, Argentina, pp. 134.
FAO (2007). FAO technical meeting on prebiotics. [Available online at http://www.fao.org/ag/agn/files/prebiotics_tech_meeting.report.pdf.]
Faria Filho, DE, Torres, KAA, Faria, DE, Campos, DMB and Rosa, PS (2006). Probiotics for broiler chickens in Brazil: systematic review and meta-analysis. Brazilian Journal of Poultry Science 8: 8998.
Fawzy, MM, El-Sadawi, HA, El-Dien, MH and Mohamed, WAM (2016). Hematological and biochemical performance of poultry following zinc oxide and sodium selenite supplementation as food additives. Annals of Clinical Pathology 4: 1076.
FDA (2013). Guidance for Industry #213: New animal drugs and new animal drug combination products administered in or on medicated feed or drinking water of food-producing animals: Recommendations for drug sponsors for voluntarily aligning product use conditions with GFI #209. [Available online at http://www.fda.gov/downloads/AnimalVeterinary/GuidanceComplianceEnforcement/GuidanceforIndustry/UCM299624.pdf]
Feighner, SD and Dashkevicz, MP (1987). Subtherapeutic levels of antibiotics in poultry feeds and their effects on weight gain, feed efficiency and bacterial cholyltaurine hydrolase activity. Applied Environmental Microbiology 53: 331336.
Ferket, PR, Santos, AA Jr and Oviedo-Rondon, EO (2005). Dietary factors that affect gut health and pathogen colonization. In: Proceedings of 32nd Annual Carolina Poultry Nutrition Conference, Research Triangle Park, North Carolina, pp. 22.
Florou-Paneri, P, Giannenas, I, Christaki, E, Govaris, A and Botsoglou, N (2006). Performance of chickens and oxidative stability of the produced meat as affected by feed supplementation with oregano, vitamin C, vitamin E and their combinations. Archiv Fur Geflügelkunde 70: 232240.
Fosgerau, K and Hoffmann, T (2015). Peptide therapeutics: current status and future directions. Drug Discovery Today 20: 122128.
Fowler, J, Li, W and Bailey, C (2015). Effects of a calcium bentonite clay in diets containing aflatoxin when measuring liver residues of aflatoxin B1 in starter broiler chicks. Toxins 7: 34553464.
Francois, AC (1961). Mode of action of antibiotics on growth. World Review of Nutrition and Dietetics 3: 2164.
Franz, C, Baser, KHC and Windisch, W (2010). Essential oils and aromatic plants in animal feeding-a European perspective-A review. Flavour and Fragrance Journal 25: 327340.
Fuller, R (1989). Probiotics in man and animals. Journal of Applied Bacteriology 66: 365378.
Gadde, U, Rathinam, T and Lillehoj, HS (2015). Passive immunization with hyperimmune egg-yolk IgY as prophylaxis and therapy for poultry diseases – a review. Animal Health Research Reviews 16: 163176.
Gaskins, HR, Collier, CT and Anderson, DB (2002). Antibiotics as growth promotants: mode of action. Animal Biotechnology 13: 2942.
Geier, MS, Torok, VA, Allison, GE, Ophel-Keller, K and Hughes, RJ (2009). Indigestible carbohydrates alter the intestinal microbiota but do not influence the performance of broiler chickens. Journal of Applied Microbiology 106: 15401548.
Ghazanfari, S, Mohammadi, Z and Moradi, AM (2015). Effects of coriander essential oil on the performance, blood characteristics, intestinal microbiota and histology of broilers. Brazilian Journal of Poultry Science 17: 419426.
Gibson, GR and Roberfroid, MB (1995). Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. Journal of Nutrition 125: 14011412.
Goldberg, AL, Baracos, V, Rodemann, P, Waxman, L and Dinarello, C (1984). Control of protein degradation in muscles by prostaglandins, Ca2+ and leukocyte pyrogen (interleukin-1). Federation Proceedings 43: 13011306.
Goode, DH, Allen, VM and Barrow, PA (2003). Reduction of experimental Salmonella and Campylobacter contamination of chicken skin by application of lytic bacteriophage. Applied Environmental Microbiology 69: 50325036.
Goñi, I, Brenes, A, Centeno, C, Viveros, A, Saura-Calixto, F, Rebolé, A, Arija, I and Estevez, R (2007). Effect of dietary grape pomace and vitamin E on growth performance, nutrient digestibility, and susceptibility to meat lipid oxidation in chickens. Poultry Science 86: 508516.
Greko, C (2001). Safety aspects on non-use of antimicrobials as growth promoters. In: Piva, A, Bach Knudsen, KE and Lindberg, KE (eds) Gut Environment of Pigs. Nottingham: Nottingham University Press, pp. 219230.
Griggs, JP and Jacob, JP (2005). Alternatives to antibiotics for organic poultry production. Journal of Applied Poultry Research 14: 750756.
Groschke, AC and Evans, RJ (1950). Effects of antibiotics, synthetic vitamins, vitamin B12 and an APF supplement on chick growth. Poultry Science 29: 616618.
Guban, J, Korver, DR, Allison, GE and Tannock, GW (2006). Relationship of dietary antimicrobial drug administration with broiler performance, decreased population levels of Lactobacillus Salivarius, and reduced bile salt deconjugation in the ileum of broiler chickens. Poultry Science 85: 21862194.
Guo, FC, Kwakkel, RP, Soede, J, Williams, BA and Verstegen, MWA (2004). Effect of a Chinese herb medicine formulation, as an alternative for antibiotics, on performance of broilers. British Poultry Science 45: 793797.
Han, W, Zhang, XL, Wang, DW, Li, LY, Liu, GL and Zhao, YX (2013). Effects of microencapsulated Enterococcus faecalis CG1.0007 on growth performance, antioxidation activity, and intestinal microbiota in broiler chickens. Journal of Animal Science 91: 43744382.
Haque, MN, Islam, KM, Akbar, MA, Chowdhury, R, Khatun, M, Karim, MR and Kemppainen, BW (2010). Effect of dietary citric acid, flavomycin and their combination on the performance, tibia ash and immune status of broiler. Canadian Journal of Animal Science 90: 5763.
Hashemipour, H, Kermanshahi, H, Golian, A and Veldkamp, T (2013). Effect of thymol and carvacrol feed supplementation on performance, antioxidant enzyme activities, fatty acid composition, digestive enzyme activities, and immune response in broiler chickens. Poultry Science 92: 20592069.
Hashemipour, H, Kermanshahi, H, Golian, A and Khaksar, V (2014). Effects of carboxy methyl cellulose and thymol + carvacrol on performance, digesta viscosity and some blood metabolites of broilers. Journal of Animal Physiology and Animal Nutrition 98: 672679.
Heo, JM, Opapeju, FO, Pluske, JR, Kim, JC, Hampson, DJ and Nyachoti, CM (2013). Gastrointestinal health and function in weaned pigs: a review of feeding strategies to control post-weaning diarrhea without using in-feed antimicrobial compounds. Journal of Animal Physiology and Animal Nutrition 97: 207237.
Hernández, F, Madrid, J, García, V, Orengo, J and Megías, MD (2004). Influence of two plant extracts on broiler performance, digestibility, and digestive organ size. Poultry Science 83: 169174.
Hernández, F, Garcia, V, Madrid, J, Orengo, J, Catalá, P and Megias, MD (2006). Effect of formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens. British Poultry Science 47: 5056.
Hoda, AA and Maha, MH (1995). Potency of copper as growth promoter in broiler chickens. Veterinary Medical Journal 43: 7785.
Højberg, O, Canibe, N, Poulsen, HD, Hedemann, MS and Jensen, BB (2005). Influence of dietary zinc oxide or copper sulfate on the gastrointestinal ecosystem in newly weaned piglets. Applied and Environmental Microbiology 71: 22672277.
Hooge, DM (2004). Meta-analysis of broiler chicken pen trials evaluating dietary mannan oligosaccharide, 1993–2003. International Journal of Poultry Science 3: 163174.
Hooge, DM and Connolly, A (2011). Meta-analysis summary of broiler chicken trials with dietary Actigen® (2009–2011). International Journal of Poultry Science 10: 819824.
Hooge, DM, Sims, MD, Sefton, AE, Connolly, A and Spring, P (2003). Effect of dietary mannan oligosaccharide, with or without Bacitracin or Virginiamycin, on live performance of broiler chickens at relatively high stocking density on new litter. Journal of Applied Poultry Research 12: 461467.
Hooge, DM, Pierce, JL, McBride, KW and Rigolin, PJ (2010). Meta-analysis of broiler chicken trials using diets with or without Allzyme® SSF enzyme complex. International Journal of Poultry Science 9: 819823.
Houshmand, M, Azhar, K, Zulkifli, I, Bejo, MH and Kamyab, A (2012). Effects of prebiotic, protein level, and stocking density on performance, immunity, and stress indicators of broilers. Poultry Science 91: 393401.
Huang, MK, Choi, YJ, Houde, R, Lee, JW, Lee, B and Zhao, X (2004). Effects of Lactobacilli and an acidophilic Fungus on the production performance and immune responses in broiler chickens. Poultry Science 83: 788795.
Huff, WE, Huff, GR, Rath, NC, Balog, JM and Donoghue, AM (2003). Bacteriophage treatment of a severe Escherichia coli respiratory infection in broiler chickens. Avian Diseases 47: 13991405.
Huff, WE, Huff, GR, Rath, NC, Balog, JM and Donoghue, AM (2004). Bacteriophage: potential role in food safety. In: Beier, RC, Pillai, SD, Phillips, TD and Ziprin, RL (eds) Preharvest and Postharvest Food Safety Contemporary Issues and Future Directions. Ames, Iowa: Blackwell Publishing, pp. 365374.
Huff, WE, Huff, GR, Rath, NC, Balog, JM and Donoghue, AM (2005). Alternative to antibiotics: utilization of bacteriophage to treat Colibacillosis and prevent foodborne pathogens. Poultry Science 84: 655659.
Hume, ME (2011). Historic perspective: prebiotics, probiotics, and other alternatives to antibiotics. Poultry Science 90: 26632669.
Huyghebaert, G, Ducatelle, R, and Van Immerseel, F (2011). An update on alternatives to antimicrobial growth promoters for broilers. The Veterinary Journal 187: 182188.
Isabel, B and Santos, Y (2009). Effects of dietary organic acids and essential oils on growth performance and carcass characteristics of broiler chickens. Journal of Applied Poultry Research 18: 472476.
Islam, RM, Oomah, DB and Diarra, MS (2016). Potential immunomodulatory effects of non-dialyzable materials of cranberry extract in poultry production. Poultry Science 110. [Available online at http://dx.doi.org/10.3382/ps/pew302.]
Issa, KJ and Omar, JMA (2012). Effect of garlic powder on performance and lipid profile of broilers. Open Journal of Animal Sciences 2: 6268.
Jackson, ME and Hanford, K (2014). Statistical meta-analysis of pen trials conducted testing heat-sensitive β-mannanase (Hemicell) feed enzyme in male broilers grown to market age. Poultry Science 93 (E-suppl. 1): 66.
Jamroz, D, Orda, J, Kamel, C, Wiliczkiewicz, A, Wertelecki, T and Skorupinska, J (2003). The influence of phytogenic extracts on performance, nutrient digestibility, carcass characteristics, and gut microbial status in broiler chickens. Journal of Animal and Feed Sciences 12: 583596.
Janardhana, V, Broadway, MM, Bruce, MP, Lowenthal, JW, Geier, MS, Hughes, RJ and Bean, AGD (2009). Prebiotics modulate immune responses in the gut-associated lymphoid tissue of chickens. Journal of Nutrition 139: 14041409.
Jang, IS, Ko, YH, Kang, SY and Lee, CY (2007). Effect of a commercial essential oil on growth performance, digestive enzyme activity and intestinal microflora population in broiler chickens. Animal Feed Science and Technology 134: 304315.
Jeong, JS and Kim, IH (2014). Effect of Bacillus subtilis C-3102 spores as a probiotic feed supplement on growth performance, noxious gas emission, and intestinal microflora in broilers. Poultry Science 93: 30973103.
Jin, LZ, Ho, YW, Abdullah, N and Jalaludiin, S (1998). Growth performance, intestinal microbial populations, and serum cholesterol of broilers fed diets containing Lactobacillus cultures. Poultry Science 77: 12591265.
Jin, LZ, Ho, YW, Abdullah, N and Jalaludin, S (2000). Digestive and bacterial enzyme activities in broilers fed diets supplemented with Lactobacillus cultures. Poultry Science 79: 886891.
Joerger, RD (2003). Alternatives to antibiotics: bacteriocins, antimicrobial peptides and bacteriophages. Poultry Science 82: 640647.
Jørgensen, H, Zhao, XQ, Theil, PK and Jakobsen, K (2008). Effect of graded levels of rapeseed oil in isonitrogenous diets on the development of the gastrointestinal tract, and utilisation of protein, fat and energy in broiler chickens. Archives of Animal Nutrition 62: 331342.
Jorge de Lemos, M, Calixto, LFL, Alves, ODS, Santos de Souza, D, Moura, BB and Reis, TL (2015). Kaolin in the diet and its effects of performance, litter moisture and intestinal morphology of broiler chickens. Ciência Rural 45: 18351840.
Józefiak, D, Kaczmarek, S and Rutkowski, A (2008). A note on the effects of selected prebiotics on the performance and ileal microbiota of broiler chickens. Journal of Animal and Feed Sciences 17: 392397.
Józefiak, D, Sip, A, Kaczmarek, S and Rutkowski, A (2010). Effects of Carnobacterium divergens AS7 bacteriocin on gastrointestinal microflora in vitro and on nutrient retention in broiler chickens. Journal of Animal and Feed Sciences 19: 460467.
Józefiak, D, Sip, A, Rawski, M, Steiner, T and Rutkowski, A (2011a). The dose response effects of liquid and lyophilized Carnobacterium divergens AS7 bacteriocin on the nutrient retention and performance of broiler chickens. Journal of Animal and Feed Sciences 20: 401411.
Jozefiak, D, Sip, A, Rawski, M, Rutkowski, A, Kaczmarek, S, Hojberg, O, Jensen, BB and Engberg, RM (2011b). Dietary divercin modifies gastrointestinal microbiota and improves growth performance in broiler chickens. British Poultry Science 52: 492499.
Józefiak, D, Sip, A, Rutkowski, A, Rawski, M, Kaczmarek, S, Wołuń-Cholewa, M, Engberg, RM and Højberg, O (2012). Lyophilized Carnobacterium divergens AS7 bacteriocin preparation improves performance of broiler chickens challenged with Clostridium perfringens . Poultry Science 91: 18991907.
Józefiak, D, Kierończyk, B, Juśkiewicz, J, Zduńczyk, Z, Rawski, M, Długosz, J, Sip, A and Højberg, O (2013). Dietary nisin modulates the gastrointestinal microbial ecology and enhances growth performance of the broiler chickens. PLoS ONE 8: e85347.
Jukes, TH, Stokstad, ELR, Taylor, RR, Cunha, TJ, Edwards, HM and Meadows, GB (1950). Growth-promoting effects of aureomycin on pigs. Archives of Biochemistry and Biophysics 26: 324325.
Juskiewicz, J, Gruzauskas, R, Zdunczyk, Z, Semaskaite, A, Jankowski, J, Totilas, Z, Jarule, V, Sasyte, V, Zdunczyk, P, Raceviciute-Stupeliene, A and Svirmickas, G (2011). Effects of dietary addition of Macleaya cordata alkaloid extract on growth performance, caecal indices and breast meat fatty acids profile in male broilers. Journal of Animal Physiology and Animal Nutrition 95: 171178.
Jung, SJ, Houde, R, Baurhoo, B, Zhao, X and Lee, BH (2008). Effects of galacto-oligosaccharides and a Bifidobacteria lactis-based probiotic strain on the growth performance and fecal microflora of broiler chickens. Poultry Science 87: 16941699.
Kabir, SML (2009). The role of probiotics in the poultry industry. International Journal of Molecular Sciences 10: 35313546.
Kabir, SML, Rahman, MM, Rahman, MB, Rahman, MM and Ahmed, SU (2004). The dynamics of probiotics on growth performance and immune response in broilers. International Journal of Poultry Science 3: 361364.
Kalavathy, R, Abdullah, N, Jalaludin, S and Ho, YW (2003). Effects of Lactobacillus cultures on growth performance, abdominal fat deposition, serum lipids and weight of organs of broiler chickens. British Poultry Science 44: 139144.
Karadas, F, Pirgozliev, V, Rose, SP, Dimitrov, D, Oduguwa, O and Bravo, D (2014). Dietary essential oils improve the hepatic antioxidative status of broiler chickens. British Poultry Science 55: 329334.
Karaoglu, M and Durdag, H (2005). The influence of dietary probiotic (Saccharomyces cerevisiae) supplementation and different slaughter age on the performance, slaughter and carcass properties of broilers. International Journal of Poultry Science 4: 309316.
Katouli, MS, Boldaji, F, Dastar, B and Hassani, S (2010). Effect of different levels of kaolin, bentonite and zeolite on broilers performance. Journal of Biological Sciences 10: 5862.
Khalaji, S, Zaghari, M, Hatami, KH, Hedari-Dastjerdi, S, Lotfi, L and Nazarian, H (2011). Black cumin seeds, Artemisia leaves (Artemisia sieberi), and Camellia L. plant extract as phytogenic products in broiler diets and their effects on performance, blood constituents, immunity, and cecal microbial population. Poultry Science 90: 25002510.
Khan, M, Raoult, D, Richet, H, Lepidi, H and La Scola, B (2007). Growth-promoting effects of single-dose intragastrically administered probiotics in chickens. British Poultry Science 48: 732735.
Khattak, F, Ronchi, A, Castelli, P and Sparks, N (2014). Effects of natural blend of essential oil on growth performance, blood biochemistry, cecal morphology, and carcass quality of broiler chickens. Poultry Science 93: 132137.
Kiarie, E, Romero, LF and Nyachoti, CM (2013). The role of added feed enzymes in promoting gut health in swine and poultry. Nutrition Research Reviews 26: 7188.
Kim, DK, Lillehoj, HS, Lee, SH, Jang, SI and Bravo, D (2010). High-throughput gene expression analysis of intestinal intraepithelial lymphocytes after oral feeding of carvacrol, cinnamaldehyde, or Capsicum oleoresin. Poultry Science 89: 6881.
Kim, GB, Seo, YM, Kim, CH and Paik, IK (2011). Effect of dietary prebiotic supplementation on the performance, intestinal microflora, and immune response of broilers. Poultry Science 90: 7582.
Kim, JS, Ingale, SL, Kim, YW, Kim, KH, Sen, S, Ryu, MH, Lohakare, JD, Kwon, IK and Chae, BJ (2012). Effect of supplementation of multi-microbe probiotic product on growth performance, apparent digestibility, cecal microbiota and small intestinal morphology of broilers. Journal of Animal Physiology and Animal Nutrition 96: 618626.
Kim, DK, Lillehoj, HS, Lee, SH, Jang, SI, Park, MS, Min, W, Lillehoj, EP and Bravo, D (2013a). Immune effects of dietary anethole on Eimeria acervulina infection. Poultry Science 92: 26252634.
Kim, DK, Lillehoj, HS, Lee, SH, Lillehoj, EP and Bravo, D (2013b). Improved resistance to Eimeria acervulina infection in chickens due to dietary supplementation with garlic metabolites. British Journal of Nutrition 109: 7688.
Kim, SC, Kim, JW, Kim, JU and Kim, IH (2013c). Effects of dietary supplementation of bacteriophage on growth performance, nutrient digestibility, carcass characteristics and fecal microflora in broilers. Korean Journal of Poultry Science 40: 7581.
Kim, JW, Kim, JH and Kil, DY (2015). Dietary organic acids for broiler chickens: a review. Colombian Journal of Animal Science and Veterinary Medicine 28: 109123.
Kim, SJ, Lee, KW, Kang, CW and An, BK (2016a). Growth performance, relative meat and organ weights, cecal microflora, and blood characteristics in broiler chickens fed diets containing different nutrient density with or without essential oils. Asian Australasian Journal of Animal Science 29: 549554.
Kim, WH, Lillehoh, HS and Gay, CG (2016b). Using genomics to identify novel antimicrobials. Revue scientifique et technique 35: 95103.
Klasing, KC, Laurin, DE, Peng, PK and Fry, DM (1987). Immunologically mediated growth depression in chicks: influence of feed intake, corticosterone and interleukin-1. The Journal of Nutrition 117: 16291637.
Knarreborg, A, Lauridsen, C, Engberg, RM and Jensen, SK (2004). Dietary antibiotic growth promoters enhance the bioavailability of alpha-tocopheryl acetate in broilers by altering lipid absorption. Journal of Nutrition 134: 14871492.
Koczulla, AR and Bals, R (2003). Antimicrobial peptides: current status and therapeutic potential. Drugs 63: 389406.
Kubena, LF, Harvey, RB, Bailey, RH, Buckley, SA and Rottinghaus, GE (1998). Effects of a hydrated sodium calcium aluminosilicate (T-Bind™) on mycotoxicosis in young broiler chickens. Poultry Science 77: 15021509.
Kurtoglu, V, Kurtoglu, F, Seker, E, Coskun, B, Balevi, T and Polat, ES (2004). Effect of probiotic supplementation on laying hen diets on yield performance and serum and egg yolk cholesterol. Food Additives and Contaminants 21: 817823.
Lee, KW, Everts, H, Kappert, HJ, Frehner, M, Losa, R and Beynen, AC (2003). Effects of dietary essential oil components on growth performance, digestive enzymes and lipid metabolism in female broiler chickens. British Poultry Science 44: 450457.
Lee, SH, Lillehoj, HS, Chun, HK, Tuo, W, Park, HJ, Cho, SM, Lee, YM and Lillehoj, EP (2007). In vitro treatment of chicken peripheral blood lymphocytes, macrophages and tumor cells with extracts of Korean medicinal plants. Nutrition Research 27: 362366.
Lee, SH, Lillehoj, HS, Park, DW, Jang, SI, Morales, A, Garcia, D, Lucio, E, Larios, R, Victoria, G, Marrufo, D, and Lillehoj, EP (2009a). Induction of passive immunity in broiler chickens against Eimeria acervulina by hyperimmune egg yolk immunoglobulin Y. Poultry Science 88: 562566.
Lee, SH, Lillehoj, HS, Park, DW, Jang, SI, Morales, A, Garcia, D, Lucio, E, Larios, R, Victoria, G, Marrufo, D, and Lillehoj, EP (2009b). Protective effect of hyperimmune egg yolk IgY antibodies against Eimeria tenella and Eimeria maxima infections. Veterinary Parasitology 163: 123126.
Lee, KW, Lee, SH, Lillehoj, HS, Li, GX, Jang, SI, Babu, US, Park, MS, Kim, DK, Lillehoj, EP, Neumann, AP, Rehberger, TG and Siragusa, GR (2010a). Effects of direct-fed microbials on growth performance, gut morphometry, and immune characteristics in broiler chickens. Poultry Science 89: 203216.
Lee, SH, Lillehoj, HS, Hong, YH, Jang, SI, Lillehoj, EP, Ionescu, C, Mazuranok, L and Bravo, D (2010b). In vitro effects of plant and mushroom extracts on immunological function of chicken lymphocytes and macrophages. British Poultry Science 51: 213221.
Lee, KW, Lillehoj, HS and Siragusa, GR (2010c). Direct-fed microbials and their impact on the intestinal microflora and immune system of chickens. Journal Poultry Science 47: 106114.
Lee, KW, Li, G, Lillehoj, HS, Lee, SH, Jang, SI, Babu, US, Lillehoj, EP, Neumann, AP and Siragusa, GR (2011a). Bacillus subtilis-based direct-fed microbials augment macrophage function in broiler chickens. Research in Veterinary Science 91: e87e91.
Lee, SH, Lillehoj, HS, Jang, SI, Lee, KW, Park, MS, Bravo, D and Lillehoj, EP (2011b). Cinnamaldehyde enhances in vitro parameters of immunity and reduces in vivo infection against avian coccidiosis. British Journal of Nutrition 106: 862869.
Lei, K, Li, YL, Yu, DY, Rajput, IR and Li, WF (2013). Influence of dietary inclusion of Bacillus licheniformis on laying performance, egg quality, antioxidant enzyme activities, and intestinal barrier function of laying hens. Poultry Science 92: 23892395.
Leusink, G, Rempel, H, Skura, B, Berkyto, M, White, W, Yang, Y, Rhee, JY, Xuan, SY, Chiu, S, Silversides, F, Fitzpatrick, S and Diarra, MS (2010). Growth performance, meat quality, and gut microflora of broiler chickens fed with cranberry extract. Poultry Science 89: 15141523.
Li, Y, Xiang, Q, Zhang, Q, Huang, Y and Su, Z (2012). Overview on the recent study of antimicrobial peptides: origins, functions, relative mechanisms and application. Peptides 37: 207215.
Liao, XD, Ma, G, Cai, J, Fu, Y, Yan, XY, Wei, XB and Zhang, RJ (2015). Effects of Clostridium butyricum on growth performance, antioxidation, and immune function of broilers. Poultry Science 94: 662667.
Lillehoj, HS, Kim, DK, Bravo, DM and Lee, SH (2011). Effects of dietary plant-derived phytonutrients on the genome-wide profiles and coccidiosis resistance in the broiler chickens. BioMed Central Proceedings 5: S34.
Lin, J (2011). Effect of antibiotic growth promoters on intestinal microbiota in food animals: a novel model for studying the relationship between gut microbiota and human obesity? Frontiers in Microbiology 2: 53.
Lin, J (2014). Antibiotic growth promoters enhance animal production by targeting intestinal bile salt hydrolase and its producers. Frontiers in Microbiology 5: 33.
Lin, J, Hunkapiller, AA, Layton, AC, Chang, YJ and Robbins, KR (2013). Response of intestinal microbiota to antibiotic growth promoters in chickens. Foodborne Pathogens and Disease 10: 331337.
Linde, A, Ross, CR, Davis, EG, Dib, L, Blecha, F and Melgarejo, T (2008). Innate immunity and host defense peptides in veterinary medicine. Journal of Veterinary Internal Medicine 22: 247265.
Liu, T, She, R, Wang, K, Bao, H, Zhang, Y, Luo, D, Hu, Y, Ding, Y, Wang, D and Peng, K (2008). Effects of rabbit sacculus rotundus antimicrobial peptides on the intestinal mucosal immunity in chickens. Poultry Science 87: 250254.
Liu, X, Yan, H, Lv, L, Xu, Q, Yin, C, Zhang, K, Wang, P and Hu, J (2012). Growth performance and meat quality of broiler chickens supplemented with Bacillus licheniformis in drinking water. Asian-Australasian Journal of Animal Sciences 25: 682689.
Liu, HN, Liu, Y, Hu, LL, Suo, YL, Zhang, L, Jin, F, Feng, XA, Teng, N and Li, Y (2014). Effects of dietary supplementation of quercetin on performance, egg quality, cecal microflora populations, and antioxidant status in laying hens. Poultry Science 93: 347353.
Lu, L, Wang, RL, Zhang, ZJ, Steward, FA, Luo, X and Liu, B (2010). Effect of dietary supplementation with copper sulfate or tribasic copper chloride on the growth performance, liver copper concentrations of broilers fed in floor pens, and stabilities of vitamin E and phytase in feeds. Biological Trace Element Research 138: 181189.
Luecke, RW, McMillen, WN and Thorp, F Jr (1950a). The effects of vitamin B12, animal protein factor and streptomycin on the growth of young pigs. Archives of Biochemistry and Biophysics 26: 326327.
Luecke, RW, Newland, HW, McMillen, WN and Thorp, F Jr (1950b). The effects of antibiotics fed at low levels on the growth of weaning pigs. Journal of Animal Science 9: 662.
Malayoğlu, HB, Baysal, Ş, Misirlioğlu, Z, Polat, M, Yilmaz, H and Turan, N (2010). Effects of oregano essential oil with or without feed enzymes on growth performance, digestive enzyme, nutrient digestibility, lipid metabolism and immune response of broilers fed on wheat-soybean meal diets. British Poultry Science 51: 6780.
McGinnis, J (1950). The antibiotics make good feeds better. Turkey World July, pp. 11.
Medeiros, MA, Oliveira, DC, Rodrigues Ddos, P and Freitas, DR (2011). Prevalence and antimicrobial resistance of Salmonella in chicken carcasses at retail in 15 Brazilian cities. Pan American Journal of Public Health 30: 555560.
M'ikanatha, NM, Sandt, CH, Localio, AR, Tewari, D, Rankin, SC, Whichard, JM, Altekruse, SF, Lautenbach, E, Folster, JP, Russo, A, Chiller, TM, Reynolds, SM and McDermott, PF (2010). Multidrug-resistant Salmonella isolates from retail chicken meat compared with human clinical isolates. Foodborne Pathogens and Diseases 7: 929934.
Miller, RW, Skinner, EJ, Sulakvelidze, A, Mathis, GF and Hofacre, CL (2010). Bacteriophage therapy for control of necrotic enteritis of broiler chickens experimentally infected with Clostridium perfringens . Avian Diseases 54: 3340.
Mohamed, MA, Hassan, HMA and El-Barkouky, EMA (2008). Effect of mannan oligosaccharide on performance and carcass characteristics of broiler chicks. Journal of Agriculture and Social Sciences 4: 1317.
Mohnl, M, Acosta Aragón, Y, Acosta Ojeda, A, Rodríguez Sánchez, B and Pasteiner, S (2007). Effect of synbiotic feed additive in comparison to antibiotic growth promoter on performance and health status of broilers. Poultry Science 86 (suppl. 1): 217.
Mookiah, S, Sieo, CC, Ramasamy, K, Abdullah, N and Ho, YW (2014). Effects of dietary prebiotics, probiotic and synbiotics on performance, caecal bacterial populations and caecal fermentation concentrations of broiler chickens. Journal of the Science of Food and Agriculture 94: 341348.
Moore, PR, Evenson, A, Luckey, TD, McCoy, E, Elvehjem, CA and Hart, EB (1946). Use of sulfasuxidine, streptothricin and streptomycin in nutritional studies with the chick. Journal of Biological Chemistry 165: 437441.
Mountzouris, KC, Tsirtsikos, P, Kalamara, E, Nitsch, E, Schatzmayr, G and Fegeros, K (2007). Evaluation of the efficacy of a probiotic containing Lactobacillus, Bifidobacterium, Enterococcus, and Pediococcus strains in promoting broiler performance and modulating cecal microflora composition and metabolic activities. Poultry Science 86: 309317.
Mountzouris, KC, Tsirtsikos, P, Palamidi, I, Arvaniti, A, Mohnl, M, Schatzmayr, G and Fegeros, K (2010). Effects of probiotic inclusion levels in broiler nutrition on growth performance, nutrient digestibility, plasma immunoglobulins, and cecal microflora composition. Poultry Science 89: 5867.
Mueller, K, Blum, NM, Kluge, H and Mueller, AS (2012). Influence of broccoli extract and various essential oils on performance and expression of xenobiotic- and antioxidant enzymes in broiler chickens. British Journal of Nutrition 108: 588602.
Murugesan, GR, Syed, B, Haldar, S and Pender, C (2015). Phytogenic feed additives as an alternative to antibiotic growth promoters in broiler chickens. Frontiers in Veterinary Science 2: 21.
Nakphaichit, M, Thanomwongwattana, S, Phraephaisarn, C, Sakamoto, N, Keawsompong, S, Nakayama, J and Nitisinprasert, S (2011). The effect of including Lactobacillus reuteri KUB-AC5 during post-hatch feeding on the growth and ileum microbiota of broiler chickens. Poultry Science 90: 27532765.
Nava, GM, Attene-Ramos, MS, Gaskins, HR and Richards, JD (2009). Molecular analysis of microbial community structure in the chicken ileum following organic acid supplementation. Veterinary Microbiology 137: 345353.
Nayebpor, M, Farhomand, P and Hashemi, A (2007). Effects of different levels of direct fed microbial (Primalac) on growth performance and humoral immune response in broiler chickens. Journal of Animal and Veterinary Advances 6: 13081313.
Niewold, TA (2007). The nonantibiotic anti-inflammatory effect of antimicrobial growth promoters, the real mode of action? A hypothesis. Poultry Science 86: 605609.
Netherwood, T, Gilbert, HJ, Parker, DS, and O'Donnell, AG (1999). Probiotics shown to change bacterial community structure in the avian gastrointestinal tract. Applied and Environmental Microbiology 65: 51345138.
Nezhad, YE, Gale-Kandi, JG, Farahvash, T and Yeganeh, AR (2011). Effect of combination of citric acid and microbial phytase on digestibility of calcium, phosphorous and mineralization parameters of tibia bone in broilers. African Journal of Biotechnology 10: 1508915093.
Ng, SC, Hart, AL, Kamm, MA, Stagg, AJ and Knight, SC (2009). Mechanisms of action of probiotics: recent advances. Inflammatory Bowel Diseases 15: 300310.
Nurmi, E and Rantala, M (1973). New aspects of Salmonella infection in broiler production. Nature 241: 210211.
O'Dea, EE, Fasenko, GM, Allison, GE, Korver, DR, Tannock, GW and Guan, LL (2006). Investigating the effects of commercial probiotics on broiler chick quality and production efficiency. Poultry Science 85: 18551863.
Ohh, SH, Shinde, PL, Jin, Z, Choi, JY, Hahn, TW, Lim, HT, Kim, GY, Park, Y, Hahm, KS and Chae, BJ (2009). Potato (Solanum tuberosum L. cv. Gogu valley) protein as an antimicrobial agent in the diets of broilers. Poultry Science 88: 12271234.
Olver, MD (1997). Effect of feeding clinoptilolite (zeolite) on the performance of three strains of laying hens. British Poultry Science 38: 220222.
Panda, AK, Rama Rao, SV, Raju, MVLN and Shyam Sunder, G (2009). Effect of butyric acid on performance, gastrointestinal tract health and carcass characteristics in broiler chickens. Asian-Australasian Journal of Animal Science 22: 10261031.
Park, JH and Kim, IH (2014). Supplemental effect of probiotic Bacillus subtilis B2A on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality of growing broiler chicks. Poultry Science 93: 20542059.
Park, IJ, Cha, SY, Kang, M, So, YS, Go, HG, Mun, SP, Ryu, KS and Jang, HK (2011). Effect of proanthocyanidin-rich extract from Pinus radiata bark on immune response of specific-pathogen-free White Leghorn chickens. Poultry Science 90: 977982.
Parvez, S, Malik, KA, Ah Kang, S and Kim, HY (2006). Probiotics and their fermented food products are beneficial for health. Journal of Applied Microbiology 100: 11711185.
Patterson, JA and Burkholder, KM (2003). Application of prebiotics and probiotics in poultry production. Poultry Science 82: 627631.
Patten, JD and Waldroup, PW (1988). Use of organic acids in broiler diets. Poultry Science 67: 11781182.
Pedroso, AA, Menten, JFM, Lambais, MR, Racanicci, AMC, Longo, FA and Sorbara, JOB (2006). Intestinal bacterial community and growth performance of chickens fed diets containing antibiotics. Poultry Science 85: 747752.
Pesti, GM and Bakalli, RI (1996). Studies on the feeding of cupric sulfate pentahydrate and cupric citrate to broiler chickens. Poultry Science 75: 10861091.
Pierce, J, Ao, T, Charlton, P and Tucker, LA (2009). Organic minerals for broilers and laying hens: reviewing the status of research so far. World's Poultry Science Journal 65: 493498.
Pimentel, JL and Cook, ME (1988). Improved growth in the progeny of hens immunized with jackbean urease. Poultry Science 67: 434439.
Pimentel, JL, Cook, ME and Jonsson, JM (1991). Increased growth of chicks and poults obtained from hens injected with jackbean urease. Poultry Science 70: 18421844.
Pirgozliev, V, Bravo, D, Mirza, MW and Rose, SP (2015). Growth performance and endogenous losses of broilers fed wheat-based diets with and without essential oils and xylanase supplementation. Poultry Science 94: 12271232.
Pourabedin, M and Zhao, X (2015). Prebiotics and gut microbiota in chickens. FEMS Microbiology Letters 362: fnv122.
Pourabedin, M, Xu, Z, Baurhoo, B, Chevaux, E and Zhao, X (2014). Effects of mannan oligosaccharide and virginiamycin on the cecal microbial community and intestinal morphology of chickens raised under suboptimal conditions. Canadian Journal of Microbiology 60: 255266.
Pourhossein, Z, Qotbi, AAA, Seidavi, A, Laudadio, V, Centoducati, G and Tufarelli, V (2015). Effect of different levels of dietary sweet orange (Citrus sinensis) peel extract on humoral immune system responses in broiler chickens. Animal Science Journal 86: 105110.
Phillips, TD (1999). Dietary clay in the chemoprevention of aflatoxin-induced disease. Toxicological Sciences 52: 118126.
Placha, I, Takacova, J, Ryzner, M, Cobanova, K, Laukova, A, Strompfova, V, Venglovska, K and Faix, S (2014). Effect of thyme essential oil and selenium on intestine integrity and antioxidant status of broilers. British Poultry Science 55: 105114.
Prvulović, D, Kojić, D, Grubor-Lajsić, G and Kosarcić, S (2008). The effects of dietary inclusion of hydrated aluminosilicate on performance and biochemical parameters of broiler chickens. Turkish Journal of Veterinary and Animal Sciences 32: 183189.
Rafacz-Livingston, KA, Parsons, CM and Jungk, RA (2005). The effects of various organic acids on phytate phosphorous utilization in chicks. Poultry Science 84: 13561362.
Ravindran, V and Son, JH (2011). Feed enzyme technology: present status and future developments. Recent Patents on Food Nutrition and Agriculture 3: 102109.
Rebolé, A, Ortiz, LT, Rodríguez, ML, Alzeuta, C, Treviño, J and Velasco, S (2010). Effects of inulin and enzyme complex, individually or in combination, on growth performance, intestinal microflora, cecal fermentation characteristics, and jejunal histomorphology in broiler chickens fed a wheat- and barley-based diet. Poultry Science 89: 276286.
Rezaei, S, Jahromi, MF, Liang, JB, Zulkifli, I, Farjam, AS, Laudadio, V and Tufarelli, V (2015). Effect of oligosaccharides extract from palm kernel expeller on growth performance, gut microbiota and immune response in broiler chickens. Poultry Science 94: 24142420.
Richards, JD, Zhao, J, Harrell, RJ, Atwell, CA and Dibner, JJ (2010). Trace mineral nutrition in poultry and swine. Asian-Australasian Journal of Animal Science 23: 15271534.
Ricke, SC (2003). Perspectives on the use of organic acids and short chain fatty acids as antimicrobials. Poultry Science 82: 632639.
Ricke, SC (2015). Potential of fructooligosaccharide prebiotics in alternative and nonconventional poultry production systems. Poultry Science 94: 14111418.
Riley, MA and Wertz, JE (2002). Bacteriocins: evolution, ecology, and application. Annual Review of Microbiology 56: 117137.
Rosen, GD (1995). Antibacterials in poultry and pig nutrition. In: Wallace, RJ and Chesson, A (eds) Biotechnology in Animal Feeds and Animal Feeding. Weinheim, Germany, pp. 143172.
Rosen, GD (2007). Holo-analysis of the efficacy of Bio-Mos® in broiler nutrition. British Poultry Science 48: 2126.
Rostami, F, Ghasemi, HA and Taherpour, K (2015). Effect of Scrophularia striata and Ferulago angulata, as alternatives to virginiamycin, on growth performance, intestinal microbial population, immune response, and blood constituents of broiler chickens. Poultry Science 94: 22022209.
Rusoff, LL, Davis, AV and Alford, JA (1951). Growth-promoting effect of aureomycin on young calves weaned from milk at an early age. Journal of Nutrition 45: 289300.
Russell, SM and Grimes, JL (2009). The effect of a direct-fed microbial (Primalac) on turkey live performance. Journal of Applied Poultry Research 18: 185192.
Salgado-Tránsito, L, Del Río-García, JC, Arjona-Román, JL, Moreno-Martínez, E and Méndez-Albores, A (2011). Effect of citric acid supplemented diets on aflatoxin degradation, growth performance and serum parameters in broiler chickens. Archivos de Medicina Veterinaria 43: 215222.
Salim, HM, Kang, HK, Akter, N, Kim, DW, Kim, JH, Kim, MJ, Na, JC, Jong, HB, Choi, HC, Suh, OS and Kim, WK (2013). Supplementation of direct-fed microbials as an alternative to antibiotic on growth performance, immune response, cecal microbial population, and ileal morphology of broiler chickens. Poultry Science 92: 20842090.
Samanta, S, Haldar, S and Ghosh, TK (2008). Production and carcass traits in broiler chickens given diets supplemented with inorganic trivalent chromium and an organic acid blend. British Poultry Science 49: 155163.
Samanta, S, Haldar, S and Ghosh, TK (2010). Comparative efficacy of an organic acid blend and bacitracin methylene disalicylate as growth promoters in broiler chickens: effects on performance, gut histology, and small intestinal milieu. Veterinary Medicine International 2010: 645150.
Samantha, AK, Jayapal, N, Senani, S, Kolte, AP and Sridhar, M (2013). Prebiotic inulin: useful dietary adjuncts to manipulate the livestock gut microflora. Brazilian Journal of Microbiology 44: 114.
Samli, HE, Senkoylu, N, Koc, F, Kanter, M and Agma, A (2007). Effects of Enterococcus faecium and dried whey on broiler performance, gut histomorphology and intestinal microbiota. Archives of Animal Nutrition 61: 4249.
Schiavone, A, Guo, K, Tassone, S, Gasco, L, Hernandez, E, Denti, R and Zoccarato, I (2008). Effects of a natural extract of chestnut wood on digestibility, performance traits, and nitrogen balance of broiler chicks. Poultry Science 87: 521527.
Schneitz, C (2005). Competitive exclusion in poultry – 30 years of research. Food Control 16: 657667.
Scott, HM (2012). Heavy metals as alternatives to antibiotics: Panacea or Pandora's box? Paper presented at the International Symposium on Alternatives to Antibiotics, Paris, France, 25–28th September.
Seal, BS, Lillehoj, HS, Donovan, DM and Gay, CG (2013). Alternatives to antibiotics: a symposium on the challenges and solutions for animal production. Animal Health Research Reviews 14: 7887.
Selle, PH and Ravindran, V (2007). Microbial phytase in poultry nutrition. Animal Feed Science and Technology 135: 141.
Sen, S, Ingale, SL, Kim, YW, Kim, JS, Kim, KH, Lohakare, JD, Kim, EK, Kim, HS, Ryu, MH, Kwon, IK, Chae, BJ (2012). Effect of supplementation of Bacillus Subtilis LS 1–2 to broiler diets on growth performance, nutrient retention, caecal microbiology and small intestinal morphology. Research in Veterinary Science 93: 264268.
Settle, T, Leonard, SS, Falkenstein, E, Fix, N, Van Dyke, K and Klandorf, H (2014). Effects of a phytogenic feed additive versus an antibiotic feed additive on oxidative stress in broiler chicks and a possible mechanism determined by Electron Spin Resonance. International Journal of Poultry Science 13: 6269.
Shanmugasundaram, R and Selvaraj, RK (2012). Effect of killed whole yeast cell prebiotic supplementation on broiler performance and intestinal immune cell parameters. Poultry Science 91: 107111.
Simon, O, Jadamus, A and Vahjen, W (2001). Probiotic feed additives-effectiveness and expected modes of action. Journal of Animal and Feed Sciences 10: 5167.
Simmering, R and Blaut, M (2001). Pro- and prebiotics-the tasty guardian angels? Applied Microbiology and Biotechnology 55: 1928.
Skinner, JT, Izat, AL and Waldroup, PW (1991). Research note: fumaric acid enhances performance of broiler chickens. Poultry Science 70: 14441447.
Slominski, BA (2011). Recent advances in research on enzymes for poultry diets. Poultry Science 90: 20132023.
Sohail, MU, Hume, ME, Byrd, JA, Nisbet, DJ, Ijaz, A, Sohail, A, Shabbir, MZ and Rehman, H (2012). Effect of supplementation of prebiotic mannan-oligosaccharides and probiotic mixture on growth performance of broilers subjected to chronic heat stress. Poultry Science 91: 22352240.
Spring, P, Wenk, C, Dawson, KA and Newman, KE (2000). The effect of dietary mannonoligosaccharides on cecal parameters and the concentrations of enteric bacteria in the ceca of Salmonella-challenged broiler chicks. Poultry Science 79: 205211.
Steiner, T (2006). Managing Gut Health: Natural Growth Promoters as a Key to Animal Performance. Nottingham, UK: Nottingham University Press.
Sunder, SG, Panda, AK, Gopinath, NCS, Rama Rao, SV, Raju, MVLN, Reddy, MR and Vijay Kumar, CH (2008). Effects of higher levels of zinc supplementation on performance, mineral availability, and immune competence in broiler chickens. Journal of Applied Poultry Research 17: 7986.
Swann, D and Romero, L (2014). A meta-analysis on effect of a multi-enzyme solution on apparent ileal undigested starch, fat and crude protein in broilers. Poultry Science 93 (E-suppl. 1): 6667.
Talebi, A, Amirzadeh, B, Mokhtari, B and Gahri, H (2008). Effects of a multi-strain probiotic (PrimaLac) on performance and antibody responses to Newcastle disease virus and infectious bursal disease virus vaccination in broiler chickens. Avian Pathology 37: 509512.
Torres-Rodriguez, A, Donoghue, AM, Donoghue, DJ, Barton, JT, Tellez, G and Hargis, BM (2007). Performance and condemnation rate analysis of commercial turkey flocks treated with a Lactobacillus spp.-based probiotic. Poultry Science 86: 444446.
Torshizi, MAK, Moghaddam, AR, Rahimi, S and Mojgani, N (2010). Assessing the effect of administering probiotics in water or as a feed supplement on broiler performance and immune response. British Poultry Science 51: 178184.
Thacker, PA (2013). Alternatives to antibiotics as growth promoters for use in swine production: a review. Journal of Animal Science and Biotechnology 4: 35.
Thomke, S and Elwinger, K (1998). Growth promotants in feeding pigs and poultry. II. Mode of action of antibiotic growth promotants. Annales De Zootechnie 47: 153167.
Tiihonen, K, Kettunen, H, Bento, MHL, Saarinen, M, Lahtinen, S, Ouwehand, AC, Schulze, H and Rautonen, N (2010). The effect of feeding essential oils on broiler performance and gut microbiota. British Poultry Science 51: 381392.
Twort, FW (1915). An investigation on the nature of ultramicroscopic viruses. Lancet 2: 12411243.
Van Der Klis, JD and Vinyeta-Punti, E (2014). The potential of phytogenic feed additives in pigs and poultry. In: Proceedings of 18th Congress of the European Society of Veterinary & Comparative Nutrition, At Utrecht, Netherlands. Volume 18.
Van Der Wielen, PW, Biesterveld, S, Notermans, S, Hofstra, H, Urlings, BA and Van Knapen, F (2000). Role of volatile fatty acids in development of the cecal microflora in broiler chickens during growth. Applied and Environmental Microbiology 71: 22062207.
Vasanth, S, Dipu, MT, Mercy, AD and Shyama, K (2015). Efficiency of copper sulphate versus flavomycin as a growth promoter in broiler chickens. International Journal of Current Research 7: 1653616539.
Verstegen, MWA and Williams, BA (2002). Alternatives to the use of antibiotics as growth promoters for monogastric animals. Animal Biotechnology 13: 113127.
Vondruskova, H, Slamova, R, Trckova, M, Zraly, Z and Pavlik, I (2010). Alternatives to antibiotic growth promoters in prevention of diarrhea in weaned piglets: a review. Veterinarni Medicina 55: 199224.
Vilà, B, Esteve-Garcia, E and Brufau, J (2010). Probiotic micro-organisms: 100 years of innovation and efficacy; modes of action. World's Poultry Science Journal 65: 369380.
Visek, WJ (1978). The mode of growth promotion by antibiotics. Journal of Animal Science 46: 14471469.
Viveros, A, Chamorro, S, Pizarro, M, Arija, I, Centeno, C and Brenes, A (2011). Effects of dietary polyphenol-rich grape products on intestinal microflora and gut morphology in broiler chicks. Poultry Science 90: 566578.
Waititu, SM, Yitbarek, A, Matini, E, Echeverry, H, Kiarie, E, Rodriguez-Lecompte, JC and Nyachoti, CM (2014). Effect of supplementing direct-fed microbials on broiler performance, nutrient digestibilities, and immune responses. Poultry Science 93: 625635.
Wang, Y and Gu, Q (2010). Effect of probiotic on growth performance and digestive enzyme activity of Arbor Acres broilers. Research in Veterinary Science 89: 163167.
Wang, L, Piao, XL, Kim, SW, Piao, XS, Shen, YB and Lee, HS (2008). Effects of Forsythia suspensa extract on growth performance, nutrient digestibility, and antioxidant activities in broiler chickens under high ambient temperature. Poultry Science 87: 12871294.
Wang, D, Ma, W, She, R, Sun, Q, Liu, Y, Hu, Y, Liu, L, Yang, Y and Peng, K (2009). Effects of swine gut antimicrobial peptides on the intestinal mucosal immunity in specific-pathogen-free chickens. Poultry Science 88: 967974.
Wang, HT, Yu, C, Hsieh, YH, Chen, SW, Chen, BJ and Chen, CY (2011). Effects of albusin B (a bacteriocin) of Ruminococcus albus 7 expressed by yeast on growth performance and intestinal absorption of broiler chickens - its potential role as an alternative to feed antibiotics. Journal of the Science of Food and Agriculture 91: 23382343.
Wang, HT, Li, YH, Chou, IP, Hsieh, YH, Chen, BJ and Chen, CY (2013a). Albusin B modulates lipid metabolism and increases antioxidant defense in broiler chickens by a proteomic approach. Journal of the Science of Food and Agriculture 93: 284292.
Wang, JP, Yan, L, Lee, JH and Kim, IH (2013b). Evaluation of bacteriophage supplementation on growth performance, blood characteristics, relative organ weight, breast muscle characteristics and excreta microbial shedding in broilers. Asian-Australasian Journal of Animal Sciences 26: 573578.
Wang, K, Yan, J, Dang, W, Xie, J, Yan, B, Yan, W, Sun, M, Zhang, B, Ma, M, Zhao, Y, Jia, F, Zhu, R, Chen, W and Wang, R (2014). Dual antifungal properties of cationic antimicrobial peptides polybia-MPI: membrane integrity disruption and inhibition of biofilm formation. Peptides 56: 2229.
Wegener, HC, Aarestrup, FM, Jensen, LB, Hammerum, AM and Bager, F (1999). Use of antimicrobial growth promoters in food animals and Enterococcus faecium resistance to therapeutic antimicrobial drugs in Europe. Emerging Infectious Diseases 5: 329335.
Wen, LF and He, JG (2012). Dose-response effects of an antimicrobial peptide, a cecropin hybrid, on growth performance, nutrient utilization, bacterial counts in the digesta and intestinal morphology in broilers. The British Journal of Nutrition 108: 17561763.
Wierup, M (2000). The control of microbial diseases in animals: alternatives to the use of antibiotics. International Journal of Antimicrobial Agents 14: 315319.
Willey, JM and van der Donk, WA (2007). Lantibiotics: peptides of diverse structure and function. Annual Review of Microbiology 61: 477501.
Willis, WL, Isikhuemhen, OS and Ibrahim, SA (2007). Performance assessment of broiler chickens given mushroom extract alone or in combination with probiotics. Poultry Science 86: 18561860.
Windisch, W, Schedle, K, Plitzner, C and Kroismayr, A (2008). Use of phytogenic products as feed additives for swine and poultry. Journal of Animal Science 86: E140E148.
Wise, MG and Siragusa, GR (2007). Quantitative analysis of the intestinal bacterial community in one-to three-week-old commercially reared broiler chickens fed conventional or antibiotic-free vegetable-based diets. Journal of Applied Microbiology 102: 11381149.
Witte, W (1998). Medical consequences of antibiotic use in agriculture. Science 279: 996997.
Whitehill, AR, Oleson, JJ and Hutchings, BL (1950). Stimulatory effects of aureomycin in the growth of chicks. Ibid 74: 1113.
Wolfenden, AD, Pixley, CM, Higgins, JP, Higgins, SE, Vicente, JL, Torres-Rodriguez, A, Hargis, BM and Tellez, G (2007). Evaluation of spray application of a Lactobacillus-based probiotic on Salmonella enteritidis colonization in broiler chickens. International Journal of Poultry Science 6: 493496.
Wolfenden, RE, Pumford, NR, Morgan, MJ, Shivaramaiah, S, Wolfenden, AD, Pixley, CM, Green, J, Tellez, G and Hargis, BM (2011). Evaluation of selected direct-fed microbial candidates on live performance and Salmonella reduction in commercial turkey brooding houses. Poultry Science 90: 26272631.
World Health Organization (2012). The evolving threat of antimicrobial resistance: options for action. [Available online at http://whqlibdoc.who.int/publications/2012/9789241503181_eng.pdf.] Accessed: 12 November 2015.
Woyengo, TA and Nyachoti, CM (2011). Review: supplementation of phytase and carbohydrases to diets for poultry. Canadian Journal of Animal Science 91: 177192.
Wu, Y, Wu, Q, Zhou, Y, Ahmad, H and Wang, T (2013). Effects of clinoptilolite on growth performance and antioxidant status in broilers. Biological Trace Element Research 155: 228235.
Xia, MS, Hu, CH and Xu, ZR (2004). Effects of copper-bearing montmorillonite on growth performance, digestive enzyme activities, and intestinal microflora and morphology of male broilers. Poultry Science 83: 18681875.
Xiao, R, Power, RF, Mallonee, D, Routt, K, Spangler, L, Pescatore, AJ, Cantor, AH, Ao, T, Pierce, JL and Dawson, KA (2012). Effects of yeast cell wall-derived mannan-oligosaccharides on jejunal gene expression in young broiler chickens. Poultry Science 91: 16601669.
Xu, ZR, Hu, CH, Xia, MS, Zhan, XA and Wang, MQ (2003). Effects of dietary fructooligosaccharide on digestive enzyme activities, intestinal microflora and morphology of male broilers. Poultry Science 82: 10301036.
Xu, QQ, Yan, H, Liu, XL, Lv, L, Yin, CH and Wang, P (2014). Growth performance and meat quality of broiler chickens supplemented with Rhodopsedomonas palustris in drinking water. British Poultry Science 55: 360366.
Yang, Y, Iji, PA and Choct, M (2007). Effects of different dietary levels of mannanoligosaccharide on growth performance and gut development of broiler chickens. Asian-Australasian Journal of Animal Science 20: 10841091.
Yang, CM, Cao, GT, Ferket, PR, Liu, TT, Zhou, L, Zhang, L, Xiao, YP and Chen, AG (2012). Effects of probiotic, Clostridium butyricum, on growth performance, immune function, and cecal microflora in broiler chickens. Poultry Science 91: 21212131.
Yazdankhah, S, Rudi, K and Bernhoft, A (2014). Zinc and copper in animal feed-development of resistance and co-resistance to antimicrobial agents in bacteria of animal origin. Microbial Ecology in Health and Disease 25: 25862.
Yeaman, MR and Yount, NY (2007). Unifying themes in host defence effector polypeptides. Nature Reviews Microbiology 5: 727740.
Yeo, J and Kim, KI (1997). Effect of feeding diets containing an antibiotic, a probiotic, or yucca extract on growth and intestinal urease activity in broiler chicks. Poultry Science 76: 381385.
Yitbarek, A, Echeverry, H, Munyaka, P and Rodriguez-Lecompte, JC (2015). Innate immune response of pullets fed diets supplemented with prebiotics and synbiotics. Poultry Science 94: 18021811.
Yogesh, K, Deo, C, Shrivastava, HP, Mandal, AB, Wadhwa, A and Singh, I (2013). Growth performance, carcass yield, and immune competence of broiler chickens as influenced by dietary supplemental zinc sources and levels. Agricultural Research 2: 270274.
Zhao, PY, Baek, HY and Kim, IH (2012). Effects of bacteriophage supplementation on egg performance, egg quality, excreta microflora, and moisture content in laying hens. Asian-Australasian Journal of Animal Sciences 25: 10151020.
Zhao, X, Guo, Y, Guo, S and Tan, J (2013a). Effects of Clostridium butyricum and Enterococcus faecium on growth performance, lipid metabolism, and cecal microbiota of broiler chickens. Applied Microbiology and Biotechnology 97: 64776488.
Zhao, XH, He, X, Yang, XF and Zhong, XH (2013b). Effect of Portulaca oleracea extracts on growth performance and microbial populations in ceca of broilers. Poultry Science 92: 13431347.
Zhang, ZF and Kim, IH (2014). Effects of multistrain probiotics on growth performance, apparent ileal nutrient digestibility, blood characteristics, cecal microbial shedding, and excreta odor contents in broilers. Poultry Science 93: 364370.
Zhang, KY, Yan, F, Keen, CA and Waldroup, PW (2005). Evaluation of microencapsulated essential oils and organic acids in diets for broiler chickens. International Journal of Poultry Science 4: 612619.
Zhang, HY, Piao, XS, Zhang, Q, Li, P, Yi, JQ, Liu, JD, Li, QY and Wang, GQ (2013). The effects of Forsythia suspensa extract and berberine on growth performance, immunity, antioxidant activities, and intestinal microbiota in broilers under high stocking density. Poultry Science 92: 19811988.