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Acidifier as an Alternative Material to Antibiotics in Animal Feed
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Acidifier as an Alternative Material to Antibiotics in Animal Feed
Kim, Y.Y.; Kil, D.Y.; Oh, H.K.; Han, In K.;
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Dietary acidifiers appear to be a possible alternative to feed antibiotics in order to improve performance of weaning pigs. It is generally known that dietary acidifiers lower gastric pH, resulting in increased activity of proteolytic enzymes, improved protein digestibility and inhibiting the proliferation of pathogenic bacteria in GI tract. It is also hypothesized that acidifiers could be related to reduction of gastric emptying rate, energy source in intestine, chelation of minerals, stimulation of digestive enzymes and intermediate metabolism. However, the exact mode of action still remains questionable. Organic acidifiers have been widely used for weaning pigs' diets for decades and most common organic acidifiers contain fumaric, citric, formic and/or lactic acid. Many researchers have observed that dietary acidifier supplementation improved growth performance and health status in weaning pigs. Recently inorganic acidifiers as well as organic acidifiers have drawn much attention due to improving performance of weaning pigs with a low cost. Several researchers introduced the use of salt form of acidifiers because of convenient application and better effects than pure state acids. However, considerable variations in results of acidifier supplementation have been reported in response of weaning pigs. The inconsistent responses to dietary acidifiers could be explained by feed palatability, sources and composition of diet, supplementation level of acidifier and age of animals.
Acidifier;Gastric pH;Weaning Pig;Antibiotics;
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Aumaitre, A., J. Peineau and F. Maec. 1995. Digestive adaptation after weaning and nutritional consequences in the piglets. Pig News Info. 16:73-79.

Barrow, P. A., R. Fuller and M. J. Newport. 1977. Changes in the microflora and physiology of the anteriorintestinal tract of pigs weaned at 2 days with special reference to the pathogenesis of diarrhea. Infect. Immun. 18:586-595.

Blank, R., R. Mosenthin, W. C. Sauer and S. Huang. 1999. Effect of fumaric acid and dietary buffering capacity on ileal and fecal amino acid digestibilities in early-weaned pigs. J. Anim. Sci. 77:2974-2984.

Bokori, J., O. Galfi and I. Boros. 1989. Swine experiment with a feed containing Na-n-butyrate. Magyar Allat Lapja. 44:501-508.

Bolduan, G., H. Jung, E. Schnabal and R. Schneider. 1988. Recent advances in the nutrition of weaner pigs. Pig New Info. 9:381-385.

Bolduan, G., H. Jung, R. Schneider, J. Block and B. Klenke. 1988a. Influence of fumaric acid and propandiol-formiat on piglets. J. Anim. Physiol. Nutr. 59:143.

Bolduan, G., H. Jung, R. Schneider, J. Block and B. Klenke. 1988b. Effect of propionic and formic acids in piglets. J. Anim. Physiol. Nutr. 59:72.

Bosi, P., H. J. Jung, In K. Han, S. Perini, J. A. Cacciavillani, L. Casini, D. Creston, C. Gremokolini and S. Mattuzzi. 1999. Effects of dietary buffering characteristic and protected or unprotected acids on piglet growth, digestibility and characteristics of gut content. Asian-Aust. J. Anim. Sci. 12(7):1104-1110.

Burnell, T. W., G. L. Cromwell and T. S. Staly. 1988. Effects of dried whey and copper sulfate on the growth responses to organic acid in diets for weanling pigs. J. Anim. Sci. 66:1100-1108.

Canibe, N., S. H. Steien, M. Overland and B. B. Jensen. 2001. Effect of K-diformate in starter diets on acidity, microbiotia, and the amount of organic acids in the digestive tract of piglet, and on gastric alterations. J. Anim. Sci. 79:2123-2133.

Cerchiari, E. 2000. Active matrix technology making more of acids. Pig Progr. 16(4):34-35.

Choct, M. 2001. Alternatives to in-feed antibiotics in monogastric animal industry. ASA Technical Bulletin. AN30:1-6.

Clark, W. A. and E. S. Bafferham. 1989. Citric acid supplementation of creep-weaner diets. In : Manipulating Pig Production II, (Ed. J. L. Barneif and D. P. Hennessy), Australation pig science association. Werribee. Australia, p. 137(Abstr.).

Close, W. H. 2000. Producing pigs without antibiotic growth promoters. Advances in Pork Production. 11:47-56.

Cole, D. J. A., R. M. Beal and J. R. Luscombe. 1968. The effect on performance and bacterial flora of lactic acid, propionic acid, calcium propionate and calcium acrylate in the drinking water of weaned pigs. Vet. Rec. 83:459-464.

Cranwell, P. D., D. E. Noakes and K. J. Hill. 1968. Observations on the stomach contents of the suckling pig. Proc. Nutr. Soc. 27. 26A (Abstr.).

Cranwell, P. D., D. E. Noakes and K. J. Hill. 1976. Gastric secretion and fermentation in the suckling pig. Br. J. Nutr. 36:71.

Cranwell, P. D. 1985. The development of acid and pepsin (EC 3. 4. 23. 1) secretory capacity in the pig; the effects of age and weaning: 1. Studies in anaesthetized pigs. Br. J. Nutr. 54:305-320. crossref(new window)

Cromwell, G. L. 1990. Antimicrobial agents. In Swine Nutrition ed Miller E. R., Ullrey D. E. and Lewis A. J. Butterworth-Heiemann, Boston, MA, USA, pp. 297-313.

Doyle, M. E. 2001. Alternatives to antibiotic use for growth promotion in animal husbandary. Food Research. April:1-17.

Easter, R. A. 1988. Acidification of diets for pigs. In: (Ed. W. Haresign and D. J. A. Cole) Recent Advances in Animal Nutrition. Butterworths, London. UK. pp. 61-72.

Easter, R. A. 1993. Acidification of diets for pigs. Recent Developments in Pig Nutrition 2. pp. 256-266.

Eckel, B., M. Kirchgessner and F. X. Roth. 1992a. Influence of formic acid on daily weight gain, feed intake, feed conversion rate and digestibility: 1. Nutritive value of organic acids in the rearing of piglets. J. Anim. Physiol. Nutr. 67:93-100.

Edmonds M. S., O. A. Izquierdo and D. H. Baker. 1985. Feed additive studies with newly weaned pigs: efficacy of supplemental copper, antibiotics and organic acids. J. Anim. Sci. 60(2):462-469.

Falkowski, J. F. and F. X. Aherne. 1984. Fumaric and citric acid as feed additives in starter pig nutrition. J. Anim. Sci. 58:935-938.

Fuller, R. 1977. The importance of lactobacilli in maintaining normal microbial balance in the crop. Br. Pout. Sci. 18:89-94.

Gabert, V. M., W. C. Sauer, M. Schmitz, F. Ahrens and R. Mosenthin. 1995. The effect of formic acid and buffering capacity on the ileal digestibilities of amino acids and bacterial populations and metabolites in the small intestine of weanling pigs fed semipurified fish meal diets. Can. J. Anim. Sci. 75:615-623.

Galfi, P. and J. Bokori. 1990. Feeding trial in pigs with a diet containing sodium n-butyrate. Acta. Vet. Hung. 38:3-17.

Gardner, W. H. 1972. Acidulants in food processing. In: CRC hand book of food additivies (2nd edn), (Ed. T. E. Furia). CRC press. Clevel and OH. USA.

Gauthier, R. 2002. Intestinal health, the key to productivity - the case of organic acids. Precongreso Cientifico Avicola IASA XXVII convencion ANECA-WPDC. Puerto Vallarta, Jal. Mexico.

Giesting, D. W. and R. A. Easter. 1985. Response of starter pigs to supplementation of corn soybean meal diets with organic acids. J. Anim. Sci. 60(5):1288-1294.

Giesting, D. W. 1986. Utilization of soy protein by the young pig. Ph. D. Thesis. Univ. Illinois, Urbana, Champaign.

Giesting, D. W. and R. A. Easter. 1991. Effect of protein source and fumaric acid supplementation on apparent digestibility of nutrients by young pigs. J. Anim. Sci. 69(6):2497-2503.

Giesting, D. W., M. A. Roos and R. A. Easter. 1991. Evaluation of the effect of fumaric acid and sodium bicarbonate addition on performance of starter pigs fed diets of different types. J. Anim. Sci. 69:2489-2496.

Grassmann, E. F. X. Roth and M. Kirchgessner. 1992. Metabolic effects of formic acid in daily use: 6. Nutritive value of organic acids in piglet rearing. J. Anim. Physiol. Nutr. 67:250-257.

Harada, E. M. Niiyama and B. Syuto. 1986. Comparison of pancreatic exocrine secretion via endogenous secretin by intestinal infusion of hydrochloric acid and monocarboxyic acid in anesthetized piglets. Jpn. J. Physiol. 36:843-856.

Harada, E., H. Kiriyama, E. Kobayashi and H. Tsuchita. 1988. Postnatal development of biliary and pancreatic exocrine secretion in piglets. Comparative Biochem. Physiol. 91:43-51

Hartman, P. A., W. E. Hays, R. O. Baker, L. W. Neage and D. V. Carton. 1961. Digestive development in the young pigs. J. Anmi. Sci. 62:1298.

Henry, R. W., D. W. Pickard and P. E. Hughes. 1985. Citric acid and fumaric acid as food additives for early-weaned piglets. Anim. Prod. 40:505-509.

Hesselman, K. and P. Aman. 1986. The effect of B-glucanase on the utilization of starch and nitrogen by broiler chickens fed on barley of low- or high-viscosity. Anim. Feed. Sci. Technol. 15:83-93.

Hill, G. M., G. L. Cromwell, T. D. Crenshaw, C. R. Dove, R. C. Ewan, D. A. Knabe, A. J. Lewis, G. W. Libal, D. C. Mahan, G. C. Shurson, L. L. Southern and T. L. Veum. 2000. Growth promotion effects and plasma changes from feeding high dietary concentrations of zinc and copper to weanling pigs (regional study). J. Anim. Sci. 78:1010-1016.

Jonson, R. 1992. Role of acidifiers and enzymes in assuring performance and health of pigs post-weaning. In: Biotechnology in the Feed industry C Proc. Alltech’s Eighth Annual Symp.) Alltech technical Publication. Nicholasville. KY. USA. PP 139-150.

Jongbloed, A. W. 1987. In: Phosphorus in the feeding of pigs. Agricultural University of Wageningen. p. 343.

Jongbloed, A. W., Z. Mroz, R. van der Weij-Jongbloed and P. A. Kemme. 2000. The effects of mircobial phytase, organic acid and their interaction in diets for growing pigs. Livest. Prod. Sci. 67:113-122.

Jung, B. N. and G. Bolduan. 1986. Zur wirkung unterschiedlicher mineralstoffanteile in der ration des absetzferkels. Mh. Vet. Med. 41:50-52.

Kershaw, G. F., J. R. Luscombe and D. J. A. Cole. 1966. Lactic acid and sodium acrylate; effect on growth rate and bacterial flora in the intestines of weaner pigs. Vet. Res. 79:296.

Kidder, D. E. and M. J. Manners. 1978. Digestibility. In digestion in the pig. Kingeton Press, Bath, UK. p. 190.

Kil, D. Y. 2004. Comparison of growth performance, nutrient digestibility and white blood cell counts by organic or inorganic acid supplementation in weaned pigs. MS Thesis. Seoul National University, Korea.

Kirchegessner, M. and F. X. Roth. 1982. Fumaric acid as a feed additive in pig nutrition. Pig News Info. 3:259.

Kirchegessner, M. and F. X. Roth. 1987a. Use of formates in the feeding of piglets. 1st communication: Calcium formate. Landwirtsch. Forsch. 40:141-152.

Kirchegessner, M. and F. X. Roth. 1990. Nutritive effect of calcium formate in combination with free acids in the feeding of piglets. Agribiol. Res. 43:53-64.

Kirchegessner, M., B. Eckel, F. X. Roth and U. Eidelsburger. 1992. Influence of formic acid on carcass composition and retention of nutrients: 2. Nutritive value of organic acids in piglet rearing. J. Anim. Physiol. Nutr. 67:101-110.

Kornegay, E. T., S. N. Hay and J. D. Blaha. 1976. Comparison of one, two and three pigs per cage and dietary citric acid for seven day old weaned pig. J. Anim. Sci. 43:254(Abstr.).

Lambert, R. J. and M. Stratford. 1999. Weak acid perservatives: modeling microbial inhibition and response. J. Applied Microbiol. 86:157-164.

Lawlor, P. G., P. B. Lynch and P. J. Caffrey. 1993. Comparison of fumaric acid, calcium formate and mineral levels in diets for newly weaned pigs. Proceedings Irish Grassland and Animal Production Association. 19th annual research meeting. pp. 81-82.

Lawlor, P. G., P. B. Lynch and P. J. Caffrey. 1994. Measurements of the acid binding capacity of ingredients used in diets for starter pigs. Anim. Prod. 58:468(Abstr.).

Lewis, C. J., P. A. Hartman, C. H. Lin, R. O. Baker and D. V. Carton. 1957. Digestive enzyme development in the young pigs. J. Anim. Sci. 20:114.

Lindemann, M. D., S. G. Cornelius, S. M. El Kandelgy, R. L. Moser and J. E. Pettigrew. 1986. Effect of age, weaning and diet on digestive enzyme levels in the piglet. J. Anim. Sci. 62:1298-1307.

Lueck, E. 1980. Antimicrobial Food Additives: Characteristics, Uses, Effects. Berlin, Germany: Springer-Verlag.

Lupton, J. R. and P. P. Krutz. 1993. Relationship of colonic luminal short-chin fatty acids and pH to in vivo cell proliferation in rats. J. Nutr. 123:1522-1530.

Lynch, P. B., S. Kavanagh, P. Lawlor, M. Young,D. Harrington, P. J. Caffrey and W. D. Henry. 1998. Effect of pre- and postweaning nutrition and management on performance of weaned pigs to circa 35 kg. Teagasc pig production. Project report-4128.

Mahan, D. C., E. A. Newton and K. R. Cera. 1996. Effect of supplemental sodium chloride, sodium phosphate, or hydrochlorich acid in starter pig diets containing dried whey. J. Anim. Sci. 74:1217-1222.

Mahan, D. C., T. D. Wiseman, E. Weaver and L. Russell. 1999. Effect of supplemental sodium chloride and hydrochloric acid added to initial diets containing sprayed-dried blood plasma and lactose on resulting performance and nitrogen digestibility of 3-week-old weaned pigs. J. Anim. Sci. 77:3016-3021.

Manners, M. J. 1976. Symposium on quantitative aspects of pig nutrition. The development of digestive function in the pig. Proc. Nutr. Soc. 35:49.

Maribo, H., B. B. Jensen and M. S. Hedemann. 2000. Different doses of organic acids to piglets. Danish Bacon and Meat Council, no. 469.

Mathew, A. G., A. L. Sutton, A. B. Scheidt, D. M. Forsyth, J. A. Patterson and D. T. Kelly. 1991. Effects of a propionic acid containing feed additive on performance and intestinal microbial fermentation of the weanling pigs. In: Proc Sixth Int Symposium on the Digestive Physiology in Pigs. PUDOC. Wageningen, The Netherlands, pp. 464-469.

Mathew, A. G., M. A. Franklin, W. G. Upchurch and S. E. Chattin. 1996a. Influence of weaning age on ileal microflora and fermentation acids in young pigs. Nutrition Research 16(5):817-827.

Maxwell, F. J. and C. S. Stewart. 1995. The microbiology of the gut and the role of probiotics. In the Neonatal Pig: Development and Survival. pp. 155-186. Wallingford. Oxon. CAB International.

Mayer, E. A. 1994. The physiology of gastric storage and emptying. In Physiology of the Gastrointestinal Tract. 3rd ed., New York. Lippencott Raven Press. Vol. 1. pp. 929-976.

Miller, B. G., A. Phillips, T. J. Newby, C. R. Stokes and F. J. bourne. 1985. A transient hypersensitivity to dietary antigens in the early weaned pig: factor in the aetiology of postweaning diarrhea. In: Proc 3rd Int Seminar on Digetive Physiology of the pig. national Institute of Animal Science, Copenhagen, Denmark, pp. 65-68.

Oh, H. K. 2004. Effect of dietary supplements on growth, nutrient digestion and intestinal morphology in monogastric animals. Ph. D. Thesis. Seoul National University, Korea.

Overland, M., T. Granli, N. P. Kjos, O. Fjetland, S. H. Steien and M. Stokstad. 2000. Effect of dietary formates on growth performance, carcass traits, sensory quality, intestinal microflora, and stomach alterations in growing-finishing pigs. J. Anim. Sci. 78:1875-1884.

Partanen, K. H. and Z. Morz. 1999. Organic acids for performance enhancement in pig diets. Nutr. Res. Rev. 12:117-145.

Paulicks, B. R., F. X. Roth and M. Kirchgessner. 2000. Effects of potassium diformate in combination with different grains and energy densities in the feed on growth performance of weaned piglets. J. Anim. Physio. Anim. Nutr. 84(3):102-110.

Pollman, D. S., D. M. Danielson and E. R. Peo. 1980. Effects of microbial feed additives on performance of starter and growing-finishing pigs. J. Anim. Sci. 51:577-581.

Radcliffe, J. S., Z. Zang and E. T. Kornegay. 1998. The effects of microbial phytase, citric acid, and their interaction in a cornsoybean meal-based diet for weanling pigs. J. Anim. Sci. 76:1880-1886.

Radecki, S. V., M. R. Juhl and E. R. Miller. 1988. Fumaric and citric acids as feed additives in starter pig diets: Effect on performance and nutrient balance. J. Anim. Sci. 66:2598-2605.

Ravindran, V. and E. T. Kornegay. 1993. Acidification of weaner pig diets: A review. J. Sci. Food Agric. 62:313-322.

Reither, B., V. M. Marshal and S. M. Philips. 1980. The antibiotic acitivity of the lactoperoxidase-thiocyanate-hydrogen peroxide system in the calf abomasum. Res. Vet. Sci. 28:116-122.

Risley, C. R., E. T. Kornegay, M. D. Lindemann, C. M. Wood and W. N. Eigel. 1992. Effect of feeding organic acids on selected intestinal content measurements at varying times postweaning in pigs. J. Anim. Sci. 70:196-206.

Roe, A. J., D. McLaggan, I. Davidson, C. Oayrne and I. R. Booth. 1998. Perturbation of anion balance during inhibition of growth of Escherichia coli by weak acids. J. Bacteriol. 180(4):767-772.

Roth, F. X. and M. Kirchgessner. 1989. Significance of dietary pH and buffering capacity in piglet nutrition. 1. pH and buffering capacity in diets supplemtented with organic acids. Landwirtschaftliche Forschung. 42:157-167.

Roth, F. X. and M. Kirchgessner. 1989. Bedeutung von-pH wert und pufferkapazitat des futters fur die ferkelfutterung. 2. Miteilung: Effekt einer pH-absenkung im futter durch orthophosphorsaure-zusatz auf wachstum und futterverwertung. Landwirtsch. Forsch. 42:168-175.

Roth, F. X., B. Eckel, M. Kirchgessner and U. Eidelsburger. 1992. Influence of formic acid on pH value, dry matter, concentration of volatile fatty acids and lactic acid in the gastrointestinal tract: 3. Communication: Investigations about the nutritive efficacy of organic acids in the rearing of piglets. J. Anim. Physiol. Nutr. 67:148.

Roth, F. X., M. Kirchgessner and Brigitte R. Paulicks. 1996. Nutritive use of feed additives based on diformates in the rearing and fattening of pigs and their effects on performance. Agribiol. Res. 49(4):307-317.

Sakata, T., M. Adachi, M. Hashida, N. Sato and T. Kojima. 1995. Effect of n-butyric acid on epithelial cell proliferation of pig colonic mucosa in short-term culture. Deutsche Tierarztliche Wochenschrift 102:163-164.

Schoenherr, W. D. 1994. Phosphoric acid-based acidifiers explored for starter diets. Feedstuffs 66(40, Sept. 26).

Sciopioni, R., G. Zaghini and B. Biavati. 1978. Researches on the use of acidified diets for early weaning of piglets. Zootechnol Nutr. Anim. 4:201-218.

Sissons, J. W. 1989. Potential of probiotic organisms prevent diarrhea and promote digestion in farm animals - a review. J. Sci. Food Agri. 49:1-13.

Smith, H. W. and J. E. T. Jones. 1963. Observations on the alimentary tract and its bacterial flora in healthy and diseased pigs. J. Pathol. Bacteriol. 86:387-412.

Straw, M. L., E. T. Kornegay, J. L. Evans and C. M. Wood. 1991. Effects of dietary pH and phosphorus source on performance, gastrointestinal tract digesta, and bone measurements of weanling pigs. J. Anim Sci. 69:4496-4504.

Stryer, L. 1988. Biochemistry, 3rd edition. New York; WH Freeman and Company. Taylor, W. H. 1959. Studies on gastric proteolysis. Biochem. J. 71:627-632.

Thaela, M. J., M. S. Jensen, S. G. Pierzynowski, S. Jakob and B. B. Jensen. 1998. Effect of lactic acid supplementation on pancreatic secretion in pigs after weaning. J. Anim. Feed Sci. 7(suppl. 1):181-183.

Thompson, J. L. and T. L. J. Lawrence. 1981. Dietary manipulation of gastric pH in the profilaxis of enteric disease in weaned pigs. Some field observations. Vet. Rec. 109:120-122.

Tschierschwitz, A., E. Grassmann, M. Kirchgessner and F. X. Roth. 1982. The effect of fumaric acid supplements on activities of liver enzymes (GOT, GPT, SUCCDH) with different supplies of energy and protein to growing rats. Zeitschrift fur Tierphysiologie, Tierernahrung und Futtermittelkunde. 48:253-259.

Tsiloyiannis, V. K., S. C. Kyriakis, J. Vlemmas and K. Sarris. 2001. The effect of organic acids on the control of porcine postweaning diarrhea. Res. Vet. Sci. 70(3):287-293. crossref(new window)

Ward, N. E., M. E. Whitacre, F. Koch, J. B. Schutte and E. J. van Weerden. 1987. Efficacy of dietary calcium formate to enhance performance on weanling pigs. J. Anim. Sci. 65(suppl.):30-31(Abstr.).

Walz, O. P. and J. Pallauf. 1997. Retention and utilization of amino acids in piglets fed ad libitum or restrictively diets supplemented with organic acids. Arch Tierernahr. 50(3):227-238.