A-landmark-contribution-to-poultry-science-Prophylactic-control-of-coccidiosis-in-poultry

A landmark contribution to poultry science—Prophylactic control of coccidiosis in poultry1 H D Chapman2 Department of Poultry Science, University of Arkansas, Fayetteville 72701 ABSTRACT “Continuous feeding of low concentrations of sulfaquinoxaline for the control of coccidiosis in poultry” by L C Grumbles, J P Delaplane, and T C Higgins [Poult Sci (1948) 27:605–608] was the first paper to demonstrate that it was possible to control coccidiosis by the continuous inclusion of a low level of a drug in the feed of chickens The principle involved (prevention or prophylaxis) has had a profound impact on our ability to grow chickens and turkeys under intensive conditions Indeed, it is possible that the modern poultry industry could never have developed to its present extent without the advent of drugs used prophylactically to control coccidiosis One particular insight was that use of a compound in this manner did not necessarily prevent the acquisition of immunity, an important principle that helps explain the con- tinued efficacy of ionophorous antibiotics used today The significance of this work to the poultry industry and individuals involved in research, whether employed by government, academia, or pharmaceutical companies, cannot be overstated Economic benefits, in terms of improved productivity, have been demonstrated in numerous studies published in Poultry Science In addition, the livelihoods of many poultry farmers have been helped by the control of a disease that in the past caused substantial morbidity and mortality in their flocks The paper is brief and contains no critical science involving novel procedures but has had a profound influence on the health of poultry for the last decades For this reason, it is nominated as a landmark contribution from the first 100 yr of Poultry Science Key words: coccidiosis, Eimeria, poultry, prophylaxis, control 2009 Poultry Science 88:813–815 doi:10.3382/ps.2008-00316 BACKGROUND best employed to treat sick birds, a procedure that, to be successful, required prompt and accurate diagnosis At the forefront of this work were John P Delaplane (1906–1957), Leland C Grumbles (1921–2006), and coworkers at Rhode Island Agricultural Experiment Station (RIAES) They produced several papers concerned with the use of sulfaquinoxaline, culminating in the manuscript published in Poultry Science (Grumbles et al., 1948) This was the first publication to clearly enunciate the principle that coccidiosis could be controlled by including a drug continuously in the feed (prophylaxis or prevention), upon which the future control of Eimeria infections would be based The same year sulfaquinoxaline was introduced as a commercial product and the “age of chemotherapy” for coccidiosis control was thus inaugurated Not all researchers were convinced Clifford HortonSmith wrote “we believe that continuous feeding of any drug, even at a low level, as a means of preventing disease is unwise because of our ignorance of the possible long-term effects on the bird itself” (Horton-Smith, 1951) He was the first to point out “the question of the possible development of resistant strains of coccidia, when exposed to low concentrations of drug, must not Sixty years ago a paper was published that profoundly influenced the development of the worldwide poultry industry In the first half of the twentieth century it was difficult to raise chickens and turkeys without devastating losses caused by coccidiosis, a protozoan disease caused by parasites of the genus Eimeria In 1949, the cost of coccidiosis to the poultry industry in the United States was estimated to be $10 million annually (Foster, 1949) The report in 1939 that a sulfonamide was capable of controlling Eimeria infections (Levine, 1939) led in the immediate post-war period to many investigations of the properties of these compounds Thus, 104 publications concerned with their efficacy in chickens were published from 1939 to 1951 (Anonymous, 1953) At that time it was thought that sulfonamides were ©2009 Poultry Science Association Inc Received July 31, 2008 Accepted August 14, 2008 Presented as part of the Landmark Symposium, July 22, 2008, at the Poultry Science Association meeting, Niagara Falls, Ontario, Canada Corresponding author: dchapman@uark.edu 813 814 Chapman Figure Left: John P Delaplane, date unknown; right: Leland C Grumbles, 1974 Faculty portraits provided courtesy of Texas A&M University College of Veterinary Medicine and Biomedical Sciences be overlooked.” Earlier, P Philip Levine, who had first reported the anticoccidial effect of sulfanilamide, had stated “medication can never take the place of proper husbandry,” and that “if domestic animals, including poultry, have to be medicated continually to keep them healthy or alive, there is something fundamentally wrong” (Levine, 1945) Unfortunately, these sentiments did not help the poultry farmer faced with catastrophic losses caused by coccidiosis Philip A Hawkins summarized the situation: “whether we like the idea of medicated feed or not, we have no choice in the matter; it is here to stay Although we may object to the adulteration of feedstuffs with medicine, we must remember that our unnatural methods of livestock and poultry production have forced us to this extreme” (Hawkins, 1950) BIOGRAPHICAL INFORMATION John Delaplane was employed by RIAES from 1931 to 1942 as poultry pathologist and associate professor of poultry husbandry After a brief spell at Texas A&M University (TAMU) from 1942 to 1946, he returned to RIAES as research professor and department head He was joined by Leland Grumbles, who was hired in 1946 (Figure 1) Grumbles had spent a brief period in private practice after military service before joining RIAES Thomas Higgins was employed as research assistant by RIAES and in 1949 was promoted to assistant research professor With the aid of federal funds and a grant of $5,000 from Merck and Co they initiated a research project titled “Sulfaquinoxaline in the prevention and control of coccidiosis in poultry” (Anonymous, 1947) In addition to their work on coccidiosis, Delaplane and Grumbles were involved in experiments concerned with fowl cholera and infectious coryza Grumbles departed for Louisiana State University in 1948 but after one year joined the College of Veterinary Medicine, TAMU, as associate professor of veterinary microbiology Dela- plane was hired by TAMU as head of the department of veterinary bacteriology and hygiene in 1950 Both men conducted research on a variety of pathological conditions affecting poultry and played pivotal roles in the foundation, in 1957, of the American Association of Avian Pathologists (AAAP) In August 1960, at the third annual meeting of the AAAP, the outgoing president presented a gavel in honor of Delaplane and in a citation stated, “his keen insight, untiring efforts and unique ability to resolve difficult disease problems have been phenomenal His scientific contributions in the field of poultry diseases have been outstanding and numerous He was respected by his professional colleagues for his scientific curiosity, integrity, modesty, and professional ethics” (Anonymous, 1961) Grumbles was head of the department of veterinary microbiology for 20 years (1957–1977) and remained as a professor until his retirement in 1984 A native of Arkansas, Grumbles held numerous distinguished positions including presidencies of the Southern Conference on Avian Diseases (1960–1961), the Animal Disease Research Workers of the Southern States (1963–1964), the American Association of Veterinary Bacteriologists (1965), and the AAAP (1974–1975) He was a member of the board of governors of the American College of Veterinary Microbiologists (1966–1972) and served as editor of Avian Diseases (1966–1973) He received numerous awards including, in 1984, the Golden Feather award, the most prestigious recognition bestowed by the Texas Poultry Federation PROPHYLAXIS AND IMMUNITY One important insight was that continuous use of sulfaquinoxaline did not necessarily prevent the acquisition of immunity Grumbles, Delaplane, and Higgins state in their introduction “It is the belief of the authors that the inclusion of the medication in the feed continuously over a sufficient period of time to allow immunity to develop from natural exposure would be the safest and most economical method for controlling coccidiosis” (Grumbles et al., 1948) In the 1970s, this principle was forgotten when several highly effective compounds were introduced that completely inhibited parasite development The consequences were predictable, with rapid development of drug resistance, and clinical outbreaks of coccidiosis following withdrawal of medication Today, the efficacy of ionophores is considered largely due to their ability to control coccidiosis but permit the acquisition of immunity (Chapman, 1999) IMPACT UPON THE POULTRY INDUSTRY The impact of this work upon poultry and allied industries has been immense Thus, prophylactic inclusion of anticoccidial agents in the feed has become standard practice in broiler chickens and meat-type turkeys 815 LANDMARK SYMPOSIUM Since the 1950s, almost every broiler chicken and meattype turkey has been reared with an anticoccidial drug in the diet Statistics produced by Agri Stats Inc (Fort Wayne, IN) indicate that, during the late 1990s, 99% of broilers were raised with an anticoccidial drug in one or more feeds (Chapman, 2001); this widespread use continues today In the case of the ionophorous antibiotics, more animals were said to have been medicated with these compounds for control of an infectious disease than any other medicinal agents in the history of veterinary medicine (Chapman, 1993) An indication of the economic significance of coccidiosis can be gained by calculating the amount spent annually on medication The most recent estimate indicates that, in the United Kingdom, approximately 6.4 million GBP are spent annually on anticoccidial drugs for the chicken (Williams, 1999) If the basis for this calculation is correct (and assuming a 10-fold-larger industry in the United States and an exchange rate of 1GBP = USD), the amount spent in the United States would be about $127 million annually Less obvious consequences of the use of anticoccidial drugs and the profits generated from their sale include employment opportunities for many scientists and veterinarians in pharmaceutical companies and the regulatory authorities responsible for product approval Advertising revenues have been generated that support many poultry magazines, provide financial support and sponsorship of professional societies and their conferences (such as the centennial meeting of the Poultry Science Association), and make grants available to support research into poultry diseases, including coccidiosis The success in controlling coccidiosis is an excellent example of what can be achieved if those employed by academia, government, and industry work together for a common cause Perusal of any journal concerned with poultry health in the latter half of the 20th century reveals the large number of papers devoted to various aspects of drug use in the control of coccidiosis Although not often acknowledged and rarely quoted, much of this research stems from the landmark contribution by Grumbles, Delaplane, and Higgins published in Poultry Science ACKNOWLEDGMENTS I would like to thank Texas A&M University College of Veterinary Medicine and Biomedical Sciences for permission to publish the portraits of Leland Grumbles and John Delaplane and for providing invaluable biographical information Since this paper was accepted for publication by Poultry Science, an article concerned with the history of sulfaquinoxaline and the role played by Grumbles, Delaplane, and Higgins in its discovery as an anticoccidial drug, has been published in the Journal of Parasitology (Campbell, 2008) REFERENCES Anonymous 1947 Research for the farmer 59th Annual Report Contribution 703, Rhode Island Agricultural Experiment Station, Kingston Anonymous 1953 Coccidiosis annotated bibliography Merck and Co Inc., Rahway, NJ Anonymous 1961 John P Delaplane (1906–1957) Avian Dis 5:1 Campbell, W C 2008 History of the discovery of sulfaquinoxaline as a coccidiostat J Parasitol 94:934–945 Chapman, H D 1993 Twenty-one years of monensin for the control of coccidiosis – A review Pages 37–44 in Proc VIth Int Coccidiosis Conf J R Barta and M A Fernando, ed University of Guelph, Guelph, Ontario, Canada Chapman, H D 1999 Anticoccidial drugs and their effects upon the development of immunity to Eimeria infections in poultry Avian Pathol 28:521–535 Chapman, H D 2001 Use of anticoccidial drugs in broiler chickens in the USA: Analysis for the years 1995 to 1999 Poult Sci 80:572–580 Foster, A O 1949 The economic losses due to coccidiosis Ann N Y Acad Sci 52:434–442 Grumbles, L C., J P Delaplane, and T C Higgins 1948 Continuous feeding of low concentrations of sulfaquinoxaline for the control of coccidiosis in poultry Poult Sci 27:605–608 Hawkins, P A 1950 Coccidiosis in poultry: A review J Am Vet Med Assoc 116:226–227 Horton-Smith, C 1951 Sulphaquinoxaline in the treatment of caecal coccidiosis in chickens caused by the coccidium Eimeria tenella (Raillet and Lucet, 1891) Pages 3–8 in Investigations of diseases and their control Sect III 9th World’s Poult Cong., Paris, France Levine, P P 1939 The effect of sulfanilamide on the course of experimental avian coccidiosis Cornell Vet 29:309–320 Levine, P P 1945 Specific diagnosis and chemotherapy of avian coccidiosis J Am Vet Med Assoc 106:88–103 Williams, R B 1999 A compartmentalised model for the estimation of the cost of coccidiosis to the world’s chicken production industry Int J Parasitol 29:1209–1229