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

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.. The si

2009 Poultry Science 88 :813–815 doi: 10.3382/ps.2008-00316

Key words: coccidiosis , Eimeria , poultry , prophylaxis , control

ABSTRACT “Continuous feeding of low

concentra-tions 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

con-trol coccidiosis by the continuous inclusion of a low

level of a drug in the feed of chickens The principle

in-volved (prevention or prophylaxis) has had a profound

impact on our ability to grow chickens and turkeys

un-der 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

immu-nity, 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 compa-nies, cannot be overstated Economic benefits, in terms

of improved productivity, have been demonstrated in

numerous studies published in Poultry Science In

ad-dition, 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 sci-ence involving novel procedures but has had a profound influence on the health of poultry for the last 6 decades For this reason, it is nominated as a landmark

contribu-tion from the first 100 yr of Poultry Science

A landmark contribution to poultry science—Prophylactic

control of coccidiosis in poultry1

H D Chapman 2

Department of Poultry Science, University of Arkansas, Fayetteville 72701

BACKGROUND

Sixty years ago a paper was published that

profound-ly 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

devastat-ing 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

(Fos-ter, 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

investi-gations 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

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

con-cerned 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 con-trolled by including a drug continuously in the feed (prophylaxis or prevention), upon which the future

con-trol 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 Horton-Smith wrote “we believe that continuous feeding of any drug, even at a low level, as a means of preventing dis-ease 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

Received July 31, 2008.

Accepted August 14, 2008.

at the Poultry Science Association meeting, Niagara Falls, Ontario,

Canada

© 2009 Poultry Science Association Inc.

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

situ-ation: “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

feed-stuffs with medicine, we must remember that our

un-natural 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 patho-logical conditions affecting poultry and played pivotal roles in the foundation, in 1957, of the American

Associ-ation 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 col-leagues 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 posi-tions 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

nu-merous 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 acqui-sition of immunity Grumbles, Delaplane, and Higgins state in their introduction “It is the belief of the au-thors 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 predict-able, with rapid development of drug resistance, and clinical outbreaks of coccidiosis following withdrawal

of medication Today, the efficacy of ionophores is con-sidered largely due to their ability to control coccidi-osis but permit the acquisition of immunity (Chapman, 1999)

IMPACT UPON THE POULTRY INDUSTRY

The impact of this work upon poultry and allied in-dustries has been immense Thus, prophylactic inclu-sion of anticoccidial agents in the feed has become stan-dard practice in broiler chickens and meat-type turkeys

Figure 1 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.

CHAPMAN

814

Since the 1950s, almost every broiler chicken and

meat-type 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

con-tinues 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

vet-erinary medicine (Chapman, 1993)

An indication of the economic significance of

coc-cidiosis can be gained by calculating the amount spent

annually on medication The most recent estimate

indi-cates 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 = 2 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

vet-erinarians in pharmaceutical companies and the

regula-tory authorities responsible for product approval

Ad-vertising revenues have been generated that support

many poultry magazines, provide financial support and

sponsorship of professional societies and their

confer-ences (such as the centennial meeting of the Poultry

Science Association), and make grants available to

sup-port research into poultry diseases, including

coccidi-osis

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

vari-ous aspects of drug use in the control of coccidiosis

Although not often acknowledged and rarely quoted,

much of this research stems from the landmark

contri-bution 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 bio-graphical 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 Jour-nal of Parasitology (Campbell, 2008).

REFERENCES

Anonymous 1947 Research for the farmer 59th Annual Report Contribution 703, Rhode Island Agricultural Experiment Sta-tion, 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 Coc-cidiosis 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 Continu-ous feeding of low concentrations of sulfaquinoxaline for the con-trol 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 dis-eases and their control Sect III 9th World’s Poult Cong., Paris, France.

Levine, P P 1939 The effect of sulfanilamide on the course of ex-perimental 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 estima-tion of the cost of coccidiosis to the world’s chicken producestima-tion industry Int J Parasitol 29:1209–1229.