Parasite Management for Natural and Organic Poultry: Coccidiosis


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Parasite Management for Natural and Organic Poultry: Coccidiosis

  1. 1. Parasite Management for Natural ATTRA and Organic Poultry: Coccidiosis A Publication of ATTRA - National Sustainable Agriculture Information Service • 1-800-346-9140 • www.attra.ncat.orgBy Anne Fanatico Both small and large poultry producers are interested in the sustainable management of the parasiticNCAT Agriculture disease coccidiosis. This publication provides information on its life cycle, transmission in free-rangeSpecialist production, management in the brooder and on pasture, natural treatments, drugs, and vaccines. On©2006 NCAT a small scale, coccidiosis can be handled without medication by careful management, especially dur- ing brooding, and adequate pasture rotation; however, on a larger scale, it is more difficult and vac- cines are an important alternative to drugs in organic production. References and further information follow the narrative.ContentsIntroduction .................... 1Life Cycle and Types ofCoccidia ............................. 2Transmission in theEnvironment ................... 2Symptoms andDiagnosis........................... 4Management forControl ............................... 5 As the size of outdoor flocks increases, more attention Coccidia are parasites that damage the gut of poultry. is needed for coccidiosis control. Photo by Joe Beasley, DVM, PhD.Natural Treatments ........ 7Drugs .................................. 8Vaccines ............................. 9 Introduction large scale with high-density flocks. Coccid- I iosis is controlled with preventative drugs.Summary ......................... 10 n the past, coccidiosis was one of the dis- In fact, high-density production becameReferences ...................... 11 eases most feared by commercial poultry growers in the U.S. Death losses of 20 possible only after the development of pre- percent or more were common. “Backyard” ventative anticoccidial drugs in the 1940s. growers are usually so small that coccidio- However, coccidia are becoming increas- sis is not a problem, but as the size of free- ingly resistant to drugs, and the poultry range flocks increases, coccidiosis becomes industry is looking for alternatives. The use a threat. of vaccines in particular holds potential for both small and large growers. Small producers in the U.S. raise birds with outdoor access and sell the meat and eggs Coccidiosis is a parasitic disease that can directly to local consumers. These “pas- cause severe losses in poultry meat and egg tured poultry” flocks are increasing in production. The parasites multiply in the number and size. Many of these producers intestines and cause tissue damage, lowered use natural production methods and avoid feed intake, poor absorption of nutrientsATTRA—National SustainableAgriculture Information Service using drugs in their flocks. Larger compa- from the feed, dehydration, and blood managed by the National Cen- nies also produce certified organic poultry Birds are also more likely to get sick fromter for Appropriate Technology(NCAT) and is funded under a under the USDA National Organic Program secondary bacterial infections. However,grant from the United States rules, which do not permit the use of anti- in low-density production or with the use ofDepartment of Agriculture’sRural Business-Cooperative Ser- coccidial drugs. preventative medication, coccidiosis gener-vice. Visit the NCAT Web site( The conventional poultry industry is like- ally remains a subclinical disease that onlyhtml) for more informa-tion on our sustainable wise interested in reducing its reliance on affects performance—without the alarmingagriculture projects. ���� drugs. The industry raises poultry on a losses of the past.
  2. 2. Producers used to dread outbreaks of oocysts can infect other birds. See the box bloody diarrhea. An outbreak of coccid- “Coccidial Multiplication” for further details iosis left untreated, eventually runs its on coccidia’s complex life cycle. course, and most of the flock will survive. The birds that recover from coccidiosis A coccidial infection differs from bacterial and gain immunity, but production may never viral infections because coccidia are “self-lim- recover. If the infection is severe, the gut iting” and usually stop multiplying before kill- remains scarred and impaired, and stunted ing the bird. broilers do not catch up in weight gain. Coccidiosis is usually a disease of young birds, but birds can be infected at any time if never before exposed. Coccidia popula- tions take time to build to dangerous lev- els, therefore outbreaks usually occur when birds are between 3 and 8 weeks of age. Coccidiosis goes hand-in-hand with gut diseases, because it damages the gutRelated ATTRA Posture of sick birds. Photo by Lloyd Keck, DVM. and allows bacteria to enter and cause sec-Publications ondary infections. Coccidia are “species-Sustainable Poultry: The production system and the stocking specific”—coccidia that affect chickens doProduction Overview density have a significant impact on coccid- not affect other livestock, and vice versaPastured Poultry iosis. Low-density production systems allow (see Species-Specific Parasites box).Nutrition a low level of exposure in which immunity develops without making the birds sick and Transmission in the damaging performance. Birds are then protected. However, as the size of flocks Environment increase, the numbers of coccidia also grow Chickens get coccidiosis by eating oocysts and can pose a threat to the flock. that have been shed in the droppings of infected chickens. Infected chickens shed oocysts for several days or weeks. Oocysts Life Cycle and Types of sporulate within two days under the proper Coccidia conditions and become infective. Chick- Knowing how coccidia develop helps to ens pick them up by pecking on the ground understand and control the disease. Coc- or in litter used for bedding in the house. cidiosis is caused in poultry by a one-celled Oocysts can also be spread by insects, parasite of the genus Eimeria. The life dust, wild birds, and humans (from shoes cycle of Eimeria takes about four to seven and equipment). days to complete. It begins when active “oocysts” are picked up by the bird and swallowed. An “oocyst” is a capsule with a thick wall protecting the parasites. They “sporulate” or become infective if moisture, temperature, and oxygen become conducive to growth. After a bird eats the oocysts, coccidia imbed in the intestinal lining and multiply several times, damaging tissue. Coccidia are parasites, so they get their nutrients from the chicken host. The mul- tiplications eventually stop, usually before Coccidia multiply in intestinal cells. Photo by Joe Beasley, DVM, PhD. causing death of the bird. The bird sheds the parasite in its droppings. These newPage 2 ATTRA Parasite Management for Natural and Organic Poultry: Coccidiosis
  3. 3. Coccidial Multiplication Species-Specific Parasites Coccidia are very prolific parasites. A single Almost all livestock are affected by different types of coccidia. Each sporulated oocyst can have a big impact when type of coccidia infects only one species of livestock—each is “species- eaten by a chicken. Each oocyst has four spo- specific.” There are seven different Eimeria that infect chickens, but rocysts in it, and each sporocyst has two spo- only three cause most of the trouble in the U.S.: Eimeria tenella, Eimeria rozoites in it. The digestive tract releases the maxima, and Eimeria acervulina. Immunity to one type does not pro- eight sporozoites from the oocyst, and they vide immunity for other types. Turkeys, ducks, geese, and other types move into the cell lining of the digestive tract. of poultry are all infected by different types of coccidia. Inside the cell, the parasite divides and invades Chicken coccidia species: Turkey coccidia species: more cells. There may be several generations of asexual multiplication; however, this stage Eimeria acervulina Eimeria adenoeides is self-limiting and eventually stops. Finally, a Eimeria maxima Eimeria meleagrimitis sexual stage occurs in which male and female Eimeria tenella Eimeria gallopavonis organisms unite and form new oocysts that are protected by a thick wall. These oocysts Eimeria necatrix Eimeria dispersa are shed in the feces. See Coccidia Life Cycle Eimeria mitis Diagram. Eimeria brunetti For more detailed information see the Web Eimeria praecox site Typical life cycle of coccidia in birds ©Saxonet. Adapted with ATTRA Page 3
  4. 4. Oocysts can survive many weeks in Symptoms and Diagnosis the soil outdoors—as long as 600 days. Outward signs of coccidiosis in chickens (Farr and Wehr, 1949) The optimum tem- include droopiness and listlessness, loss perature for sporulation is around 72°F. The of appetite, loss of yellow color in shanks, rate of sporulation is slower if temperatures pale combs and wattles, ruffled, unthrifty are much cooler or hotter. Oocysts feathers, huddling or acting chilled, blood are killed either by freezing or very or mucus in the feces, diarrhea, dehydra- high temperatures. tion, and even death. Other signs include Sporulation also requires oxygen and mois- poor feed digestion, poor weight gain, and ture (at least 20 percent moisture in the poor feed efficiency. Some symptoms can litter for optimal sporulation). If the lit- be confused with other diseases. For exam- ter feels damp to the back of your hand, ple, necrotic enteritis is a gut disease that it is damp enough for sporulation. Once also causes bloody diarrhea. sporulated, the oocyst remains infective for Producers in the past identified coccid- months if protected from very hot, dry, or iosis outbreaks as either severe-acute freezing conditions. or chronic, which was less severe butO ocysts are In very large poultry houses, oocysts do not more widespread. killed either last long in the litter because of the action of If concerned about coccidiosis, do a nec- by freezing ammonia released by decomposition of lit- ropsy—put on plastic gloves and cut open ter and manure and by the action of moldsor very high temper- the chicken. Look at the intestines and then and bacteria. However, there are usuallyatures. cut them open. If done soon after death, so many oocysts that birds continue to pick it may be possible to identify characteris- them up and get sick. tic lesions or sores in the gut. Coccidiosis causes a thickening of the intestines, which The type and location of lesions in the gut indicates the species of Eimeria. • Eimeria acervulina affects the upper part of the small intestine. You may see small red spots and white bandsChicks can pick up on it.oocysts both indoorsand on pasture. • Eimeria maxima affects the entire small intestine. The intestines look watery, and in later stages have blood and mucus. The intestine may look thickened and ballooned with red pinpoint lesions. • Eimeria tenella affects the blind sacs (ceca) of the gut. They may be filled with blood and pus and turn into a solid core.Small intestines affectedby Eimeria maxima. Themiddle sample is openedto show white spots.Photo by Lloyd Keck,DVM. Note the ballooning. Photo by Lloyd Keck, DVM.Page 4 ATTRA Parasite Management for Natural and Organic Poultry: Coccidiosis
  5. 5. make them feel like a sausage. There may the size of the flocks grows, more problemsbe light-colored spots on the surface of the are encountered and more management isgut, and inside the gut, hemorrhages and required for natural immunity.streaks. If you want to confirm a diag- Immunity is especially important in turkeys,nosis, you can send scrapings of the gut layers, breeders, and slow-growing broilerslining to a state diagnostic lab. The USDA’s that are kept longer than fast-growing broil-Animal and Plant Health Inspection ers marketed at a younger age.Service’s Web site ( lists diagnostic labs. Small-Scale Poultry Production SystemsManagement for Control Small poultry producers often provide outdoor access with either a per-Management has always been important to manent house and yard or portable houses. Small pens that are movedcoccidiosis control, especially before drugs daily are also used.were available. Management focuses onreducing the number of coccidia to keep These small growers usually brood chicks in a separate area before mov- ing them to the outdoor facility for growout. However, some growersinfection at a minimum until immunity brood chickens in the same house in which they are grown. See ATTRA’sis established. Sustainable Poultry: Production Overview for more information on small production systems.Natural ImmunityA small-scale, low-density production sys-tem can allow a low level of exposure tococcidia, which permits the chick to developimmunity without triggering the disease. House with yard.However, birds may not pick up enoughparasites to cause immunity, or they maybe overwhelmed by too many. In addition,immunity is only species-specific. Expo-sure to one type of coccidia will not protecta chicken from the other six types that caninfect it.Ea rly detect ion i s a ma na gementmethod to avoid the use of preventativemedication. If you can catch the disease Small pen moved towhen it initially infects only a few birds, you fresh pasture.may have time to treat the birds with a res-cue drug or make a management change,such as moving the birds to fresh pasture.Early detection requires close observationand experience. Watch feed intake in par-ticular—it goes down in the early stagesof coccidiosis.The choice of production system is animportant management decision. High-den-sity, large-scale production almost alwaysrequires the use of anticoccidial medica- Portable houses withtion. In contrast, in low-density, small-scale fence.production, the birds tend to stay ahead ofthe parasites and may not require medica-tion. Many small-scale producers do notuse anticoccidial medication; however, ATTRA Page 5
  6. 6. Brooder and Growout • Put waterers and feeders at a height level with the backs of the birds, so Management they cannot defecate or scratch litter When chicks are brooded in a separate into them. Keep birds from roost- area before moving them to the growout ing on the feeders with anti-roost- facility (two-stage production), the brooder ing wire. Suspend waterers or put stays clean of infective oocysts since fast- them on wire-covered platforms to growing broilers do not remain past three help keep them clean. weeks of age. However, chicks are at risk for coccidiosis if they stay in the brooder • Clean the waterers and feeders longer than three weeks. Pullet chicks frequently. for egg laying grow slowly and stay in the • Keep older birds away from chicks, brooder longer. If chicks are brooded and since old birds are carriers. grown out in the same facility (one-stage • Add fresh litter or rake litter fre- production), they seed the area with coc- quently to cover parasites. cidia. These birds may require a lower den- sity or, possibly, medication. The following Litter ManagementG ood brood- management strategies for good brooding can help. Keep the litter dry to reduce sporulation ing prac- of oocysts. Remove any wet or crusted tices can Good brooding practices can reduce the litter. Moisture in the litter is affected byreduce the need need for medication and include not only the following: sufficient space but also sanitation and lit-for medication and • Heat source: A propane radi- ter management. Give birds adequate floorinclude not only suf- space and feeder/waterer space to pre- ant brooder heats a larger areaficient space but vent overcrowding. Small flock producer and dries out litter more than aalso sanitation and Robert Plamondon recommends at least heat lamp.litter management. one square foot of floor space per chick • Ventilation: Housing should prevent and four tube feeders per 100 chicks. drafts but not be airtight. Humid- (Plamondon, 2003) ity, along with ammonia and other gases, needs to escape. • Water leaks: Water leaks mustThe chicks are kept in be prevented.this brooder for only • Condensation: Condensation maya few weeks and later occur in buildings with uninsulatedmoved to a growout penor small house. roofs and walls and will contribute to litter moisture. • Feed: Rations with excessive pro- tein or excessive salt can result in wet litter. Keep the feeders full. If feeders go empty, birds forage in the litter and ingest oocysts. The longer they peck at contaminated litter, the more oocysts they will ingest. Sanitation Disinfectants are not effective against coc- cidia, so sanitation focuses on good hygiene and removing infected droppings. Keep litter dry by preventing water spills.Page 6 ATTRA Parasite Management for Natural and Organic Poultry: Coccidiosis
  7. 7. In the large-scale industry, “new-house coccidiosis outbreaks in late spring, sum-coccidiosis syndrome” sometimes occurs mer, and early fall.when birds are placed on brand-new litter. In the warm, humid South, coccidiosis is aThere is no low-level population of coccidia greater problem than in dry western establish immunity, so the flock is more Dry conditions on pasture greatly reducesusceptible, coccidiosis problems are more coccidiosis. In cold areas, although oocystslikely, and medication may be needed. on pasture may die during winter, the chick-Some small flock producers are interested ens in the house during winter still carryin the built-up or composting litter as an oocysts and reseed the pasture with themecosystem of microbes. in the spring. Poultry-house litter becomes significantly It is important to control areas of high traffic anti-coccidial after about six months’ use, outdoors to reduce the number of oocysts. as organisms that eat coccidia start to The locations of the waterers and feeders, thrive and knock down the coccidia popula- the pasture, and the house itself, if possi- tion… By never removing more than half the ble, should be rotated. Straw, litter, or bark brooder house litter at a time, it can keep its can help control muddy areas. Controlling P anti-microbial properties indefinitely. coccidiosis on pasture is trickier with broil- roducers (Plamondon, 2002a) ers than with layers, since the broilers are provide out-Plamondon recommends starting with at faster-growing and less active. They eat a door accessleast six inches of shavings and adding a lot, generating large amounts of manure, to allow poultrythin layer of fresh litter on top, which will and congregate in shaded areas. Layers get off the ground to roost on perches. Keeping to express naturalprevent chicks from eating old litter at first. birds in a floorless pen that is moved daily behavior, increaseHe turns it daily with a spading fork to keepit from getting packed down and crusted eliminates coccidiosis by breaking the life space, and to pro-over. If the litter seems too wet, he adds cycle—oocysts cannot re-infect birds. vide fresh air andmore dry litter. He only removes litter sunlight.when it is too deep to manage or when too Natural Treatmentswet. (Plamondon, 2002b) Keeping birds in general good health is always important. Some small produc-Also, although oocysts can be destroyed ers provide raw milk, yogurt, apple ciderby microbes in the litter and soil, there vinegar, or probiotics to birds, believingmay be so many oocysts that the birds that beneficial microbes will prevent orbecome infected. Unfortunately, there is lit- treat coccidiosis. Actually, coccidia do nottle scientific information available on com- compete with bacteria in the gut; there-posting litter. fore, beneficial bacteria and other microbes will not eliminate coccidial development.Pasture However, anything that improves the over-Producers provide outdoor access to all health of the gut and the bird can helpallow poultry to express natural behavior, reduce the impact of coccidiosis. Also, aincrease space, and to provide fresh air population of beneficial bacteria is alwaysand sunlight. Outside, birds may pick up better than pathogenic bacteria, since coc-fewer oocysts, since they are more likely to cidia weaken the gut wall, and bacteria maypeck forage instead of droppings; however, pass through. In short, feeding dairy prod-access to the outdoors has both advantages ucts or probiotics will not stop the coccidiaand disadvantages for coccidial control. through “competitive exclusion” but doesExtreme heat and cold outdoors can reduce provide nutrients or beneficial bacteria thatsporulation or kill oocysts. Yet warmth and are useful in any situation.moisture are favorable conditions for coc- Producers sometimes give diatomaceouscidia. Before the use of medication, com- earth (DE) to the birds in the belief that themercial producers used to experience sharp edges of the fossilized diatoms ATTRA Page 7
  8. 8. damage the parasites and reduce coccidio- • Quinolones: Quinolones are “coccid- sis; however, there is no scientific data to iostats” that arrest the coccidia in support its use. an early stage of development. An example is decoquinate (Deccox®). Drugs The drugs are used for prevention. Drugs are used for two different purposes: • Ionophores: Ionophores are anti- coccidials commonly used in the • To prevent illness large-scale industry. They alter the • To treat illness function of the cell membrane and rupture the parasite. Ionophores Although a producer may depend on man- also have antibacterial action and agement for coccidiosis control, a drug such help prevent secondary gut diseases. as amprolium is useful for rescue treatment Ionophores are not synthetic drugs; in the case of an outbreak. There is no they are produced by fermentation need to destroy infected birds; they can be and include monensin (Coban®) treated. In large houses, it is necessary to and salinomycin (Sacox®). How- routinely use drugs or vaccines because ofD ever, some ionophores are now com- rugs are the high density of birds. pletely ineffective against coccidia used to because of resistance the coccidia prevent or Types of Drugs have developed. They are usedtreat illness. Sulfa • Sulfa drugs: An exciting discovery for prevention.drugs and ampro- in the 1930s was that sulfa drugs • Other drugs: There are many otherlium treat coccid- would prevent coccidiosis—the first anticoccidial drugs in various chem-iosis. drugs shown to do so. Sulfa drugs ical classes with various modes also have some antibacterial action. of action. Examples are Nicarb® However, a relatively large amount (nicarbizone) and Clinicox®. of sulfa was needed (10-20 percent of the diet) and could be tolerated Using Drugs by the bird for only a short time, You need a veterinarian’s prescription to since it caused rickets. (Reid, 1990) use drugs for poultry (but not to use vac- Sulfa drugs had to be used intermit- cines). Feed mills need a license to put tently (e.g., three days on and three drugs in feed. days off). Nowadays, comparatively small amounts of sulfamonaides, In the large-scale industry, drugs are used such as sulfaquinoxaline, are for prevention rather than treatment. If you used. They work only against treat the bird after an outbreak, the damage Eimeria acervulina and Eime- is already done. Many preventative drugs ria maxima, not against Eimeria are effective only in the first part of the par- tenella. Sulfamonaides are used to asite life cycle, and therefore must be used treat coccidiosis. early if they are to be used at all. • Amprolium: Amprolium is an anti- Drawbacks of using preventative drugs coccidial drug. It has also been are their expense and the resistance that used for many years and needs no coccidia have developed. The drugs withdrawal time to guard against are not as effective now as when they residue in the meat. It is given in were first introduced. Large companies the drinking water and interferes use a drug rotation or shuttle program to with metabolism of the vitamin thia- reduce resistance. min (vitamin B1) in coccidia. Amp- There are not many new anticoccidial drugs rolium treats both intestinal and because of the extensive process for FDA cecal coccidia. approval. It costs millions of dollars toPage 8 ATTRA Parasite Management for Natural and Organic Poultry: Coccidiosis
  9. 9. develop a new anticoccial drug and get it is produced by Schering Ploughapproved for use. Animal Health.In the large-scale industry, most anticoc- • Immucox®: This vaccine was devel-cidial drugs are withdrawn a week before oped in Canada by Vetech Labora-slaughter of broilers to save money or to tories. It is distributed by Wingo.prevent residue in the meat. Drugs are • Advent®: This vaccine was recentlywithdrawn before layers begin laying eggs developed in the U.S. by Viridusto prevent residues in the eggs. Animal Health. It is marketed asSmall producers often give pullets medi- having more viable oocysts (trulycated feed while in the brooder, and then sporulated oocysts that can causeremove medication when they are older and immunity) than other vaccines.placed in pasture-based systems. The vaccines above can actually cause some lesions and occurrence of coccidio-Unfortunately, drugs used for preven- sis in birds because they are not “attenu-tion usually interfere with development of ated” or weakened in some way. It is a con-immunity to coccidia. On the other hand, trolled occurrence, but it may be necessary Vusing drugs for treatment only does allow accines are to treat for secondary gut disease, usingimmunity to develop. If signs of the disease antibiotics or alternatives such as probiot- recognizedappear, use drugs that are appropriate for ics. In contrast, coccidiosis vaccines used as the onlycoccidia’s late life cycle—only sulfonamides in Europe are attenuated. They are altered practical alterna-and amprolium. (Reid, 1990) When birds because the coccidia used in the vaccineare getting sick, they lose their appetite. tive to anticoccidial are designed to mature quickly and have aTherefore, soluble medication should be drugs in large-scale short (“precocious”) life cycle and low fer-provided in the drinking water. production. tility. They are not pathogenic—disease- causing—and are more costly to produceVaccines than the nonattenuated vaccines. TheyInterest is growing in controlling coccidio- include Paracox®, Livacox®, and Viracox®sis by vaccination because immunological which are marketed in other countries butcontrol is recognized as the only practical not currently in the U.S.alternative to anticoccidial drugs in large- More types of vaccines are likely to be devel-scale production. (Chapman, 2002) oped, because the government approval pro-La rge pou lt r y compa n ies usua l ly cess is much cheaper for vaccines than forvaccinate chicks at company-owned hatch- anticoccidial drugs.eries. Smaller producers buy chicks from Since immunity is species-specific, anticoc-independent hatcheries, but some hatch- cidial vaccines include mixtures of specieseries do not offer coccidiosis vaccination. of Eimeria that affect chickens. It is espe-Small producers may need to do the vac- cially important to include the three typescination themselves, once the chicks arrive that cause the most damage in chickens:at the farm. Eimeria acervulina, Eimeria maxima, and Eimeria tenella.Types of VaccinesAt the time of this writing (2006), coccid- Using Vaccinesial vaccines licensed in the U.S. include Birds need good protection by the time theythe following: are three weeks old, so vaccines should be • Coccivac®: This vaccine was devel- given at the hatchery or by one week. oped in the early 1950s. The “B” Methods of application: and “D” types are different mix- tures of Eimeria species; the “T” • Spray cabinets: These are used at type is for turkeys. Coccivac® hatcheries on day-old chicks ATTRA Page 9
  10. 10. may include a dye to indicate appli- Vaccines are usually sold only in large cation. This is the most uniform amounts. Advent is sold in 1,000-dose method of application, resulting in vials that cost about $13.50 each and must 90 to 95 percent of chicks exposed be purchased in boxes of 10 vials per box. to the vaccine. (Chapman, 2000) Immucox can be purchased in smaller • Edible gel: Gel pucks are placed in amounts. A tube of gel costs about $70 transport crates or on the floor of and has 28 “slices.” Each slice serves 100 the house when the chicks arrive. birds. Half tubes can also be purchased The gel is brightly colored to attract for about $35. the attention of the chicks. Immu- Since the vaccines contain live oocysts, they cox® is administered in this form. should not be frozen. Birds need access • Feed spray: Vaccines are mixed with to their droppings in order for the vaccine water in a garden pressure-sprayer to work, since oocysts must be reingested. and sprayed on a 24-hour supply of Vaccines are not effective for birds raised in feed. Advent® is either sprayed on batteries or cages with wire floors. the feed in this manner or appliedI in a spray cabinet at the hatchery. Vaccines have been used for some time to t is important to • Drinking water: The chicks should provide immunity for broiler breeders and apply vaccines be slightly water-starved to encour- commercial egg layers, but there is less use uniformly to in broilers. age them to drink. Since oocystsensure the birds get are heavy and fall to the bottoms Vaccine boosters are not normally given.equal exposure. of drinkers, they are mixed with Broilers usually have a short life and do not a suspension agent to keep them need boosters. Longer-lived birds like lay- evenly distributed. (Chapman, ers are constantly re-exposed to coccidia, 2000) This method can be used for so immunity is topped off constantly. older chicks. Vaccines cannot be given through proportioners or Do not give drugs and vaccines to the same nipple drinkers. flock—they are opposed to each other. To confirm the method of application, check If your flock is raised under intensive con- the tag. For example, Coccivac® is given to ditions, you will eventually need to vacci- turkey poults by spray cabinet at 1 day old; nate or use drugs. Tips for using vaccines feed spray at 1 to 3 days old, and via drink- in large-scale production are provided in ing water from 3 to 14 days old. the sidebar. Although most large poultry It is important to apply vaccines uniformly companies work with their veterinarians on to ensure the birds get equal exposure. If health issues, these tips will be useful. birds receive too much of a nonattenuated vaccine, the parasites can cause lesions. Summary If attenuated vaccines are not given in adequate doses, the birds will be sus- Small-scale producers can control coccid- ceptible to field strains of the coccidia. iosis with a good understanding of its life (Chapman, 2000) cycle and conditions for transmission, by management strategies such as good litter The environment must allow the oocysts and pasture rotation, and by using drugs to sporulate, since the goal of vaccination only for rescue, if needed. Large-scale is to introduce the parasite in small num- producers, especially organic producers, bers. Litter should be damp but not wet. increasingly rely on vaccines. (Chapman, 2000) After vaccination, birds excrete fresh oocysts onto the litter. Birds For more information, contact Anne then eat these (second cycle) oocysts. (Chap- Fanatico at man, 2000) Two cycles of replication are needed for good protection.Page 10 ATTRA Parasite Management for Natural and Organic Poultry: Coccidiosis
  11. 11. Tips for Using Vaccines in Large-scale Production “Partial house” brooding and brooder rings can cause problems for coccidiosis management in large-scale production. In partial-house brooding, part of the house is sectioned off for brooding, while the rest of the house is vacant. Therefore, the whole house is not seeded with a low level of oocysts to help establish immunity. Producers should either release broilers to the whole house before 6 days of age or hold them until 12 days. (Chapman, 2002) Although organic companies cannot use routine drugs, it is important to know about drug/vaccine interactions. The conven- tional poultry industry uses vaccines in combination with drugs to help deal with the problem of drug resistance in broilers. Sensitivity testing can determine the level of resistance. Vaccines are prepared with coccidia strains that are susceptible to drugs. The vaccinal coccidia reproduce with field-strain coccidia in the broiler house and transfer drug susceptibility to drug- resistant strains. Vaccines essentially seed a house with coccidia that are sensitive to drug use. Therefore, large producers rotate drugs with vaccines to restore drug sensitivity to the field strains or replace the field strains with drug-sensitive strains. Since the nonattenuated (unweakened) vaccines can cause lesions, pathogenic bacteria can enter the gut. You may need to treat for necrotic enteritis at 16 to 17 days with an antibiotic. (Chapman, 2002) These secondary bacterial infections are a particular problem for organic companies. Treating birds with antibiotics for necrotic enteritis means removing them from the organic program. Fortunately, there are natural alternatives to antibiotics, such as probiotics. It is also important to con- trol factors that predispose birds to necrotic enteritis, such as feeding fishmeal. Poor uniformity of vaccine application and partial-house brooding or brooder rings can increase the incidence of complications.References Long, P.L. 1968. The effect of breed of chickens on resistance to Eimeria infections. British Journal of Poul-Chapman, D. 2000a. Practical use of vaccines for the try Science. Vol. 9. p. 71-78.control of coccidiosis in the chicken. World’s PoultryScience Journal. Vol. 56. p. 7-12. Merck Manual On-Line, D. 2002b. Sustainable coccidiosis con-trol in poultry production: The role of live vaccines. Organic Livestock Research Group. 2000. Coc-International Journal for Parasitology. Vol. 32. p. 617- cidiosis. In: Poultry Health and Welfare in Organic629. Farming. Veterinary Epidemiology and Eco- nomics Research Unit (VEERU), DepartmentFarr, M.M., and E.E. Wehr. 1949. Survival of Eimeria of Agriculture, The University of Reading, U.K.acervulina, E. tenella, and E. maxima oocysts on soil various field conditions. Annual N.Y. Academy coccid/coccid1.htmof Science. Vol. 52. p. 468-472.Plamondon, Robert. 2003. Re: Probiotics (Also Coc-cidiosis). E-mail posting to PasturePoultry listserver.March 1.Plamondon, Robert. 2002a. Re: Coccidiosis. E-mailposting to PasturePoultry listserver. December 20.Plamondon, Robert. 2002b. Coccidiosis control. E-mail posting to PasturePoultry listserver. April 3.Reid, Malcolm, W. 1990. History of avian medicinein the United States. X. Control of coccidiosis. AvianDiseases. Vol. 34. p. 509-525.Further ResourcesBuvanderan, V., and P. Kulasegaram. 1972. Resis-tance of breeds and breed crosses of chickens toexperimental Eimeria necatrix infection. British Vet-erinary Journal. Vol. 128. p. ATTRA Page 11
  12. 12. Parasite Management for Natural and Organic Poultry: Coccidiosis By Anne Fanatico NCAT Agriculture Specialist ©2006 NCAT Paul Driscoll, Editor Cynthia Arnold, Production This publication is available on the Web at: and IP245 Slot 263 Version 052206Page 12 ATTRA