\V* ,f '*/ Division of Agricultural Sciences UNIVERSITY OF CALIFORNIA ^ihftf CALIFORNIA AGRICULTURAL Experiment Station Extension Service CIRCULAR 455 LARYNGOTRACHEITI (LT) FOWL POX INFECTIOUS BRONCHITI (IB) A sound vaccination program plus good management prac- tices will protect you against heavy losses from these diseases. Planning ahead is important, for once disease strikes, vacci- nation rarely does much good. An effective vaccination program depends on these factors: Your type of operation and your purpose in vaccinating. The brooding schedule on your ranch. The age, condition, and type of bird involved. The kind of vaccine you will use. This circular outlines the points you should bear in mind in planning a program and setting up a vaccination schedule to meet your particular needs. It describes recommended pro- cedures for administering vaccines, sets forth the conditions under which they will be most effective, and comments on the advantages and limitations of present-day vaccines. THE AUTHORS: Raymond A. Bankowski is Associate Professor of Veterinary Science and Associate Veterinarian in the Experiment Station, Davis. Arnold S. Rosenwald is Agriculturist (Poultry Pathologist) in the Agricultural Extension Service, Davis. SEPTEMBER, 1956 POULTRY VACCINATION WHY and HOW RAYMOND A. BANKOWSKI ARNOLD S. ROSENWALD H .ERE IS GENERAL INFORMATION to help you consider your problems clearly and guide you in planning your vaccination program. What vaccines do . . . A vaccine, properly applied, stimulates resistance to a specific disease. It sets up a reaction in the bird's body, which, in time, will produce an immunity. Most vaccines have value only as dis- ease preventives. Once a disease strikes a flock, vaccination rarely does any good — it may even be harmful. (Laryngo- tracheitis vaccine is an exception; it may be used to stop the spread of infection.) A vaccine for a disease stimulates spe- cific protection against that disease only. . . . and cannot do Even when properly applied, vaccina- tion cannot take the place of good man- agement. It is only part of your over-all operation. Do not rely on vaccine alone to control even a single disease. To be effective, a vaccination program must be combined with other disease-prevention methods including sanitation. Vaccines do not "give" immunity. The bird must develop its own immunity over a period of time after vaccination. Im- munity is a result of interaction between properly applied vaccine and the bird. A vaccine is of no use and may actu- ally increase losses if used during out- breaks of other diseases. This is particu- larly true of vaccines used to prevent respiratory diseases of chickens and tur- keys. No one "best" vaccination program There is no one vaccination program that can be applied to every ranch. Con- ditions vary from flock to flock, from area to area; so do methods of operation. If it is to be successful, the program must be tailored to fit your own needs. This calls for careful planning ahead of time. Talk over the general disease situation with your veterinarian, your Farm Ad- visor, and the diagnosticians at the state or county laboratory nearest you — and keep informed. Here are the basic factors that should guide you when you plan your program : The prevalence of diseases in your area. [3] The previous disease history (as es- tablished by laboratory diagnosis) and vaccination experience on your ranch. The type of bird involved (fryers, layer replacements, etc.). The condition (age, health) of the birds. Your facilities for handling and vacci- nating the birds. The season of the year. Setting up your vaccination schedule Your vaccination schedule will also depend on the basic factors listed above, which are peculiar to your ranch and area. In addition, scheduling calls for a knowledge of the vaccines available. A thorough understanding of your situa- tion and needs, together with informa- tion about the advantages and limitations of various vaccines, will help you to make sound decisions. For example, in some parts of Cali- fornia certain diseases affect the birds early in life. In such cases early vaccina- tion is necessary, although a better and more lasting immunity might result from vaccination when the birds are older. Elsewhere, different timing might be de- sirable. The method of brooding and the prev- alence of other diseases in the area may make a difference in both the time and order of vaccination. If possible, give the birds time to de- velop immunity to one disease and re- cover from that vaccination before administering the next. In setting up your schedule, then, keep these points in mind: The nature of the disease you want to prevent. The type of operation (broiler produc- tion, egg production, breeder, etc.). How the birds are housed and man- aged (litter floor, wire floor, etc.). The characteristics of the vaccines you might use. You may also want to weigh the costs of vaccination against the possible cost of an outbreak of the disease. Some of the variables in poultry vaccination The kind or strain of vaccine, the age and condition of the birds, and the type of bird — these factors are all important and must be kept in mind. Some strains or kinds of virus vac- cines must be applied in certain parts of the body to be effective. For example, if fowl-pox virus is to stimulate immu- nity it must be applied to broken skin, and so it is given with a "stick" to the skin of the flank, thigh, or web of the wing depending on the age of the bird. Individually administered vaccine for in- fectious bronchitis, on the other hand, acts through the respiratory mucous membranes and is dropped into the bird's nostril or eye. The kind of vac- cine you use will, therefore, determine the correct method of application. The age of the bird and its general health have an important bearing on the results. With one exception, young birds under 4 or 6 weeks of age are rarely good subjects for vaccination. The ex- ception is fowl pox, which can be given to day-old or 10-day-old chicks with sat- isfactory results; the recommended age for turkey poults, however, is 6 to 8 weeks. In all cases birds must be in good health when they are vaccinated or you cannot expect them to respond satisfac- torily. In addition, species differ in their re- action to, or resistance toward, specific diseases. For example, turkeys are not susceptible to laryngotracheitis and in- fectious bronchitis, two common diseases of chickens. Furthermore, turkeys and chickens have different vaccination re- quirements for the diseases they do have in common. The recommended age for fowl-pox vaccination, mentioned above, is one example. [4] Vaccines used in combination As a rule, birds should be vaccinated against only one disease at a time. Your vaccination schedule should be designed to protect against the disease that is apt to cause trouble first. The birds should have time to develop immunity to that particular infection before being exposed to the stress of further vaccination against other diseases. Fowl pox and larynogotracheitis are an exception to this general rule. Vacci- nation for both at the same time but by different routes, as recommended, seems to be both safe and satisfactory. Combining Newcastle disease and in- fectious bronchitis vaccines may cause an unduly severe reaction, and this com- bination may prevent the development of a good immunity to either or both of these diseases. Do not, if you can help it, vaccinate against fowl pox and either infectious bronchitis or Newcastle disease at the same time. A combination of Newcastle disease wing-web and fowl-pox vaccines is particularly risky. Erysipelas vaccine for breeder turkeys Erysipelas vaccine has proved useful in California for turkeys kept as breeders. This is a bacterin — in other words, a product using the killed agent, which thus cannot cause the disease. The recommended amount is two 2-cc doses, the second dose to be given 2 to 6 weeks after the first. Both doses should be given before the breeding season. This vaccine should be injected into the mus- cle of the breast or thigh with a syringe and needle. Often in California only the toms kept for breeding are vaccinated. Although this vaccine can be used for hens as well, it is expensive and may not be necessary. Find out what local needs and practices are, since it is sometimes desirable to [ vaccinate the entire breeder flock, or, in rare cases, meat birds. Some diseases do not warrant vaccination Certain diseases affecting either chick- ens or turkeys, or both, do not result in useful immunity after the birds have recovered. These include: infectious coryza (in chickens), fowl cholera, fowl typhoid, paratyphoid, and paracolon in- fections. It is useless to vaccinate against these diseases, for there are no bacterins or vaccines that will induce a practical immunity. Vaccination against PPLO infection (CRD of chickens, infectious sinusitis of turkeys) is definitely not warranted. Mixed bacterins, though often sold and used, have proved completely ineffective in preventing or treating PPLO infec- tions. Guide to vaccination On the following pages is a brief guide to vaccination against four major poul- try diseases: laryngotracheitis, fowl pox, infectious bronchitis, and Newcastle dis- ease. This guide is intended to provide the essential information you need to develop a program on your ranch. The basic facts are given. But you will have to use the guide carefully and with good judgment. It will not give you the complete answer to your problems; it should help you in solving them. If you already have a satisfactory vac- cination program, don't change it unless you feel that a change might improve results. If your program is a good one, this guide may help you understand why. If there are improvements you should make, the guide may suggest them to you. The charts are designed for quick and easy reference, summarizing the recom- mendations available to date. But do not rely on these charts alone for guidance. Note the comparative advantages and limitations, discussed in detail in the ac- companying text. 5] In Brief — reminders for successful vaccination: 1. Use a program suited to your area and ranch. 2. Know the disease history of your flock, as determined by laboratory di- agnosis, before vaccinating. 3. Vaccinate only flocks in good health. 4. Get a careful, competent diag- nosis of any disease outbreak. 5. Do not vaccinate to treat a serious outbreak of a disease, with the excep- tion of laryngotracheitis. Vaccination is a preventive measure. 6. Vaccinate earliest against the dis- ease that is apt to cause trouble first. 7. Vaccinate against one specific dis- ease only at any one time. (The com- bination of laryngotracheitis and fowl- pox vaccines is the one exception.) 8. Use the vaccines that meet your needs. 9. Remember that most vaccines are living, disease-causing agents. 10. Know a vaccine's advantages and limitations. Use it with these in mind. 11. Use fresh vaccine. 12. Keep the vaccine cool, out of the sun, and well mixed. 1 3. Follow the manufacturer's printed directions. 14. Use equipment provided by the vaccine manufacturer for doing the job. 15. Get the vaccine onto the instru- ment; have enough vaccine to cover the needle or brush. If you use mass methods, follow the manufacturer's printed directions exactly. 16. Get the vaccine into the bird — don't brush it off on the feathers. 17. Dip the vaccinating tool into the vaccine between each application. 18. Don't "stretch" the vaccine by trying to use it on too many birds. When you buy vaccine for 500 birds, you pay for immunity for 500 birds. Stretching the vaccine may save cents but cost dollars. 19. Do a careful, thorough job. Don't try to set a speed record! 20. Disinfectants destroy living vac- cines. Be particularly careful with disin- fectants and chemicals when using water vaccines. 21. Discard leftover vaccine and con- tainers by burning or with strong dis- infectants immediately after you finish the job. LARYNGOTRACHEITIS (LT) CHICKENS Chickens and pheasants are suscepti- ble to LT; turkeys are not. The use of a vaccine against this disease is indicated in districts where it is known to be pres- ent, or if chickens that have recovered from a natural outbreak are on the ranch. Birds recovered from natural outbreaks are carriers and can spread infection. However, four weeks after vaccination, properly vaccinated birds are not perma- nent carriers of LT virus. Get a diagnosis if you suspect an outbreak of this disease in your flock. If it is detected early and the vaccine is used immediately, the spread of an in- fection can be stopped. The vaccine gives prompt immunity (within 4 to 6 days) and, if used in the unaffected pens, limits the outbreak. However, proper vaccination of sus- ceptible birds before an outbreak occurs L6] Positive take following laryngotracheitis vaccination four days before. Note swelling and reddening of the mucous membrane of the cloaca, just in front of the vent. will give good protection. It is far better to plan your program in advance. Remember, this is a live-virus vaccine and can cause the disease; use it with care. As a rule, however, properly ap- plied LT vaccine causes no general reac- tion and usually does not disturb egg production. In an emergency it can be used on layers, though application dur- ing the growing period is preferable. Vaccination against laryngotracheitis and fowl pox at the same time but by different routes, as recommended, is ap- parently both safe and effective. This is the only combination of vaccines that seems to be satisfactory. LT Vaccination Recommendations Age to vaccinate 6 to 16 weeks is the recommended age range. If necessary, this vaccine can be administered at any age, even 4 days, although such extremely early vaccination is less satisfactory. Location and method Apply in vent (cloaca) with a stiff brush. This is the only method recommended; no other is so uniformly effective. Check for takes (see illustration) Vent lips will become reddened and swollen, vent feathers will be soiled, and a cheesy or mucous discharge appears in the vent 3 to 5 days later in approximately 90% of the birds. Revaccinate if adequate takes are not observed. Protection Lifelong immunity. [7] FOWL POX (POX) CHICKENS and TURKEYS Fowl-pox vaccine is easily applied and gives practically lifelong immunity in chickens, varied immunity in turkeys. Its use on chickens of any age is indicated in an area or at a time of year when pox can cause real trouble. It may even be given to chicks between 1 and 14 days of age, and it is the only vaccine capable of producing a durable immunity with one application at this early age. The vaccine can cause the disease, so use it with care. It may set off unnoticed infection by other disease agents (espe- cially PPLO). It causes a general reac- tion, decreased appetite, and a drop in production, and it may aggravate an ex- isting disease. It is, therefore, desirable to baby the birds for two or three weeks after vac- cination. You may wish to coax them to eat with moist mash and greens or any useful, economical stimulant that will en- courage full feed consumption. Pigeon-pox vaccine is not recom- mended because it gives short-time, im- perfect protection. It requires feather- follicle vaccination and can cause as great a drop in egg production as fowl- pox vaccine. However, occasionally its use may be warranted for chickens. See your veterinarian, your Farm Advisor, or the diagnosticians at the nearest state or county laboratory for advice on the use of pigeon-pox vaccine. Vaccinate chicks with special care Chicks under 2 weeks of age have been successfully vaccinated against fowl pox for years. For such young chicks it is particularly important to vaccinate care- fully and correctly. The following steps Method of applying fowl pox vaccination. The "X" shows the area in which the needle must hit for this type of vaccination for chicks under 2 weeks of age. Pox Vaccination Recommendations Chickens Turkeys Age to vac- cinate 1 day to maturity ; preferably dur- ing the growing period and be- fore egg production begins. Meat birds: at least 1 month be- fore marketing or when a few days old. 4 weeks to 9 months. 4- to 14-week-old poults: at least 6 weeks before marketing. Breeders: revaccinate before egg production. Laying birds : do NOT vaccinate. Location and method 1- to 15-day-old birds: use "stick" in skin of FLANK. (See illustra- tion.) Do NOT use wing web on such young birds. 3 weeks to maturity : apply in bare spot on thigh, or use wing web with "stick" applicator. Use "stick" on bare spot on thigh. (See illustration.) Wattle application has been used. Do NOT use wing web. Check for takes Scab at point of vaccination will form 7 to 10 days after vaccina- tion in 90% of birds. Scab at point of vaccination will form 7 to 14 days after vaccina- tion in 90% of birds. Protection Serviceable immunity throughout the chickens' productive life. Until market time for poults vac- cinated between 4 and 14 weeks. Through breeding season if vac- cinated between 6 and 9 months. (See "Caution.") Cautions Chicks under 3 weeks: do NOT use wing web. Disease may spread, cause severe losses. Chicks under 10 days : do not box after vaccination; protect from injury. Laying birds : vaccination may re- duce production. Vaccinate only in emergency. Immunity varies. Revaccinate a few breeders at 6 to 9 months and before production starts. If you find takes in about 50%, re- vaccinate the flock. If not, delay revaccination until about 1 month before egg production starts. First vaccination of birds kept for breeders may, under certain local conditions, be delayed until after the meat birds are sold. Then vaccinate breeders about 1 month before egg production begins. [9] Application of fowl pox vaccine to a more mature turkey using a stick on bare part of thigh. will insure good protection — do not neg- lect any one of them: 1. Use full-strength fowl-pox vaccine. 2. Vaccinate in the flank, not in the web of the wing. 3. Use only one prong of the needle. 4. Handle the chicks gently and prick the skin ; do not tear it by rough or hasty handling. 5. Do not hold the chicks and thus spread the vaccine into the eyes or on other parts of the skin. Preferably, the operation should be conducted by two persons, one to handle the chicks, the other to administer the vaccine. 6. After the chicks are vaccinated, do not let them crowd together or get chilled or overheated. INFECTIOUS BRONCHITIS (IB) CHICKENS Infectious bronchitis is a highly con- tagious disease which, alone, seldom causes severe mortality. But outbreaks of the disease often seem to "spark off" severe outbreaks of other respiratory diseases. In California this disease has been most serious when it affects susceptible laying chickens. Egg production usually drops sharply, and the flock may not re- turn to normal production for two months or even longer — perhaps never. Economic losses may be even greater than those of a production slump, since IB can cause damage to the reproductive organs that seriously impairs egg quality. The major purpose of vaccination is, therefore, to immunize replacement pul- lets before they start to lay so that pro- tection will be assured throughout their productive life. The need for vaccinating fryers and broilers is questionable. If vaccination for IB seems desirable, it should be done before the birds are 3 weeks old to avoid "triggering" CRD or other latent infec- tions. Vaccination for IB gives the disease to the growing birds at the best time for them and for you. In other words, you can dictate your own terms and give your flock this protection when it is most con- venient for you, or least expensive. Do not vaccinate young replace- ment birds unless you are sure the laying birds are immune. Remember — IB vaccine is a live-virus vaccine and the virus spreads very readily (the danger is even greater than with Newcastle disease). If your flock includes susceptible layers, production will slump. The vaccine, like the disease, may also cause damage to the reproduc- tive organs, and egg quality will suffer. If IB is prevalent in your area, or if you suspect it may have been present in the flock, have a challenge or other test [10] made to find out whether or not the birds are immune. Flocks are often immune as the result of exposure to a light attack of IB. If the laying birds are immune, you can vaccinate your replacement chicks without danger. If you find the laying hens to be susceptible, it may be best not to vaccinate replacements against IB. How to test for immunity Special blood or egg tests or a chal- lenge test will tell whether or not your laying flock is immune. Arrange for the tests in advance with your local veteri- narian so that he will be prepared to assist you. Ask him to check with the nearest state laboratory or with the Uni- versity of California if he needs chal- lenge virus or more specific information. Then send him 3 to 6 birds from each age group of layers on your ranch. In certain cases and by previous ar- rangement, you may send the birds to the Department of Poultry Pathology, University of California at Davis. Before shipping, be sure to make arrangements through your local veterinarian or Farm Advisor. Several brands of vaccine available Certain brands of vaccine commer- cially available have been approved for use in California. This approval means only that they did not cause high mor- tality when used on young chicks under conditions of the test. It does not mean that they are all equally effective in stimulating immunity when applied in the same manner or at the same intervals. In choosing a vaccine, be sure to check with your veterinarian or the state labo- ratory regarding its characteristics and effectiveness. The ability of these vaccines to stimu- late prolonged protection against a drop IB Vaccination Recommendations Check procedure with your veterinarian, diagnostic laboratory, or Farm Advisor. Method (Use any one) Age to vaccinate Intranasal Intraocular Dust Spray Drinking water For REPLACEMENT BIRDS, follow any one of these three schedules : f 1st application : 1 to 7 days A. < 2nd application : 6 to 8 weeks ( 3rd application : at 14 weeks B / 1st application : 2 to 3 weeks \ 2nd application : 12 to 14 weeks C. Single application at 12 to 14 weeks BE SURE TO VACCINATE AT LEAST 1 MONTH BEFORE THE CHICKENS START TO LAY. For FRYERS, follow one of these schedules: A. One application at 1 to 3 weeks B / 1st application : 1 to 10 days 1 2nd application : 4 to 6 weeks [11] in egg production when the birds become layers has not been entirely determined. Therefore, revaccinate according to the printed directions in the package circu- lar. Reaction to the vaccine Since IB vaccination means giving the flock a mild case of the disease, all the vaccines available today should cause symptoms of sneezing in some or all of the birds in your flock (if it is suscepti- ble) . It will cause a drop in egg produc- tion in susceptible laying birds, and it will spread from the vaccinates to sus- ceptible birds of any age. Be sure to start vaccinating early — not later than 12-14 weeks. If susceptible birds are given their first vaccination as they are coming into production, their reproductive capacity may be perma- nently damaged. Any one of the schedules given in the chart at the end of this sec- tion will be satisfactory. Multiple vaccinations Simultaneous vaccination with New- castle disease and IB vaccines is not ad- visable. The birds may fail to develop a good immunity to one or both of these diseases. Vaccination with these two vi- ruses may also place too severe a stress on the chicks, increasing losses. Mass methods are effective In the case of infectious bronchitis, field experience indicates that mass methods of vaccine administration with present-day vaccines are as satisfactory as treating the birds individually, for ef- fective IB vaccine sets up a spreading infection. If the IB vaccine infects some chicks, the rest of the brood will probably pick it up. It is not so necessary, as it is with Newcastle disease, for each bird to receive the vaccine directly. If the vaccine is added to the drinking water, be sure that the water is clean, cool, and free from chlorine or other dis- infectants. The birds may be starved for 2 to 4 hours before the vaccine is admin- istered by this method. Follow the manu- facturer's directions. Revaccination For maximum immunity and protec- tion against a drop in egg production, revaccinate as recommended in the manu- facturer's printed directions. With some strains of IB virus, additional revaccina- tion during lay may not be necessary. NEWCASTLE DISEASE (ND) CHICKENS and TURKEYS Newcastle disease is a common, wide- spread disease of chickens, turkeys, and other birds. Outbreaks vary considerably in severity. In young birds mortality may be high, averaging between 10 and 20 per cent in growing chicks, somewhat less in young turkeys. In adult chickens and turkeys the loss usually is largely economic — due mainly to a drop in egg production and quality. However, heavy mortality may occasionally occur. Proper vaccination can help prevent excessive death loss and stunted growth. It can also prevent a decline in egg pro- duction and quality. All these vaccines are fairly recent developments, however, and much information is still needed about them. When to vaccinate All ND vaccines produce a better im- mune response if birds are vaccinated after 4 to 6 weeks of age. In general, be- cause of ranch conditions, the age range for first vaccination is between 2 weeks and 4 months. In certain situations, how- ever, there are exceptions (see the chart at the end of this section). [12] In susceptible laying birds vaccination is risky. If, during production, such birds become diseased or are vaccinated, they usually lay fewer eggs. After recovery, their eggs are likely to have poor albu- men and shell quality. For three or four weeks after hatching, chicks from an immune hen often have a passive immunity that has been trans- mitted from the hen through the egg yolk. This immunity lasts for a variable time — up to about 4 weeks. It interferes with the production of a good response to vac- cination, but it will partially protect the birds against mild field exposure. Wing-web strains are not recom- mended for chicks or poults under 4 weeks of age. In extremely young birds these strains can cause a severe reaction with excessive death loss. What kind of vaccine to use Your choice of a vaccination program depends on the job you want it to do for you. Will short-term protection answer your needs? Or should your flock be as- sured permanent immunity? Do you want protection against all the hazards of ND or only certain ones? The answers to these questions depend on the type of operation you have. Some vaccines stimulate a good but short-lived immunity. If you are a broiler raiser, this shorter immunity will be sat- isfactory. But if you are in commercial egg production, you will want a vaccina- tion program that will insure a good and permanent immunity. ND vaccines also vary in the complete- ness of the protection they induce. In vaccinating for ND you may need only two kinds of protection — against death from the disease and against stunting (or decreased rate of growth). But egg producers, again, will want the complete, three-way protection that will insure them against a drop in egg production and quality as well. A combination program using either killed-virus vaccine or one of the mild strains early in the chick's life (under 2 weeks and possibly again at 5 to 6 weeks) followed by wing-web vaccination later (at 8 to 14 weeks), has generally proved satisfactory for replacement pullets. Whether you adopt such a program or a different combination will depend on your particular needs and facilities. In choosing a vaccine or selecting a program, then, consider these factors: 1. Your reasons for vaccinating (to prevent death, stunting, decrease in egg production) . 2. The conditions under which you will use the vaccine. 3. The state of health and age of the birds to be vaccinated. 4. The characteristics of the vaccines you plan to use. Killed- vs. live- virus vaccines Live-virus vaccines are used against the four major diseases discussed in this circular. For Newcastle disease killed- virus vaccines are also available. A killed-virus vaccine has the advan- tage of safety in that it cannot cause the disease. The immunity it provides, how- ever, is not as complete or as lasting as that resulting from live-virus strains. Since live-virus vaccines can cause the disease, they must be handled with care. They can damage the birds if used im- properly or at the wrong time. But be- cause they induce a better and more du- rable immunity, they are preferable to the killed-virus vaccines in many cases. Killed-virus vaccine for chickens only Killed-virus vaccine is most useful for fryers and growing birds, providing good protection against death, crippling, and stunting. Two doses given 1 to 4 months apart will prevent a high death loss and severe stunting or crippling. It will also protect against nervous symptoms. [13] ND Vaccination I Killed- Virus Vaccine Age to vaccinate Brooder birds : 1 to 30 days old. Growing birds : 1 to 5 months old. Location and method Syringe and needle. Brooder chicks: 1 dose i}A cc) into thigh or breast, or according to manu- facturer's printed directions. Growing birds: 2 doses (14 cc each) 2 to 4 weeks apart, or according to manufacturer's printed directions. Protection Against death, crippling, and stunting: 2 to 5 weeks. Useful for fryers or growing birds. Against drop in egg production : Not good enough to warrant use for this purpose. • Used alone, killed-virus vaccine is not recommended for laying-flock replace- ments. It will not prevent respiratory symptoms or a drop in egg production. Live-virus vaccines: "mild" and wing-web Live-virus vaccines are prepared from at least four strains of Newcastle-disease virus. Two strains — B-l and LaSota (717) — are known as "mild" and may be administered in a variety of ways. The other two — Roakin and Massachusetts MK107 — are used in the production of wing-web vaccines. Of all the ND vac- cines available, the wing-web strains in- duce the most durable immunity that can be effected by one application. Each of the four strains has its own special characteristics. Each induces a slightly different response in the birds. And each strain and method of applica- tion has specific advantages and limita- tions. B-l strain (Hitchner or Blackburg strain) is used for the vaccination of fryers or growing chicks. In areas of severe infection it may have to be used - [14] Recommendations — Chickens Live- Virus Vaccines Mild strains Wing-web strains LaSota (717) 1 day to 43^ months. 1 day to 43^ months. If chicks under 10 days are vaccinated, repeat at 5 to 6 weeks and again about 2 to 4 weeks before lay begins. Use on susceptible layers only in emergencies.* Not under 2 weeks if used intra- muscularly. Place in nostril or eye with dropper. Follow manufacturer's direc- ' tions. Mass methods : May be added to drinking water, or sprayed or dusted on the birds according to manufacturer's printed direc- tions. Can also be administered intra- muscularly. Roakin and MK107 1 to 4 months. NOT for chicks under 4 weeks of age. Not for laying birds. Breeding birds : at least 8 weeks before hatching eggs are saved. Wing-web "stick." Dip needle in vaccine, then punc- ture web of wing. Apply carefully. Do not spread around. Against death, paralysis, and stunting: 1 to 6 months for young birds. Birds vaccinated later in life have better immunity than * those vaccinated under 6 weeks of age. Against drop in egg production: Revaccinate every 4 months for adequate protection. - Against death, paralysis, and stunting : Solid and durable im- munity throughout laying year. Against drop in egg production: Solid and serviceable immu- nity throughout laying year. See page 13 concerning use of mild strains followed by wing web. twice even for fryers (first before 10 days old, again at 5 weeks) . It is sometimes given to young chicks at about 10 days and perhaps again at 5 to 6 weeks to protect them until they are old enough for further vaccination. This use of B-l also seems to protect against excessive losses from death and crippling following wing-web vaccine used at 8 and 14 weeks. (This effect is based only on field observation, how- ever.) Such early use of B-l does not stimulate a lasting immunity. Do not depend on this single application to prevent a drop in egg production, par- ticularly if, during lay, the birds are vaccinated with wing-web vaccine or an outbreak of ND occurs. It may be used to vaccinate replace- ment flocks. In this case, to maintain immunity revaccinate as indicated by the manufacturer, or follow the recommen- dations in the chart at the end of this section. B-l strain has these advantages : The infection that results is mild, and this strain can be used on very young (day-old) chicks. Experimentally, it will [15 not cause paralysis even when injected directly into the brain. It is easy to apply, and you may choose among a wide variety of methods: in- tranasal or intraocular application, spray, dust, or drinking-water adminis- tration. However, individual treatment, which insures the proper dosage for each bird, is preferable; mass methods may miss some. Water administration is the least satis- factory of the mass methods, and fre- quent "breaks" due to an unsatisfactory response have been reported. The many variables involved in water administra- tion may be responsible for this. The resulting immunity against death and retarded growth is good but short- lived. Revaccination at recommended in- tervals is necessary to maintain a high degree of immunity. In general, it results in less virus spread than any of the other live-virus strains. It is pneumotropic — that is, it invades respiratory tissue and little else. To be effective, then, it must get to the respira- tory tract. B-l also has the following disadvan- tages : Immunity is short-lived. Repeated re- vaccination is necessary to maintain im- munity and to protect against a drop in egg production and quality. If used on susceptible laying birds, it may cause some drop in egg production. LaSota (717) is apparently similar to B-l, but less information has been pub- lished about it. It seems slightly more "potent." Like B-l, it is sometimes used to pro- tect the chicks against ND until they are ND Vaccination Recommendations — Turkeys Live-Virus vaccines Mild strains B-l and LaSota (717) Wing-web strains Roakin and MK107 Age to vac- cinate 1 day or older. 1 to 6 months. Breeders : 6 to 8 weeks before lay. NEVER for hens in lay. Location and method Individual : place in nostril or eye with dropper. Mass methods: water, spray, or dust. Wing-web stick. Protection Against death, crippling, and stunt- ing : Good but for short time. Re- vaccination needed. Not suggested as permanent pro- gram for breeding birds. Against death, crippling, and stunt- ing : Probably permanent for prac- tical purposes. Against drop in egg production: Good throughout the breeding season. [16] iyw*> *4||| Day-old chick vaccination into the eye for ND or IB. old enough for wing-web vaccination, and it seems to decrease excessive reac- tions when the wing-web vaccine is ad- ministered later. Again, however, this is not confirmed by experimental evidence. Three methods of application are used : 1. Intranasal or intraocular (in the eye). For short-time immunization the vaccine in this form can be given at any age. To maintain immunity revaccina- tion is necessary. 2. Drinking water. This, too, can be given at any age for short-time immuni- zation. 3. Intramuscular. This method should not be used on birds under 3 weeks of age. Immunity from one application lasts about 7 to 9 weeks during the growing period. For extended immunity revacci- nation is necessary. Birds vaccinated at 3 to 4 weeks must be revaccinated before the laying period begins. Follow the manufacturer's printed directions. Roakin and MK107 (the wing-web vaccines), when properly applied, may produce an infection that spreads. If the birds are affected with other diseases, mortality after vaccination may be higher than 1 to 2 per cent. Of the four live-virus strains, these two are the most risky if not properly used; however, of the available strains, they provide in a single application the best and most lasting protection against New- castle disease, especially for replacement pullets. They have this important advantage: When properly applied, one application will stimulate durable and complete im- munity against death from ND, against crippling, and against a drop in egg pro- duction. These vaccines have, in general, provided satisfactory immunity through- out the laying period for commercial egg- production flocks. They have been used for this purpose longer than any of the other live-virus vaccines. [17] Disadvantages are these: A post-vaccination reaction with losses is possible. This is particularly true if the birds are affected with coccidiosis or some other infection at the time of vac- cination. The wing-web vaccines must be used before egg production begins. When used on susceptible laying birds, they may cause as severe a drop in egg pro- duction as some natural outbreaks, and future egg quality will be impaired. They are risky when used on birds under 30 days of age. Although they have been used on birds 20 to 30 days old, such use is not recommended. No mass method of application is available. Individual vs. mass methods Since individual administration at fre- quent intervals poses many practical problems, particularly when the birds need to be vaccinated against so many diseases, the mass methods are more gen- erally used where repeated revaccination is necessary. However, these too have drawbacks, for vaccination for ND by any of the mass methods may fail to stimulate immunity in all of the birds. Unlike the infectious bronchitis virus, "mild" ND vaccine does not set up an infection that spreads readily. Only the chicks that receive the proper dosage of ND vaccine can develop immunity, and mass methods may miss some. With in- dividual application, on the other hand, you know that each bird has received the recommended amount of vaccine. Because of the many variables that can affect it, the drinking-water method of vaccinating for Newcastle disease has thus far been the least satisfactory of the mass methods. The temperature of the water, exposure to the sun, dust or disin- Wing web vaccination for Newcastle disease using double needle. [18] fectants (including chlorine) in the water — all these and other factors may reduce the effectiveness of this method. Drinking-water application is particu- larly unreliable where continuous-flow or drip systems are used, or where the wa- tering device has to be changed to ad- minister the ND vaccines. Spray or dust used in the open, wire- floored houses or cages presents a similar problem. Again, you cannot be sure that each bird will receive an adequate dose. ND vaccines for turkeys With turkeys, vaccination for New- castle disease is most useful to protect breeder birds against a drop in egg pro- duction. In general, mortality from New- castle disease in market turkeys has not been great, and the need for universal vaccination is debatable. The following recommendations are for live-virus vaccines only. The killed- virus vaccine does not stimulate a useful immunity against a drop in egg produc- tion. It is therefore not recommended for turkeys. B-l and LaSota (717) are both satis- factory for early poult protection or before wing-web vaccine is used. At pres- ent these strains are not recommended for inducing permanent immunity in breeder turkeys. Roakin and MK107 are the best vac- cines for potential breeders. Live-virus wing-web stick vaccine, used before lay- ing begins, will induce solid protection. It should be applied 6 to 8 weeks before CAUTION . . . Improper use of vaccines is dan- gerous. Use them carefully, accord- ing to the manufacturer's printed directions. In human beings, Newcastle-dis- ease virus can cause localized eye infections. Be careful not to get it in your eyes. If you make mass ap- plications, use masks or goggles and respirators. In birds, live-virus vaccines actu- ally cause infection. They usually do not cause as high mortality as a natural disease outbreak, but they may cause a drop in egg production and quality. Do not use a wing-web ND strain and fowl-pox vaccine at the same time. Do not use Newcastle-disease vaccine during an outbreak in your flock. At such a time the administra- tion of killed-virus vaccine will do no good. Live-virus vaccine, on the other hand, may add fuel to the fire and thus increase your losses. egg production starts to avoid possible transfer of ND virus from the vaccine through the egg to the poult. The wing-web strains should not be used on laying turkey hens. The upset to egg production and quality will be as bad as that from a severe natural infec- tion. Co-operative Extension work in Agriculture and Home Economics, College of Agriculture, University of California, and United States Department of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, and June 30, 1914. George B. Alcorn. Director, California Agricultural Extension Service 15wj-9,'56(C0206)BEB [19] IT JUST COULD BE . . . that the farm problems troubling you have also troubled others. And it's also possible that with a little help from the right source your problems can be eased, if not cured. Here's how to go about getting help. Take your problems to your County Farm Advisor. He's an agricultural specialist with a background of practical knowl- edge about farming in your lo- cality. He will help you if he can ... or he will get the information you need from someone who does know the answers. Office of Agricultural Publico 22 University of Cal Berkeley 4, Cal Ask your Farm Advisor for a copy of AGRICULTURAL PUBLI- CATIONS— a catalog that lists the bulletins and circulars pro- duced by the University of Cali- fornia College of Agriculture, or write to the address below. You'll be amazed at the wide range of information covered in these publications. Yes ... it just could be that your problems aren't nearly as hard to solve as you think. Make use of the free services of your University.