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Poultry Disease Control in California
Poultry Disease Control in California A . S. ROSENWALD Agricultural Extension Service, College of Agriculture, University of California, Berkeley (Received for publication July 27, 1948)
B
TABLE 1.—California farms and population* California Total Area: 100,353,920 acres
1925 j 1945 | Percent increase
Number farms
Farms producing poultry
Acres in farms
136,409 138,917 1.7
87,611**
27,516,955 35,054,379 27
Population Total
Farm
4,700,000 8,800,000 83
531.000 538,000 1.3
* U. S. Census of Agriculture 1945. ** Only 40,064 sold poultry products.
efficiency of production and enable the producer of livestock, poultry, or products of livestock and poultry to have a greater return from the time and money invested. The title of this paper is somewhat misleading, in that one might get the impression that in the State of California we have a single program of disease control. For rather obvious reasons this is not true. Wide variation is found in California. For example, the highest and lowest elevations in the United States are situated in that state less than 100 miles apart. These are Mt. Whitney, 14,501 feet above sea level, and Death Valley, 286 feet below
These figures indicate that the total population in the state has almost doubled in the past 20 years, while the farm population has increased very little. There has been no highly significant change in the number of chickens raised nor in the numbers of eggs produced since 1930. Consequently the state has become an importing, rather than a major exporting state. Since 1930, the number of turkeys raised has been almost quadrupled; yet the number of turkey ranches has decreased to almost one-half those present in the state 18 years ago. Last year, California ranked first in turkey production in the nation.
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sea level. The diversity in the field of poultry might be emphasized by mentioning a few types of houses used by successful poultrymen in the state. These range from ranches where virtually no shelter is provided to individual cages, through various stages of wire-bottom houses to poultry houses with almost no openings. Without sounding like a Chamber of Commerce, the figures in Tables 1 and 2, taken from the U. S. Census of Agriculture 1945, should be of interest.
ASICALLY, the purpose of any attempt to control diseases of livestock and poultry is the reduction of the economic loss due to pathological conditions. This applies equally whether the abnormalities causing the decreased income are infectious or non-infectious; whether they cause mortality or decreased efficiency of production. Similarly, the difference between disease control and disease eradication is merely a matter of degree. Each attempts to increase the
174
A . S. ROSENWALD TABLE 2.—Production of poultry products in California* Year
I
1925
1930
1940
1945
No. chickens raised \ Farms reporting
14,382,861
26,644,797 81,793
24,750,462 61,645
33,003,636 77,741
Eggs produced (doz.) i Farms reporting !
97,907,325
159,421,612
129,686,042 68,380
158,892,261 79,072
1,246,993 19,776
2,593,406 8,148
4,093,769 9,870
No. turkeys raised Farms reporting
i j
* U. S. Census of Agriculture 1945. TABLE 3.—Value of poultry and poultry products sold, 1945
California: Three High Counties Sonoma Los Angeles San Bernardino
$103,218,755
100.0
44,253,606
42.8
§21,763,455 14,066,970 8,423,181
Three Low Counties Trinity Sierra Mono
16,120
TABLE 4.—Poultry disease control agencies Federal and State 1. U. S. Department of Agriculture a. Bureau of Animal Industry b. Production and Marketing Administration (Poultry meat inspection) 2. California Department of Agriculture a. Bureau of Livestock Disease Control Pathology Laboratories (diagnostic) Disease Control Specialists (investigation) 3. University of California—College of Agriculture a. Agricultural Experiment Station Veterinary Science Poultry Husbandry b. Agricultural Extension Service * County and Other 4. County Agencies a. Livestock Sanitary Departments Laboratory and field b. Veterinarians c. Agricultural Commissioners 5. Quasi-official Agencies a. Poultry Improvement Advisory Board 6. Veterinarians (Private) a. Chicken Pharmacy b. Poultry Practice 7. Commercial Service Personnel a. Feed Companies b. Hatcheries c. Biologic and Drug Companies 8. Poultry Producers
0.015
7,265 5,619 3,236
In 1945, 4 of the 5 leading counties in turkey production, and 3 of the 5 leading counties in chicken population were California counties. As noted in Table 3, the value of poultry and poultry products in , Sonoma County, our leading county where Petaluma is located, was in excess of 21 million dollars. Our 3 leading counties produced over 40 percent of the poultry and poultry products sold in California in 1945. In contrast, the 3 lowest counties produced less than .02 of one percent of similar agricultural commodities. One is impressed with the impossibility of any one single poultry disease control system being applicable. However, California poultrymen do have available to them some of the best diagnostic and disease control facilities in the country. They are outlined in Table 4. The Federal Government is represented through the Bureau of Animal Industry
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Percent
Value
POULTRY DISEASE CONTROL IN CALIFORNIA
stock Department of San Diego County of an excellent diagnostic laboratory with some research facilities. Other counties are less active, but participate through the county livestock inspector or veterinarian. There also exist quasi-official agencies. Outstanding among these is the Poultry Improvement Advisory Board which is charged with the administration of California's participation in the pullorum phase of the National Poultry and Turkey Improvement Plans. Among the employees of this board there are several well trained poultry pathologists. Certain veterinary practitioners do considerable poultry practice, both in the field of diagnosis and treatment. In Petaluma the unique "Chicken Pharmacy" operated by a veterinarian has been serving the Petaluma poultrymen for many years. Feed companies and other commercial concerns abound and flourish in the state. Field men and other representatives of these concerns enter into the poultry disease control picture. Certainly any discussion of poultry disease control would be incomplete without mention of the members of the industry, that is the producers themselves and of such organizations, formed by them or in which they participate as members. There are a number of active producerorganizations. The Poultry Department of the California Farm Bureau Federation is one of these; the several co-ops are others. This, then, is a resume of the facilities and personnel for poultry disease control which are present in California. Some of the accomplishments of these agencies might be highlighted by mention of the autopsies performed at the State Department of Agriculture laboratories. Table 5 shows the number performed, and indicates the important groups or specific
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and the Production and Marketing Administration. The Division of Animal Industry, State Department of Agriculture is charged with regulatory activities. Diagnosis of disease is part of its responsibility. To accomplish this, one general laboratory and three poultry pathology laboratories have been established and are currently in operation. These are staffed by veterinary personnel, trained in pathology, with the assistance of competent technical help. The Los Angeles poultry laboratory is projected as a general laboratory; and a fifth laboratory, also to be general, is projected for the central San Joaquin Valley. Certain diagnostic work is, of course, accomplished by the University of California. The California State Department of Agriculture also has live livestock disease control specialists who are charged with field investigations which are deemed necessary in connection with the diagnostic and regulatory work. The University of California has two parts in disease control. The Agricultural Experiment Station is charged with research and investigation in agricultural fields. The Department of Veterinary Science has accomplished noteworthy results in its scientific endeavors. Much of its work has been done cooperatively with other departments and divisions of the University of California, especially with the Poultry Division. The Agricultural Extension Service is also part of the College of Agriculture, and is charged with "extending" the results of research and assisting in the practical application thereof. Certain of the counties, through their livestock departments, do considerable' poultry disease work. This county participation includes cooperative work with the State laboratory by members of the Los Angeles County Livestock Department, and the maintenarice by the Live-
175
176
A. S. R.OSENWALD
diagnoses made during the years noted. To an extent it shows the trend of the problems in our state. There has been a marked increase in the number of diagnoses of respiratory infections but, of the individual diagnoses, TABLE 5.—Autopsies by state laboratories* Year
Total
1938 1946 1947
7,974 13,982
Agglutination tests for Pullorum disease 159,020 841,449 590,746
Disease Coccidiosis Coryza and colds Pneumoencephalitis Neoplasms Laryngotracheitis Pullorum Infection Bronchitis Fowl Cholera Pox
Average 1946 1938-45 633 432 137 477 11 572 113 50 84
575 445 267 336 210 308 61 61 45
1947 757 569 417 321 290 227 75 69
—
More Numerous Diagnoses Turkeys Disease Coccidiosis Blackhead Paratyphoid and Paracolon Hexamitiasis Pullorum Infection Fowl Cholera Pox Pneumoencephalitis
Average 1946 1938-45
1947**
100 65
139 67
93 47
90 108 135 10 11 12
47 79 122 9 7 5
40 33
— 16 15
—
* Calif. Department of Agriculture 1947-48. ** Turkey population and autopsies decreased greatly.
coccidiosis still maintains the position as the one most frequently found. There has been a very marked increase in the numbers of pneumoencephalitis (Newcastle disease) cases diagnosed since the 193845 average was determined. In part this
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More Numerous Diagnoses Chickens
could be due to the increased efficiency and availability of accurate diagnostic tests and also to the increasing awareness of the poultrymen of the need for laboratory verification of field diagnoses. One extremely interesting and, to a certain extent, alarming finding is the increasing number of cases of laryngotracheitis diagnosed. This increase may be accounted for in part by the advent of new poultrymen into the state. Much of it, however, is due to relaxation of care in actual vaccinating practice, to the use of new or short-cut methods which are not most effective, and to attempts to get by without vaccinating in areas where the disease is prevalent. This trend, however, should give pause to those who advocate so enthusiastically the development of live-virus vaccines for the control of pneumoencephalitis. The decrease in the diagnoses of pullorum infection is a tribute to the State Department of Agriculture, the industryoperated Poultry Improvement Advisory Board, and the sound eradication program. Where does Agricultural Extension Service activity fit in this picture? The Agricultural Extension Service is an integral part of the University of California and the farm advisors (county agents), their assistants, the specialist in poultry pathology and the specialist in poultry all participate in poultry disease control. The Extension agents in several of the counties are well trained in the field of poultry, but are not veterinarians and do not function as field diagnosticians. The specialist in poultry pathology is a veterinarian. In California the farm advisors and all technical or professional members of the Agricultural Extension Service are staff members of the University itself, as noted in Chart A. County financial participation in the
177
POULTRY DISEASE CONTROL IN CALIFORNIA
Extension program is limited to supplying clerical and non-technical personnel, equipment and facilities for work, transportation, office space and supplies. The philosophy underlying the California Agricultural Extension Service is that there
ties, not having full-time poultry specialists, certain farm advisors or assistant farm advisors spend one-third or more of their time in poultry Extension Activities. It is the responsibility of the specialists to train the county Extension workers and
CHART A.—U. C. Organization (Agriculture)
COLLEGE OF AGRICULTURE
Home. Demon. Agents 39 Asst. Home Dem. A. 26
Number of men per county
SCHOOLS AND DEPTS. (RESIDENT INSTRUCTION)
AGR. EXTEN. SER.
Specialists Total 31 Poultry 2
Farm Advisors 48 Asst. Farm Advisors 155
Number of counties
Home Economics Specialists 6
County Poultry Specialists (men per county)
i-i
1
More than 1
1
8
o
—
—
2
7
2
—
—
3-4
18
4
—
5-8
11
5
— 1
9-12
4
0
T otal 203
48
11
should be large competent county staffs with a minimum of expenditures for specialists at state level. This is in accordance with the expressed wishes of the people of California and has resulted in the development of commodity specialists resident within some of the counties, as shown in the chart. In a number of coun-
|
i
*
3
1
4
2
help make them competent to hold meetings, do the demonstrating, and to carry out an Extension program in a given field. Any program is based on local needs. While the specialists also work directly with the farmers of the state, in practically all instances the county Extension worker is the primary moving force. It is these
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AGR. EXP. STA.
178
A. S. ROSENWALD
under differing individual set-ups, is a matter of ingenuity and straight thinking. As mentioned before, the county staffs are relatively large and there are few specialists. The job of the specialist is to train, and train well, the individuals doing work in the counties so that they in turn can develop their own programs. We feel that the so-called Sectional Conference is an effective teaching method. At such conferences small groups of Extension workers are invited to meet with men from adjoining counties, with the specialist, or with members of the Experiment Station staff and discuss some particular subject in considerable detail. These discussion meetings are informal and provide an opportunity for the presentation of basic information by the specialist. They also give the farm advisor a chance to discuss problems from the field. The job of the specialist is one of teacher-training, as indicated in Chart B. We work very closely with the men in the counties to provide them with the facts and the tools to do an effective job of adult education and to accomplish valid experimental work concerning local problems. In these endeavors full use is made of the extremely valuable cooperation of other agencies interested in poultry disease control. Quite often meetings are arranged with representatives from the State Department of Agriculture, the Experiment Station, and the county workers in order that a problem may be more fully discussed or some specific field trial set up. Many of these field trials are not at all "method or result demonstrations," but are purely experimental in outline and intent. Results therefrom are beneficial not only for the men doing the work in the county, but may have much value in solving a more general problem. The farm advisors are fully cognizant of the need for improved use of existing
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county workers who do most, if not all of the Extension poultry disease work in our state. The Agricultural Extension Service has a triple function: 1. Dissemination to farm people of new information and research findings, and demonstration of improved practices. This embraces the clarification of problems by sane interpretation of all known facts, and the development of new information to suit local conditions. 2. Adaptation and utilization of facts for improved agricultural practices. 3. Observation of farm problems and the need for further research. The conception of the Agricultural Extension Service as a coordinating agency is not new. Its prime function is to extend to the rancher the fullest knowledge of research and improved practices. This information must be adapted to the rancher's needs and to local conditions. In California we feel that the county Extension workers can most effectually improve poultry disease control practices by coordinating the information available from the many sources listed above. This concept involves a dual function: clarification of conflicting and confusing information, and recognition and solution of new and different problems of the local poultry producers. Very definitely it includes the development of pertinent information. Certain practices have been proved in the laboratory. Extensive field trials under widely divergent conditions fall in the category both of developing information for local use, and of increasing the use of proved beneficial practices. The information of the county Extension worker must be based on fact and on sound general principles since each ranch differs in many ways from all other poultry units. The application of this basic factual material,
POULTRY DISEASE CONTROL IN CALIFORNIA
disease control facilities. With increased diagnostic facilities now available, considerable emphasis has been placed on fuller and more intelligent use of the laboratories. We feel very strongly that disease prevention is far better than treatment. The value of most diagnoses in relation to the treatment of a current outbreak of disease might be very slight. The real value of accurate diagnosis is that, be-
179
in the control of coccidiosis over 20 years ago, this disease still ranks first among the diagnoses at the pathological laboratories. Emphasis of these basic principles will enable an individual poultryman to adjust his management to control coccidiosis without severe loss, or to use much-touted drugs more effectively and economically. The basic principles of immunity and dosage and of sporulation (importance of
CHART B.—California extension teaching pattern A.E.S. local field trials SOURCES OF INFORMATION
Field observation
^ F a r m Advisor and Staff
Specialist^
Poultryman cause facts are understood, it enables a producer to prevent the recurrence of losses. There is considerable inter-relationship of management and disease control; we assume this is an undisputed fact. The major portion of the county workers' time is directed, therefore, toward improved management practices. In addition to the increased use of existing facilities, there is need for a better understanding and fuller application of basic facts and principles. For example, in spite of the fact that Johnson (1927) stated some of the basic principles involved
life cycle) are still valid today. The "why" of any regime is more important in the economical control of coccidiosis than the empiric "how" of that procedure. The diversity of our poultry industry has been mentioned. Perhaps a few illustrations of poultry disease control in various areas would be interesting. Pneumoencephalitis, or Newcastle disease, has certainly received its share of attention. Until recently it has been felt that the disease was of little economic consequence to turkey growers in the state. An alert assistant farm advisor in one of the
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Agr. Exper. Stations U.S.D.A. Public Service Agencies, State Department, etc. Commercial investigation
180
A . S. ROSENWALD
occurred before on the ranch. On this same ranch there were pullets as yet unaffected. Vaccination trials with modified live-virus were started. The State Department of Agriculture, the farm advisor, the extension specialist in poultry pathology, and a member of the Department of Veterinary Science participated. The results were not conclusive, nor were they especially encouraging. However, other such trials will be made, or are now in progress. Coryza is a major problem to our poultrymen. We have a number of trials in which the diagnoses were made by the State Department of Agriculture at one of its laboratories. The actual control measures are being supervised by the farm advisor. These trials are of value to all participants and are valid since they are well controlled. A number of these trials are essential before any broad principle can be derived. However, through the cooperation of the Experiment Station, the State Department of Agriculture, the poultrymen themselves, and certain commercial representatives, additional facts will be obtained which can be used to improve poultry disease control. Some of the county Extension workers are testing various sulfonamides used in the treatment of coccidiosis. The trials, with some untreated groups, are well controlled. The results, whether negative or positive, add to our knowledge of coccidiosis. These results are also useful in formulating recommendations for the control of this disease. One final example: some of the assistant farm advisors felt that in proportion to the time spent, there was insufficient improvement in poultry disease control. After a number of Sectional Meetings, it was sug- gested that all public service agencies get together and discuss possible integration and clarification, both of information and program, in an effort to hasten prog-
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counties noted that just prior to market time certain flocks were experiencing undue mortality and unthriftiness. He also noted in one flock that there was an abnormally high number of broody hens in the breeding flock. Facts obtained in conferences indicated that this might be due to pneumoencephalitis. Some affected birds, and blood samples from others, were submitted to the Department of Veterinary Science of the University and the disease was proved to be pneumoencephalitis. About this time some day-old poults were brought to the ranch and vaccination procedures Were discussed. It was decided that it was too late to improve conditions by vaccination. The farm advisor, however, instituted a complete study of the outbreak which included egg production records, numerous serological tests and autopsies, a mortality record of both hens and poults, and a survey of the situation during the following (current) year. He also has started several field trials using killed-virus vaccine in additional flocks of turkeys in areas where the disease is enzootic in chickens. These tests are well controlled. The point to be emphasized here is the fact that these trials involve full cooperation and considerable special work for not only the farm advisor, but also for the State Department of Agriculture, the research departments of the University, and certainly for the farmer. These field trials and the observations in outbreaks of the disease in turkeys will form a valuable part of the information concerning the ecology of pneumoencephalitis. New information, greatly needed, is being developed by the county agent. In another instance, the assistant farm advisor spotted an outbreak of disease in chickens. The diagnosis of pneumoencephalitis was made by the State Department of Agriculture. The disease had not
POULTRY DISEASE CONTROL IN CALIFORNIA
these measures to local needs. This implies coordination so that the poultrymen may make the best use of all information and facilities available to them. Subject matter conferences, for the discussion of both general and local problems, are extremely helpful. Furthermore, numerous field trials, experimental in design and intent, are conducted cooperatively on privately owned ranches by the Agricultural Extension Service, the Experiment Station, State Department of Agriculture, and other agencies. These aid greatly in the development of needed information. Progress must be based on facts properly applied. In the search for facts and for better practices in any field, coordination is essential. Poultry disease control in California is based on this premise. REFERENCES
California Department of Agriculture, 1947. Poultry disease activities. Nulaid News 24: 12, pp. 22-24. California Department of Agriculture, 1948. Report on State's poultry disease laboratories. Nulaid News 25: 12, p. 27. Johnson, W. T., 1927. Two basic factors in coccidial infection of the chicken. Journal A.V.M.A. 70: 560-583. U. S. Census of Agriculture, 1945. 1: 8-81.
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ress. One of the diseases confusing many poultrymen is pneumoencephalitis, and it was chosen as the first subject for discussion. A meeting was held at which it was possible to reach, if not unanimity, at least agreement as to actual facts concerning this disease: those which are known, those which are questionable, and those concerning which we need more information. The information gathered at this seminar will be disseminated through secondary meetings and individual contacts. It was felt that if the same information reached individual poultrymen from many different sources, much confusion would be avoided and better practices might be possible. Part of the duty of the Agricultural Extension Service, and any other educational agency, is to correct misconceptions. Some things which appear in the press are not founded on fact, and it is our duty to seek the facts and know them well to dissipate such errors. Such "seminars" seem a good method for this purpose. It is hoped that this rather rambling description will lead to a better understanding of some of our poultry disease control measures. Diverse conditions within the state make it necessary to adapt
181
B
TABLE 1.—California farms and population* California Total Area: 100,353,920 acres
1925 j 1945 | Percent increase
Number farms
Farms producing poultry
Acres in farms
136,409 138,917 1.7
87,611**
27,516,955 35,054,379 27
Population Total
Farm
4,700,000 8,800,000 83
531.000 538,000 1.3
* U. S. Census of Agriculture 1945. ** Only 40,064 sold poultry products.
efficiency of production and enable the producer of livestock, poultry, or products of livestock and poultry to have a greater return from the time and money invested. The title of this paper is somewhat misleading, in that one might get the impression that in the State of California we have a single program of disease control. For rather obvious reasons this is not true. Wide variation is found in California. For example, the highest and lowest elevations in the United States are situated in that state less than 100 miles apart. These are Mt. Whitney, 14,501 feet above sea level, and Death Valley, 286 feet below
These figures indicate that the total population in the state has almost doubled in the past 20 years, while the farm population has increased very little. There has been no highly significant change in the number of chickens raised nor in the numbers of eggs produced since 1930. Consequently the state has become an importing, rather than a major exporting state. Since 1930, the number of turkeys raised has been almost quadrupled; yet the number of turkey ranches has decreased to almost one-half those present in the state 18 years ago. Last year, California ranked first in turkey production in the nation.
173
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sea level. The diversity in the field of poultry might be emphasized by mentioning a few types of houses used by successful poultrymen in the state. These range from ranches where virtually no shelter is provided to individual cages, through various stages of wire-bottom houses to poultry houses with almost no openings. Without sounding like a Chamber of Commerce, the figures in Tables 1 and 2, taken from the U. S. Census of Agriculture 1945, should be of interest.
ASICALLY, the purpose of any attempt to control diseases of livestock and poultry is the reduction of the economic loss due to pathological conditions. This applies equally whether the abnormalities causing the decreased income are infectious or non-infectious; whether they cause mortality or decreased efficiency of production. Similarly, the difference between disease control and disease eradication is merely a matter of degree. Each attempts to increase the
174
A . S. ROSENWALD TABLE 2.—Production of poultry products in California* Year
I
1925
1930
1940
1945
No. chickens raised \ Farms reporting
14,382,861
26,644,797 81,793
24,750,462 61,645
33,003,636 77,741
Eggs produced (doz.) i Farms reporting !
97,907,325
159,421,612
129,686,042 68,380
158,892,261 79,072
1,246,993 19,776
2,593,406 8,148
4,093,769 9,870
No. turkeys raised Farms reporting
i j
* U. S. Census of Agriculture 1945. TABLE 3.—Value of poultry and poultry products sold, 1945
California: Three High Counties Sonoma Los Angeles San Bernardino
$103,218,755
100.0
44,253,606
42.8
§21,763,455 14,066,970 8,423,181
Three Low Counties Trinity Sierra Mono
16,120
TABLE 4.—Poultry disease control agencies Federal and State 1. U. S. Department of Agriculture a. Bureau of Animal Industry b. Production and Marketing Administration (Poultry meat inspection) 2. California Department of Agriculture a. Bureau of Livestock Disease Control Pathology Laboratories (diagnostic) Disease Control Specialists (investigation) 3. University of California—College of Agriculture a. Agricultural Experiment Station Veterinary Science Poultry Husbandry b. Agricultural Extension Service * County and Other 4. County Agencies a. Livestock Sanitary Departments Laboratory and field b. Veterinarians c. Agricultural Commissioners 5. Quasi-official Agencies a. Poultry Improvement Advisory Board 6. Veterinarians (Private) a. Chicken Pharmacy b. Poultry Practice 7. Commercial Service Personnel a. Feed Companies b. Hatcheries c. Biologic and Drug Companies 8. Poultry Producers
0.015
7,265 5,619 3,236
In 1945, 4 of the 5 leading counties in turkey production, and 3 of the 5 leading counties in chicken population were California counties. As noted in Table 3, the value of poultry and poultry products in , Sonoma County, our leading county where Petaluma is located, was in excess of 21 million dollars. Our 3 leading counties produced over 40 percent of the poultry and poultry products sold in California in 1945. In contrast, the 3 lowest counties produced less than .02 of one percent of similar agricultural commodities. One is impressed with the impossibility of any one single poultry disease control system being applicable. However, California poultrymen do have available to them some of the best diagnostic and disease control facilities in the country. They are outlined in Table 4. The Federal Government is represented through the Bureau of Animal Industry
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Percent
Value
POULTRY DISEASE CONTROL IN CALIFORNIA
stock Department of San Diego County of an excellent diagnostic laboratory with some research facilities. Other counties are less active, but participate through the county livestock inspector or veterinarian. There also exist quasi-official agencies. Outstanding among these is the Poultry Improvement Advisory Board which is charged with the administration of California's participation in the pullorum phase of the National Poultry and Turkey Improvement Plans. Among the employees of this board there are several well trained poultry pathologists. Certain veterinary practitioners do considerable poultry practice, both in the field of diagnosis and treatment. In Petaluma the unique "Chicken Pharmacy" operated by a veterinarian has been serving the Petaluma poultrymen for many years. Feed companies and other commercial concerns abound and flourish in the state. Field men and other representatives of these concerns enter into the poultry disease control picture. Certainly any discussion of poultry disease control would be incomplete without mention of the members of the industry, that is the producers themselves and of such organizations, formed by them or in which they participate as members. There are a number of active producerorganizations. The Poultry Department of the California Farm Bureau Federation is one of these; the several co-ops are others. This, then, is a resume of the facilities and personnel for poultry disease control which are present in California. Some of the accomplishments of these agencies might be highlighted by mention of the autopsies performed at the State Department of Agriculture laboratories. Table 5 shows the number performed, and indicates the important groups or specific
Downloaded from http://ps.oxfordjournals.org/ by guest on April 8, 2015
and the Production and Marketing Administration. The Division of Animal Industry, State Department of Agriculture is charged with regulatory activities. Diagnosis of disease is part of its responsibility. To accomplish this, one general laboratory and three poultry pathology laboratories have been established and are currently in operation. These are staffed by veterinary personnel, trained in pathology, with the assistance of competent technical help. The Los Angeles poultry laboratory is projected as a general laboratory; and a fifth laboratory, also to be general, is projected for the central San Joaquin Valley. Certain diagnostic work is, of course, accomplished by the University of California. The California State Department of Agriculture also has live livestock disease control specialists who are charged with field investigations which are deemed necessary in connection with the diagnostic and regulatory work. The University of California has two parts in disease control. The Agricultural Experiment Station is charged with research and investigation in agricultural fields. The Department of Veterinary Science has accomplished noteworthy results in its scientific endeavors. Much of its work has been done cooperatively with other departments and divisions of the University of California, especially with the Poultry Division. The Agricultural Extension Service is also part of the College of Agriculture, and is charged with "extending" the results of research and assisting in the practical application thereof. Certain of the counties, through their livestock departments, do considerable' poultry disease work. This county participation includes cooperative work with the State laboratory by members of the Los Angeles County Livestock Department, and the maintenarice by the Live-
175
176
A. S. R.OSENWALD
diagnoses made during the years noted. To an extent it shows the trend of the problems in our state. There has been a marked increase in the number of diagnoses of respiratory infections but, of the individual diagnoses, TABLE 5.—Autopsies by state laboratories* Year
Total
1938 1946 1947
7,974 13,982
Agglutination tests for Pullorum disease 159,020 841,449 590,746
Disease Coccidiosis Coryza and colds Pneumoencephalitis Neoplasms Laryngotracheitis Pullorum Infection Bronchitis Fowl Cholera Pox
Average 1946 1938-45 633 432 137 477 11 572 113 50 84
575 445 267 336 210 308 61 61 45
1947 757 569 417 321 290 227 75 69
—
More Numerous Diagnoses Turkeys Disease Coccidiosis Blackhead Paratyphoid and Paracolon Hexamitiasis Pullorum Infection Fowl Cholera Pox Pneumoencephalitis
Average 1946 1938-45
1947**
100 65
139 67
93 47
90 108 135 10 11 12
47 79 122 9 7 5
40 33
— 16 15
—
* Calif. Department of Agriculture 1947-48. ** Turkey population and autopsies decreased greatly.
coccidiosis still maintains the position as the one most frequently found. There has been a very marked increase in the numbers of pneumoencephalitis (Newcastle disease) cases diagnosed since the 193845 average was determined. In part this
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More Numerous Diagnoses Chickens
could be due to the increased efficiency and availability of accurate diagnostic tests and also to the increasing awareness of the poultrymen of the need for laboratory verification of field diagnoses. One extremely interesting and, to a certain extent, alarming finding is the increasing number of cases of laryngotracheitis diagnosed. This increase may be accounted for in part by the advent of new poultrymen into the state. Much of it, however, is due to relaxation of care in actual vaccinating practice, to the use of new or short-cut methods which are not most effective, and to attempts to get by without vaccinating in areas where the disease is prevalent. This trend, however, should give pause to those who advocate so enthusiastically the development of live-virus vaccines for the control of pneumoencephalitis. The decrease in the diagnoses of pullorum infection is a tribute to the State Department of Agriculture, the industryoperated Poultry Improvement Advisory Board, and the sound eradication program. Where does Agricultural Extension Service activity fit in this picture? The Agricultural Extension Service is an integral part of the University of California and the farm advisors (county agents), their assistants, the specialist in poultry pathology and the specialist in poultry all participate in poultry disease control. The Extension agents in several of the counties are well trained in the field of poultry, but are not veterinarians and do not function as field diagnosticians. The specialist in poultry pathology is a veterinarian. In California the farm advisors and all technical or professional members of the Agricultural Extension Service are staff members of the University itself, as noted in Chart A. County financial participation in the
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POULTRY DISEASE CONTROL IN CALIFORNIA
Extension program is limited to supplying clerical and non-technical personnel, equipment and facilities for work, transportation, office space and supplies. The philosophy underlying the California Agricultural Extension Service is that there
ties, not having full-time poultry specialists, certain farm advisors or assistant farm advisors spend one-third or more of their time in poultry Extension Activities. It is the responsibility of the specialists to train the county Extension workers and
CHART A.—U. C. Organization (Agriculture)
COLLEGE OF AGRICULTURE
Home. Demon. Agents 39 Asst. Home Dem. A. 26
Number of men per county
SCHOOLS AND DEPTS. (RESIDENT INSTRUCTION)
AGR. EXTEN. SER.
Specialists Total 31 Poultry 2
Farm Advisors 48 Asst. Farm Advisors 155
Number of counties
Home Economics Specialists 6
County Poultry Specialists (men per county)
i-i
1
More than 1
1
8
o
—
—
2
7
2
—
—
3-4
18
4
—
5-8
11
5
— 1
9-12
4
0
T otal 203
48
11
should be large competent county staffs with a minimum of expenditures for specialists at state level. This is in accordance with the expressed wishes of the people of California and has resulted in the development of commodity specialists resident within some of the counties, as shown in the chart. In a number of coun-
|
i
*
3
1
4
2
help make them competent to hold meetings, do the demonstrating, and to carry out an Extension program in a given field. Any program is based on local needs. While the specialists also work directly with the farmers of the state, in practically all instances the county Extension worker is the primary moving force. It is these
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AGR. EXP. STA.
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A. S. ROSENWALD
under differing individual set-ups, is a matter of ingenuity and straight thinking. As mentioned before, the county staffs are relatively large and there are few specialists. The job of the specialist is to train, and train well, the individuals doing work in the counties so that they in turn can develop their own programs. We feel that the so-called Sectional Conference is an effective teaching method. At such conferences small groups of Extension workers are invited to meet with men from adjoining counties, with the specialist, or with members of the Experiment Station staff and discuss some particular subject in considerable detail. These discussion meetings are informal and provide an opportunity for the presentation of basic information by the specialist. They also give the farm advisor a chance to discuss problems from the field. The job of the specialist is one of teacher-training, as indicated in Chart B. We work very closely with the men in the counties to provide them with the facts and the tools to do an effective job of adult education and to accomplish valid experimental work concerning local problems. In these endeavors full use is made of the extremely valuable cooperation of other agencies interested in poultry disease control. Quite often meetings are arranged with representatives from the State Department of Agriculture, the Experiment Station, and the county workers in order that a problem may be more fully discussed or some specific field trial set up. Many of these field trials are not at all "method or result demonstrations," but are purely experimental in outline and intent. Results therefrom are beneficial not only for the men doing the work in the county, but may have much value in solving a more general problem. The farm advisors are fully cognizant of the need for improved use of existing
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county workers who do most, if not all of the Extension poultry disease work in our state. The Agricultural Extension Service has a triple function: 1. Dissemination to farm people of new information and research findings, and demonstration of improved practices. This embraces the clarification of problems by sane interpretation of all known facts, and the development of new information to suit local conditions. 2. Adaptation and utilization of facts for improved agricultural practices. 3. Observation of farm problems and the need for further research. The conception of the Agricultural Extension Service as a coordinating agency is not new. Its prime function is to extend to the rancher the fullest knowledge of research and improved practices. This information must be adapted to the rancher's needs and to local conditions. In California we feel that the county Extension workers can most effectually improve poultry disease control practices by coordinating the information available from the many sources listed above. This concept involves a dual function: clarification of conflicting and confusing information, and recognition and solution of new and different problems of the local poultry producers. Very definitely it includes the development of pertinent information. Certain practices have been proved in the laboratory. Extensive field trials under widely divergent conditions fall in the category both of developing information for local use, and of increasing the use of proved beneficial practices. The information of the county Extension worker must be based on fact and on sound general principles since each ranch differs in many ways from all other poultry units. The application of this basic factual material,
POULTRY DISEASE CONTROL IN CALIFORNIA
disease control facilities. With increased diagnostic facilities now available, considerable emphasis has been placed on fuller and more intelligent use of the laboratories. We feel very strongly that disease prevention is far better than treatment. The value of most diagnoses in relation to the treatment of a current outbreak of disease might be very slight. The real value of accurate diagnosis is that, be-
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in the control of coccidiosis over 20 years ago, this disease still ranks first among the diagnoses at the pathological laboratories. Emphasis of these basic principles will enable an individual poultryman to adjust his management to control coccidiosis without severe loss, or to use much-touted drugs more effectively and economically. The basic principles of immunity and dosage and of sporulation (importance of
CHART B.—California extension teaching pattern A.E.S. local field trials SOURCES OF INFORMATION
Field observation
^ F a r m Advisor and Staff
Specialist^
Poultryman cause facts are understood, it enables a producer to prevent the recurrence of losses. There is considerable inter-relationship of management and disease control; we assume this is an undisputed fact. The major portion of the county workers' time is directed, therefore, toward improved management practices. In addition to the increased use of existing facilities, there is need for a better understanding and fuller application of basic facts and principles. For example, in spite of the fact that Johnson (1927) stated some of the basic principles involved
life cycle) are still valid today. The "why" of any regime is more important in the economical control of coccidiosis than the empiric "how" of that procedure. The diversity of our poultry industry has been mentioned. Perhaps a few illustrations of poultry disease control in various areas would be interesting. Pneumoencephalitis, or Newcastle disease, has certainly received its share of attention. Until recently it has been felt that the disease was of little economic consequence to turkey growers in the state. An alert assistant farm advisor in one of the
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Agr. Exper. Stations U.S.D.A. Public Service Agencies, State Department, etc. Commercial investigation
180
A . S. ROSENWALD
occurred before on the ranch. On this same ranch there were pullets as yet unaffected. Vaccination trials with modified live-virus were started. The State Department of Agriculture, the farm advisor, the extension specialist in poultry pathology, and a member of the Department of Veterinary Science participated. The results were not conclusive, nor were they especially encouraging. However, other such trials will be made, or are now in progress. Coryza is a major problem to our poultrymen. We have a number of trials in which the diagnoses were made by the State Department of Agriculture at one of its laboratories. The actual control measures are being supervised by the farm advisor. These trials are of value to all participants and are valid since they are well controlled. A number of these trials are essential before any broad principle can be derived. However, through the cooperation of the Experiment Station, the State Department of Agriculture, the poultrymen themselves, and certain commercial representatives, additional facts will be obtained which can be used to improve poultry disease control. Some of the county Extension workers are testing various sulfonamides used in the treatment of coccidiosis. The trials, with some untreated groups, are well controlled. The results, whether negative or positive, add to our knowledge of coccidiosis. These results are also useful in formulating recommendations for the control of this disease. One final example: some of the assistant farm advisors felt that in proportion to the time spent, there was insufficient improvement in poultry disease control. After a number of Sectional Meetings, it was sug- gested that all public service agencies get together and discuss possible integration and clarification, both of information and program, in an effort to hasten prog-
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counties noted that just prior to market time certain flocks were experiencing undue mortality and unthriftiness. He also noted in one flock that there was an abnormally high number of broody hens in the breeding flock. Facts obtained in conferences indicated that this might be due to pneumoencephalitis. Some affected birds, and blood samples from others, were submitted to the Department of Veterinary Science of the University and the disease was proved to be pneumoencephalitis. About this time some day-old poults were brought to the ranch and vaccination procedures Were discussed. It was decided that it was too late to improve conditions by vaccination. The farm advisor, however, instituted a complete study of the outbreak which included egg production records, numerous serological tests and autopsies, a mortality record of both hens and poults, and a survey of the situation during the following (current) year. He also has started several field trials using killed-virus vaccine in additional flocks of turkeys in areas where the disease is enzootic in chickens. These tests are well controlled. The point to be emphasized here is the fact that these trials involve full cooperation and considerable special work for not only the farm advisor, but also for the State Department of Agriculture, the research departments of the University, and certainly for the farmer. These field trials and the observations in outbreaks of the disease in turkeys will form a valuable part of the information concerning the ecology of pneumoencephalitis. New information, greatly needed, is being developed by the county agent. In another instance, the assistant farm advisor spotted an outbreak of disease in chickens. The diagnosis of pneumoencephalitis was made by the State Department of Agriculture. The disease had not
POULTRY DISEASE CONTROL IN CALIFORNIA
these measures to local needs. This implies coordination so that the poultrymen may make the best use of all information and facilities available to them. Subject matter conferences, for the discussion of both general and local problems, are extremely helpful. Furthermore, numerous field trials, experimental in design and intent, are conducted cooperatively on privately owned ranches by the Agricultural Extension Service, the Experiment Station, State Department of Agriculture, and other agencies. These aid greatly in the development of needed information. Progress must be based on facts properly applied. In the search for facts and for better practices in any field, coordination is essential. Poultry disease control in California is based on this premise. REFERENCES
California Department of Agriculture, 1947. Poultry disease activities. Nulaid News 24: 12, pp. 22-24. California Department of Agriculture, 1948. Report on State's poultry disease laboratories. Nulaid News 25: 12, p. 27. Johnson, W. T., 1927. Two basic factors in coccidial infection of the chicken. Journal A.V.M.A. 70: 560-583. U. S. Census of Agriculture, 1945. 1: 8-81.
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ress. One of the diseases confusing many poultrymen is pneumoencephalitis, and it was chosen as the first subject for discussion. A meeting was held at which it was possible to reach, if not unanimity, at least agreement as to actual facts concerning this disease: those which are known, those which are questionable, and those concerning which we need more information. The information gathered at this seminar will be disseminated through secondary meetings and individual contacts. It was felt that if the same information reached individual poultrymen from many different sources, much confusion would be avoided and better practices might be possible. Part of the duty of the Agricultural Extension Service, and any other educational agency, is to correct misconceptions. Some things which appear in the press are not founded on fact, and it is our duty to seek the facts and know them well to dissipate such errors. Such "seminars" seem a good method for this purpose. It is hoped that this rather rambling description will lead to a better understanding of some of our poultry disease control measures. Diverse conditions within the state make it necessary to adapt
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