Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016
Performing Department
Poultry Science
Non Technical Summary
A. Coccidiosis is a major limitation to production of pheasants, chukars and bobwhite quail in North America. Outbreaks often kill 25% or more of flocks on large farms, where tens of thousands of birds are produced annually. There is currently not enough knowledge of control methods to provide relief for these farmers. B. The first step in gaining control of this threat is to define the problem. We will conduct a national survey of game-bird producers, in cooperation with the North American Game Bird Association (NAGA), to identify the species of parasites largely responsible for these losses, and to build a collection of field isolates which will form the basis for later studies. Molecular diagnostic tools will be developed to aid in this process. C. Drugs used to control coccidiosis in other animals (mainly chickens) have not been adequately evaluated for possible use in game birds. We will conduct several tests in pheasants, chukars, and bobwhites to evaluate zoalene, robenidine, semduramicin, salinomycin, lasalocid, decoquinate, rofenaid, and diclazuril. The tests will be similar to those used for evaluation of such drugs in chickens, where birds are given the medicated feed, inoculated with coccidia, and evaluated on the basis of weight gain and lesion scores in a 7 day test. It is hoped that effective products will be identified which will give the producers short-term relief from these losses. D. Vaccines for control of coccidiosis: Considerable success has been attained with the use of live vaccines in chickens. Vaccines are considered the main alternative to the use of drugs and antibiotics. In this study, we will choose candidates from among the field isolates, attenuate them by selection for early development, and constitute vaccines with the important species for each bird. Tests in the laboratory and field will help to guide the development of these products, which will be commercialized with the aid of a commercial partner. The availability of vaccines which would prevent mortality in pheasants, chukars and bobwhites is the ultimate goal of this project.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Goals / Objectives
Coccidiosis is a major limitation to the production and marketing of game species of birds in America, principally the bobwhite quail, the Chinese ringnecked pheasant, and the chukar partridge. Virtually no research has been conducted on the disease agents other than to describe some of the species and to conduct small tests on the potential for control by existing anticoccidial drugs. Clearly, an organized effort is needed to generate the technical capability for control of coccidiosis and to produce vaccines for more reliale prevention. The envisioned research program will have the following goals: 1. Identification of the responsible disease agents. Coccidia of these birds is host specific, so that the coccidia of each bird are unique to that bird. A national survey of coccidia involved in outbreaks on commercial farms will identify the most important species of coccidia, to be targeted in subsequent control efforts. In conjunction with this survey, molecular techniques (PCR) will be used to improve diasnosis accuracy and speed. 2. Existing anticoccidial drugs used in the poultry industry will be tested for efficacy against the game-bird species, to provide interim information to the producers on the use of drugs to prevent outbreaks. 3. Vaccines against the major species in each bird species will be developed following the technology developed in the poultry industry, that is, the attenuation of selected species of coccidia to be given as a modified live vaccine.
Project Methods
Part 1: Survey of coccidia. The aid of diagnostic veterinarians and farmers will be solicited for obtaining isolates of coccidia from outbreaks in pheasants, chukars and bobwhite quail in North America. These isolates will be characterized as to probable species and used for latter experiments on drugs and as candidates for vaccine strains. PCR primers will be devised for use in diagnostics, for rapid and accurate identification of species. Part 2: Drugs used in poultry. Several anticoccidial drugs commonly used in chickens have not been tested extensively in game birds. Battery tests will be conducted using a model commonly used for broiler chickens, to determine the efficacy of these products in chukars, pheasants and bobwhites. These tests will be aimed at prophylactic application of products for use as permitted under veterinary prescription. Part 3: Development of vaccines for coccidiosis in game bird species. The ultimate goal of this project is the development of modified live organisms which can be used to vaccinate birds as day-old chicks, following the approach currently used for broiler chickens. Attenuation of coccidia can be accomplished by selection for early oocyst production (precocious development) following the procedures of Jeffers and others. The effectiveness of a vaccine is measured by challenge of vaccinated birds by virulent organisms and measurement of effects on weight gain and lesion scores. It is anticipated that only one or two species will be required for each bird, to adequately interrupt the disease/mortality cycle.