The value of the Newcastle disease I-2 thermostable vaccine use in the rural free-range poultry management system in Uganda

J Illango, G Mukiibi-Muka, P P Abila, G Musisi and A Etoori 

National Livestock Resources Research Institute, P.O. Box 96, Tororo Uganda
jamesillango@yahoo.com

Abstract 

The Newcastle disease (ND) I-2 thermostable vaccine of Embryo-infective dose (EID₅₀) 10⁹ per ml, applied singly and in combination with levamisole medication, was used for vaccinating at least 1,315 local village chickens from 92 households in three rural areas of Uganda between 2006 and 2007.In two areas, the vaccine was given by the eye-drop method to housed and unhoused free-range chickens. In the third area, the vaccine was given to free-range chickens, in two separate sets of households, orally using either water only or water medicated with levamisole. Serum and fecal samples collected from chickens after each vaccination were tested to establish Newcastle disease protection levels and endo- parasite infestation rates by Hemagglutination Inhibition (HI) test and floatation method respectively.

Housed chickens attained 100% protection to Newcastle disease with Mean ND antibody HI log ₂ titre of 6.19± 1.3 compared with 89% protection by unhoused chickens with Mean ND antibody HI log ₂ titre of 5.40. ± 2.5. Chickens given oral I-2 vaccine/levamisole mixture attained 86% protection with Mean ND antibody HI log₂ titre 4.91± 4.5 and reduced sample parasite infestation rates from 34.3% to 2.3% while those given the vaccine orally in water without levamisole attained 79.1% protection with Mean ND antibody log 2 titre of 4.50± 2.6 and sample parasite infestation rate of 37.5% after three vaccinations. The major endo-parasites identified were Capillaria, Heterakis, Ascaridia, Syngamus, Strongyloides and Reilletina species. The benefits and adaptability of these poultry health interventions are discussed in view of the rural poultry management system in Uganda.

Keywords: chickens, levamisole, parasites, vaccination

Introduction

In rural areas of Africa, Newcastle disease (ND) and parasites are of major economic importance in poultry production (Musiime 1992; Kitalyi 1998).This is due to the favorable epidemiological factors in the free-range poultry management systems (Yongolo 1996; Permin and Hansen 1998).Although vaccination offers an effective control method for ND, consideration of the poultry management system is necessary for the overall success of any vaccination program (Alders and Spradbrow 2001).The Newcastle disease thermostable vaccines offer an appropriate technology for the disease control in rural free-range poultry management systems where cold-chain facilities, logistics, management and husbandry factors need consideration (Alders and Spradbrow 2001).In Uganda, the use of the ND I-2 thermostable vaccine is being promoted for ND control in village chickens to increase poultry production in rural households for  poverty eradication programs.

Endo-parasites and their effects on poultry health and productivity are well understood, hence the need for their control (Permin and Hansen 1998). In preliminary studies conducted using laboratory chickens to assess the immunogenicity of the ND I-2 thermostable vaccine given orally in levamisole-medicated water, it was feasible to vaccinate chickens against ND and treat against endo-parasites at the same time in a single application (Illango et al 2005).   This study was intended to demonstrate the benefits of the I-2 thermostable vaccine and test its adaptability with levamisole for oral application in village chickens for the control of both ND and endo-parasites under rural conditions in Uganda  

Materials and methods 

Project areas, farmer selection and preparatory activities

Three rural areas in Uganda were selected based on the free-range poultry management system practised, history of high ND prevalence with no previous chicken vaccinations. A total of 92 farmers were selected in the three areas based on poultry flock sizes of, at least, 10 chickens per household and farmer’s initiative in poultry production. After conducting sensitization meetings, baseline studies were done by farmer interviews using a questionnaire. A study poultry population of 1,315 local chickens, major constraints affecting household poultry production and management practices were established during the studies. In addition, 206 serum samples, representing 48.1%, were collected from adult chickens in all the three project areas, by bleeding chickens using the wing veins. The serum samples were tested for ND antibody titres to establish the pre-vaccination sero-status using the Haemagglutination Inhibition (HI) test (Allan and Gough 1974).In one project area, 71 fecal samples, representing 47.0%, were collected from adult chickens, directly from their cloacas using gloves, and tested for endo-parasite infestation rates by floatation and microscopy method as described by Permin and Hansen (1998).

Vaccinations

Vaccine and application methods

A locally-produced wet ND I-2 thermostable vaccine, of Embryo-Infective dose, (EID₅₀) of 10⁹ per ml, was used for chicken vaccinations in the three areas (Spradbrow et al 1995). In two areas, the vaccine was applied to chickens by the eye-drop method using an eye-dropper previously calibrated to deliver 1 dose of vaccine, (EID ₅₀ 10⁶) per drop, as described by Alders and Spradbrow (2001). In the first area, the chickens in each household were kept indoors throughout the study period and provided with feed and water ad lib, while in the second project area chickens were on free-range during the day and housed only at night. The farmers participated alongside the scientists in all the chicken vaccinations in the two areas.  Vaccinations were repeated every 3 months (Alders and Spradbrow 2001). In the third area, where chickens were also on free-range during day time and housed only at night, two sets each of 14 households were randomly established for oral vaccine administration in chickens using drinking water.  Two weeks prior to vaccination, each household was provided with a water drinker and advised to accustom chickens to daily provision of drinking water from a local source. For the first set of households, the I-2 vaccine was applied to the chickens using water medicated with levamisole (ANUPCO, Ipswich, England) while for chickens in the second set of households the vaccine was applied in drinking water without levamisole.On the day of vaccination, each farmer was required to withhold drinking water from chickens until vaccination time. A levamisole solution, using water from a local source, was prepared for the number of chickens in each household following the manufacturer’s instructions. In the freshly-prepared levamisole solution, adequate vaccine doses were added using the calibrated eye-dropper, mixed before giving the chickens in the water drinker .To vaccinate chickens in the second set of households, the number of chickens in all the households was established by census. This was used to make up the I-2 vaccine solution consisting of adequate water, at a rate of 10 mls of water per chicken, to which adequate vaccine doses were added using the calibrated dropper as recommended by Alders and Spradbrow (2001). The vaccine solution was then dispensed in the water drinkers for chickens in each household at rate of 10 mls per chicken. As above, each farmer was required to withhold water from the chickens until vaccination time.  In the third project area, chicken vaccinations were repeated in each household, as above, after 2 weeks and thereafter every 3 months with farmer participation alongside the scientists in the preparation of the vaccine/ levamisole and vaccine mixtures respectively. Three vaccinations were conducted for the chickens in all three project areas.

Monitoring

Serum samples were collected from all the adult chickens in the three project areas by bleeding using wing veins (Alders and Spradbrow 2001). From the chickens given the vaccine by the eye-drop method, samples were collected 3 months after each vaccination exercise while samples from the chickens vaccinated orally, were collected 1 month after first vaccination and thereafter every 3 months. A total of 342 serum samples were collected from adult chickens given the vaccine by eye-drop method and 284 serum samples from adult chickens given the vaccine orally after three vaccinations. The serum samples were stored frozen at -20C before testing for protection against ND by the HI test (Allan and Gough 1974).A total of 280 fecal samples were collected, as above, from all adult chickens at the same times as serum samples, in the households where the vaccine was given to the chickens orally. The fecal samples were immediately tested to establish the household, sample and parasite species infestation rates using the floatation and microscopy method (Permin and Hansen 1998). Household data on poultry stock numbers was also collected by farmer interviews during sampling periods using field data record sheets.

Results 

Over 50% of chickens in all project areas sero-converted with protective immunity to ND after first vaccination using the two vaccine application methods (Table 1.).

The mean ND antibody titres for housed chickens in project area one were higher than the corresponding titers of the unhoused chickens in project area two, given the I-2 thermostable vaccine by the eye-drop  method in all the three applications. Antibody titres of chickens given the I-2 thermostable vaccine by eye-drop method were generally higher, in the two project areas one and two, than those of the chickens in area three, given the same vaccine by oral route using either drinking water alone or water medicated with levamisole in all the three vaccinations given (Table 1).

A mixture of levamisole and the I-2 thermostable vaccine for oral application in drinking water, as given to chickens in set 2 in the project area three, produced protective immunity in all the three vaccinations comparable, in each case, to that of chickens in set one (Table 2).

There was considerable reduction of household, sample and parasite infestation rates after each treatment in the first set of households. In the second set of households, the parasite infestation rates remained high throughout the study period. Capillaria, Heterakis, Ascaridia, syngamus, strongyloides and Reilletina were the major nematode and cestode helminth parasites respectively, prevalent in the chickens in the project area (Table 3 a and b).

Capillaria, Ascaridia and Strongyloides parasite species were eliminated after first levamisole application but Heterakis and Reilletina species were recovered after second and third treatments respectively (Table 3 a).

Discussion 

The capacity of the ND I-2 thermostable vaccine, given either by eye-drop or orally in drinking water, to provide protective immunity in chickens against ND was demonstrated in this study. The eye-drop method was superior to the oral method in producing stronger immunity after each application. Using the eye-drop method ensures that each chicken receives adequate dose of vaccine delivered in close proximity of the harderian gland, an immune organ in a chicken eye (Spradbrow 1992). These were in agreement with earlier findings by other workers (Foster et al 1999; Bensink and Spradbrow 1999; Wambura et al 2000).The eye-drop method is thus better recommended for ND vaccination in chickens (Alders and Spradbrow 2001). In Uganda, as in other African countries where free-range poultry management is practised, labour is required for catching chickens .Farmers need to be sensitized and mobilized to work together for a common good. In this study there was adequate sensitization of the farmers to provide a collective effort to catch the chickens and even participate in vaccinations which made the approach successful. Oral method of ND vaccination of chickens generally stimulates low immunity (Alders and Spradbrow 2001). In the rural poultry management systems, there is also the effect of mixed poultry stocks in the households. Chickens of different age groups, sizes and in some cases different poultry species were kept together. It was noted that chickens scrambled for drinking water during vaccination times. It became a disadvantage for the chicks and other weaker chickens. It is therefore possible that the disadvantaged groups of chickens did not take adequate vaccine in drinking water. These factors accounted for the low immunity development in chickens given the vaccine orally.

Housed chickens in area one, developed relatively higher immune responses to ND vaccination than their unhoused counterparts in area two in all the three applications. This could be attributed to the relatively better management system, feed and water provisions given to the chickens, possible low parasite challenge and thus better health status. High immune responses to ND vaccination in housed chickens was  noted by earlier workers using the V4 thermostable vaccine (French et al 1967).It was attributed to the horizontal spread of the vaccine in housed chickens, another advantage of the ND thermostable vaccines over cold-chain vaccines (Alders and Spradbrow  2001).This was demonstrated here in a rural poultry set-up and can serve as a good extension message for rural poultry farmers in Uganda who do not provide housing for their chickens (Illango et al  2002).After application in chickens, the  vaccine I-2 virus undergoes multiplication in the tissues before excretion still in a viable state able to give a booster effect to other housed chickens either  through contact or in feed and water.  

Control of endo-parasites in free-range poultry is necessary for improved productivity (Permin  and Hansen 1998).High prevalence of endo-parasites in rural chickens had been demonstrated in Uganda (Bwangamoi 1968; Ssenyonga 1982) This justified the need to assess the possibility of the combined use of the I-2 vaccine and levamisole, as a possible cost-effective single oral application targeting Newcastle disease and endo-parasites control for chickens under rural conditions of Uganda. The 3-months vaccination schedule recommended for ND, if practised, would also provide regular deworming of local chickens using levamisole (Alders and Spradbrow 2001). This treatment regimen would cater for endo- parasite re-infestation of chickens, likely to occur in a free-range poultry management system (Permin and Hansen 1998). Levamisole is suitable because of its broad-spectrum activity on helminths and immuno-modulating properties observed by some workers (Singh and Dhawedkar 1993). In this study, a high parasite infestation was demonstrated in the chickens as shown by earlier workers (Bwangamoi 1968; Ssenyonga 1982).  The approach was effective in reducing parasite infestation rates in the chickens and found practical for farmer use in rural areas following the simple instructions on the accompanying leaflets. The oral application of the I-2 vaccine provides another beneficial option for rural farmers in Uganda, possibly lacking labour to catch chickens, and wanting to control both ND and parasites using single application. This approach is adaptable for farmer use because the instructions are simplified for farmers. Heterakis species which was recovered after second application possibly indicated a case of parasite re-infestation. Reilletina species which did not respond to the treatment, in all the three applications, calls for a need to explore similar approach using cestode antihelmintics.

Conclusions 

• The ND I-2 thermostable vaccine for chickens is potent for ND control and adaptable for rural farmer use. Newcastle Disease vaccination using the I-2 thermostable vaccine in housed chickens improves flock immunity.

  
  

• The ND I-2 thermostable vaccine and levamisole are compatible and effective in combined application in drinking water for chicken vaccination against ND and endo-parasite control in rural poultry management conditions.

Acknowledgements 

I wish to acknowledge the support received from the Director, National Livestock Resources Research Institute, Tororo, Uganda, for this work. The District Veterinary Officers of Kamuli, Rakai, Tororo and Sembabule districts, Uganda, are given special thanks for the organization of the field activities in their respective districts which contributed to the success of this work and the farmers of the districts for interest, support and active participation in the project activities. This work was supported by funds from the National Agricultural Research Organisation for which I am very grateful.

References 

Alders R and Spradbrow P 2001 Introduction to live thermostable Newcastle vaccines. In: Controlling Newcastle disease in village chickens. A field manual. Alders R and Spradbrow P (editors), ACIAR. No.82, Canberra, Australia 37-44

Allan and Gough R G 1974 A standard Heamagglutination Inhibition test for Newcastle disease. Veterinary Records 95: 147-149

Bensink Z and Spradbrow P 1999 Newcastle disease virus strain 1-2, a prospective thermostable vaccine for use in developing countries. Veterinary Microbiology 68:131-139

Bwangamoi O 1968 Poultry helminth parasites of Uganda. Bulletin of Epizootic diseases of Africa 16: 429-459

Foster H A, Chitukuro H R, Tuppa E, Mwanjala T and Kusila C 1999 Thermostable Newcastle disease vaccines in Tanzania. Veterinary Microbiology 68:  127-130

French E L, St George T D and Percy J J 1967 Infection of chicks with recently isolated Newcastle disease viruses of low virulence. Australian Veterinary Journal 43: 404-409

Illango J, Etoori A, Olupot H, Mabonga J 2002 Rural poultry production in two Agro-ecological zones of Uganda. In: Characteristics and parameters of family poultry production in Africa. Results of a FAO/IAEA Co-ordinated Research Programme.IAEA, VIENNA, Austria.117-136 http://www.iaea.org/nafa/d3/public/12-rural-illango.pdf

Illango J, Olaho-Mukani W, Mukiibi-Muka G, Abila P P and Etoori A 2005 Immunogenicity of a locally-produced Newcastle Disease I-2 thermostable vaccine in chickens in Uganda. Tropical Animal Health and Production, Kluwer Academic Publishers 37: 25-31

Kitalayi A J 1998 Village chicken production systems in rural Africa: Household food security and gender issues. FAO Animal Health and Production Paper No 142. FAO, Rome http://www.fao.org/DOCREP/003/W8989E/W8989E00.HTM

Musiime J T 1992 Poultry diseases in Africa and Newcastle disease problem. An overview. In: P B Spradbrow (editor), Newcastle disease in village chickens. ACIAR Proceedings No. 39, Canberra, Australia 174-176

Permin A and Hansen J W 1998 Poultry and parasites. In: A Permin and J W Hansen (editors), Epidemiology, Diagnosis and control of poultry parasites. FAO Animal Health Manual, 4 Rome Italy 1-6

Singh K C P and Dhawedkar R G 1993 Immunomodulating effects of levamisole in chicks immuno-compromised by infectious bursal disease virus. Tropical Animal Health and Production 25: 11-14

Spradbrow P B 1992 Heat-stable vaccines as one approach to the control of Newcastle disease in village chickens. In: P B Spradbrow (editor), Newcastle disease in village chickens. ACIAR Proceedings No.39, Canberra, Australia 11-14

Spradbrow P, Bensink Z and Grimes S 1995 Small-scale production and testing of Newcastle Disease vaccine. Laboratory manual produced for use at a workshop hosted by Poultry Reference Laboratory, University of Pretoria and Australian Centre for International Agricultural Research, Canberra 2-25

Ssenyonga G S Z 1982 Prevalence of helminth parasites of domestic fowl (Gallus domesticus) in Uganda. Tropical Animal Health and Production 14: 201-204

Wanbura P N, Kapaga A M and Hyera J M K 2000 Experimental trials with a thermostable Newcastle disease virus (1-2) in commercial and village chickens in Tanzania. Preventive Veterinary Medicine 43: 75-83

Yongolo M G S 1996 Epidemiology of Newcastle disease in village chickens in Tanzania. PhD. Dissertation. Sokoine University of Agriculture, Morogoro. United Republic of Tanzania

Received 6 June 2008; Accepted 10 June 2008; Published 4 September 2008

Go to top