Evaluation of strategies to improve village chicken production-controlled field trials to assess effects of Newcastle disease vaccination and altered chick rearing in Myanmar

Henning, J., Morton, J., Pym, R., Hla, T. and Meers, J. (2009) Evaluation of strategies to improve village chicken production-controlled field trials to assess effects of Newcastle disease vaccination and altered chick rearing in Myanmar. Preventive Veterinary Medicine, 90 1-2: 17-30. doi:10.1016/j.prevetmed.2009.04.007


Author Henning, J.
Morton, J.
Pym, R.
Hla, T.
Meers, J.
Title Evaluation of strategies to improve village chicken production-controlled field trials to assess effects of Newcastle disease vaccination and altered chick rearing in Myanmar
Journal name Preventive Veterinary Medicine   Check publisher's open access policy
ISSN 0167-5877
1873-1716
Publication date 2009-07-01
Year available 2009
Sub-type Article (original research)
DOI 10.1016/j.prevetmed.2009.04.007
Open Access Status
Volume 90
Issue 1-2
Start page 17
End page 30
Total pages 14
Editor M.D. Salman
Place of publication Amsterdam, The Netherlands
Publisher Elsevier Science
Language eng
Subject 0707 Veterinary Sciences
C1
Abstract Previous research identified Newcastle disease and poor management of chicks (birds younger than 6 weeks of age) as major constraints to village chicken production in Myanmar. Based on these findings, controlled trials were conducted in 124 randomly selected households in nine villages in Myanmar over a period of 12 months to evaluate strategies to enhance survival of village chickens. Two intervention strategies were assessed: Newcastle disease vaccination using the thermostable 1-2 vaccine and changes to the management of chick rearing (confinement and supplementary feeding). These interventions were applied in two trials: (1) a randomised controlled trial to compare 1-2 vaccination, altered chick management and no intervention (apart from placebo treatment) at household level and (2) nested within this trial, a double-blinded controlled trial at bird-level to compare serological titres between 1-2 vaccinated and placebo-treated birds both between and within households. Outcomes measured in the first trial were crude incidence rate of mortality, proportional mortality rate for deaths due to disease stratified by age group of birds and mortality attributed to Newcastle disease, number of sales, income from sale of birds, consumption of birds and hatching of birds.
Formatted abstract
Previous research identified Newcastle disease and poor management of chicks (birds younger than 6 weeks of age) as major constraints to village chicken production in Myanmar. Based on these findings, controlled trials were conducted in 124 randomly selected households in nine villages in Myanmar over a period of 12 months to evaluate strategies to enhance survival of village chickens. Two intervention strategies were assessed: Newcastle disease vaccination using the thermostable I-2 vaccine and changes to the management of chick rearing (confinement and supplementary feeding). These interventions were applied in two trials: (1) a randomised controlled trial to compare I-2 vaccination, altered chick management and no intervention (apart from placebo treatment) at household level and (2) nested within this trial, a double-blinded controlled trial at bird-level to compare serological titres between I-2 vaccinated and placebo-treated birds both between and within households. Outcomes measured in the first trial were crude incidence rate of mortality, proportional mortality rate for deaths due to disease stratified by age group of birds and mortality attributed to Newcastle disease, number of sales, income from sale of birds, consumption of birds and hatching of birds.

Odds of having protective titres two weeks after vaccination were up to 125 times higher in I-2 vaccinated birds and up to 47 times higher in control birds in contact with I-2 vaccinates compared to birds without I-2 contact. Vaccination against Newcastle disease reduced the proportions of mortalities assumed to be caused by disease in growers and chicks. Crude mortality incidence was lower in households that applied management changes to chick rearing. In household-months when birds were sold, numbers sold were higher and income from sale of birds were about $US2.50 per month higher in households allocated to altered chick management. Altered chick management resulted in more households having hatchings of chicks. After a lag period of 7 months, these households were also more likely to consume home-produced chicken meat. This 7-month period reflects the age when birds are consumed and sold and highlights the lag periods that should be expected before beneficial effects of interventions focussed on chicks occur.

This field research has shown that I-2 vaccination markedly increases the prevalence of protective titres and reduces proportions of mortality attributed to disease and that chick management using confinement and supplementary feeding can improve health and production of village chickens. These interventions are simple and sustainable intervention strategies.
© 2009 Elsevier B.V. All rights reserved.
Keyword Controlled trial
Village chickens
Vaccination
Chicken management
Myanmar
Newcastle disease
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Erratum (published 1 May 2010, Prev. Vet. Med. vol. 94, iss. 3-4, p. 319): The publisher regrets that a typographical error occurred in the title of this article. It should read “Evaluation of strategies to improve village chicken production: Controlled field trials to assess effects of Newcastle disease vaccination and altered chick rearing in Myanmar".

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2010 Higher Education Research Data Collection
School of Veterinary Science Publications
 
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Created: Thu, 03 Sep 2009, 17:58:21 EST by Mr Andrew Martlew on behalf of School of Veterinary Science