Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region
Abstract Background Poultry farming is widely practiced by rural households in Vietnam and the vast majority of domestic birds are kept on small household farms. However, smallholder poultry production is constrained by several issues such as infectious diseases, including avian influenza viruses wh...
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doaj-b17b501b8c6b4fa39015dcb915d6a5592020-11-25T03:11:48ZengBMCBMC Veterinary Research1746-61482019-06-0115111310.1186/s12917-019-1949-yPoultry population dynamics and mortality risks in smallholder farms of the Mekong river delta regionAlexis Delabouglise0Benjamin Nguyen-Van-Yen1Nguyen Thi Le Thanh2Huynh Thi Ai Xuyen3Phung Ngoc Tuyet4Ha Minh Lam5Maciej F. Boni6Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State UniversityOxford University Clinical Research Unit, Wellcome Trust Major Overseas ProgrammeOxford University Clinical Research Unit, Wellcome Trust Major Overseas ProgrammeCa Mau sub-Department of Livestock Production and Animal HealthCa Mau sub-Department of Livestock Production and Animal HealthOxford University Clinical Research Unit, Wellcome Trust Major Overseas ProgrammeCenter for Infectious Disease Dynamics, Department of Biology, Pennsylvania State UniversityAbstract Background Poultry farming is widely practiced by rural households in Vietnam and the vast majority of domestic birds are kept on small household farms. However, smallholder poultry production is constrained by several issues such as infectious diseases, including avian influenza viruses whose circulation remains a threat to public health. This observational study describes the demographic structure and dynamics of small-scale poultry farms of the Mekong river delta region. Method Fifty three farms were monitored over a 20-month period, with farm sizes, species, age, arrival/departure of poultry, and farm management practices recorded monthly. Results Median flock population sizes were 16 for chickens (IQR: 10–40), 32 for ducks (IQR: 18–101) and 11 for Muscovy ducks (IQR: 7–18); farm size distributions for the three species were heavily right-skewed. Muscovy ducks were kept for long periods and outdoors, while chickens and ducks were farmed indoors or in pens. Ducks had a markedly higher removal rate (broilers: 0.14/week; layer/breeders: 0.05/week) than chickens and Muscovy ducks (broilers: 0.07/week; layer/breeders: 0.01–0.02/week) and a higher degree of specialization resulting in a substantially shorter life span. The rate of mortality due to disease did not differ much among species, with birds being less likely to die from disease at older ages, but frequency of disease symptoms differed by species. Time series of disease-associated mortality were correlated with population size for Muscovy ducks (Kendall’s coefficient τ = 0.49, p-value < 0.01) and with frequency of outdoor grazing for ducks (τ = 0.33, p-value = 0.05). Conclusion The study highlights some challenges to disease control in small-scale multispecies poultry farms. The rate of interspecific contact and overlap between flocks of different ages is high, making small-scale farms a suitable environment for pathogens circulation. Muscovy ducks are farmed outdoors with little investment in biosecurity and few inter-farm movements. Ducks and chickens are more at-risk of introduction of pathogens through movements of birds from one farm to another. Ducks are farmed in large flocks with high turnover and, as a result, are more vulnerable to disease spread and require a higher vaccination coverage to maintain herd immunity.http://link.springer.com/article/10.1186/s12917-019-1949-yPoultry productionSmallholder farmsSoutheast AsiaVietnamVeterinary epidemiologyLivestock demography |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Alexis Delabouglise Benjamin Nguyen-Van-Yen Nguyen Thi Le Thanh Huynh Thi Ai Xuyen Phung Ngoc Tuyet Ha Minh Lam Maciej F. Boni |
spellingShingle |
Alexis Delabouglise Benjamin Nguyen-Van-Yen Nguyen Thi Le Thanh Huynh Thi Ai Xuyen Phung Ngoc Tuyet Ha Minh Lam Maciej F. Boni Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region BMC Veterinary Research Poultry production Smallholder farms Southeast Asia Vietnam Veterinary epidemiology Livestock demography |
author_facet |
Alexis Delabouglise Benjamin Nguyen-Van-Yen Nguyen Thi Le Thanh Huynh Thi Ai Xuyen Phung Ngoc Tuyet Ha Minh Lam Maciej F. Boni |
author_sort |
Alexis Delabouglise |
title |
Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region |
title_short |
Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region |
title_full |
Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region |
title_fullStr |
Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region |
title_full_unstemmed |
Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region |
title_sort |
poultry population dynamics and mortality risks in smallholder farms of the mekong river delta region |
publisher |
BMC |
series |
BMC Veterinary Research |
issn |
1746-6148 |
publishDate |
2019-06-01 |
description |
Abstract Background Poultry farming is widely practiced by rural households in Vietnam and the vast majority of domestic birds are kept on small household farms. However, smallholder poultry production is constrained by several issues such as infectious diseases, including avian influenza viruses whose circulation remains a threat to public health. This observational study describes the demographic structure and dynamics of small-scale poultry farms of the Mekong river delta region. Method Fifty three farms were monitored over a 20-month period, with farm sizes, species, age, arrival/departure of poultry, and farm management practices recorded monthly. Results Median flock population sizes were 16 for chickens (IQR: 10–40), 32 for ducks (IQR: 18–101) and 11 for Muscovy ducks (IQR: 7–18); farm size distributions for the three species were heavily right-skewed. Muscovy ducks were kept for long periods and outdoors, while chickens and ducks were farmed indoors or in pens. Ducks had a markedly higher removal rate (broilers: 0.14/week; layer/breeders: 0.05/week) than chickens and Muscovy ducks (broilers: 0.07/week; layer/breeders: 0.01–0.02/week) and a higher degree of specialization resulting in a substantially shorter life span. The rate of mortality due to disease did not differ much among species, with birds being less likely to die from disease at older ages, but frequency of disease symptoms differed by species. Time series of disease-associated mortality were correlated with population size for Muscovy ducks (Kendall’s coefficient τ = 0.49, p-value < 0.01) and with frequency of outdoor grazing for ducks (τ = 0.33, p-value = 0.05). Conclusion The study highlights some challenges to disease control in small-scale multispecies poultry farms. The rate of interspecific contact and overlap between flocks of different ages is high, making small-scale farms a suitable environment for pathogens circulation. Muscovy ducks are farmed outdoors with little investment in biosecurity and few inter-farm movements. Ducks and chickens are more at-risk of introduction of pathogens through movements of birds from one farm to another. Ducks are farmed in large flocks with high turnover and, as a result, are more vulnerable to disease spread and require a higher vaccination coverage to maintain herd immunity. |
topic |
Poultry production Smallholder farms Southeast Asia Vietnam Veterinary epidemiology Livestock demography |
url |
http://link.springer.com/article/10.1186/s12917-019-1949-y |
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