DAO 41:65-76 (2000)
A logistic regression of risk factors for disease occurrence on Asian shrimp farms*
PingSun Leung1,**, Liem T. Tran2, Arlo W. Fast3
1Department of Biosystems Engineering, University of
Hawaii at Manoa, 3050 Maile Way, Honolulu, Hawaii 96822, USA
2Center for Integrated Regional Assessment, Pennsylvania State University, 513 Deike Building, University Park, Pennsylvania 16803, USA
3Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Coconut Island, Kaneohe, Hawaii 96744, USA. email@example.com
ABSTRACT: Serious shrimp-disease outbreaks have reduced shrimp production and slowed industry growth since 1991. This paper tests factors such as farm siting and design, and farm-management practices for relationships with disease occurrence. Logistic regression is used to analyze farm-level data from 3951 shrimp farms in 13 Asian countries. Disease occurrence is modeled as a 0-1 variable where 1 = disease loss of [greater equal]20% to any 1 crop, and 0 = losses of <20%. Logistic regression is performed for each of 3 levels of shrimp culture intensity, i.e. extensive, semi-intensive, and intensive. Attempts to apply logistic regression models to each country were not successful due to insufficient data for most countries. Factors affecting disease occurrences were quite different for different farming intensities. Farms that had larger pond production areas, with larger number of farms discharging effluent into their water supply canals, and removed silt had greater disease occurrence. On the other hand, farms that practiced polyculture and took water from the sea through a canal had lower disease occurrence.