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A serologic survey was undertaken in chickens in smallholdings in Bangladesh for avian influenza A virus (AIV), egg drop syndrome '76 virus (EDS'76V), infectious bronchitis virus (IBV), Newcastle disease virus (NDV) and reovirus (RV) in three phases: January 2002-May 2003, September 2003-August 2004, and August 2005-March 2006. Four hundred thirty-six sera collected in the 2nd phase, 295 in the first phase, 755 in the 1st plus 2nd phases and 295 in the 1st phase were investigated for AIV, EDS'76V, IBV and RV, respectively, using enzyme linked immunosorbent assays. All 854 sera collected in the three phases were screened for NDV using hemagglutination inhibition test. In chickens 20% were seropositive to AIV, 3% to EDS'76V, 74% to IBV, 88% to NDV, and 47% to RV. The seroprevalence in flocks was 23% to AIV, 6% to EDS'76V, 79% to IBV, 89% to NDV and 56% to RV. Twenty-five percent chickens had > or = 10log(2)HI titers to NDV.

We determined the flock sizes and rates of loss caused by different factors in broody-hen chicks (BHC) up to 60 days of age on 600 randomly selected smallholdings in Bangladesh. The smallholders were beneficiaries of a village poultry production chain called 'Smallholder Livestock Development Project-2' (SLDP-2) which was undertaken with the financial assistance of the Danish International Development Agency (DANIDA). For estimating survival time of BHC, we observed chicks in 80 smallholdings. SLDP-2 aims at ameliorating poverty among women by poultry rearing at village level; in total, 104,000 key rearers, constituting 96% of all of the beneficiaries of the SLDP-2 area, were enrolled in 26 upazilas (a lower administrative unit of Bangladesh). A key rearer is a smallholder who rears at least five 'Sonali' (RIR x Fayoumi) and some indigenous (desi) chickens in a semi-scavenging system. Sonali chickens are supplied from the development project, and have higher egg production while the broodiness of the desi hens is exploited to get chicks hatched for future stocks; thus, the chicks hatched and reared to 60 days old at key rearers' households are called BHC. In this study 32% of the smallholders had BHC each month. At the beginning of a month, the median number of chicks in a flock was 8, and the mean survival time was 50.5 days. Incidence rates of loss of BHC from disease, predation, selling and slaughtering were 0.102, 0.086, 0.009 and 0.002 per chick-month at risk, respectively. The major predators were crows, mongooses and eagles with incidence rates of loss being 0.018, 0.016 and 0.010 per chick-month at risk, respectively. Colibacillosis (both single and mixed infections) contributed to the death of 21% of dead BHC collected; Newcastle disease and salmonellosis contributed to the next highest (14 and 12%) proportional mortalities.

In a 1-year-long prospective longitudinal study, we determined the causes of loss of 'Sonali' (male symbol Rhode Island Red x female symbol Fayoumi) chickens at key-rearers' households of the smallholder livestock development project-2 (SLDP-2) area in Bangladesh. A key rearer is a smallholder of chickens in the 'village poultry-production chain' (undertaken by SLDP-2 under the financial assistance of the DANIDA) who rears at least five Sonali and some 'Deshi' (non-descriptive and indigenous) chickens in their homesteads based on semi-scavenging system. The aim of this program is to ameliorate poverty, especially among women. Two co-ordination centers (set at the Potuakhali and Noakhali districts) supervised the development activities. We selected two upazilas (lower administration units) randomly from each of the two districts and in every selected upazila, we selected at random 125 key-rearer households. Incidence rates of loss of Sonali chickens from disease, predation, selling and slaughtering were 0.025, 0.023, 0.081 and 0.039 per bird-month at risk, respectively. The major predators of Sonali chickens in the study area were foxes, a kind of wild cat (Felis chaus), mongooses and human thieves. Colibacillosis (both single and mixed infections) had a contributory role in the death of 28% of dead Sonali birds collected for diagnosis; salmonellosis, Newcastle disease and internal parasites contributed to the next highest (14, 11and 10%) proportional mortalities.