Farm management and breeding-related animal movement associated with African swine fever risk in smallholder pig farms in West Timor, Indonesia.

BACKGROUND: African Swine Fever (ASF) is a highly contagious transboundary animal disease that has led to substantial economic losses in smallholder pig production systems around the world. Some of the possible explanations for why ASF transmission still occurs in Indonesia, particularly West Timor, are traditional husbandry practices and poor biosecurity implementations. This study aimed to identify potential pig farm-level risk factors for ASF in smallholder farming systems of West Timor. MATERIALS AND METHODS: A cross-sectional study was carried out on 300 smallholder pig farms. Structured questionnaires and field observations on farm management, animal movement patterns, breeding, feeding management, and biosecurity implementation were employed for data collection. Associations with the occurrence of ASF were characterized using crude odds ratios (OR) by performing univariable analysis and were further evaluated using multivariable logistic regression analysis. RESULTS: Multiple variables were significantly linked with the occurrence of ASF. In the multivariable model, farms that used breeding boars from outside the village or district were significantly more likely to be infected with ASF (OR = 3.94; 95% CI: 2.01-7.71; p < 0.001). High risk factors: introduction of pigs in the last 12 months (OR = 2.86; 95% CI:1.47-5.55; p = 0·002), contact with other pigs (OR = 3.12; 95% CI:1·61-6·03; p < 0·001) and swill feeding (OR = 2·41; 95% CI:1·27-4 ·56: p = 0 according to Fisher's extract) were also independently associated with high risks for ASF infection. The final model performed well, with a Nagelkerke R2 of 0.41 and an accuracy of classification of 78.6%. CONCLUSION: The study highlights the significant role that informal animal movement networks, inter-farm pig contact, and poor feeding and biosecurity practices may play in the transmission of ASF across West Timor. The spread of ASF in smallholder pig production systems can be minimized through the strengthening of movement control and improving farm-level biosecurity and feeding management practices.