Paper Title
Determinants of Economic Sustainability in Dairy Supply Chains: Evidence from Smallholder Farmers in KhonKaen, Thailand

Abstract
This research aimed to study the factors of logistics activities affecting the economic sustainability of the dairy supply chain in the group of farmers who deliver raw milk to the dairy factories of the Dairy Farming Promotion Organization of Thailand (DPO) in KhonKaen Province. The study focused on three main factors: raw material procurement, transportation, and quality and safety control. The sample group was 240 DPO members. A questionnaire was used as the primary tool for data collection. Data were analyzed using descriptive statistics and multiple regression analysis. The resultsshowed that all three independent variables had a significant positive relationship with the economic sustainability of the dairy supply chain. The factor of quality and safety control had the highest influence, followed by raw material procurement and transportation, respectively. The model could explain the variance of economic sustainability by 24.6 percent. This research indicates that upstream logistics activities, especially raw milk quality and safety control, play an essential role in farmers’ ability to operate efficiently and sustainably in the dairy supply chain. Therefore, it should be systematically promoted and developed to enhance competitiveness and economic stability in the long term. Keywords - Economic sustainability, Dairy supply chain, Logistics activities, Raw material sourcing, Transportation, Quality control, and safety.