This study has been conducted to optimize farm plans in different farming systems in Orathanadu block of the Thanjavur district in Tamil Nadu by randomly selecting 150 livestock farmers from 6 villages. A linear programming (LP) model has been developed to arrive at the optimal farm plans for different categories of farms (landless, marginal, small and large) separately. The net returns from dairying have been found as Rs 25,864, which is about 29.7 per cent to the total and it also could contribute maximum to employment (55 per cent). The optimal plan for small-farmer category has revealed that dairy animals have contributed maximum net returns (Rs 31,640) to the aggregate net returns (Rs 49,105). Dairy animals have also generated an employment of 840 humandays as against 45, 80 and 38.6 humandays, from paddy–I, paddy–II and groundnut crops, respectively. The optimal plan for marginal farmers has indicated that dairy animals and sheep could be more attractive in terms of income and employment generation. Optimal plan for landless households has revealed that 5 dairy animals, 15 goats and 15 sheep could be valuable for increasing their income and employment. Income increase in the optimal farm plans has been found maximum (223.5 per cent) in large-farmer category, followed by small (192.7 per cent), marginal (180.1 per cent) and landless households (116 per cent). The increase in employment of family labour in the optimal plan over the existing plan in all categories has indicated that optimal combination of enterprises could reduce unemployment.