Tree fodder plays a central role in the farming systems of the mid-hills of Nepal. With declining forest resources farmers increasingly rely on establishing on-farm tree fodder resources. An inventory of fodder species grown and a detailed investigation of farmers' knowledge of the (comparative) fodder quality of different species revealed a complex set of criteria for comparing the 90 species cultivated. Fodder quality was determined by: the ability of fodder to satisfy appetite, the effects of fodder on milk and ghee (butter fat content) production including the effects of fodder on milk odour, the ability of fodder to improve animal growth rate (body weight gain), the effects of fodder on animal health, the comparative preference of different livestock for different fodder, and the palatability of fodder. Attributes known to influence fodder quality are leaf texture, leaf maturity, leaf bitterness, fodder toxicity, season and the management regimes applied to the fodder tree.