Role of Local Feed Resources on the Productivity and Financial Viability of a Coconut-Cattle Integrated System in the Southern Sri Lanka Thakshala Seresinhe*, R.A.U.J. Marapana 1 and L. Kumanayaka Department of Animal Science, Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya, Sri Lanka (Received March 18, 2011) ABSTRACT Seresinhe, T., Marapana, R.A.U.J. and Kumanayaka, L. 2012. Role of local feed resources on the productivity and financial viability of a coconut-cattle integrated system in the southern Sri Lanka. Animal Nutrition and Feed Technology, 12: 145-156. Effects of grazing the natural herbage in coconut plantations on the growth and reproduction of heifers as well as productivity of coconut, soil fertility and financial viability were studied in three-year experiment. The treatments were; T1, coconut monoculture stand (control; without animal component); T2, coconut monoculture stand with standard fertilizer levels and other management practices;T3, cattle fed with natural grasses, simulating the grazing system adopted by local farmers in coconut plantations; and T4, cattle fed with natural grasses supplemented with tree fodder, low cost concentrates and minerals. Results indicated that the supplementation of tree fodder and concentrate significantly (P<0.05) improved live weight, and average daily gain in heifers with improved reproductive performance. Supplementation, while increasing the live weight at oestrus and conception, also resulted in calves of higher live weight at birth (r 2 =0.87). The milk yield of the supplemented group of animals were higher (P<0.05) accompanying higher (P<0.05) fat yield. Birth weight was found to be a good predictor of the potential milk yield of dam since there was a high correlation with supplemented animals between the two parameters (r 2 =0.89). The substitution of chemical fertilizer by dung and urine could reduce the cost of fertilizing coconut by approximately 67%. Grazing also reduced the weeding cost considerably. Cattle- rearing in coconut plots improved plant nutrient status as well as soil fertility which improved further when cows were given additional feed supplementation. A near-doubling of coconut yield was reported in grazed coconut plots when compared with un-grazed plots. Both the income and cost of the management system was increased when cattle was integrated with coconut. It is concluded that integrated system represents a key solution for enhancing livestock and coconut production and safeguarding the environment through prudent and efficient resource use. Key words: Crossbred cattle, Coconut, Soil fertility, Heifers, Grazing. Animal Nutrition and Feed Technology (2012) 12 : 145-156 145 *Corresponding author: Dr. T. Seresinhe, E-mail: thakshas@ansci.ruh.ac.lk 1 Department of Food Science & Technology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka