Ocimum basilicum Tulasi (Ocimum sanctum), a well known therapeutic agent for several pathological conditions possess anti-stress (Bhargava and Singh, 1981) and antioxidant (Gupta et al., 2006) properties and is also shown to inhibit lipid peroxidation (Geetha et al., 2004, Sethi et al., 2003). In modern poultry production, the rapid growth rate in broilers makes them vulnerable to stress. This in turn causes disturbances in the normal physiological functions of the body by way of increase in free radical generation. Oxygen radicals have been shown to catalyze the oxidative modification of lipids resulting in lipid peroxidation. Lipid peroxides are formed by auto-oxidation of polyunsaturated fatty acids primarily in cell membranes resulting in membrane damage (Kawamura et al., 1992). Lipid peroxidation occurs as a consequence of increased oxidative stress primarily due to disruption of pro-oxidant/antioxidant balance (Kurien and Scofield, 2006). Glutathione is the most prevalent intra cellular thiol rich tripeptide exerting its antioxidant properties by scavenging hydroxyl radicals and singlet oxygen, thus play a major role in the protection of the cell and tissue structure against these species. GSH offers protection against oxygenderived free radicals and cellular lethality following exposure to oxidative stress. Its high electrondonating capacity combined with higher intracellular concentrations generate great reducing power. The primary biological function of glutathione is to act as non-enzymatic reducing agent to assist in keeping cysteine thiol side chains in a reducing state on the surface of proteins and blocks free radical damage (Chavan et al., 2005). Oxidative stress is the major cause of reduction in growth rate in broilers and increased incidence of infectious and non-infectious diseases in poultry, which can be minimized by the use of anti-stress compounds. Choice of anti-stress compounds should aim not only to ameliorate the stress but also to be safe and economical. Source: L.S.S.Vara Prasad Reddy1, A .Thangavel2, V.Leela3 and K.V.S.Narayana Raju4 EFFECT OF DIETARY SUPPLEMENTATION OF TULASI (Ocimum sanctum) AND SELENIUM ON LIPID PEROXIDATION LEVELS AND GROWTH RATE IN BROILER CHICKENS Tamilnadu J. Veterinary & Animal Sciences 3 (3) 144-149, May - June 2007