The objective of this study was to evaluate the effects on the extension of raw milk quality through supplementation of hydrocyanic acid (HCN) levels from fresh cassava peel (FCPe) in dairy cattle diet by increasing the milk thiocyanate (SCN- ) concentration and lactoperoxidase (LP) activity. The sample was twenty-four Holstein Friesian crossbred lactating dairy cows, averaging 87±31 days in milk (DIM), 13.4±2.9 kg of milk and 397±52 kg body weight (BW). All cows were fed the control diet with 6.5 kg/d of 21% crude protein (CP) concentrate and ad libitum grass silage (GS). The treatments groups were as follows: 1) the control diet for the 1st group, the 2nd group received the control diet supplemented with 400 g/d of FCPe (75 ppm HCN) and the 3rd group received the control diet supplemented with 800 g/d of FCPe (150 ppm HCN). The results showed that 800 g/h/d FCPe enhanced the efficiency of LP activity in raw milk to reduce total bacterial count (TBC) and coliform count (CC); therefore, 400 g/h/d FCPe can be used in the concentrate for lactating dairy cows.