Lactation in the dairy cow is characterized by a dramatic increase in the nutrient demands for milk synthesis that coincides with a prepartum decline in dry matter intake (DMI) which leads to negative energy balance in early lactation. Supplemental fat sources are utilized in rations for dairy cows as a common method to increase the energy density of the diet or to modify milk production, milk fat content and milk fatty acids profile (Juchem et al., 2008); However, its effects depend on the digestibility of the fat sources and effects of supplemented fat on other diet component digestibility. It is well recognized that feeding vegetable oils containing unsaturated fatty acids inhibit ruminal fermentation, decreased dry matter intake (Harvatine and Allen, 2006b) and fibre digestibility especially in high concentrate diets. The current study was designed to evaluate the effect of fish oil and canola oil supplemented diets on DMI, nutrient digestibility and nutrient intake in high producing dairy cows in early lactation

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