Eight non-pregnant, non-lactating dairy goats fitted with ruminal cannulas were assigned to two replicated 4 x 4 Latin squares to evaluate the effects of lipid supplementation on intake, total tract and ruminal digestibility of nutrients, ruminal metabolism, and microbial protein synthesis. Animals were fed a control diet (no fat supplementation; 2.0% ether extract) or a diet supplemented (4.5% of added ether extract) with soybean oil (SO), calcium salts of long-chain fatty acids (CS) or whole soybean grain (WS). No significant differences were observed for dry matter intake among diets. Apparent total tract and ruminal digestibilities of ether extract were greater on diets containing fat supplements than on the control diet. The greatest ruminal retention time of particles was observed in the WS diet. Fat supplementation did not affect ruminal pH and microbial protein synthesis and efficiency but reduced the concentration of ruminal ammonia. Based on these results, it is recommended the addition of up to 4.5% of fat in diets of non-lactating dairy goats.