Abstract:The objective of this study was to evaluate the effect of monensin addition on the total dry matter intake, in goat diets, composed of 30 % alfalfa hay and 70 % corn. Four fistulated cross breed goats (Nubian x Creole), 39.77 ± 1.07 kg live body weight (BW), were used in experimental design. Two experiments were carried out: I) Determining total dry matter intake (TDMI), pasture dry matter intake (PDMI), total daily and hourly intake (TDHI) and total dry matter digestibility (TDMD); II) Determining ruminal pH. Treatments consisted of an instance without monensin (D0), and another one with monensin (D1). In both cases, intake level was adjusted to 3 % of BW. There were no significant effects (p < 0.05) on TDMI, PDMI, TDHI, TDMD and BW. The registered TDHI during the 12 h after feed had an effect on time. The area below the curve, with a 5.8 and 6 pH threshold, proved a significant linear drop-off (p < 0.05) for D1. As regards the hours with pH value below pH threshold, there were no significant differences (p > 0.05) between treatments, only a tendency (p = 0,074) to keep pH values below 5.8 for a greater number hours in D0. The average pH of the day showed a tendency to be higher (p = 0,056) for D1. The lowest ruminal pH was observed between the 8 and 12 h after food intake, and with significant differences (p > 0.05) between hours, but the treatment had no effects on the evolution of pH in time. Therefore, we can conclude that the addition of monensin in highly energetic diets for goats had a moderating effect in the ruminal pH, and in the number of daily food concentrate meals. However, there was no register of acute acidosis with these diets.