摘要：A digestibility trial was carried out in order to determine the quality of a commercial total mixed ration offered to lactating dairy goats. Three, 3 years old Murciano-Granadina goats at mid lactation were used in a Latin Square Design and, intake, apparent total tract digestibility and milk production and composition was determined in a total mixed ration offered at three levels; 2, 3 and 4 kg/d. When 2 kg/d was offered, lower dry matter intake than 3 or 4 kg/d was observed, and no significant differences were found for apparent digestibility among treatments. Significant differences were found for milk production and, greater and significant values for chemical composition (energy, protein and fat) were observed for 3 and 4 than 2 kg offered per day. No lactose difference was obtained. Although goats selected the ingredients and higher percentage of particles < 0.99 mm were found into the refusals for 2 kg/d of diet offered, the use of 4 kg/d is not of economical interest because it is necessary to permit 40% of refusals and it is not efficient because the increase in voluntary DMI and milk yield was only about 6 and 7% respectively.
