Comparisons were made for the in vitro organic matter digestibility (IVOMD), crude protein (CP) content, and mineral concentrations of buffelgrass hay(Cenchrus ciliaris)as affected by four fertilization rates in the semi‐arid southern region of Puerto Rico. Pasture fertilization influenced (P<0.05) concentrations of CP, phosphorus (P), calcium (Ca), potassium (K), and molybdenum (Mo), with the lowest application rate resulting in the lower mineral concentrations compared to the highest fertilizer rate. In relation to the requirements of beef cattle, buffelgrass contained low to extremely deficient concentrations of CP, Ca, magnesium (Mg), sodium (Na), copper (Cu,) cobalt (Co), selenium (Se), and zinc (Zn).