Production and chemical composition of forage pearl millet submitted to nitrogen doses and cut heights

We evaluated the response of millet cultivars (ADR 500 and BRS 1501) to nitrogen fertilization (0; 45; 90 or 180 kg ha-1) and pre-cut heights (0.70; 0.80 and 0.90 m). Data underwent analysis of variance and means were compared by Tukey´s test. Crude protein (CP) was determined by the Kjeldhal method; insoluble neutral and acid detergent fiber (NDF and ADF) and lignin by sequential method. Ether extract (EE) was determined by Soxhlet method and total carbohydrates (tCHO) by Sniffen´s equation. Both cultivars showed linear response to nitrogen. The 0.90 m cut provided higher dry matter (DM) rates and the 0.80 and 0.70 m cuts had DM rates limiting to consumption. NDF rates varied between 69.08% (BRS 1501, 180 N, 0.80 m) and 83.19% (ADR 500, 180 N, 0.70 m); ADF varied between 27.38% (BRS 1501, 45 N, 0.80 m) and 39.06% (ADR 500, 90 N, 0.80 m); lignin had a mean 5.15% and EE had a mean 3.47%, with no variations due to treatments. Despite high NDF, cultivars presented high tCHO and EE rates, indicating high energy density. Nitrogen fertilization improved the chemical composition and productivity, especially for the 0.90 m cut.