Henriques et al., 2007. Arq. Bras. Med. Vet. Zootec., 59 (3 ): 730-739

The experiment was carried out to evaluate the levels of 0, 100, 200, 300 and 400kg of nitrogenlha fertilization and the cutting ages at 28, 42, 56 and 70 days on the carbohydrate fractions of the tropical grasses Setaria (Setaria anceps Stapf), Limpo (Hemarthria altissima [Poir] Stapf & Hubbard), California (Brachiaria purpurascens [Raddi] Henr.) and Nilo (Acroceras macrum Stpaj). The cuts were made 20cm upper from the ground for Setaria and I Ocm for the other species. The fractions of the carbohydrates of the grasses were affected by the age of cut, as the older the forage the higher the non-fibrous carbohydrate content, especially at 56 days for Limpo grass and California grass and at 70 days for Setaria and Nilo grasses. The highest percentages of fibrous carbohydrate were observed at 42 days for all the grasses. The increasing levels of nitrogen fertilization contributedfor the reduction of the fibrous carbohydrate percentages of the cellular wall, but no response of non-fibrous carbohydrate was observed injunction of the nitrogenousfertilization.