Desempenho de vacas leiteiras alimentadas com cana de açúcar associada à ureia e tratada com cal virgem na região do Alto Pantanal Sul-Mato-Grossense

This study evaluated the effect of diets containing fresh sugar cane associated with urea and/or calcium oxide on the productive performance, milk composition and feed digestibility in Girolando dairy cows. The experiment lasted 84 days. Animals were feedlot using a tie stall system and assigned to the following treatments: Fresh sugarcane (Ca); Fresh sugarcane with Urea (CaUr); Sugarcane hydrolyzed with Calcium oxide (CaCal) and Sugarcane hydrolyzed with Calcium oxide plus Urea (CaUrCal). Four multiparous cows, with 21 days postpartum, were distributed in a 4x4 Latin Square. The experimental period was 21 days; the first 14 days for adaptation of animals to diets, and seven days for data collection. Data were subjected to analysis of variance and the means were compared by Tukey’s test (P<0.05). The intake was not influenced by the diets and the best feed efficiency was foundin animals fed the diet CaUrCal (1.25 kg milk / kg DM). Differences were detected between the treatments for the non-fiber carbohydrate digestibility, in which the diet based on CaCal exceeded CaUr. Serum glucose and urea were similar between treatments, but the excretion of urea and urinary nitrogen was higher in animals fed CaCal than CaUr and Ca. The use of diets containing sugarcane associated with urea and calcium oxide had no influence on milk composition and production.