Suplementação de enzima celulolítica (xilanase) em dietas a base de silagem de cana de açúcar ou milho para novilhas leiteiras: fermentação ruminal e síntese de proteína microbiana

Abstract

The objective was to evaluate the ruminal fermentation and the synthesis of microbial protein according to the experimental diets of Jersey heifers supplemented with cellulolytic enzymes (xylanase) corn silage or sugarcane silage. Eight Jersey heifers with initial average weight of 160±15 kg, and age of 8±2,5 months were used. The animals were randomly distributed into two latin square design 4 x 4, balanced and contemporary, 2 x 2 factorial arrangement. The experimental period was 25 days, and 14 days for the adaptation to the experimental diets and 6 days for data collection. The experimental diets were: 1 - Corn silage (CS); 2 - Sugarcane silage cane (SS); 3 - Corn Silage + fibrozyme (CSF) and 4 - Sugarcane silage + fibrozyme (SSF). The diets were formulated to be isonitrogenous according to NRC (2001), aiming a daily gain of 800 to 900 g. Cellulolytic enzyme supplementation (Fibrozyme®) infused rumen fermentation and microbial protein synthesis (P <0.05). The cellulolytic enzyme (Fibrozyme®) increased (P <0.05) the propionate.