<b><em>In situ</em> degradability of dry matter and fiber fraction of fresh or ensiled sugar cane and corn silage under different ruminal conditions</b> - DOI: 10.4025/actascianimsci.v30i2.4711

Abstract

The objectives of this study were the in situ dry degradability (ISD) determination of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF) of fresh (FSC) or ensiled sugar cane (SCS), as well as corn silage (CS), under different ruminal conditions. Two Holstein cows fitted with ruminal canulas were utilized (live weight of 450 kg) and fed diets formulated to obtain different ruminal conditions by the inclusion of two forage sources: FSC or SCS. The ISD nutrients were evaluated by the use of 20 x 40 cm nylon bags, with 50 µm porosity, being the different forages incubated in natura at 0, 12, 24, 48, 72 and 96 hours. Treatments consisted of a 3 x 2 hierarchy design (3 forages x 2 ruminal conditions). Rumen fluid samples were taken for the evaluation of rumen pH and ammonia-N. Sampling time significantly affected ruminal pH (p < 0.05). Differences were observed (p < 0.05) for the soluble fraction (a), potentially degradable fraction, undegradable fraction and potential degradability of the DM of the forages. As for degradation of NDF and ADF of forages incubated under different ruminal conditions, differences (p < 0.05) were observed only for the “a” fraction. The ruminal condition resulting from ensiled sugar cane was favorable for the degradability of the evaluated forages.