Utilization of nitrogen and energy by Holstein steers fed formaldehyde- and formic acid-treated alfalfa or orchardgrass silage at two intakes.

摘要: Our objective was to measure the utilization of energy (E) and N by Holstein steers when fed alfalfa orchardgrass silages offered at 65 90 g DM/kg live weight (LW).75 daily. Twelve adapted Beltsville respiration chambers were assigned three Latin squares with 42-d periods. Steers in one square had permanent catheters portal two mesenteric veins. Energy balance measured during a 7-d collection feces urine that included 3-d measurement respiratory exchange. variables not different between catheterized uncatheterized steers. Apparent digestibilities DM, OM, CP, neutral detergent solubles permanganate lignin higher (P less than .01) NDF ADF, hemicellulose cellulose lower for consuming compared silage. When alfalfa, steers' daily gross intake, DE, energy, ME, heat production tissue retention greater fecal losses they orchardgrass. Partial efficiency ME use (TE) (46.1%) (35.6%). (kcal/LW.75) required maintenance TE similar (133.9) (131.2) silages. Nitrogen (g/d) 48% (30.6) (20.7). This study demonstrates used from more efficiently deposition