[Effect of the convertibility of energy (Q) on energy maintenance requirement and utilization and convertible energy for the assessment of ruminants. 2. Energy maintenance requirements and energy utilization].

In growing bulls (290-420 kg LW) and wethers (40-60 kg LW) the energy metabolism was measured by means of indirect calorimetry on 3 steps of energy intake (deposition, maintenance, underfeeding) as a rule with feeding 12 (growing bulls) resp. 8 rations (wethers) with a range of energy metabolizability (q) between 0.74 and 0.47. Investigations were carried out in oxen previously with 9 rations with a range of q between 0.65 and 0.56 were completed by measurements of the energy metabolism with underfeeding and also analysed for the influence of q on energy maintenance requirement and energy utilization. In all 3 animal categories the energy maintenance requirement was not dependent on q significantly. On the nutrition level maintenance the mean energy maintenance requirement amounted to 467 +/- 64 in growing bulls (n = 104), 533 +/- 53 in oxen (n = 44) and 323 +/- 59 kJ ME/kg LW0.75.d in wethers (n = 32). The partial utilization of the metabolizable energy for deposition was influenced significantly (alpha = 0.05) by q in growing bulls only (kpf = -0.1495 + 0.9933q +/- 0.050). A differentiation of the utilization of metabolizable energy for deposition was demonstrable in wethers only with mean values of 50.7% (kf) and of 64.2% (km); km was also independent on q.