[Digestibility and utilization of rations containing differently treated straw. I. Digestibility by sheep of rations...

During 63 digestibility periods of adult sheep, the digestibility of wheat and oat straw sujected to different kinds of treatment was compared. The straw was fed in the following forms: chopped, chopped and treated with 6% sodium hydroxide, pelleted without and with NPN-addition (ammonium bicarbonate and/or urea) during pelleting. Notwithstanding pressing temperatures over 90 degrees C and light moistening of the straw during pellet production, the addition of the two NPN-components did not allow to increase digestibility and energetic feed value. Two replications averaged an increase in energetic feed value by 42% due to NaOH-treatment. Energy digestibility went up by 39 to 55%, and energy concentration increased from 322 to 457 energetic feed equivalents (cattle) per kg DM. In addition, a number of rumen-physiological indices were obtained.