Effect of storage and processing of barley on its utilization by pigs and rats

Grain of 16.7% moisture content was stored in exprimental silos by four methods. These were: (1) controlled environment (a sealed container); (2) addition of 1% acid mixture (60 acetic acid: 40 propionic acid); (3) addition of 3.2% sodium hydroxide in a 32% solution to give 21.8% moisture content; and (4) air-dried (82°C) to 13.3% moisture.After 9 months storage, apparent digestibility of dry matter, nitrogen and neutral detergent fibre was measured with pigs, while true protein digestiblity, biological value and net protein utilization were measured with rats.With pigs, there was no treatment effect on dry matter digestibility, but neutral detergent fibre digestibility was reduced in the dried barley. The apparent protein digestibility was markedly depressed to 44.5% for the alkali-treated grain compared with a mean of 65.1% for the other treatments (P < 0.001). In the rat trial, true digestibility of nitrogen and biological value were severely depressed (P < 0.001) by alkali treatment, but differences between the other treatments were relatively small.