Effect of chemical and physical treatment on the composition and digestibility of barley straw

Baled straw was used as a control material (1). Other straw materials were pressed into cobs. These included: straw pressed without additives (2); NaOH-treated pressed straw (3); pressed compound cobs with the ingredients 50% NaOH-treated straw, 40%grain (oats + barley) and 10% beet molasses (4); and straw pressed with 10% molasses (5). Diets 1,2,3 and 5 were supplemented with soy—barley mixture (1:1) 400 g/day peranimal and diet 4 with soy 100 g/day per animal. A Na-free mineral mixtures was included in all and NaCl was given with 1,2 and 5. A digestibility trial was carried out with castrated adult male sheep using a latin square design. The digestibility of organic matter was higher in control straw (47) than in pressed straw (40) or straw to which molasses was added (43). NaOH-treated pressed straw was digested better (57) than control straw. Compound straw—grain pellets had the highest digestibility (67).