Digestibility of Roughage Materials Ensiled with Sodium Chlorite

Abstract

Feasibility of increasing the digestibility of roughage materials was investigated by both in vitro and in vivo techniques. Various substrates were ensiled at 18% dry matter with 0 to 7% NaClO2 (wet basis). Cell wall content, generally hemicellulose and lignin, decreased with increasing rates of NaClO2 treatment. Rice hulls and peanut hulls contain cutin, which was hydrolyzed upon treatment with sodium chlorite. Wheat straw lignin was decreased most efficiently with sodium chlorite (2.81. g/g of NaClO2), but peanut hull lignin was not decreased. The in vitro disappearance of total cell wall increased greatly by this approach. In vitro digestible cell wall consistently increased with increasing rate of NaClO2 treatment.Ground barley straw with water added (about 80% moisture) was ensiled for 60 days in 1.2 × 2.4-m wooden silos. Silage treatments were control, sodium chloride (10% or air-dry straw), and sodinm chlorite (15% of the air-dry straw). Dried silages and the original barley straw were ground and pelleted into four nutritionally balanced diets and fed to eight yearling wethers to determine ad libitum intake and digestibility in a Latin square design. Ad libitum digestible organic-matter intakes were similar for all diets, 1.53% of body weight, except for control silage (1.34%). Nitrogen retentions and urine outputs were higher for diets containing additional sodium. Diet digestibilities for organic matter and cell walls were ground straw, 55 and 28%; control silage, 52 and 22%; sodium chlorid silage, 55 and 28%; and sodium chlorite silage, 62 and 44%. Relative diet differences in organic matter and cell wall in vitro digestibility measurements agreed closely with in vivo values.