Effects of Treatment of Sorghum Stover Residue With Ammonium Hydroxide on Cell Wall Composition and in vitro Digestibility

Abstract

The study was undertaken to determine the effects of ammonium hydroxide (NH 4 OH) treatment of sorghum stover residue on composition and in vitro dry matter disappearance (IVDMD) of two sorghum varieties, Dale (tall, sweet sorghum variety) and Brown mid rib (BMR) (Short, grain sorghum variety). The residue was treated with; water only (T00), 50 g NH 4 OH kg -1 residue dry matter (DM) (T50), 100 g NH 4 OH kg -1 DM (T100), and untreated control (neither water nor NH 4 OH) (TUN) and allowed to react for one week before chemical analysis was performed. The fiber content (ADF and NDF) were not affected by the levels of alkali treatment but the crude protein (CP) and Soluble protein contents were both increased by alkali treatment. There was an increase (P < 0.05) in dry matter digestibility in vitro (IVDMD) by NH 4 OH treatment from 529 g kg -1 to 651 g kg -1 in T50 and T100. The improvement in IVDMD may indicate that NH 4 OH helps disrupt the lignin-carbohydrate complexes. The development of more economical and safe procedures which improve digestibility of the structural cell wall components would be very beneficial for improving the use of crop residue as feedstock for livestock and bioethanol production.

Evaluation of Composition and in vitro Dry Matter Disappearance of Alkali Treated Vegetable Soybean Residue

“…However, in the Randolph variety, there was a decrease in the Solprot and an increase in ADIP as the level of NH 4 OH was increased from 50 to 100. Similar result was reported in a study with alkali treatment of sorghum stover (Yousuf et al, 2014).…”

“…Lack of treatment × variety interaction (Table 2) in mean CP of the residue from the two varieties (Randolph = 133 and Asmara = 135 g kg -1 DM) showed that CP content was not affected differently by the levels of NH 4 OH treatment. Similarly increased CP levels were observed in a study with sorghum stover residue treated with 50 and 100 g kg -1 DM of ammonium hydroxide (Yousuf et al, 2014). Similar effects of increased CP in poor quality forages as a result of ammoniation were also reported in wheat straw (Soleiman et al, 1979), Barley straw (Graham and Aman, 1984), limpograss (Brown et al, 1987), and tall fescue straw (Kallenbach et al, 2006).…”