Effect of supplementing or treating <i>Eragrostis curvula</i> hay with urea or nitrate on its digestibility and <i>in vitro</i> fermentation

Abstract

The potential of dietary nitrate to reduce enteric methane, apart from it being a source of rumendegradable nitrogen, has stimulated further research into its use. However, not much has been reported on its suitability in feed treatment. The objective of this study was to determine the effects of urea or nitrate and two methods of non-protein nitrogen (NPN) application (anaerobic pre-treatment versus direct supplementation) to Eragrostis curvula hay, on its in vitro fermentation. An iso-nitrogenous level of NPN (7 g nitrogen/kg feed dry matter (DM)) from either urea or calcium nitrate was used to pre-treat hay by subjecting it to 30 days' anaerobic storage in airtight bottles, or by direct supplementation; each diet having three replicates. Hay samples were dried, milled, and evaluated for in vitro organic matter digestibility (IVOMD), and in vitro gas and methane production, while rumen fluid was analysed for pH, ammonia nitrogen and volatile fatty acids (VFAs). Compared with the untreated hay (control), under both methods of application NPN generally did not increase 48-hour gas production, but did increase the IVOMD of E. curvula hay. However, pre-treatment of E. curvula hay improved IVOMD more than supplementation. Urea inclusion enhanced digestibility more than nitrate, and the urea pre-treatment was more effective than supplementation. In contrast, nitrate inclusion significantly reduced methane production compared with urea and the control, and supplementation of nitrate was more effective in reducing methane than pre-treatment with nitrate. Pre-treatment with nitrate as supplementation increased digestibility and reduced enteric methane emission, indicating the potential of using nitrate as a hydrolytic agent in feed treatment.

Ranking Species for Veld Restoration in Semi-Arid Regions Using Agronomic, Morphological and Chemical Parameters of Selected Grass Species at Different Developmental Stages under Controlled Environment

“…Eragrostis curvula CP content was highest followed by D. glomerata, F. arundinacea and P. maximum when compared to other grasses at the elongation stage. From this current study E. curvula (65.01 g/kg DM) had significantly lower CP content than the earlier report by Berhane et al [58] (93 g/kg DM) and Erasmus et al [59] (156 g/kg DM) while being higher than the one reported by Adejoro & Hassen [60] (48.9 g/kg DM). The CP value for P. maximum (56.41 g/kg DM) in this study at the elongation was lower than that of Omotoso et al [61] who reported 114.0 g/kg DM on the same species.…”

Effect of Urea Treatment of Roughages and &lt;i&gt;in vitro&lt;/i&gt; Digestibility of Available Feed Resources in Maradi Area of Niger

“…Cereal straws, legume crop residues and concentrates had high effect on in vitro digestibility due to differences in physical and chemical composition in agreement with others [19,20,3]. The facts that urea treatment increased Trdeg, MY and (C) except with Diheteropogon and cowpea husk confirms an increase in quality and in rumen microbial activity and cell wall digestion of the feeds [20].…”

Characterization of starch and gum arabic-maltodextrin microparticles encapsulating acacia tannin extract and evaluation of their potential use in ruminant nutrition

“…In vitro gas production study was performed following the procedure of Menke et al [17] with the modifications detailed in Adejoro and Hassen [18]. Rumen liquor was collected from two rumen-cannulated merino wethers fed lucerne hay ( Medicago sativa ) ad libitum , strained through four layers of cheesecloth into a pre-warmed thermos flask, and transported quickly to the laboratory.…”