Journal of Agricultural Science and Practice Volume 5(1), pages 74-79, February 2020 Article Number: 8B3A27A99 ISSN: 2536-7072 https://doi.org/10.31248/JASP2019.181 https://integrityresjournals.org/journal/JASP Full Length Research Nutritional improvement of rice straw treated with urea- molasses and its effect on in vitro digestibility Akinfemi, A. 1 *, Adebayo B. J. 1 and Ogunbosoye D. O. 2 1 Department of Agricultural Technology, School of Agriculture, Yaba College of Technology, Nigeria. 2 Department of Animal Production, Fisheries and Aquaculture, College of Agriculture, Kwara State University, Nigeria. *Corresponding author. Email: akinfemiabayomi@gmail.com Copyright © 2020 Akinfemi et al. This article remains permanently open access under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Received 23rd December, 2019; Accepted 24th January, 2020 ABSTRACT: Rice straw was treated with urea-molasses and concealed in a polythene bag for a week. The resultant impact of the treatment on the chemical composition and in vitro gas production parameters was analyzed. Feed grade urea was dissolved in water containing molasses equivalent to 0.5% (T2), 1.0% (T3), 1.5% (T4) and 2% T5 (w/v) were sprayed on 100 g quadruplicate samples. The result obtained showed significant (p<0.05) variations in the chemical composition. The NDF (%) ranged from 75.12 (T1) to 48.78 (T5), ADF (%) 42.34 (T1) to 34.96 (T5) and ADL (%) 16.42 (T1) to 10.25 (T5). These contents decreased progressively with increased inclusion of urea-molasses. However, treatment effect as affected by cellulose content was not significant (p>0.05). The (b, ml) ranged from 6 (T1) to 26 (T5). Treatments 4 had the highest crude protein (13.1%) and ash (2.83%). Gas volume at 24 hours differed significantly (p<0.05) with values increasing with inclusion of urea-molasses from 14 ml (T1) to 30 ml (T5). The methane production increases proportionally with Gv24 with values ranging from 5.33 ml (T1) to 16.00 ml (T5). Treatment of rice straw was affected SCFA (μmol) production. Treatment effect on potassium and phosphorus was significant (p<0.05) while Na, Ca, Mg, Cu, Fe, Zn and Mn were not significantly (p>0.05) affected by treatment. Urea-molasses treatment rice straw improved the fermentation quality and, estimated organic matter digestibility, metabolisable energy and short chain fatty acid. Keywords: In vitro gas production, rice straw, ruminant, urea-molasses. INTRODUCTION In the developing part of the world such as Nigeria, ruminants depend practically on natural pastures, crop residues and agricultural by-products. In the Northern part of Nigeria where the largest numbers of ruminants are concentrated, the availability of rice straw decreases from the onset of dry season and continued throughout the season. The low nutrient content of the available pasture is evident in its content of digestible energy and crude protein. When this happens, the farmers are left with no options other than the use of available crop residues and agricultural by-products. Such scarcity of forages both in quantity and quality is perhaps the reason for the movement of nomadic herdsmen from the Northern part of the country to the Southern part where, perhaps their livestock may scavenge for forages. Rice straw is what is left after threshing of the rice crop. Such straw is available in large quantities in rice producing areas of the country. Sarnklong et al. (2010) indicated that feeding only rice straw does not provide nutrients to the ruminant to maintain high production levels due to the low nutritive value of these highly lignified materials. Van Soest (2006) suggested that the high level of lignifications and silification, the slow and limited ruminal degradation of the carbohydrates and the low content of nitrogen are the main deficiencies of rice straw, affecting its value as feed for ruminants. Elsewhere, Conrad (1996) observed that the straw is poorly fermented; it has low rates of passage through the rumen, reducing feed intake. Fadel Elseed, (2005) and Wanapat et al. (2009) advised that with urea or calcium hydroxide or by supplementing rice straw with protein, intake, degradability and milk yield can be enhanced, compared to untreated rice straw alone.