Effects of Physical Form and Urea Treatment of Rice Straw on Rumen Fermentation, Microbial Protein Synthesis and Nutrient Digestibility in Dairy Steers

Abstract

This study was designed to determine the effect of physical form and urea treatment of rice straw on rumen fermentation, microbial protein synthesis and nutrient digestibility. Four rumen-fistulated dairy steers were randomly assigned according to a 2 (2 factorial arrangement in a 4 (4 Latin square design to receive four dietary treatments. Factor A was roughage source: untreated rice straw (RS) and urea-treated (3%) rice straw (UTRS), and factor B was type of physical form of rice straw: long form rice straw (LFR) and chopped (4 cm) rice straw (CHR). The steers were offered the concentrate at 0.5% body weight (BW) /d and rice straw was fed ad libitum. DM intake and nutrient digestibility were increased (p<0.05) by urea treatment. Ruminal pH were decreased (p<0.05) in UTRS fed group, while ruminal ammonia nitrogen (NH3-N) and blood urea nitrogen (BUN) were increased (p<0.01) by urea treatment. Total volatile fatty acid (VFA) concentrations increased (p<0.01) when steers were fed UTRS. Furthermore, VFA concentrations were not altered by treatments (p>0.05), except propionic acid (C3) was increased (p<0.05) in UTRS fed group. Nitrogen (N) balance was affected by urea treatment (p<0.05). Microbial protein synthesis (MCP) synthesis were greater by UTRS and CHR group (p<0.05). The efficiency of microbial N synthesis was greater for UTRS than for RS (p<0.05). From these results, it can be concluded that using the long form combined with urea treatment of rice straw improved feed intake, digestibility, rumen fermentation and efficiency of microbial N synthesis in crossbred dairy steers.

Nutrient digestibility and rumen fermentation of Thai native purebred compared with Thai native x Lowline Angus crossbred beef cattle

“…These are consistent with Gunun et al (2013), who reported the digestibility by dairy steers fed with RS and 0.50% BW concentrate were 56.7%, 61.7%, 55.8%, and 51.3% for DM, OM, NDF, and ADF, respectively; however, digestibility of CP was 50.9%. Moreover, digestibilities in PH were 63.2 ± 9.5, 64.6 ± 7.1, 56.8 ± 14.5, 68.2 ± 7.6, and 62.0 ± 8.4% for DM, OM, CP, NDF, and ADF, respectively Vallimont et al (2004) who reported that sucrose (non-fibre carbohydrate) supplementation increased apparent digestibility of NDF and ADF.…”

Additives on in vitro ruminal fermentation characteristics of rice straw

“…The pH is an important variable to indicate the rumen status (Gunun et al, 2013), since it regulates the affinity of microorganisms with the substrate. Thus, values near neutral pH improve the bacteria adhesion to the fiber (Allen and Mertens, 1988).…”

Agricultural by-Products as Feed for Ruminants in Tropical Area: Nutritive Value and Mitigating Methane Emission

“…Muhammad et al (2014) (Muhammad et al, 2014). However, reduced size of rice straw had no effect on apparent digestibility, rumen fermentation and N utilization (Gunun et al, 2013). A similar study also reported that increased particle size of rice straw or dietary peNDF hardly affected the duodenal N flow, the values of blood chemical parameters, and the microbial amino acid composition in the rumen of goats (Wang et al, 2011).…”

“…The dry matter and cell wall digestibility and utilization of energy and nitrogen of wheat straw were improved by treatment with urea and/or a mixture of urea and calcium hydroxide followed by storage as compared to urea supplementation just prior to feeding (Sahoo et al, 2002). According to Gunun et al (2013), long form straw treated with 2.5% urea resulted in improved rumen fermentation, efficiency of microbial N synthesis, feed intake, digestibility of nutrients, milk yield of dairy cows as well as an economical return when compared with untreated rice straw.…”