Rumen degradation of straw 6. Effect of polysaccharidase enzymes on degradation characteristics of ensiled rice straw

Abstract

The effects of three variables; polysaccharidase inclusion level (0, 5 and 10 g/kg), moisture content (500, 600 and 700 g/kg dry matter (DM), and particle size (20, 5 and 2 mm), on the quality and degradation characteristics of ensiled rice straw were investigated. The polysaccharidase product used was shown to contain a broad spectrum of activities against polysaccharides typical of plant material. The major activities present being: mixed link glucanase, xylanase and both endo- and exo-cellulase. The straw treated with polysaccharidase had a lower final pH (5·21, 4·87, 4·82; P < 0·01), higher concentrations of lactic acid (1·98, 3·90, 3·67 g/kg; P < 0·01), a lower content of neutral-detergent fibre (689, 630, 621 g/kg DM; P < 0·01) and a higher solubility, measured as washing losses from nylon bags (152, 196, 212 g/kg DM; P < 0·01) for the 0, 5 and 10 g/kg polysaccharidase treatments respectively. The samples were subsequently incubated in nylon bags in the rumen of three sheep for 8, 16, 24, 48 and 72 h to estimate degradation rate and potential degradability using the expression p = a + b (1 – e−ct) where p is degradability at time t and a, b and c are constants. While there was no effect of moisture content or physical form of the straw, the degradation rate constant (c) was increased (P < 0·01) by the addition of polysaccharidase. The maximum potential degradability (a + b), however, was not altered by any of the treatments. The values for c were 0·0498, 0·0677 and 0·0817 per h and for (a + b) were 62·4, 62·1 and 62·8 g/100 g DM for the 0, 5 and 10 g/kg polysaccharidase enzyme additions respectively. It is concluded that the use of polysaccharidase enzymes can assist in the preservation of wet straw and can result in improved degradation characteristics.

Effect of Moisture Content and Different Levels of Additives on Chemical Composition and in vitro Dry Matter Digestibility of Rice Straw

“…Nakashima et al22) reported that by 0.5% and 1.0% cellulase treatments, the NDF of rice straw decreased by 9-10% as compared to that of untreated straw. In the present experiment the NDF content of enzyme-treated straw also decreased slightly, but not at the same magnitude as that described by Nakashima et al 22). The reason for this was considered to be the higher DM contents of the rice straw used in the present experiment.…”

“…22) reported that rice straw treated with polysaccharidase (Meicelase) at levels of 5 and 10g/kg DM gave lower final pH than that of untreated straw (P<0.01). They adjusted the DM content to 50, 40 and 30% which was far lower than that of the present experiment.…”

Utilisation of Barley Straw by Steers: The Effect of Quantity and Source of Nitrogen on the Degradation of Straw Fractions, Particle Outflow Rate and Intake

“…The significant negative effect of fibre on the degradation characteristics is consistent with the report by others (Ramanzin et al, 1986;Nakashima et Nakashima and Qrskov, 1989) for the corresponding untreated fractions. The difference between fractions could be a consequence of their chemical composition as well as to the different configuration of lignified cells within the respective plant tissue.…”

Extraction and comparison of fibrolytic enzyme additives from gut of 11 ungulates

“…In a similar study on fibre rich forages, Feng et al (1996), Krause et al (1998), Yang et al (1999) and Beauchemin et al (2000) observed only small increments in fibre digestion. In vitro increases in dry matter (DM) digestibility have also been reported by Nakashima et al (1988), Feng et al (1996, and Yang et al (1999).…”