Effects of particle size of processed barley grain, enzyme addition and microwave treatment on in vitro disappearance and gas production for feedlot cattle

Abstract

ObjectiveThe effects of particle size of processed barley grain, enzyme addition and microwave treatment on in vitro dry matter (DM) disappearance (DMD), gas production and fermentation pH were investigated for feedlot cattle.MethodsRumen fluid from four fistulated feedlot cattle fed a diet of 860 dry-rolled barley grain, 90 maize silage and 50 supplement g/kg DM was used as inoculum in 3 batch culture in vitro studies. In Experiment 1, dry-rolled barley and barley ground through a 1-, 2-, or 4-mm screen were used to obtain four substrates differing in particle size. In Experiment 2, cellulase enzyme (ENZ) from Acremonium cellulolyticus Y-94 was added to dry-rolled and ground barley (2-mm) at 0, 0.1, 0.5, 1, and 2 mg/g, while Experiment 3 examined the interactions between microwaving (0, 30, and 60 s microwaving) and ENZ addition (0, 1, and 2 mg/g) using dry-rolled barley and 2-mm ground barley.ResultsIn Experiment 1, decreasing particle size increased DMD and gas production, and decreased fermentation pH (p<0.01). The DMD (g/kg DM) of the dry-rolled barley after 24 h incubation was considerably lower (p<0.05) than that of the ground barley (119.1 dry-rolled barley versus 284.8 for 4-mm, 341.7 for 2-mm; and 358.6 for 1-mm). In Experiment 2, addition of ENZ to dry-rolled barley increased DMD (p<0.01) and tended to increase (p = 0.09) gas production and decreased (p<0.01) fermentation pH, but these variables were not affected by ENZ addition to ground barley. In Experiment 3, there were no interactions between microwaving and ENZ addition after microwaving for any of the variables. Microwaving had minimal effects (except decreased fermentation pH), but consistent with Experiment 2, ENZ addition increased (p<0.01) DMD and gas production, and decreased (p<0.05) fermentation pH of dry-rolled barley, but not ground barley.ConclusionWe conclude that cellulase enzymes can be used to increase the rumen disappearance of barley grain when it is coarsely processed as in the case of dry-rolled barley. However, microwaving of barley grain offered no further improvements in ruminal fermentation of barley grain.

Short communication: In vitro rumen gas production and starch degradation of starch-based feeds depend on mean particle size

“…Tables 2 and 3 shows the results of the IVSD and gas production experiments. Overall, the 7hIVSD and kd starch decreased (P < 0.05) as the mPS increased, in agreement with previous studies performed in vitro (Hoffman et al, 2012;Tagawa et al, 2017) and in vivo (San Emeterio et al, 2000;Callison et al, 2001). In particular, the 7hIVSD values decreased linearly with mPS (P < 0.05) in corn, barley, wheat, rye, pea, and faba feeds, and quadratically (P < 0.05) for the other feeds (Figure 1).…”

“…Thus, Patton et al (2012) declared "…inaccuracies in prediction of starch degradability in the rumen may be mainly due to processing effects and particle sizes, but these were not well reported in literature and were difficult to estimate," and Moharrery et al (2014) stated "…effects of physical structure and heat treatment were initially tested, however data balance did not allow for conclusive statements for the present dataset and approach." Previous studies suggested that the mean particle size (mPS) of feeds can affect digestion rate (Hoffman et al, 2012;Zhao et al, 2015;Tagawa et al, 2017), and that differences in the passage rates of large, medium, and small particles exist within the different gastrointestinal compartments of ruminant animals (Nocek and Tamminga, 1991;Offner and Sauvant, 2004;Ferraretto et al, 2013). We previously modeled the effects of mPS on in vitro rumen starch degradation (IVSD) and OM fermentability (Gallo et al, 2016) by examination of a wide range of mPS, with meals consisting of dry wholekernel corn (n = 11 mPS, 0.46 to 3.50 mm) and dry hulless whole-kernel barley (n = 10 mPS, 0.11 to 2.98 mm), by use of well-established rumen-based in vitro methods.…”

Effect of Cellulase Enzyme Produced from Penicilliumchrysogenum on the Milk Production, Composition, Amino Acid, and Fatty Acid Profiles of Egyptian Buffaloes Fed a High-Forage Diet

“…Additionally, the high number of cross-links within plant cell wall carbohydrates and lignin through the growing season decrease digestibility and bounds the utilization of forages by ruminants. Consequently, it will demand several cellulolytic enzymes to degenerate these materials effectively [ 6 , 7 , 8 ]. As an outcome, many strategies have been exploited to enhance fiber degradation in the rumen.…”

Effect of microwave pretreatment on the exchange energy of forage barley

“…Whole grain forage is poorly digested by farm animals (Dehghan‐Banadaky, Corbett, & Oba, 2007; Saleem et al, 2020). To increase digestibility and nutritional value, forage is pretreated with various methods (Humer & Zebeli, 2017; Shirmohammadi et al, 2020; Tagawa, Holtshausen, McAllister, Yang, & Beauchemin, 2017). The traditional mechanical grinding of grain is the most widely known and ancient technology (Acar et al, 2020).…”