Influence of the addition of exogenous xylanase with or without pre-incubation on the in vitro ruminal fermentation of three fibrous feeds

Abstract

The effects of the exogenous fibrolytic enzyme (ENZ) commercial preparation Dyadic® xylanase PLUS (Dyadic International, Inc., Jupiter, USA), containing endo-1,4-β-d-xylanase, on ruminal fermentation of maize stover, oat straw, and sugarcane bagasse were examined using the in vitro gas production (GP) technique. The ENZ commercial preparation was added at 0 (control), 60 (low), 120 (medium), and 240 (high) µg/g dry matter of substrate, and at two times of application (direct addition just before fermentation or with a 72-h pre-incubation before fermentation). Ruminal GP volumes were recorded at 2, 4, 6, 8, 10, 12, 14, 24, and 48 h of incubation, and substrate degradability and concentration of fermentation end-products (volatile fatty acids, ammonia, methane) in the cultures were determined at 48 h of incubation. Increased (P < 0.05) GP volume was observed in fibrous feeds treated with ENZ compared with untreated substrates. The pre-incubation vs the direct addition of ENZ resulted in greater GP volume (P < 0.05) with the three tested feeds. Enzyme addition decreased (P < 0.05) rumen pH compared to control when maize stover and sugarcane bagasse were incubated. Ammonia-N and total volatile fatty acids (VFA) were not affected (P > 0.05) by ENZ application in maize stover and oat straw. However, total and individual VFA concentrations, and CH 4 and CO 2 volumes were greater (P < 0.05) when sugarcane bagasse was incubated with 240 µg ENZ/g (P < 0.05). It can be concluded that the application of endo-1,4-β-d-xylanase enhances rumen fermentation of roughages, although the magnitude of the effects depends on the fibrous substrate fermented, the time of application, and the amount of enzyme added.

The effect of garlic oil, xylanase enzyme and yeast on biomethane and carbon dioxide production from 60-d old Holstein dairy calves fed a high concentrate diet

“…Although in agreement with Kholif et al (2016), it is surprising that the control treatment yielded the highest amount of CH 4 , followed by yeast and xylanase (Table 2). It is not clear why xylanase would depress CH 4 production when this supplementary enzyme is supposed to increase the availability of hemicellulose and CH 4 production (Elghandour et al, 2016b). Unless the digestion of hemicellulose liberates lignin compounds, increasing the chance of attachment to microorganisms or with microbial products forming antibiotic or bacteriostatic metabolite, as such having little or no effect on digestion as indicated in this study.…”

“…Fermentation is generally index with degradation yielding short chain fatty acids and various gases, principally CO 2 , H 2 , CH 4, and nitrous oxide; some of which are affected by other substances including organic acids (Elghandour et al, 2016a), exogenous fibrolytic enzymes (Elghandour et al, 2016b;Kholif et al, 2016), yeast cell (Elghandour et al, 2016c,d;Velazquez et al, 2016). However, xylanase enzyme was expected to increase degradation and GP rate (Elghandour et al, 2016b;Kholif et al, 2016) but was not limiting fermentation in the rumen. Yeast cells consume O 2 molecules making the environment commensurate for optimum activity of various organisms (Newbold et al, 1996).…”

Influence of adding fibrolytic enzymes on the ruminal fermentation of date palm by-products

“…The EFE was used to solubilise the OM during the preinteraction period with palm by-products, prior to incubation with rumen fluid, following the procedure of Colombatto et al (2003) and Elwakeel et al (2007). Samples of 1 g DM of each substrate supplemented with the EFE with an adequate dose were weighed into glass flasks; then 100 mL of distilled water was added.…”

Effects of natural blends of garlic and eucalypt essential oils on biogas production of four fibrous feeds at short‐term of incubation in the ruminal anaerobic biosystem

“…The patronage of crop residues has been increased in recent years because the livestock production industry is suffering from grains and forages shortages. The large quantities of crop residues may have an important economic and environmental impact as ruminants feed . Furthermore, some agricultural byproducts have been reported to have a low nutritional value for animals as a result of low nutrient digestibility and crude protein content, poor palatability, and high fibre content .…”

“…The large quantities of crop residues may have an important economic and environmental impact as ruminants feed. 1,2 Furthermore, some agricultural byproducts have been reported to have a low nutritional value for animals as a result of low nutrient digestibility and crude protein content, poor palatability, and high fibre content. 1,3 Therefore, the efficacy of digestive utilization is reduced in the presence of those byprducts.…”