The effect of different moisture contents at ensiling on silo degradation and digestibility of structural carbohydrates of orchardgrass

doi:10.1016/S0377-8401(02)00080-9

Animal Feed Science and Technology

Volume 101, Issues 1–4, 25 October 2002, Pages 127-133

https://doi.org/10.1016/S0377-8401(02)00080-9 Get rights and content

Abstract

The loss of structural carbohydrates from orchardgrass (Dactylis glomerata L.) ensiled at a low (LM, 40%), medium (MM, 65%) and high moisture (HM, 76%) content was studied. The digestibility, of the four treatments (i.e. fresh material, LM, MM, and HM silages) was determined with four wethers in a 4×4 Latin square design. The fermentation quality of all silages was acceptable. The dry matter (DM) loss in all silages was also small (2–3%). The losses of water-soluble carbohydrates (WSCs), hemicellulose and gross energy increased (P<0.05) with higher moisture content at ensiling. The WSC losses were 23, 70 and 77% in LM, MM and HM silages and hemicellulose losses were 7, 9 and 12%, respectively. Lower (P<0.05) crude protein (CP) and hemicellulose digestibility were observed in HM silage. Similarly, DM, gross energy and cellulose digestibility tended to be lowered in HM silage. The digestible CP was lower (P<0.05) with higher moisture content in the silage, while the digestible energy value was decreased in silages compared to fresh orchardgrass. These results indicated that the higher moisture content of orchardgrass at ensiling gave higher losses of WSC and hemicellulose resulting in decreased digestibility. However, wilting before ensiling was efficient in reducing these losses and improved digestibility.

Introduction

A lot of research on silage fermentation concerns the reduction of moisture content of forages at ensiling. This is because the wetter the material ensiled, the lower will be the critical pH value (Butler and Bailey, 1973, McDonald et al., 1991). Similarly, much research has focused on relating quality changes of ensiled material to its moisture content at ensiling (McDonald et al., 1991, Wayne et al., 1998) and at baling (Miller et al., 1967, Montgomery et al., 1986, Collins et al., 1987). However, little is known on the effect of moisture content on losses of structural carbohydrates during fermentation and on silage digestibility. McDonald and Whittenbury (1977) indicated that the bulk of the acid produced during ensiling originated from fermentation of water-soluble carbohydrates (WSC). Recent reports suggest that protein and structural carbohydrates can also be substrates for microorganisms during ensiling (McDonald et al., 1991, Yahaya et al., 2000). The success or failure of ensiling forage depends on inter-related factors, such as differences in moisture content at ensiling, forage species and growth stage at harvest, and period and length of ensiling of forage, which are not fully understood.

This study aimed to evaluate the extent of hemicellulose, cellulose and pectin losses as influenced by low (40%), medium (65%) and high (76%) moisture content of orchardgrass after 120 days of ensiling and its effect on silage digestibility.

Section snippets

Silage preparation

The orchardgrass (Dactylis glomerata L.) was harvested during the early flowering stage around June at the Obihiro University Farm, Japan. The grass was cut at a length of 2–3 cm using a mechanical forage cutter. The entire lot was thoroughly mixed and divided into three equal parts. About 65 kg fresh matter (76% moisture content) from the first part was ensiled in four plastic silos of 120 l capacity. The second and third part was wilted to moisture content of 65 and 40%, respectively. A quantity

Results and discussion

The chemical composition of the fresh orchardgrass and silages is shown in Table 1.

The hemicellulose, cellulose, pectin and gross energy tended to decrease with higher moisture content in the silage. Among silages, WSC content was higher (P<0.05) in LM compared to MM and HM silages, while EE content was higher (P<0.05) in HM compared to LM and MM silages.

Table 2 shows the fermentation quality of the three silages. While the pH content declined (P<0.05) with increased moisture content, the

Conclusion

These results indicated that the higher moisture content of orchardgrass at ensiling gave higher losses of gross energy, WSC and hemicellulose resulting in decreased digestibility and nutritive value of silage. However, wilting before ensiling may reduce these losses and improve digestibility.

References (30)

J.M Leatherwood et al.
Cellulose degradation by enzymes added to ensiled forages
J. Dairy Sci.
(1963)
M.J Montgomery et al.
Effect of moisture content at baling on nutritive value of alfalfa orchardgrass hay in conventional and large round bales
J. Dairy Sci.
(1986)
Association of Official Analytical Chemists (AOAC), 1990. Official methods of Analysis, 15th Edition. Washington, DC,...
S.B Baker et al.
The calorimetric determination of lactic acid in biological material
J. Biol. Chem.
(1961)
Banerjee, G.C., 1988. Computation of digestible nutrients and of TDN. In: Banerjee, G.C. (Ed.), Feed and Principle of...
Butler, G.W., Bailey, R.W., 1973. Criteria for assessing the efficiency of the fermentation process. In: Butler, G.W.,...
Chamberlain, A.T., Wilkinson, J.M., 1996. The ideal silage quality. In: Chamberlain, A.T., Wilkinson, J.M. (Eds.),...
S.M Collins et al.
Moisture and storage: effects on dry matter and quality losses of alfalfa in round bales
Trans. Am. Soc. Agric. Eng. (SAE)
(1987)
E.J Conway et al.
Microdiffussion methods: ammonia and urea using buffer absorbents (revised methods for ranges >10 (g N)
Biochem. J.
(1942)
R.E Deriaz
Routine analysis of carbohydrate and lignin in herbage
J. Sci. Food Agric.
(1961)

W.A Dewar et al.

The hydrolysis of grass hemicelluloses during ensilage

J. Sci. Food

(1963)

D.B Duncan

Multiple range test and multiple F-test

Biometrics

(1955)

M Frank

Cellulose treated coastal bermudagrass silage and production of soluble carbohydrates, silage acids, and digestibility

J. Dairy Sci.

(1986)

F.C George et al.

Analysis of fiber components in feed and forages using gas–liquid chromatography

J. Sci. Food Chem.

(1979)

McDonald, P., Whittenbury, R., 1977. The silage fermentation quality. In: Butler, G.W., Bailey, R.W. (Eds.), Chemistry...

Cited by (25)

Intake, digestibility, and nitrogen balance by sheep offered ensiled tall fescue, meadow fescue or orchardgrass that was fertilized with dairy slurry or urea
2022, Animal Feed Science and Technology
Citation Excerpt :
However, changes in WSC concentrations between pre- and post-ensiling were numerically lowest from MFC, which also indicates a lower degree of fermentation of the WSC to lactic acid in those forages. Hemicellulose concentrations decreased by 3.8 (TFS) to 17.0 % (OGC) which is consistent with that reported by Yahaya et al. (2002) and likely indicates acid or enzymatic hydrolysis of the hemicellulose. Only TFC silages approached what was suggested as acceptable lactic acid concentrations for grass silage (Kung et al., 2018).
Silage intake and utilization by ruminants can be affected by several factors including forage type and fertilization. The objective of this study was to evaluate intake, digestion, and N balance by sheep offered three different ensiled grasses following fertilization with either urea (C) or dairy slurry (S). Plots of meadow fescue (MF), tall fescue (TF) or orchardgrass (OG) were fertilized with urea (52 kg N/ha; MFC, TFC and OGC) or slurry (71,150 L/ha; MFS, TFS, and OGS) on 2 July 2018 following an initial harvest on 29 June 2018. A second harvest was baled 6 August at approximately 57 % moisture and wrapped in plastic. Eighteen lambs (59 ± 1.5 kg) were allocated randomly to one of the 6 treatment combinations to provide 3 lambs per treatment within each of 3 periods for a total of 9 replications per treatment. Each period consisted of a 10-d adaptation and 7-d total fecal and urine collection. Data were analyzed as a 2 × 3 factorial arrangement using PROC MIXED of SAS. Post-ensiled crude protein (CP) concentrations were greatest from MFS and lowest from OGS (P < 0.05), and aNDF, ADF and lignin were greater (P < 0.05) from OG vs TF and MF, regardless of fertilization. Lactic acid concentrations (g/kg DM) in baled silages were greatest from TFC and lowest from MFC and OGS (P < 0.05). Dry matter (DM) and organic matter (OM) intakes (g/kg BW and BW^0.75), digestibility and digestible DM and OM intakes (g/kg BW and BW^0.75) were greater (P < 0.05) from MF than from TF and OG across fertilization type and digestible OM intake was greater (P < 0.05) from C vs. S across forages. Digestibility of NDF (g/kg NDF) was greater (P < 0.05) from MF and OG vs. TF across fertilization treatments. Nitrogen retention (g/kg N intake) tended (P = 0.08) to be greater from MF vs. OG and urine N (g/kg N intake and g/kg N excreted) was greater from TF and OG compared with MF across fertilization treatments. Therefore, meadow fescue has the potential to provide a higher-quality forage that will increase intake and digestibility over more conventional orchardgrass and tall fescue. Fertilization with dairy slurry affected certain forage chemical components and reduced organic matter intake but did not impact digestibility when applied 35 d prior to a subsequent harvest.
Effects of malate, citrate, succinate and fumarate on fermentation, chemical composition, aerobic stability and digestibility of alfalfa silage
2020, Animal Feed Science and Technology
Citation Excerpt :
The increasing of DM content could lead to a lower plant respiration rate and plant enzyme activity, and ultimately result in low non-protein nitrogen (NPN) content in ensiled forage (Muck, 1987). Moreover, greater crude protein (CP), water-soluble carbohydrates (WSC) and hemicellulose were observed in silages ensiled with a high DM than in silages with a low DM (Yahaya et al., 2002). Although our previous work (Ke et al., 2017, 2018) have suggested that MA and CA could promote the growth of lactic acid bacteria during ensiling, little information is available on the effects of succinic and fumaric acids on the fermentation of ensiled forages, and comparison on the effects of fumaric, malic, citric, and succinic acids, known as key intermediates in the citric acid cycle, on fermentation profiles, proteolysis, lipolysis, aerobic stability and digestibility of silage ensiled at different DM is still unknown.
This study was to evaluate the effects of malate, citrate, succinate and fumarate on the fermentation quality, proteolysis and lipolysis and aerobic stability of alfalfa silage ensiled at two different dry matter (DM) contents. Alfalfa was harvested in the late bud to the early flower stage and wilted to DM contents of approximately 330 (normal DM) and 400 (high DM) g/kg fresh weight. The wilted and chopped alfalfa was ensiled in vacuum-sealing polyethylene plastic bags with treatments of control (distilled water), 0.5 % dl-malic acid (MA), 0.5 % citric acid (CA), 0.5 % sodium succinate (SS) and 0.5 % sodium fumarate (SF). All the application rates were based on the fresh weight of forage. After 60 days of ensiling, alfalfa silages ensiled at a normal DM had greater concentrations of lactic acid, acetic acid, non-protein N (NPN), ammonia N (NH₃-N), greater aerobic stability and lower concentration of water soluble carbohydrates (WSC), DM loss when compared to the silages ensiled at a high DM (P < 0.05). These four additives had positive effects on increasing the concentrations of lactic acid and WSC in treated silages ensiled at two different DM contents but the lower pH was only observed in MA and CA-treated silages. Unlike the lower concentrations of acetic acid in MA and CA-treated silages, SS and SF-treated silages with a normal DM had greater acetic acid. Application of these four additives reduced the concentration of NPN and NH₃-N in treated silages (P < 0.05) and the lowest concentrations of NPN and NH₃-N were observed in MA and CA-treated silages with a high DM content. Application of MA, CA and SS reduced the aerobic stability of ensiled alfalfa with normal DM content but CA and SF improved aerobic stability of the silage with high DM content. In addition, MA and CA increased in vitro dry matter digestibility (IVDMD) at two different DM contents but no effects were found in SS and SF treatments. Application of MA and CA led to higher polyunsaturated fatty acid (PUFA) proportions in ensiled alfalfa at a normal DM than those in the control silage (P < 0.05). Moreover, greater residues of MA, CA and succinic acid were observed in treated silages except for comparable MA in SS and SF-treated silages. However, no fumaric acid was observed in ensiled silages. These results indicate that including MA and CA could improve silage fermentation quality and digestibility, limit proteolysis and lipolysis and DM loss. However, little effect was observed in SS or SF treatments.
Co-ensiling, co-composting and anaerobic co-digestion of vegetable crop residues: Product stability and effect on soil carbon and nitrogen dynamics
2017, Scientia Horticulturae
Citation Excerpt :
Compared to ensiling, composting is a more labor intensive treatment and demands an extra financial investment, because it requires specific tools to monitor and manage the compost piles (Viaene et al., 2016). Furthermore, to ensure a good composting process, bulking agents with a higher C/N ratio should be added (Huang et al., 2004a), while a proper ensiling process requires mixing drier biomass with fresh crop residues (Yahaya et al., 2002). This implies that the biomass (i.e. woody material for composting and straw for ensiling) must be readily available for the farmer, which is not always the case (Viaene et al., 2016).
Nitrogen (N)-rich vegetable crop residues left in the field may result in a high risk for N losses during autumn. Removal and conservation of these residues followed by reuse in the field could contribute to improved recycling of nutrients, but some form of processing is required to allow storage before re-application. We have compared co-ensiling, co-composting and anaerobic co-digestion as conservation and valorization options for fresh crop residues. We studied (1) the product quality and stability and (2) the short-term effects of application of these silages, composts and digestates on soil C and N mineralization and N₂O emissions. Ensiling resulted in highly biodegradable products with a low pH (4.2-5.2) and more NH₄⁺-N compared to composts. Consequently, soil incorporation of silages resulted in higher net C mineralization (up to 47% after 82 days) and microbial biomass C (up to 93 μg C g⁻¹ soil after six weeks), and temporary N immobilization (up to 42 mg kg⁻¹ soil). Digestates and composts led to lower C mineralization rates (between 2 and 27%) and microbial biomass C (max. 51 μg C g⁻¹ soil) and no net N immobilization nor mineralization. Application of digestates resulted in high mineral N contents (47–192 mg kg⁻¹ soil) and a decrease of the soil pH. In all three treatments, short-term N₂O losses after soil application were very small (<0.11 kg N ha⁻¹ after 12 days). Growers can choose the most appropriate treatment option and application moment and location, depending on the local soil and crop requirements and the on-farm facilities. Furthermore, we conclude that the parameters biodegradation potential (based on the biochemical composition) and oxygen uptake rate have potential as less time-consuming proxies for C mineralization to assess the product stability.
Short communication: The effects of dry matter and length of storage on the composition and nutritive value of alfalfa silage
2016, Journal of Dairy Science
Citation Excerpt :
Luchini et al. (1997) also found that DM content did not influence fiber content of alfalfa silages stored in O2-limiting and tower silos. In contrast, Yahaya et al. (2002) reported that high-moisture orchardgrass silage (23.7% DM) was lower in NDF-D compared with fresh forage, but when wilted to higher DM contents, NDF-D was actually higher than fresh material. In our study, there was an interaction (P = 0.03) between DM content at ensiling and length of storage for NDF-D primarily because NDF-D was greater and similar in fresh forages but was slightly lower from d 45 onward for HDM compared with LDM silage, with the former being slightly lower.
During the ensiling of feeds, various processes result in chemical changes that can affect their ultimate nutritive value at feed out. The primary objective of this study was to evaluate the effect of prolonged ensiling times on potential changes in in vitro digestibility of neutral detergent fiber (NDF-D) of alfalfa ensiled at about 33% [low dry matter (DM), LDM] or 45% (high DM, HDM) whole-plant DM. Alfalfa from the same field (direct chopped or wilted) was chopped with a conventional forage harvester set for a theoretical length of cut of 0.95 cm and ensiled in mini silos for 45, 180, 270, and 360 d. Fresh forages and silages were analyzed for nutrient content, fermentation end-products, and 30-h NDF-D. The pH of the fresh forages ranged from 6.1 to 6.2 and decreased to approximately 4.7 and 4.3 in HDM and LDM silages, respectively. Production of acids and alcohols were less in HDM compared with LDM as expected. Concentrations of soluble protein and NH₃-N also increased with time of storage as expected but soluble protein was greater, whereas NH₃-N was lower in HDM compared with LDM silage. The effect of length of storage and DM on hemicellulose and NDF concentrations were very small, whereas DM content at harvest tended to slightly increase the concentration of acid detergent fiber in HDM compared with LDM up to 270 d of storage. The NDF-D was greater in fresh forage compared with corresponding silages. However, time of storage between 45 and 360 d had no effect on the NDF-D of alfalfa silage, regardless of DM concentration at ensiling.
Effect of ensilaged vegetable crop residue amendments on soil carbon and nitrogen dynamics
2015, Scientia Horticulturae
Citation Excerpt :
The final pH and biodegradability may hence be indicators of the success of the ensilaging process and resulting silage quality. To obtain a high quality silage a moisture content of more than 75% should be avoided as this leads to undesirable fermentation in later ensilage phases (Chedly and Lee, 2000; Yahaya et al., 2002). Given the low DM content of vegetable crop residues a material with a high organic matter (OM) and DM content should be added to ensure proper ensilage.
Vegetable crop residues aid in maintaining soil quality and fertility, but pose a high risk of N-losses during autumn. Removal and conservation of these residues followed by a timely reapplication in spring may aid in synchronizing nutrient demand and availability. Crop residues of four vegetables were co-ensilaged with maize straw in a 1:1 ratio on volume base. Silage of leek and white cabbage were incubated with soil for measuring C and N mineralization and N fertilizer replacement value (NFRV). Vegetable crop residue silage promoted microbial activity when reapplied to the soil. This led to a temporary N immobilization up to 30% of the applied N after 14 days. A limited remineralization of up to +4% took place after 115 days which was confirmed by the positive NFVR. Nitrogen (N) losses during co-ensilage of vegetable crop residues were small and may help reduce N losses in intensive vegetable crop rotations during winter.
Forage fermentation product measures are related to dry matter loss through meta-analysis
2015, Professional Animal Scientist
Forage preservation through fermentation can result in substantial DM and economic losses. The objective of this research by the use of meta-analysis was to determine whether fermentation end-product measures and forage parameters were capable of predicting forage DM losses following ensiling. The data set was built by searching a database for “forage,” “fermentation,” and “dry matter loss.” The data set contained 405 means from 43 peer-reviewed research reports. Forage DM losses (% of original forage DM) ranged from 0 to 28.6% with a raw mean of 6.2%. Report, forage biology, fermentation treatment, fermentation length, DM, pH, lactic acid, and acetic acid parameters were related to natural logarithm DM loss using a mixed-model approach. Parameters were evaluated for linear and quadratic effects and linear interactions. Report was classified as a random effect. The resulting model had a 1.403 mean natural logarithm DM, R² of 0.813, and root mean square error of 0.418. Forage DM (%), acetic and lactic acid, pH, fermentation length, and forage biology were related to losses. Fermentation treatments tended (P < 0.10) to differ. Forage pH × lactic acid, DM × fermentation treatment, DM × forage biology, and lactic acid × forage biology all exhibited interactions. Forage DM, biology, fermentation, and treatment parameters were capable of describing most DM-loss variation across a range of published research reports (P ≤ 0.01). The final model described here has utility to predict forage DM losses due to fermentation and may be useful to diagnose problematic fermentations and assess opportunity costs.

View all citing articles on Scopus

View full text

The effect of different moisture contents at ensiling on silo degradation and digestibility of structural carbohydrates of orchardgrass

Abstract

Introduction

Section snippets

Silage preparation

Results and discussion

Conclusion

J. Dairy Sci.

J. Dairy Sci.

The calorimetric determination of lactic acid in biological material

J. Biol. Chem.

Moisture and storage: effects on dry matter and quality losses of alfalfa in round bales

Trans. Am. Soc. Agric. Eng. (SAE)

Microdiffussion methods: ammonia and urea using buffer absorbents (revised methods for ranges >10 (g N)

Biochem. J.

Routine analysis of carbohydrate and lignin in herbage

J. Sci. Food Agric.

The hydrolysis of grass hemicelluloses during ensilage

J. Sci. Food

Multiple range test and multiple F-test

Biometrics

Cellulose treated coastal bermudagrass silage and production of soluble carbohydrates, silage acids, and digestibility

J. Dairy Sci.

Analysis of fiber components in feed and forages using gas–liquid chromatography

J. Sci. Food Chem.