Effect of microbial inoculation and storage length on the fermentation profile and nutritive value of high-moisture corn ensiled at 2 different dry matter concentrations.

The objective of this experiment was to evaluate the effect of microbial inoculation and storage length on the fermentation profile and nutrient composition of high-moisture corn (HMC) ensiled at 2 different dry matter (DM) concentrations. High-moisture corn was harvested when kernel DM concentrations were approaching 65% as-fed, and either left undried (HMC65; 67.6% DM) or dried at 40 °C to approximately 70% DM (HMC70; 71.0% DM), and then ensiled in quadruplicate vacuum pouches untreated (CON) or after one of the following inoculant treatments: 6.36 × 105 cfu of Lentilactobacillus buchneri DSM 12856, Lactiplantibacillus plantarum DSM 12836, and Pediococcus acidilactici DSM 16243 per g of HMC (LBLP); or 3.0 × 105 cfu of Lentilactobacillus buchneri DSM 12856, Lentilactobacillus diolivorans DSM 32074, and P. acidilactici DSM 16243 per g of HMC (LBLD). Vacuum pouches were allowed to ferment for 7, 14, 28, or 56 d. A three-way interaction was observed (P = 0.01) for the pH of HMC, where CON for HMC70 was greatest across storage lengths and HMC65 treatments generally had a lower pH than other treatments. Concentrations of total acids were greater (P = 0.001) in HMC65 than HMC70 and greater (P = 0.001) in HMC treated with LBLP and LBLD than CON. An interaction between DM concentration, microbial inoculation, and storage length was observed (P = 0.05) for concentrations of acetic acid. At 14 d, acetic acid concentrations were greater in HMC65 treated with LBLD than other treatments. Likewise, at 56 d, concentrations of acetic acid were greatest in HMC65 treated with LBLD, followed by HMC70 treated with LBLD. An interaction between DM concentration, microbial inoculation, and storage length was observed (P = 0.05) for 7-h starch disappearance (starchD). Across all DM concentration and inoculant treatment combinations, starchD increased with increasing storage length. StarchD was also generally greater for HMC65 treatments compared to HMC70, with small differences among inoculants. Results suggest that microbial inoculation can improve fermentation of HMC by increasing the production of antifungal acetic acid, but that DM concentration at ensiling remains a primary determinant of HMC fermentability.

High-moisture corn (HMC) short-term fermentation is affected by dry matter (DM) concentration. Thus, producers try to influence HMC fermentation by using microbial inoculants and by harvesting HMC at different DM concentrations. This study aimed to evaluate the effects of different DM concentrations, heterofermentative microbial inoculants, and storage length on the fermentation and nutritive value of HMC. Total acid production was greater in HMC with a lower DM and treated with microbial inoculants. Lactic acid concentrations were generally greater in lower DM HMC. Microbial inoculants increased the production of acetic acid, an antifungal acid. Because acetic acid can improve aerobic stability, these results demonstrate microbial inoculation and lower DM can improve HMC fermentation. However, DM concentration seems to influence fermentation to a greater extent than the use of microbial inoculants. Although starch concentration was not affected by microbial inoculants or DM concentration, starch digestibility was greater in lower DM HMC. This demonstrates lower DM may improve nutritive value in addition to improving fermentation by increasing the production of total acids and lactic acid in HMC.

Effect of cutting height, microbial inoculation, and storage length on fermentation profile and nutrient composition of whole-plant corn silage.

This study aimed to evaluate the effects of cutting height, heterofermentative microbial inoculants, and storage length on the fermentation profile and nutrient composition of whole-plant corn silage. The experiment was a completely randomized design with a 2 (cutting height) × 3 (microbial inoculation) × 5 (storage length) factorial arrangement of treatments. Corn forage was harvested at two cutting heights: either 25 cm (REG) or 65 cm (HI). Then, forage was inoculated with one of three microbial inoculants: (1) 300,000 CFU/g of fresh forage of Pediococcus acidilactici DSM 16243, Lentilactobacillus buchneri DSM 12856, and L. diolivorans DSM 32074 (LBLD; Bonsilage Speed inoculant, Provita Supplements Inc., Mendota Heights, MN), (2) 500,000 CFU/g of fresh forage of Lactiplantibacillus plantarum DSM 12837 and L. buchneri DSM 16774 (LPLB; Bonsilage Corn + WS inoculant, Provita Supplements Inc., Mendota Heights, MN), or (3) distilled water (CON). Last, forage was randomly assigned to ferment for 5, 7, 14, 28, or 56 d of storage in vacuum-sealed bags. Silage pH was affected by a three-way interaction (P = 0.01), where CON treatments decreased continually over time while LPLB and LBLD began to increase at later storage lengths. Acetic acid concentration was greater (P = 0.001) in LPLB and LBLD than CON silage after 56 d of storage. Silage treated with LBLD did not have detectable levels of propionic acid (P > 0.05), although 1-propanol concentration was greater (P = 0.001) in LBLD treatments after 56 d of storage. The concentrations of total acids and acetic acid were greater (P = 0.01 and P = 0.001, respectively) for REG silage compared to HI. Additionally, HI silage had greater (P = 0.001 and P = 0.001, respectively) concentrations of dry matter (DM) and starch, while neutral detergent fiber (aNDF) and lignin concentrations were lower (P = 0.001 and P = 0.001, respectively) in HI silage compared to REG silage. Last, HI silage had a greater (P = 0.001) NDF digestibility than REG silage. The results of this study demonstrate that increasing cutting height can improve nutrient composition of whole-plant corn silage. Additionally, results demonstrate that heterofermentative microbial inoculants can be used to shift silage fermentation to the production of lactic and acetic acids.

Effects of lignocellulolytic enzymes on the fermentation profile, chemical composition, and in situ ruminal disappearance of whole-plant corn silage.

The objective of this study was to examine the enzyme activities of an enzymatic complex produced by Pleurotus ostreatus in different pH and the effects of adding increased application rates of this enzymatic complex on the fermentation profile, chemical composition, and in situ ruminal disappearance of whole-plant corn silage (WPCS) at the onset of fermentation and 30 d after ensiling. The lignocellulolytic enzymatic complex was obtained through in vitro cultivation of P. ostreatus. In the first experiment, the activities of laccase, lignin peroxidase (LiP), manganese peroxidase, endo- and exo-glucanase, xylanase, and mannanase were determined at pH 3, 4, 5, and 6. In the second experiment, five application rates of enzymatic complex were tested in a randomized complete block design (0, 9, 18, 27, and 36 mg of lignocellulosic enzymes/kg of fresh whole-plant corn [WPC], corresponding to 0, 0.587, 1.156, 1.734, and 2.312 g of enzymatic complex/kg of fresh WPC, respectively). There were four replicates per treatment (vacuum-sealed bags) per opening time. Bags were opened 1, 2, 3, and 7 d after ensiling (onset of fermentation period) and 30 d after ensiling to evaluate the fermentation profile, chemical composition, and in situ dry matter and neutral fiber detergent disappearance of WPCS. Laccase had the greatest activity at pH 5 (P < 0.01), whereas manganese peroxidase and LiP had the greatest activity at pH 4 (P < 0.01; P < 0.01). There was no effect of the rate of application of enzymatic complex, at the onset of fermentation, on the fermentation profile (P > 0.21), and chemical composition (P > 0.36). The concentration of water-soluble carbohydrate quadratically decreased (P < 0.01) over the ensiling time at the onset of fermentation, leading to a quadratic increase of lactic acid (P = 0.02) and a linear increase of acetic acid (P = 0.02) throughout fermentation. Consequently, pH quadratically decreased (P < 0.01). Lignin concentration linearly decreased (P = 0.04) with the enzymatic complex application rates at 30 d of storage; however, other nutrients and fermentation profiles did not change (P > 0.11) with the enzymatic complex application rates. Addition of lignocellulolytic enzymatic complex from P. ostreatus cultivation to WPC at ensiling decreased WPCS lignin concentration 30 d after ensiling; however, it was not sufficient to improve in situ disappearance of fiber and dry matter.

Effects of Microbial Inoculation and Storage Length on Fermentation Profile and Nutrient Composition of Whole-Plant Sorghum Silage of Different Varieties.

This study aimed to assess the effects of a heterofermentative microbial inoculant and storage length on fermentation profile, aerobic stability, and nutrient composition in whole-plant sorghum silage (WPSS) from different varieties. Experiment 1, a completely randomized design with a 2 × 3 factorial treatment arrangement, evaluated microbial inoculation [CON (50 mL distilled water) or LBLD (Lactobacillus plantarum DSM 21762, L. buchneri DSM 12856, and L. diolivorans DSM 32074; 300,000 CFU/g of fresh forage)] and storage length (14, 28, or 56 d) in forage WPSS. The LBLD silage had lower pH compared to CON, and greater concentrations of succinic acid, ethanol, 1,2-propanediol (1,2-PD), 1-propanol, 2,3-butanediol and total acids. After 56 d, lactic acid concentration was greater for CON, while acetic acid and aerobic stability were greater in LBLD silage. Experiment 2, a completely randomized design with a 2 × 3 factorial treatment arrangement, evaluated effects of microbial inoculation (same as experiment 1) and storage length (14, 28, or 56 d) in WPSS of three varieties [forage sorghum (Mojo Seed, OPAL, Hereford, TX), sorghum-sudangrass (Dyna-gro Seed, Fullgraze II, Loveland, CO, United States), or sweet sorghum (MAFES Foundation Seed Stocks, Dale, MS State, MS)]. The LBLD forage sorghum had greater acetic acid and 1,2-PD concentrations at 56 d and 28 d, respectively, but lower concentrations of propionic acid at 56 d and butyric acid at 14 and 28 d. Additionally, WSC concentration was greater for CON than LBLD at 28 d. Furthermore, CON sweet sorghum had greater lactic acid, propionic acid, and butyric acid concentrations. However, greater acetic acid and 1,2-PD were observed for LBLD sweet sorghum. The CON sweet sorghum had greater concentration of WSC and yeast counts. The CON sorghum sudangrass had greater lactic and butyric acid concentrations than LBLD at 14 d, but lower acetic acid and 1,2-PD concentrations at 56 d. Yeast counts were greater for CON than LBLD sorghum sudangrass silage. Overall, results indicate inoculation of WPSS with Lactobacillus plantarum DSM 21762, L. buchneri DSM 12856, and L. diolivorans DSM 32074 improves heterofermentative co-fermentation allowing the accumulation of acetic acid concentration and increasing antifungal capacities and aerobic stability of WPSS.