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 cultivar and harvest days after planting on dry matter yield and nutritive value of teff.

One of the most pressing issues facing the dairy industry is drought. In areas where annual precipitation is low, irrigation for growing feed presents the greatest water-utilization challenge for dairy producers. Here, we investigated the effects of cultivar and harvest days after planting (DAP) on dry matter (DM) yield and nutritive value of teff (Eragrostis tef), a warm-season annual grass native to Ethiopia that is well adapted to drought conditions. Eighty pots were blocked by location in a greenhouse and randomly assigned to four teff cultivars (Tiffany, Moxie, Corvallis, and Dessie) and to five harvest times (40, 45, 50, 55, or 60 DAP). Cultivars had no effect on DM yield and nutritive value. As harvest time increased from 40 to 60 DAP, DM yield and ash-free neutral detergent fiber (aNDFom) concentrations increased, while crude protein (CP) concentrations and in vitro NDF digestibility decreased. To assess carryover effects of time of harvest on yield and nutritive value, two additional cuttings were taken from each pot. Increasing first-cutting harvest time decreased CP concentrations in the second cutting and reduced DM yields in the second and third cutting. Harvesting teff between 45 and 50 DAP best optimized forage yield and nutritive value in the first and subsequent cuttings.