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

Abstract

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 Lentilactobacillus buchneri DSM 16774 (LPLB; Bonsilage Corn + WS inoculant, Provita Supplements Inc., Mendota Heights, MN), or 3) distilled water (CON). Lastly, 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. Lastly, 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 heterofermentative microbial inoculants can be used to shift silage fermentation to the production of lactic and acetic acids.

Nutritional Value and Chemical Composition of Corn Silage Depending on Cutting Height and Forage Losses

“…Hulse et al (2017), recommend harvesting corn at a height of 40 cm because it provides the best balance between the quantity and nutritional quality of the prepared silage. Kennington et al (2005) and Diepersloot et al (2022) prove that stem cutting heights over 60 cm result in a decrease in crude protein content in silage.…”

“…At the same time, the content of crude ash decreases, which is a consequence of the increase in the share of grains in corn silage. With an increase in the proportion of grain in the silage, there is an increase in the concentration of starch and a decrease in the crude fiber content (Bernard et al, 2004;Horst et al, 2021), which significantly affects the increase in the nutritional value of the silage (Diepersloot et al, 2022). In addition to starch, calcium and phosphorus are considered the primary minerals in the diet of dairy cows, important for the skeletal structure of the animals.…”

Effect of cutting height, a bacterial inoculant and a fibrolytic enzyme on corn (Zea mays L.) silage quality

“…Neylon and Kung (2003), did not find pH changes between corn cutting heights at 12.7 or 45.7 cm, at 34% of DM. Usually, when adding an inoculant, studies focus both on pH and acid concentration (9,24); given the speed at which pH falls and stops enzymatic and bacterial activity plays a key role in avoiding unnecessary nutrient loss. However, in this work pH was not measured at different times.…”

“…In fact, the low degradability of cell wall fractions (cellulose, hemicellulose, pectin and lignin) is a key factor limiting its use by rumen microorganisms. In addition to corn variety, crop maturity, kernel processing and particle cut length (12), another alternative to improve fiber degradability of corn silage is to increase cutting height at harvest (9) improving both forage quality and milk production (9,12,21).…”