Microbial characterization and fermentative characteristics of crop maize ensiled with unsalable vegetables

Abstract

Incorporation of carrot or pumpkin at 0, 20 or 40% dry matter (DM-basis) with crop maize, with or without a silage inoculant was evaluated after 70 days ensiling for microbial community diversity, nutrient composition, and aerobic stability. Inclusion of carrots or pumpkin had a strong effect on the silage bacterial community structure but not the fungal community. Bacterial microbial richness was also reduced (P = 0.01) by increasing vegetable proportion. Inverse Simpson’s diversity increased (P = 0.04) by 18.3% with carrot maize silage as opposed to pumpkin maize silage at 20 or 40% DM. After 70 d ensiling, silage bacterial microbiota was dominated by Lactobacillus spp. and the fungal microbiota by Candida tropicalis, Kazachstania humilis and Fusarium denticulatum. After 14 d aerobic exposure, fungal diversity was not influenced (P ≥ 0.13) by vegetable type or proportion of inclusion in the silage. Inoculation of vegetable silage lowered silage surface temperatures on day-7 (P = 0.03) and day-14 (P ≤ 0.01) of aerobic stability analysis. Our findings suggest that ensiling unsalable vegetables with crop maize can successfully replace forage at 20 or 40% DM to produce a high-quality livestock feed.

Ensiled Mixed Vegetables Enriched Carbohydrate Metabolism in Heterofermentative Lactic Acid Bacteria

“…After ensiling and the aerobic exposure period, K. humilis was a dominant taxon in fungal communities of 40% DM vegetable mixture silages, irrespective of probiotic, a result similarly observed when maize ensiled with 40% DM pumpkin was subjected to aerobic exposure [6]. Metabolising glucose as a growth substrate, K. humilis added to sourdough fermentation with Saccharomyces cerevisiae has previously increased the production of lactate, acetate, and ethanol [77].…”

“…The anaerobic fermentation of plant material via ensiling for ruminant feed production presents a twofold opportunity to utilise vegetable waste while value-adding low protein crops such as maize or sorghum which range from 10.6-11.6% dry matter (DM), respectively compared to lucerne at 15.3% DM [5]. Previously, ensiling maize with up to 40% DM carrot or pumpkin decreased neutral detergent fibre (NDF) by 6.72%, increased crude protein by 34.9%, and in vitro dry matter digestibility (IVDMD) by 6.63%, indicating promise as a ruminant feed [6], with similar effects also noted in sorghum [7].…”

Strategies to improve the efficiency of beef cattle production

“…Using food that does not meet the quality grade for human consumption reduces the extent to which components in ruminant diets compete with food for humans. For example, incorporation of unsalable carrot or pumpkin waste at up to 40% of dry matter in ensiled corn or sorghum did not alter silage quality and improved in vitro dry matter digestibility (Forwood et al 2019;Hooker et al 2019). Similarly, grazed forages, hay, silages, and grains are often contaminated by a wide range of mycotoxins, toxic molecules produced by fungi, often as a result of unfavourable ensiling and storage conditions (Gallo et al 2015).…”

Unsalable Vegetables Ensiled With Sorghum Promote Heterofermentative Lactic Acid Bacteria and Improve in vitro Rumen Fermentation

“…Vegetables such as carrot or pumpkin at 20 or 40% dry matter (DM) are potential candidates for ensiling and for use as fodder substitutes for sorghum or maize. Silages supplemented with vegetables favor the growth of Lactobacillus spp., simultaneously increasing the microbial diversity with sorghum, while maintaining in vitro fermentation and gas parameters [mL/g DM gas; percent, mg/g DM; mg/g CH 4 digestible dry matter (DMD)] with maize ( Forwood et al, 2019 ; Hooker et al, 2019 ). Moreover, in vitro studies have also utilized pumpkin ensiled at 30% DM with corn stover, which increased in vitro DM digestibility by 25%, while consequently decreasing gas production by 6% ( Crosby-Galván et al, 2018 ).…”