Effects of Sodium Formate and Calcium Propionate Additives on the Fermentation Quality and Microbial Community of Wet Brewers Grains after Short-Term Storage.

Jingyi Lv,Chao Zhao,Yang Li,Guanzhi Feng,Yonggen Zhang,Xinpeng Fang,Guangning Zhang

doi:10.3390/ani10091608

Jingyi Lv, Chao Zhao + Show 5 more

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https://doi.org/10.3390/ani10091608

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Abstract

Simple SummaryThe objective of this study was to examine the effect of sodium formate and calcium propionate on the fermentation quality and microbial community of wet brewers grains (WBG) after short-term storage. Both additives improved the silage quality of WBG ensiled for 20 days to different extents. However, ensiled WBG treated with sodium formate had higher contents of dry matter, water-soluble carbohydrates, and neutral detergent fibers and better fermentation quality, rumen degradation, and microbial composition. The addition of sodium formate enhances the abundance of desirable Lactobacillus and reduces the abundance of undesirable microorganisms, including Clostridium. In summary, during short-term storage of high-moisture feed, sodium formate has a more beneficial preservation effect than an equivalent dose of calcium propionate.The objective of this research was to examine the effect of sodium formate (SF) and calcium propionate (CAP) on the fermentation characteristics and microbial community of wet brewers grains (WBG) after short-term storage. In the laboratory environment, fresh WBG was ensiled with (1) no additive (CON), (2) sodium formate (SF, 3 g/kg fresh weight), and (3) calcium propionate (CAP, 3 g/kg fresh weight) for 20 days. After opening, fermentation characteristics, chemical composition, rumen effective degradability, and the microbial community of ensiled WBG were analyzed. The addition of CAP had no effect on pH and lactic acid concentration and increased the concentrations of propionic acid; the SF group had the lowest pH and acetic acid, butyric acid, and ammonia nitrogen contents and the highest lactic acid concentration. After fermentation, the SF group had the highest contents of dry matter (DM), water-soluble carbohydrates (WSCs), and neutral detergent fiber (NDF). The contents of the three nutrients in the CAP group were significantly higher than those in the CON group. The addition of the two additives had little influence on the crude protein (CP) and acid detergent fiber (ADF) contents of the ensiled WBG. Two additives elevated in situ effective degradability of DM and NDF compared with the parameters detected in the CON group; WBG ensiled with SF had higher effective in situ CP degradability than that in the CON and CAP groups. The results of the principal component analysis indicate that the SF group and two other groups had notable differences in bacterial composition. The analysis of the genus level of the bacterial flora showed that the content of Lactobacillus in the SF group was significantly higher than that in the two other treatment groups, while the content of Clostridium was significantly lower than that in the two other treatment groups. Therefore, the addition of sodium formate can suppress the undesirable microorganisms, improve the fermentation qualities, and ensure that WBG is well preserved after 20 days of ensiling.

Highlights

Wet brewers grain (WBG) is a byproduct of the brewing process and is a suitable alternative feed source for dairy [1] and beef cattle [2,3] due to its unique nutrient composition combined with low price
Silage is a common processing method of high-moisture feed; most sugars are removed from WBG during the malting process leaving inadequate levels of the substrate for silage fermentation, which can result in silage failure [5]
WBG contained 4.75 log10cfu/g fresh weight (FW) of lactic acid bacteria (LAB) and 3.79 log10cfu/g FW of yeasts; mold was not detected in WBG

Summary

Introduction

Wet brewers grain (WBG) is a byproduct of the brewing process and is a suitable alternative feed source for dairy [1] and beef cattle [2,3] due to its unique nutrient composition combined with low price. The seasonality and low dry matter (DM) content, which hinders storage and preservation of WBG, are the main limiting factors for the effective use of WBG [4]. Silage is a common processing method of high-moisture feed; most sugars are removed from WBG during the malting process leaving inadequate levels of the substrate (water-soluble carbohydrates, WSCs) for silage fermentation, which can result in silage failure [5]. Adding a substrate to WBG to enhance its DM and WSC concentrations is an option that can improve the fermentation effect of WBG. Compared with WBG alone, WBG mixed with beet pulp pellets [6] and dry group corn [5] improved fermentation. Compared with WBG alone, the addition of soy hulls to WBG increased DM and nutrient losses [7]

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