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OCL
Volume 32, 2025
Green and white biotechnologies in the fields of lipids and oil- and proteincrops / Biotechnologies vertes et blanches dans les domaines des lipides et oléoprotéagineux
Article Number 20
Number of page(s) 12
DOI https://doi.org/10.1051/ocl/2025010
Published online 01 July 2025

© V. Heuzé et al., Published by EDP Sciences, 2025

Licence Creative CommonsThis is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Highlights

  • Fermentation generally improves the feed value of soybean and rapeseed meals for pigs.

  • The process reduces anti-nutritional factors, proteins size and produces probiotics.

  • Efficacy varies based on strain selection and fermentation parameters resulting in variable outcomes in digestibility of energy and proteins, as well as animal health status.

1 Introduction

Soybean meal (SBM) and rapeseed meal (RSM) are by-products of exceptional quality, very readily available and form a large part of livestock rations. However, they have certain limitations—namely, anti-nutritional factors and deficiencies in certain amino acids—that everyone is trying to minimise, and substantial research has been conducted on fermentation processes. Between 2020 and 2023, 46 articles on fermented soybean meal (FSBM, n=28) and fermented rapeseed meal (FRSM, n=18) and their use in pig diets were identified in the literature. This article uses those studies to assess the potential of meal fermentation for pigs by examining its effects on composition, nutritional value, animal performance, health, microbiota, carcass/meat quality, economics and environmental impact.

2 Methodology

The FSBM articles were identified by querying the CAB abstracts as follows TI = (soybean meal OR soybean meal OR soybean oil meal OR soybean oil meal OR soybean oil meal OR soybean oil meal OR soybean meal OR soybean meal OR soybean oil meal OR soybean oil meal OR soybean oil meal) AND (ferment*) AND AB = (digest* OR nutri* OR perform* OR quality OR methane OR greenhouse OR environm* OR econom*) AND SU = (pig*). A similar search was done for FRSM. During the analysis, composition, processes and each observed effect were recorded. Each effect was described and assigned to an effect class (composition, anti-nutritional factors, health, etc.) and given a “positive” or “negative” criterion, allowing quantitative and qualitative analysis of the results. The proximal compositions unless otherwise specified are expressed as a percentage of the [as-it / dry] material.

3 Characteristics of conventional oilmeals

Soybean meal (SBM) is the reference protein feed: highly palatable, rich in protein (52.6 ± 1.1% of dry matter (DM) for SBM 48 and 55.2 ± 1.6% for SBM 50) and lysine (6.2% crude protein (CP)), and low in crude fibre (6.8 ± 0.7% for SBM 48 and 4.4 ± 0.6% for a SBM 50). The digestibility of amino acids is high (more than 90% for lysine in pigs and poultry). However, its content of sulphur amino acids (methionine + cysteine 3.0% of CP) is insufficient for monogastric animals and methionine supplementation is necessary (INRAE et al., 2024). SBM contains oligosaccharides (raffinose and stachyose) that may cause flatulence and diarrhoea in monogastric animals, affecting digestion and nutrient absorption (Heuzé, Tran, et Kaushik, 2020).

Rapeseed meal (RSM) is widely used in animal feed, where it is often used as a substitute for SBM due to its high protein content (38.1 ± 1.3% for RSM type 00 and 41.0 ± 2.3% for canola-type RSM). Its protein is less rich in lysine than that of SBM (5.3% of CP), but it contains more sulphur amino acids (methionine + cysteine 4.4% of CP). RSM is richer in fibre than SBM, both in terms of crude fibre (14.3 ± 1.2% of DM) and lignin content (9.7 ± 1.2% DM vs. <1% for SBM) (INRAE et al., 2024). Its lower lysine content and high fibre content make RSM less suitable for monogastric animals, and feeding pigs RSM as the only source of protein can lead to reduced performance (Heuzé, Tran, Sauvant et al., 2020) however, recent research suggests that RSM can effectively replace SBM in pig diets when properly balanced with synthetic amino acids, enabling comparable growth performance and carcass quality without compromising nutrient digestibility or nitrogen retention (Kasprowicz-Potocka et al., 2023).

4 Fermentation and Its effects

4.1 Fermentation processes for oilmeals

The technological processes used for the fermentation of the oilmeals in the study consist mainly of solid-state fermentation: preparation of the substrate by sterilisation or pasteurisation under a humidity of 30–40%, followed by inoculation of the bacterial or mycelial culture with incubation at 37°C for two −6 days. Although the humidification of oilmeals can pose a risk of pathogenic bacterial growth, such as Salmonella spp., pre-treatment methods like sterilisation or pasteurisation effectively mitigate these risks, while lactic acid fermentation further inhibits undesirable microbial development by lowering the pH to inhibitory levels (Couto & Sanromán, 2006).

Not all the publications reviewed provide details on the specific microorganism species used. Of the 48 studies that mention at least one species, 22 used a single strain, 10 used two strains, 15 used three strains, and one used four strains. Table 1 presents the various species utilised. These include four fungal genera, Aspergillus, Aureobasidium, Neurospora and Rhizopus, presumably a single genus of yeast (Saccharomyces), and seven genera of bacteria. Among the bacteria, two genera are more prevalent: Bacillus and Lactobacillus. The most represented species, in order of frequency, are B. subtilis (21 occurrences), S. cerevisiae (9 occurrences), A. oryzae (4 occurrences), and L. acidophilus (5 occurrences). However, among the eight mentions of Lactobacillus spp., a significant number is likely associated with the acidophilus species. Among the 40 microorganisms for which strain names are indicated, only two strains were used where the same strain was used across multiple studies (3 B. subtilis 87Y, two B. subtilis TJ-C9). Consequently, it is challenging to draw comparisons between these studies, as they do not address similar products.

There is considerable heterogeneity in the description of the fermentation processes in use. The most in depth descriptions specify the origin of the strains used and their development in fermenters. They detail the substrate used, the strains’ concentration in water, fermentation temperature, aeration, and agitation conditions. The preparation of the oilseed meal may include grinding to varying degrees of fineness and optional pasteurisation or sterilisation treatments, which can be performed in an autoclave, by dry heat, or through exposure to saturated steam. As microorganisms require water for growth, a certain amount of water is added to obtain a mixture containing 30–60% water − most often between 30–40% to limit the energy required for drying after fermentation. Fermentation typically involves a phase maintained at a temperature close to 37°C under anaerobic conditions, sometimes preceded by an aerobic phase when the inoculum includes aerobic species. Aerobic fermentation, which is required when fungi are used, can last up to seven days, whereas mixed fermentation is generally shorter, usually 12–24 hours and up to three days. The duration of anaerobic fermentation ranges from one to 14 days, with eight cases limited to one day, six cases between one and two days, three cases from 2–3 days, six cases between four and five days, and two cases beyond this range. During the anaerobic period, the mixture is often placed in airtight bags equipped with one-way valves to release fermentation gases. A decrease in pH is observed in the presence of lactic acid bacteria, which produce organic acids, mainly propionic and lactic acid. The concentration of microorganisms in the inoculum varies from 106 CFU/g to 109 CFU/g of oilseed meal. This data is rarely indicated, but it can be assumed that higher initial concentrations allow for reduced fermentation duration. Some publications have compared the effect of fermentation duration on the composition of oilseed meals. Due to their heterogeneity, it is difficult to draw universal lessons. Microorganisms primarily consume fermentable sugars, which disappear while producing organic acids and CO2. Residual fats can also serve as an energy substrate. Mineral matter and nitrogen are conserved.

After fermentation, the oilseed meals are typically dried and then ground. When mentioned, the drying conditions indicate moderate temperatures (30–75°C), which aim to preserve thermosensitive compounds in the fermented product and, in some cases, maintain the viability of microorganisms. A Romanian research team (Taranu et al., 2022), working on rapeseed meal, implements a washing step of the fermented product at the end of the process to reduce the content of antinutritional factors. The meal is soaked in 2−3 volumes of water, after which the water is removed by decantation.

Table 1

Distribution of microorganisms by kingdoms, genera and for the most represented genera, species (N=number of occurrences in studies where the microorganisms are specified).

4.2 Chemical composition

Table 2 summarises the effects of fermentation on the composition of the meals for the publications where data were provided. Fermentation processes lead to organic matter loss, reducing initial dry matter. This loss is often underreported in literature. In aerobic conditions, substrate oxidation produces CO2, consuming carbohydrates and lipids. Anaerobic fermentation, particularly lactic fermentation, limits dry matter loss by acidifying the medium and restricting organic matter consumption. However, it does not degrade cell wall carbohydrates (pectins, hemicelluloses, celluloses), which constitute a significant portion of rapeseed’s nitrogen-free extract. The hydrolysis of these components could potentially enhance meal digestibility.

The main effect is the increase in protein content (N x 6.25), which varies from +1.8% to +18.1% for fermented soybean meal (FSBM) (Abdel Raheem et al., 2022; Tsai et al., 2022) with an average variation of 9.4% and a positive effect for all 15 reported results. For the FRSM the range of variation was comprised between −1.3 and +17.0% (Liu et al., 2023; Vlassa et al., 2022) with an average of 7.0% and two negative effects out of 26 results. The increase in crude protein corresponds to the increase in amino acid content (Sembratowicz et al., 2020; Liu X,et al., 2021; Lu et al., 2023; Wu et al., 2020; Abdel-Raheem et al., 2023) for FSBM and FRSM, and for FSBM, that of soluble proteins and small peptides (Wu et al., 2020; Yu et al., 2020; Li et al., 2022; W. Wang et al., 2020; Tsai et al., 2022; Zhang et al., 2020; Jiang et al., 2023). Microorganisms can utilise amino acids for their energy requirements and synthesise new amino acids from the resulting inorganic nitrogen. This process can affect the amino acid balance of the fermented meal. In the case of soybean meal, three studies report a greater increase in lysine content compared to the increase in total protein content, while three other studies show smaller increases in lysine relative to total protein. For methionine in soybean meal, one study observes a decrease, whereas five studies report increases exceeding that of total protein content. Regarding rapeseed meal, lysine content decreases in three studies, increases less than total protein content in six cases, and shows a significant increase in two articles. Methionine follows a similar trend, with the exception of the study by Olukomaiya et al. (2021), which observes a decrease in lysine and a 75% increase in methionine.

Another notable effect of fermentation is the more or less pronounced hydrolysis of storage proteins, which should improve their digestibility. Thavonnan et al. (2020), Deng et al. (2023), and Jiang et al. (2023) report reductions of glycinin (Gly) levels by 41–77%, β-conglycinin (βc) by 36–83% in FSBM. Li et al. (2020) observed 90 and 84 % decrease in Gly and βc. Liu X. et al. (2021) observed also a large reduction in Gly and βc (99 and 92%). Sembratowicz et al. (2020) observed an almost total disappearance of βc after Lactobacillus fermentation. Wang et al. (2020) observed a reductions of 57% for Gly and 40% for βc after fermentation. Yan et al. (2022) reported reduction of about 60 % for both Gly and βc. On rapeseed, Wu et al. (2021) observed an 156 % increase of polypeptides after fermentation.

Lipids (measured by ether extract) can serve as an energy substrate for microorganisms; however, not all microorganisms have the enzymatic equipment to utilise this substrate effectively. Consequently, a reduction in fat content is most frequently observed (7/12 for soybean, 8/12 for rapeseed). The range of variation is wide (−59% to +116% for soybean and −39% to +24% for rapeseed), indicating the probable formation of new lipids in certain cases, as in the case of Tsai et al. (2022).

The other notable effect is the reduction in the fibre content, which is "digested" by fermentation in the two oil meals. This phenomenon is particularly evident in soybean, where a decrease in crude fibre content is observed in nine out of 10 cases, with an average reduction of 16%. However, Espinoza et al. (2020) reported a 29% increase, which may be attributed to the use of a single lactic ferment. The situation for rapeseed is more varied, with 10 out of 18 cases showing higher fibre content, and a range of variation from −47% to +46%. As with soybean, these differences can be explained by the nature of the ferments used. For instance, Taranu et al. (2022) employed a yeast (Saccharomyces sp.) lacking the enzymatic equipment to break down cell wall components but capable of producing its own cell walls. In contrast, Taheri et al. used a Aspergillus niger, a fungus capable of digesting cell walls. Alhomodi et al. (2022), utilising fungal strains either individually or in combination, observed contrasting effects depending on the strains employed. Aureobasidium pullulans alone does not digest cellulose, whereas when combined with Neurospora crassa, it facilitates a 10% reduction in crude fibre content, suggesting the possibility of synergistic interactions.

Regarding ash content, it is typically increasing due to the loss of organic matter during fermentation. This increase is expected to be comparable to that observed for protein content. This hypothesis is broadly supported by the average variations observed in the literature. For soybean meal, the average increase in protein content is 9.4%, while the average increase in ash content is 7.0%. Similarly, for rapeseed meal, the average increase in protein content is 7.0%, with a corresponding increase in ash content of 6.3%. However, there is no correlation between the increase in ash and protein content. It is probable that in some cases, the inoculum is injected with residual mineral content from the culture medium rich in mineral elements, which impacts the overall balance. It is surprising to observe in 6 out of 19 cases a decrease in ash content at the same time as an increase in protein content, assuming that the concentration is an effect of the consumption of sugars and lipids by the ferments. One hypothesis is that the inoculum contributed a portion of the nitrogen on which the protein content estimation is based. This hypothesis cannot be excluded for certain studies that do not provide details on inoculum preparation. However, in some cases, it is specified that microorganisms are recovered after centrifugation and then redispersed in water (Taranu et al., 2022).

Table 2

Effect of the fermentation on the composition of the soybean meals (Fermented ‐ Raw) / Raw x 100.

4.3 Anti-nutritional factors

Fermentation has been shown to significantly reduce or even eliminate the presence of anti-nutritional factors in feed ingredients. In the case of FSBM, antitrypsin activity was reduced in all five studies where it was measured, with an average reduction of 87% (range: 48–100%). Similarly, alpha-galactosides, including raffinose and stachyose, were reduced in all six studies where measurements were conducted, with an average reduction of 93% (range: 76–100%). Espinoza et al. (2020) reported a 52% reduction in phytic phosphorus content in FSBM. Furthermore, Luo et al. (2021) observed that fermentation using Aspergillus oryzae and Lactobacillus reuteri led to a 370% increase in free isoflavones by converting glycosylated isoflavones.

In the case of rapeseed meal, fermentation reduced glucosinolates and isothiocyanates in 15 out of 17 studies, with an average reduction of 45% (range: +24% to −95%). Phytic phosphorus content was decreased in 16 out of 18 studies on FRSM, with an average reduction of 30% (range: +4% to −100%).

4.4 Nutritional value

The majority of studies (13 articles) on the nutritional value of FSBM conclude that the digestibility of energy and of the main nutrients in pigs (growing and finishing) and sows improves for an inclusion rate between one and 35% (Thavonnan et al., 2020; Yan et al., 2022; Espinosa et al., 2020; Muniyappan et al., 2023; Kim & Jang, 2023; Muniyappan et al., 2022; Liu et al., 2022; Johannsen et al., 2023; Feng et al., 2020). However, two articles note that fermentation has no effect on the digestibility of FRSM (Czech, Grela, et Kiesz, 2021) and on the digestible and metabolisable energy of FSBM (Espinosa et al., 2020).

FSBM increases the enzymatic activities of lipase, maltase invertase (Yan et al., 2022) and trypsin (Liu et al., 2022). Increased blood protein is reported in unweaned piglets whose dams received FSBM (Huang et al., 2023). On the other hand, two studies report unchanged blood glucose and protein levels in finishing pigs and sows (Xie et al., 2022; Huang et al., 2023).

The effects of RSM fermentation on its nutritional value were evaluated in three papers where FRSM was incorporated at 4-9% to replace SBM. Total apparent digestibility and protein and fibre levels are improved in growing pigs. This work also shows improved bioavailability and retention of calcium and potassium, and better blood mineral status (Czech et al., 2023; Czech et al., 2020). Plasma total protein and albumin levels are improved, indicating their good availability in piglets (Wlazło et al., 2022).

In a comparison between RSM and FRSM incorporated at 14% in grower-finisher pigs, FRSM has better digestible energy (13.8 vs. 11.7 MJ/kg as-fed), nitrogen digestibility (about 70% vs. 60% regardless of the method of calculation) and amino acids (except cysteine) (Zhou et al., 2020).

4.5 Animal performance

The inclusion of FSBM as a replacement for SBM in diets fed to grower-finisher pigs and pregnant sows improves weight gain, feed intake and feed efficiency (Liu et al., 2021; Muniyappan et al., 2023; Liu et al., 2022; Xiong et al., 2021). similar effects have been reported in organic farming (Johannsen et al., 2023) and in animals under health stress (Wang et al., 2020; Wang et al., 2020). In pregnant sows where FSBM replaces fishmeal, weight gain and feed efficiency are improved while lactation weight loss and reproductive performance are unchanged (Huang et al., 2023). In lactating sows, feeding FSBM increases colostrum protein and total solids, litter intake and litter weight, but does not alter litter size or offspring survival rate (Luo et al., 2021).

Across our research, nine articles provide growth performance values. Eight include fermented soybean meal, and two include fermented rapeseed meal (Table 4). The substituted products are often non-fermented soybean meal but, several studies on piglets used animal proteins (Deng et al., 2023; Hui et al., 2021) or pre-treated soybean formulations to improve digestibility (Thavonnan et al., 2020). In the study of Jiang et al. (2023), 10% by the whole feed was fermented. In all trials where the comparison was made with non-fermented material meal at substitution allowed protein content to be equal in the diets, the effect on average daily feed intake (ADFI) tended to increase (5 occurrences versus 1). Variations were below the significance threshold in five studies (including one only for the 3% dose) and significant in two. Regarding average daily gain (ADG), all studies showed positive effects, that were consistently above the significance threshold. The feed conversion ratio (FCR: feed/gain) decreased significantly in five out of six studies, with one study showing an increase that did not exceed the statistical significance threshold.

The studies focusing on the substitution of more digestible proteins presented in the last three rows of Table 4 show report no significant differences compared to the control group. As the aim of these studies was to demonstrate that fermented meals were viable substitutes for more expensive products, such as fishmeal or hydrolysed oilseed meals, the absence of significant differences may be considered a satisfactory outcome. However, the limitation of these results lies in their dependence on alpha risk and the insufficient statistical power to prove equivalence.

Table 3

Effect of the fermentation on the composition of the rapeseed/canola meals (Fermented ‐ Raw) / Raw x 100x

Table 4

Growth performances in pig production. The first line for each reference gives the performance for the control and the following lines the variation versus control in percentage (test − control)/control x 100.

4.6 Animal Health

The vast majority of trials on oilmeal fermentation have focused on its effects on animal health.

4.6.1 General effects

The use of FSBM in the diet of growing pigs reduces mortality by four to 11% and decreases the prevalence of diarrhoea (Jiang et al., 2023; Wang et al., 2020; Liu et al., 2021; Muniyappan et al., 2023; Liu et al., 2022; Wang et al., 2020). On a high-protein diet, the use of FSBM limits the risk of post-weaning diarrhoea (Johannsen et al., 2023).

FRSM reduces diarrhoea by 100% in the 1st week of post-weaning (Taranu, Marin et al., 2022).

4.6.2 Blood Parameters

The addition of FSBM to replace SBM reduces blood urea nitrogen levels in pigs (growers, finishers, sows and their progeny) (Huang et al., 2021; Huang et al., 2023; Muniyappan et al., 2022). It reduces creatinine levels (Feng et al., 2020) and improves cholesterol levels and HDL/LDL ratios (Xie et al., 2022; Huang et al., 2021). When used as a replacement for fishmeal in finishers, FSBM does not worsen biochemical parameters or alter lipid metabolism (Huang et al., 2023; Huang et al., 2021). However, an increase in triglyceride levels has been observed in finishing pigs (Feng et al., 2020).

Feeding FRSM maintains urea and uric acid levels, even when replacing SBM (Czech, Stępniowska et al., 2022; Taranu et al., 2022 Taranu, Marin et al., 2022), and it reduces total and low-density cholesterol and triglyceride levels in growing pigs and pregnant or lactating sows (Wlazło et al., 2022; Czech et al., 2020; Czech, Sembratowicz et al., 2021).

4.6.3 Blood cells and immune molecules

When immune responses are observed, FSBM has a systematic effect on the immunity of growing pigs, as observed in the expression of innate immunity genes (Toll Like Receptors, MUC-1, MUC-2, ZO-1 protein genes, Occludine and Claudin-1) (Lu et al., 2020; Yu et al., 2020). In sows and their progeny, the addition of FSBM increases interferon gamma, a mediator of cellular immunity (Huang et al., 2023).

Humoral immunity is enhanced: increased production of IgA, IgM and IgG (Yan et al., 2022; Jiang et al., 2023; Y. Liu et al., 2021; X. Liu et al., 2021; Lu et al., 2020; Deng et al., 2023). IgG increases for sows, as do levels of IGF-1 (Insulin Growth Factor) and its receptors in colostrum (Huang et al., 2023; Luo et al., 2021). Zhang et al. (2020) hypothesized that, beyond an effect on digestibility, protein hydrolysis may reduce the intestinal inflammation in piglets.

In growing pigs fed a fermented mixture of SBM and feather meal, mucosal infiltration by macrophages decreases, indicating less pathogenicity of the diet, while lyzozyme (immune regulation and infection control factor) increases (Jiang et al., 2023; Huang et al., 2021).

FRSM used as a replacement for SBM in gilts and growing pigs results in improved blood cell counts (red blood cells, haematocrit, haemoglobin) and the white blood cell count (Czech et al., 2020; Czech, Stępniowska et al., 2022; Czech et al., 2021). There is also an increase in the levels of immunoglobulins IgG and IgA levels in growing pigs (Czech, Sembratowicz et al., 2021). In sows, FRSM has no effect on haemoglobin levels, IgG levels and other immunological parameters (Czech, Stępniowska et al., 2022).

4.6.4 Molecules of antioxidant and inflammatory processes

FSBM and FRSM increase antioxidant activity. The antioxidants sodium dismutase and glutathione peroxidase increased with both diets in all types of pigs (Gu et al., 2023; Y. Liu et al., 2021; Xie et al., 2022; Yan et al., 2022), as did plasma vitamin C in piglets and sows (Czech, Stępniowska et al., 2022). FSBM reduced the level of malondialdehyde (MDA, an indicator of oxidative stress) in growing pigs and lactating sows (Luo et al., 2021; Xie et al., 2022; Yan et al., 2022) and for all types of animals with the FRSM (Czech et al., 2020; Czech, Nowakowicz-Debek et al., 2022; Czech et al., 2022; Stępniowska et al., 2022; Taranu et al., 2022; Marin et al., 2022). For sows with FRSM, catalase and MDA levels are also reduced (Czech et al., 2020; Czech, Nowakowicz-Debek et al., 2022).

Anti-inflammatory activity is enhanced by FSBM and FRSM: increased anti-inflammatory interleukin IL-4 (Yan et al., 2022) and decreased pro-inflammatory cytokines such as tumour necrosis factor (TNF-α) and interleukins IL-1β and IL-6 (X. Liu et al., 2021; W. Wang et al., 2020; Zhang et al., 2020). Studies in infected intestinal cells show a reduction in inflammation for both FSBM and FRSM (Taranu, Pistol, Anghel et al., 2022; M. Wang et al., 2020; Yu et al., 2020). However, when FSBM replaces animal proteins, an increase in oxidative stress (MDA) and inflammation (elevated TNFα) is reported (Deng et al., 2023).

4.6.5 Digestive enzymes and the digestive system

The introduction of FSBM in the diet of growing pigs increases the height of the intestinal villi (better absorptive capacity), reduces intestinal cell apoptosis, and strengthens the intestinal barrier (Liu et al., 2021; Liu et al., 2022; Wang et al., 2020; Xiong et al., 2021).

In sows and their piglets, the replacement of low-dose fishmeal with FSBM (1-3% in the sow diet) leads to a decrease in the level of Alanine Transferase (ALT), an indicator of the proper liver function (Huang et al., 2023). The same observation is made for the use of FRSM in growing pigs (Wlazło et al., 2022). Enzyme activity in the liver of sows decreases —a sign of good liver function (Czech et al., 2020; Czech, Nowakowicz-Debek et al., 2022).

The use of FRSM increases the size of the stomach and large intestine, lowers the pH and maintains or reduces the viscosity of the digestate (Czech, Nowakowicz-Debek et al., 2022). It improves the gut health in growing pigs by strengthening the colonic mucosal barrier and reducing lymphocyte infiltration into the gut (Czech, Grela, and Kiesz, 2021; Hui et al., 2021).

The few adverse health effects relate to inflammatory processes, and an increased concentration of alkaline phosphatase which may indicate liver or bone disease (Wlazło et al., 2022).

4.6.6 Blood and bone mineral status

Blood mineral status is either unchanged or improved by the use of FRSM as a replacement for SBM, with increases in mineral concentrations attributed to their increased digestibility (Ca, P, Mg, Fe, Se, Zn, Cu, and Mn) (Czech, Stępniowska et al., 2022; Wlazło et al., 2022; Czech et al., 2021). Bone mineral status is maintained (Muszyński et al., 2023) or improved (Czech, Grela, Nowakowicz-Dębek et al., 2021). With FRSM, the femurs are heavier, and the cross-sectional area of the mid-diaphysis is increased, but the strength of the femoral bone and the relative weight of the femur to the weight of the animal is unchanged, as are the density and mineral content of the femur. In addition, there is a deterioration in overall bone status (yield stress and breaking stress) when pigs are fed FRSM (Muszyński et al., 2023).

4.7 Microbiota

The effects of FSBM on the microbiota of finishing pigs are consistently positive, with a reduction in pathogen populations and an increase in beneficial populations (Feng et al., 2020). In growing pigs, the effects are more variable: the richness and diversity of the gut microbiota may increased (Wang et al., 2020; Muniyappan et al., 2023; Wang et al., 2020; Xiong et al., 2021), unchanged (Czech, Grela, and Kiesz, 2021), or even decreased when FSBM replaces animal protein (Deng et al., 2023). FSBM increases the composition of the faecal microbiota with beneficial bacteria such as Lactobacillus and regulates Bacteroides populations (Jiang et al., 2023).

FRSM also improves the microbiota (Hui et al., 2021; Czech, Grela, et Kiesz, 2021), increases the content of lactic acid bacteria (Wlazło et al., 2022; Czech, Nowakowicz-Debek et al., 2022), including Lactobacillus (Wlazło et al., 2022) and reduces the number of fungal species in faeces (Wlazło et al., 2022). Replacing SBM with FRSM does not increase Clostridium perfringens and Escherichia coli and the total coliform count remains unchanged (Czech, Nowakowicz-Debek et al., 2022).

4.8 Quality of animal products

Studies on the effects of FSBMs on pork quality all show positive outcomes (15 vs. 0) on tenderness (Feng et al., 2020), muscle colour (Xie et al., 2022; Feng et al., 2020), reduction in water loss during cooking (Feng et al., 2020; Lu et al., 2021) and flavour, through an increase in aromatic amino acids (Lu et al., 2021) and loin fat content (Xie et al., 2022).

The inclusion of FSBMs in pig diets may be of interest for consumer health as it increases the levels of polyunsaturated fatty acids (eicosapentaenoic acid and heptadecanoic acid) in the meat, which have a protective role against cardiovascular disease (Lu et al., 2021). The use of FSBM may confer antioxidant properties to meat by increasing the expression of myofiber genes (Xie et al., 2022).

For the FRSM, observations from a single study are difficult to interpret (Gu et al., 2023). This lack of results encourages further research into the effects of FRSM use on pork quality.

4.9 Environment

For growing pigs receiving 3–20% FSBM in the ration, the use of FSBM (in both conventional and organic systems) reduces urinary nitrogen excretion, thereby reducing associated pollution (Muniyappan et al., 2023; Johannsen et al., 2023). Fermentation, by increasing the availability of phosphorus, avoids the use of inorganic phosphorus that would eventually end up in the environment (Espinosa et al., 2020). The environmental impact of FRSM has not been studied.

5 Conclusion

The fermentation of SBM and RSM offers many benefits in terms of chemical composition, antinutritional factors, nutritional value, animal performance, health, microbiota, quality of animal products (except for rapeseed which remains to be studied) and environment.

However, this process has certain limitations. High energy consumption is required for pasteurisation/sterilisation and drying of the fermented meal (Pandey et al., 2008; Mitchell et al., 2006). To preserve their probiotic quality, they must be dried at low temperatures, below 60°C, to maintain the viability of the micro-organisms (Broeckx et al., 2016), which reduces the energy efficiency of the process and increases the drying time, leading to higher costs (Huang et al., 2017) with increased risks of microbial contamination during this prolonged drying.

Fermented meals tend to clump together, forming lumps or cake-like structures that are difficult to handle and dry evenly (Chen et al., 2013). To overcome this problem, the agglomerated material must be broken up prior to drying, creating fine particles that pose potential health and safety concerns and an increased risk of contamination (Schutyser et al., 2004). Temperature control during fermentation is another critical challenge. The implementation of efficient heat removal systems may be required, which can have a significant impact on production costs (Couto and Sanromán, 2006). Finally, microbial metabolism can lead to a reduction in dry matter, typically in the range of 5–15% depending on process conditions (Pandey et al., 2008). This loss must be taken into account in yield calculations and can affect the economics of the process. Balancing these factors to achieve optimal fermentation while minimising energy costs is a major challenge in the commercial implementation of solid media fermentation processes for oilcakes. In the French context, the costs of this process can be estimated at €80 to €100 per tonne: pasteurisation of biomass, wetting of the meal to a level of 30%, drying at moderate temperature (final moisture content of 12%), biomass loss of about 5%, labour, analysis, depreciation and other financial costs.

As, to our knowledge, no experiments have been carried out in France, it would be interesting to carry out local tests to compare them with the results described above and to evaluate the relevance of the process and the limits of incorporation of fermented meals in our technical and economic context.

Conflicts of interest

The authors declare non conflicts of interest.

Author contribution statement

Valérie Heuzé: investigations, original draft, reviewing & editing; Patrick Carré: investigations, original draft, reviewing & editing; Isabelle de la Borde: reviewing & editing; Elodie Tormo: funding, review and editing; Gilles Tran: Investigations, reviewing & editing.

References

  • Abdel-Raheem S.M. et al., 2023. Double-fermented soybean meal totally replaces soybean meal in broiler ra-tions with favorable impact on performance, digestibility, amino acids transporters and meat nutritional value. Animals, 13. [Google Scholar]
  • Alhomodi, A. F.; Kasiga, T.; Berhow, M.; Brown, M. L.; Gibbons, W. R.; Karki, B. Combined Effect of Mild Pretreatment and Fungal Fermentation on Nutritional Characteristics of Canola Meal and Nutrient Digestibility of Processed Canola Meal in Rainbow Trout. Food and Bioproducts Processing 2022, 133, 57–66. https://doi.org/10.1016/j.fbp.2022.03.002. [CrossRef] [Google Scholar]
  • Broeckx G, Vandenheuvel D, Claes IJJ, Lebeer S, Kiekens F. 2016. Drying techniques of probiotic bacteria as an important step towards the development of novel pharmabiotics. Int J Pharm 505: 303–318. [CrossRef] [PubMed] [Google Scholar]
  • Chen L, Madl RL, Vadlani PV. 2013. Nutritional enhancement of soy meal via Aspergillus oryzae solid-state fermentation. Cereal Chem 90: 529–534. [CrossRef] [Google Scholar]
  • Couto SR, Sanromán MÁ. 2006. Application of solid-state fermentation to food industry—A review. J Food Eng 76: 291–302. [CrossRef] [Google Scholar]
  • Czech A, Nowakowicz-Debek B, et al. 2022. Effect of fermented rapeseed meal in the mixture for growing pigs on the gastrointestinal tract, antioxidant status, and immune response. Sci Re p 12. [Google Scholar]
  • Czech A, Grela ER, Kiesz M. 2021. Dietary fermented rapeseed or/and soybean meal additives on performance and intestinal health of piglets. Sci Re p 11. [Google Scholar]
  • Czech A, Grela ER, Kiesz M, Kłys S. 2020. Biochemical and haematological blood parameters of sows and piglets fed a diet with a dried fermented rapeseed meal. Ann Anim Sci 20: 535–550. [CrossRef] [Google Scholar]
  • Czech A, Grela ER, Nowakowicz-Dębek B, Wlazło Ł. 2021. The effects of a fermented rapeseed meal or/and soybean meal additive on the blood lipid profile and immune parameters of piglets and on minerals in their blood and bone. PLoS ONE 16. [Google Scholar]
  • Czech A, Sembratowicz I, Kiesz M. 2021. The effects of a fermented rapeseed or/and soybean meal additive on antioxidant parameters in the blood and tissues of piglets. Animals 11. [PubMed] [Google Scholar]
  • Czech A, Stępniowska A, Kiesz M. 2022. Effect of fermented rapeseed meal as a feed component on the redox and immune system of pregnant sows and their offspring. Ann Anim Sci 22: 201–219. [CrossRef] [Google Scholar]
  • Czech A, Wlazło Ł, Łukaszewicz M, Florek M, Nowakowicz-Dębek B. 2023. Fermented rapeseed meal enhances the digestibility of protein and macro- and microminerals and improves the performance of weaner pigs. Anim Feed Sci Technol 300. [Google Scholar]
  • Deng Z, Duarte ME, Kim SY, Hwang Y, Kim SW. 2023. Comparative effects of soy protein concentrate, enzyme-treated soybean meal, and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs. J Anim Sci Biotechnol 14: 89. [CrossRef] [PubMed] [Google Scholar]
  • Espinosa CD, et al. 2020. Nutritional value of a new source of fermented soybean meal fed to growing pigs. J Anim Sci 98. [Google Scholar]
  • Feizi LK, et al. 2022. Biotechnological valorisation of fermented soybean meal for sustainable ruminant and non-ruminant feeding: modulating ruminal fermentation, gut or ruminal microflora, immune system, and growth performance. Biomass Convers Biorefinery 14: 9047–9058. [Google Scholar]
  • Feng H, et al. 2020. Effect of fermented soybean meal supplementation on some growth performance, blood chemical parameters, and faecal microflora of finishing pigs. Rev Bras Zootec 49. [Google Scholar]
  • Gao M, et al. 2023. Effects of raw and fermented rapeseed cake on ruminal fermentation, methane emission, and milk production in lactating dairy cows. Anim Feed Sci Technol 300. [Google Scholar]
  • Gu F, et al. 2023. Effects of low protein diet supplemented with fermented canola meal on growth performance and meat quality of finishing pigs. Chin J Anim Nutr 35: 1489–1500. [Google Scholar]
  • Heuzé V, Tran G, Kaushik SJ. 2020. Soybean meal. In: Feedipedia, a programme by INRAE, CIRAD, AFZ and FAO. Available from: https://www.feedipedia.org/node/674 (last consult: 2024/09/27). [Google Scholar]
  • Heuzé V, Tran G, Sauvant D, Lessire M, Lebas F. 2020. Rapeseed meal. In: Feedipedia, a programme by INRAE, CIRAD, AFZ and FAO. Available from: https://www.feedipedia.org/node/52 (last consult: 2024/09/27). [Google Scholar]
  • Huang H, et al. 2023. Two-stage fermented feather meal-soybean meal product improves the performance and immunity of lactating sows and piglets. Fermentation 9. [Google Scholar]
  • Huang H, Weng B, Hsuuw Y, Lee Y, Chen K. 2021. Dietary supplementation of two-stage fermented feather-soybean meal product on growth performance and immunity in finishing pigs. Animals 11. [PubMed] [Google Scholar]
  • Huang S, et al. 2017. Spray drying of probiotics and other food-grade bacteria: A review. Trends Food Sci Technol 63: 1–17. [CrossRef] [Google Scholar]
  • Hui Y, et al. 2021. Supplementation of a lacto-fermented rapeseed-seaweed blend promotes gut microbial- and gut immune-modulation in weaner piglets. J Anim Sci Biotechnol 12. [PubMed] [Google Scholar]
  • INRAE, CIRAD, AFZ. 2024. FeedTables. Tables INRAE-CIRAD-AFZ: Composition et valeurs nutritionnelles des matières premières pour bovins, ovins, caprins, porcs, volailles, chevaux, lapins et salmonidés. AFZ. Available from: https://www.feedtables.com (last consult: 2024/09/27). [Google Scholar]
  • Jiang D, et al. 2023. Three-stage fermentation of the feed and the application on weaned piglets. Front Vet Sci 9. [Google Scholar]
  • Johannsen J, Nogaard J, Theil P, Andersen H, Kongsted A. 2023. Effects of a high protein starter diet with fermented soybean cake on growth performance of organic pigs weaned outdoor. Livest Sci 267. [Google Scholar]
  • Kasprowicz-Potocka M, Zaworska A, Kaczmarek SA, Rutkowski A, Hejdysz M. 2023. The possibility of using 00-rapeseed meal combined with faba bean or yellow lupine as an alternative to soybean meal in grower-finisher pig diets. Animals 13 (5): 890. [CrossRef] [PubMed] [Google Scholar]
  • Kim SW, Jang KB. 2023. Evaluation of standardised ileal digestibility of amino acids in fermented soybean meal for nursery pigs using direct and difference procedures. Anim Biosci 36: 275–283. [CrossRef] [PubMed] [Google Scholar]
  • Li P, et al. 2022. Effect of rapeseed meal degraded by enzymolysis and fermentation on the growth performance, nutrient digestibility and health status of broilers. Arch Anim Nutr 76: 221–232. [CrossRef] [PubMed] [Google Scholar]
  • Li Y, et al. 2020. Effects of fermented soybean meal supplementation on the growth performance and cecal microbiota community of broiler chickens. Animals 10. [PubMed] [Google Scholar]
  • Liu X, et al. 2022. Effects of a new fermented soya bean meal on growth performance, serum biochemistry profile, intestinal immune status and digestive enzyme activities in piglets. J Anim Physiol Anim Nutr 106: 1046–1059. [CrossRef] [PubMed] [Google Scholar]
  • Liu X, et al. 2021. Effects of fermented soybean meal on growth performance, serum biochemical indices and intestinal function of weaned piglets. Chin J Anim Nutr 33: 3142–3153. [Google Scholar]
  • Liu Y, et al. 2021. Fermented corn-soybean meal mixed feed modulates intestinal morphology, barrier functions and cecal microbiota in laying hens. Animals 11: 3059. [CrossRef] [PubMed] [Google Scholar]
  • Lu J, et al. 2021. Effect of fermented corn-soybean meal on carcass and meat quality of grower-finisher pigs. J Anim Physiol Anim Nutr 105: 693–698. [CrossRef] [PubMed] [Google Scholar]
  • Lu J, et al. 2020. Impact of fermented corn-soybean meal on gene expression of immunity in the blood, level of secretory immunoglobulin A, and mucosa-associated bacterial community in the intestine of grower-finisher pigs. Front Vet Sci 7. [PubMed] [Google Scholar]
  • Lu Z, et al. 2023. Dietary replacement of soybean meal by fermented feedstuffs for aged laying hens: effects on laying performance, egg quality, nutrient digestibility, intestinal health, follicle development, and biological parameters in a long-term feeding period. Poult Sci 102. [Google Scholar]
  • Luo W, et al. 2021. Fermented soybean meal affects the reproductive performance and oxidative status of sows, and the growth of piglets. Animals 11. [PubMed] [Google Scholar]
  • Ma H, et al. 2022. Protease-producing lactic acid bacteria with antibacterial properties and their potential use in soybean meal fermentation. Chem Biol Technol Agric 9. [Google Scholar]
  • Mitchell DA, Berovič M, Krieger N, eds. 2006. Solid-state fermentation bioreactors: fundamentals of design and operation. Springer, Berlin, Heidelberg. [Google Scholar]
  • Muniyappan M, Lee Y, Kim I. 2022. Comparative efficacy of soybean meal vs fermented soybean meal on ileal digestibility and urine contents in weaned pigs. Livest Sci 263. [Google Scholar]
  • Muniyappan M, Shanmugam S, Park J, Han K, Kim I. 2023. Effects of fermented soybean meal supplementation on the growth performance and apparent total tract digestibility by modulating the gut microbiome of weaned piglets. Sci Re p 13. [Google Scholar]
  • Muszyński S, et al. 2023. Effect of fermented rapeseed meal in feeds for growing piglets on bone morphological traits, mechanical properties, and bone metabolism. Animals 13. [PubMed] [Google Scholar]
  • Olukomaiya, O. O., L. Pan, DaGong Zhang, R. Mereddy, Y. Sultanbawa, et XiuHua Li. 2021. Performance and ileal amino acid digestibility in broilers fed diets containing solid-state fermented and enzyme-supplemented canola meals. Animal Feed Science and Technology .275. https://doi.org/10.1016/j.anifeedsci.2021.114876. [Google Scholar]
  • Pandey A, Soccol CR, Larroche C, eds. 2008. Current developments in solid-state fermentation. Springer, New York, NY. [CrossRef] [Google Scholar]
  • Schutyser MAI, Briels WJ, Boom RM, Rinzema A. 2004. Combined discrete particle and continuum model predicting solid-state fermentation in a drum fermentor. Biotechnol Bioeng 86: 405–413. [CrossRef] [PubMed] [Google Scholar]
  • Sembratowicz I, Chachaj R, Krauze M, Ognik K. 2020. The effect of diet with fermented soybean meal on blood metabolites and redox status of chickens. Ann Anim Sci 20: 599–611. [CrossRef] [Google Scholar]
  • Taheri M, Dastar B, Ashayerizadeh O, Mirshekar R. 2023. The effect of fermented rapeseed meal on production performance, egg quality and hatchability in broiler breeders after peak production. Br Poult Sci 64: 259–267. [CrossRef] [PubMed] [Google Scholar]
  • Taranu I, Marin D, Pistol GC, Untea A, Vlassa M, Filip M, Anghel AC. 2022. Assessment of the ability of dietary yeast-fermented rapeseed meal to modulate inflammatory and oxidative stress in piglets after weaning. J Anim Feed Sci 31 (2): 109–122. [CrossRef] [Google Scholar]
  • Taranu I, Pistol GC, Anghel AC, Marin D, Bulgaru C. 2022. Yeast-fermented rapeseed meal extract is able to reduce inflammation and oxidative stress caused by Escherichia coli lipopolysaccharides and to replace ZnO in Caco-2/HTX29 co-culture cells. Int J Mol Sci 23. [Google Scholar]
  • Thavonnan W, Songserm O, Jitviriyanon S. 2020. Use of fermented soybean meal with Bacillus subtilis TJ-C9 in nursery pig diets. Kaen Kaset Khon Kaen Agric J 48: 323–332. [Google Scholar]
  • Tsai CF, et al. 2021. Assessment of intestinal immunity and permeability of broilers on partial replacement diets of two-stage fermented soybean meal by Bacillus velezensis and Lactobacillus brevis ATCC 367. Animals 11. [PubMed] [Google Scholar]
  • Tsai CF, et al. 2022. Effects of fermented soybean meal with Bacillus velezensis, Lactobacillus spp. or their combination on broiler performance, gut antioxidant activity and microflora. Anim Biosci 35: 1892–1903. [CrossRef] [PubMed] [Google Scholar]
  • Vlassa M, et al. 2022. The yeast fermentation effect on content of bioactive, nutritional and antinutritional factors in rapeseed meal. Foods 11. [Google Scholar]
  • Wang M, et al. 2020. Research progress on the application of microbial fermentation in improving the quality of rapeseed meal. Chin J Oil Crop Sci 42: 313–324. [Google Scholar]
  • Wang W, et al. 2020. Dietary fermented soybean meal replacement alleviates diarrhoea in weaned piglets challenged with enterotoxigenic Escherichia coli K88 by modulating inflammatory cytokine levels and cecal microbiota composition. BMC Vet Res 16. [Google Scholar]
  • Wlazło Ł, Nowakowicz-Dębek B, Ossowski M, Łukaszewicz M, Czech A. 2022. Effect of fermented rapeseed meal in diets for piglets on blood biochemical parameters and the microbial composition of the feed and faeces. Animals 12. [PubMed] [Google Scholar]
  • Wu P, et al. 2020. Effect of partial replacement of soybean meal with high-temperature fermented soybean meal in antibiotic-growth-promoter-free diets on growth performance, organ weights, serum indexes, intestinal flora and histomorphology of broiler chickens. Anim Feed Sci Technol 269. [Google Scholar]
  • Xie K, et al. 2022. Effects of fermented soybean meal on growth performance, meat quality, and antioxidant capacity in finishing pigs. J Funct Foods 94. [Google Scholar]
  • Xiong Y, et al. 2021. Effects of compound probiotics solid-state fermented soybean meal on growth performance, intestinal morphology and intestinal microbiota of weaned piglets. Chin J Anim Nutr 33: 747–759. [Google Scholar]
  • Yan H, et al. 2022. Fermented soybean meal increases nutrient digestibility via the improvement of intestinal function, antioxidative capacity and immune function of weaned pigs. Animal 16. [Google Scholar]
  • Yu J, et al. 2020. Dietary protease improves growth performance and nutrient digestibility in weaned piglets fed diets with different levels of soybean meal. Livest Sci 241: 104179. [CrossRef] [Google Scholar]
  • Zhang Y, et al. 2020. Peptides derived from fermented soybean meal suppress intestinal inflammation and enhance epithelial barrier function in piglets. Food Agric Immunol 31: 120–135. [CrossRef] [Google Scholar]
  • Zhou XR, et al. 2020. Evaluation of nutritional value of fermented rapeseed meal in growing-finishing pigs. Acta Vet Zootech Sin 51: 524–533. [Google Scholar]
  • Zhu X, Wang L, Zhang Z, Ding L, Hang S. 2021. Combination of fibre-degrading enzymatic hydrolysis and lactobacilli fermentation enhances utilisation of fibre and protein in rapeseed meal as revealed in simulated pig digestion and fermentation in vitro. Anim Feed Sci Technol 278. [Google Scholar]

Cite this article as: Heuzé V, Carré P, Borde IdL, Tormo E, Tran G. 2025. Could fermentation of soybean and rapeseed meal be an avenue for innovation in French pig feed? OCL 32: 20. https://doi.org/10.1051/ocl/2025010

All Tables

Table 1

Distribution of microorganisms by kingdoms, genera and for the most represented genera, species (N=number of occurrences in studies where the microorganisms are specified).

In the text
Table 2

Effect of the fermentation on the composition of the soybean meals (Fermented ‐ Raw) / Raw x 100.

In the text
Table 3

Effect of the fermentation on the composition of the rapeseed/canola meals (Fermented ‐ Raw) / Raw x 100x

In the text
Table 4

Growth performances in pig production. The first line for each reference gives the performance for the control and the following lines the variation versus control in percentage (test − control)/control x 100.

In the text

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