The increasing demand for plant-based dairy alternatives highlights the need to improve the texture, stability, and microbial performance of soy milk yogurts. Using whole soy milk that retains okara enables direct valorization of soybean residue, eliminating okara as a by-product and reducing waste generation in soybean processing. Therefore, the objective of this study was to investigate the effect of mechanical and ultrasonic treatments on the physicochemical properties and bacterial activity of fermented dairy products made from whole soy milk containing okara (WSM). For this purpose, standard soy milk without okara (SSM) and WSM were prepared and used as references. The WSM was subjected to high-shear mixing (HSM), ultrasound (US), a combination of HSM and US (HSM+US) or a combination of HSM and high-pressure homogenization (HSM+HPH). All samples were fermented using a mixture of Streptococcus thermophilus and Lactobacillus bulgaricus. The results showed that WSM reduced the time required to reach pH 4.5 by 32% and enhanced the viability of S. thermophilus, maintaining a cell count above 107 CFU/g at the end of cold storage. WSM also reduced syneresis by 40% and increased hardness by 613% after HSM+US and by 594% after US compared to SSM. These findings suggest that stable soy milk-based yoghurt products with enhanced properties can be produced by combining WSM with mechanical or ultrasonic treatments.

Rising fall and winter temperatures associated with climate change can disrupt the cold acclimation process of perennial plants, leading to winter injuries and increased mortality. Using recurrent selection, new populations of the perennial forage alfalfa (Medicago sativa L.) were developed to increase winter survival and improve freezing-tolerance. Recurrent selection can lead to profound changes in plant traits, however, little is known about how shifts in plant biochemical profiles and allocation across seasons may influence recruitment of plant microbiomes. We conducted an overwintering experiment in an unheated greenhouse with two different alfalfa cultivars and corresponding recurrently selected populations planted in agricultural soils. We quantified changes in plant biomass, root and aboveground metabolomes, and nodule and root microbiomes (including microbial community composition and functional potential), from initial growth (non-acclimated), over winter (cold acclimated) and into spring (de-acclimated). Plants selected for freezing tolerance had increased spring shoot and root biomass. Distinct changes in biochemical profiles were linked with degree of selection and changes in the root and nodule microbial communities. Degree of cultivar selection was associated to variation in bacterial nodule communities during spring regrowth. The potential for microbial nitrogen fixation and the size of the recruited rhizobia (Sinorhizobium (Ensifer) meliloti) population in both root and nodule tissues was also strongly influenced by season, but not by degree of selection. Our results demonstrate that selection for freezing tolerance along with season, strongly influences plant metabolomes and microbial community structure, but not the potential for microbial nitrogen fixation.

Effects of contrasted energy to protein ratios in alfalfa on in vitro rumen degradation characteristics and microbial composition were evaluated. Thirty-six alfalfa forages categorized as either superior (2.0) non-fiber carbohydrates (NFC) to crude protein (CP) ratio (NFC/CP; Ratio +; n = 18) or inferior (0.9) NFC/CP ratio (Ratio –; n = 18) were compared using a batch-culture in vitro technique. Forages were similar in their neutral detergent fiber concentrations (340 g/kg). Statistical analysis model considered treatment (Ratio + and Ratio –) as fixed effect while incubation run was a random effect, with significant treatment effect declared at P ≤ 0.05. After 24 h of incubation, apparent degradability of dry matter (DM; 57 vs. 53%), total gas production (263 vs. 228 mL) and total volatile fatty acids concentration (VFA; 48 vs. 42 mM) in ruminal fluid were greater for Ratio + than Ratio – alfalfa. Microbial N use efficiency (69 vs. 56 g of microbial N/100 g of N incubated) was greater with Ratio + than Ratio –, which was associated with an increase in ammonia-utilizing bacteria in the Ratio +. This work highlights the potential to reduce the environmental footprint of ruminants through forage management and plant breeding.

In forages, genetic improvement in readily fermentable energy can improve the energy‐to‐protein balance, thus reducing N losses to the environment. This study aimed to evaluate the effects of recurrent selection targeting high nonfiber carbohydrate (NFC) concentrations in alfalfa stems on nutritive value and biomass yield. Populations developed after one to three cycles of recurrent selection for NFC (NFC1, NFC2, and NFC3) and a control population (NFC0) were evaluated in a field trial at three sites across Canada, and in a greenhouse trial along with the population developed after a fourth cycle of selection for NFC (NFC4). When comparing NFC3 to NFC0, increases in NFC concentration of 14 and 28 g kg −1 dry matter (DM) were observed in field and greenhouse trials, respectively. This increase reached 45 g kg −1 DM for NFC4 compared to NFC0 in the greenhouse trial. Crude protein (CP) concentration was similar among populations in both trials, resulting in an increase in their NFC/CP ratio. Fiber concentrations were lowered, which resulted in an increase in in vitro DM digestibility of more than 10 g kg −1 DM for NFC3 in the field and for NFC4 in the greenhouse trials, as compared with NFC0. None of the selected populations displayed significant annual yield differences. The recurrent phenotypic selection for high stem NFC concentrations is an effective approach to improve alfalfa NFC concentration while increasing its energy‐to‐protein balance and digestibility, and maintaining its biomass productivity.

Rhizobia strain selection is mostly based on nodulation efficiency with host-plant. Selected strains also require a high capacity to compete with indigenous soil rhizobia under various abiotic stresses to prevent nodule occupation by competitive but low-efficient native strains. In this experiment, three highly-efficient strains were selected out of six genetically-divergent strains, based on nodulation speed, nitrogenase activity, and alfalfa biomass accumulation under spring conditions. Strain competitiveness was assessed by determining the percent of alfalfa nodules occupancy by selected tagged strains. Two alfalfa populations, A-TF0 and A-TF7, differing in their tolerance to freezing as well as two soils originating from south and north of Quebec containing indigenous rhizobia were tested. More nodules were recorded on roots of freezing-tolerant alfalfa in southern soil. Highly-efficient strain NRG34, isolated from northern Canada, proved to be very competitive as shown by a greater nodule occupancy percentage than any other strain in cold soil.

Background: Winter climate change including frequent freeze-thaw episodes and shallow snow cover will have major impacts on the spring regrowth of perennial crops. Non-bloating perennial forage legume species including sainfoin, birdsfoot trefoil, red clover, and alsike clover have been bred for their adaptation to harsh winter conditions. In parallel, the selection of cold-tolerant rhizobial strains could allow earlier symbiotic nitrogen (N) fixation to hasten spring regrowth of legumes. Methods: To identify strains forming nodules rapidly and showing high N-fixing potential, 60 rhizobial strains in association with four temperate legume species were evaluated over 11 weeks under spring soil temperatures for kinetics of nodule formation, nitrogenase activity, and host yield. Results: Strains differed in their capacity to form efficient nodules on legume hosts over time. Strains showing higher nitrogenase activity were arctic strain N10 with sainfoin and strain L2 with birdsfoot trefoil. For clovers, nitrogenase activity was similar for control and inoculated plants, likely due to formation of effective nodules in controls by endophyte rhizobia present in seeds. Conclusions: Selection based on nodulation kinetics at low temperature, nitrogenase activity, and yield was effective to identify performant rhizobial strains for legume crops. The use of cold-tolerant strains could help mitigate winter climatic changes.

Highlights Sweet sorghum and sweet pearl millet are interesting feedstocks for ethanol production. Biomass and juice storage are key steps for carbohydrate preservation. Produced bagasse can be valorized in many ways, including as silage or for cellulosic ethanol production. Abstract. Sweet sorghum and sweet pearl millet have been considered as potential energy crops. They have many advantages in terms of ethanol production compared to corn and sugarcane, such as lower requirements for water and fertilizers, higher tolerance to drought, and lower competition with the food sector. Sweet sorghum and sweet pearl millet stems are rich in water-soluble carbohydrates (WSC) (sucrose, fructose, and glucose), and their biomass has to be crushed for juice extraction. However, the extraction efficiency of WSC varied widely depending on the press type used and the parameters considered during the pressing process (stripping stems from leaves or not, compressive force magnitude, smooth or grooved press rollers, number of times of biomass pressing, etc.). WSCs are easily degradable, causing technical challenges related to crop handling before pressing and juice storage thereafter. Some studies focused on stem preserving methods, whereas others dealt with extending the shelf life of the juice. To make the use of sweet sorghum and sweet pearl millet as energy crops more profitable, the bagasse (residue) generated from biomass pressing can be valorized in different ways, mainly as silage or for second generation ethanol production. The objective of this review was to assess the efficiency of different presses used for juice extraction and discuss various methods tested for WSC conservation from deterioration as well as possible bagasse valorization. Keywords: Bagasse, Carbohydrates, Ethanol, Press, Sweet pearl millet, Sweet sorghum.

The ability to tolerate low freezing temperatures is an important component of winter survival and persistence of red clover. Cold acclimation (CA) allows plants to acquire higher levels of freezing tolerance. However, the biochemical responses to cold and the importance of such changes for the plant to acquire adequate freezing tolerance have not been investigated in red clover of Nordic origin, which has a distinct genetic background. To shed light on this, we selected five freezing tolerant (FT) and five freezing susceptible (FS) accessions and studied the effect of CA on the contents of carbohydrates, amino acids, and phenolic compounds in the crowns. Among those compounds which increased during CA, FT accessions had higher contents of raffinose, pinitol, arginine, serine, alanine, valine, phenylalanine, and one phenolic compound (a pinocembrin hexoside derivative) than FS accessions, suggesting a role for these compounds in the freezing tolerance in the selected accessions. These findings, together with a description of the phenolic profile of red clover crowns, significantly add to the current knowledge of the biochemical changes during CA and their role in freezing tolerance in Nordic red clover.

The study of winter stress tolerance in perennial legumes needs to consider the complete symbiotic system including both plants and bacteria since these two partners are differentially affected by stress conditions. Here, we compared the regrowth after a freezing stress of four different associations of two alfalfa populations differing in freezing tolerance (A-TF0 and A-TF7) inoculated with two Sinorhizobium (Ensifer) meliloti strains (B399 and NRG34) of contrasted adaptation to cold. To understand the contribution of each partner to a better regrowth performance of an association after freezing, we identified molecular traits having major roles in cold acclimation, freezing tolerance, and those involved in the crosstalk between alfalfa and its symbiotic partner. Regrowth after exposure to a freezing stress was 35% larger in the A-TF7 × NRG34 than in the A-TF0 × B399 association. The metabolomic study of roots, crowns and, more specifically, nodules, revealed profound changes in these organs, switching from a sink to support cold acclimation to a source of reserves enabling regrowth after deacclimation. Marked increases in concentrations of stachyose and raffinose, two sugars of the raffinose-family oligosaccharides (RFO), and in the expression level of a gene of the RFO synthetic pathway were observed in response to cold acclimation supporting the importance of a protective role for RFO in alfalfa. Both cold-adapted partners of the symbiotic association contributed to increases in arginine concentration in nodules in response to cold acclimation and deacclimation underscoring the importance of N storage and remobilization for a successful overwintering in alfalfa.

Alfalfa (Medicago sativa L., AL)-based forage mixtures are a major constituent of ruminant rations, and optimizing their energy-to-protein ratio has been identified as a way to improve N use efficiency. This study aimed to determine whether the energy-to-protein ratio could be improved by adding red clover (Trifolium pratense L., RC) or birdsfoot trefoil (Lotus corniculatus L., BT) at different seeding proportions, and/or one grass species [timothy, Phleum pratense L., or tall fescue, Schedonorus arundinaceus (Schreb.) Dumort] to AL. Annual forage yield, species proportion in botanical composition, and nutritive value of forage were measured at three sites in Canada for 2 post-seeding years. The addition of RC or BT did not affect the annual forage yield but it increased the concentration of forage nonfiber carbohydrates (NFCs), particularly of soluble sugars, and decreased concentrations of crude protein (CP), nonprotein nitrogen (NPN), and rapidly degradable protein (PB1) of AL-based mixtures. The addition of one percentage unit of RC or BT to forage botanical composition improved the NFC/CP ratio by 0.005, and the NFC/(NPN + PB1) ratio by 0.024. The addition of either grass species to AL mixtures also increased the two ratios, but it was related to a CP decrease with no increase in NFC concentrations. Adding RC or BT to AL-based mixtures is therefore a valuable strategy to increase the forage energy to protein ratio.

Sweet sorghum and sweet pearl millet are considered promising alternative feedstocks for bioethanol production. Water soluble carbohydrate (WSC) extraction from the stems for first generation ethanol production is practically well mastered. However, structural carbohydrate (SC) release from the bagasse for cellulosic ethanol production still needs to be more understood and improved, especially for sweet pearl millet. In this study, the effects of two bagasse particle sizes (4.5–9 mm and 1 mm) and two pretreatment solutions (NaOH and H2SO4) at two concentrations (1

Alfalfa ( Medicago sativa L.) cultivars developed for improved digestibility by conventional breeding or genetic modification have not been evaluated in eastern Canada. This study compared yield, nutritive value, and profitability of two reduced-lignin genetically modified (GM) cultivars, three conventionally selected for low lignin or high pectin, and one population with improved stem degradability, with two commercially adapted cultivars as controls. Alfalfa was harvested at the early bud (intensive management) or early flower (extensive management) stage of development during the first post-seeding year at three sites and the second post-seeding year at one site. All cultivars/populations had similar annual dry matter (DM) yields, except for the lower DM yield (−20%) of the improved stem degradability population. Conventionally selected cultivars for improved digestibility did not differ from control cultivars for in vitro DM digestibility (IVTD) and neutral detergent fiber digestibility (NDFd). Reduced-lignin GM cultivars, however, had a greater IVTD and NDFd (+10%) and less lignin (−10%) than control cultivars at the same stage of development. Reduced-lignin GM cultivars under extensive management had similar NDFd and greater annual DM yield (+1 to 2 Mg DM ha −1 ), but reduced total digestible nutrients (−41 to 44 g kg −1 DM), in comparison to control cultivars under intensive management. Using partial budget analysis, the comparison of more digestible GM cultivars to the control cultivars resulted in an increase in annual farm net profits ranging from CAD$7.40 to $79.60 cow −1 year −1 depending on stage of development at harvest. Further investigations are needed to quantify the performance of dairy cows fed cultivars with improved digestibility.

Fall dormancy is a vital component of alfalfa (Medicago sativa L.) yield in northern climates, but selection for the trait is often done at the expense of winter survival. We performed one cycle of selection to reduce fall dormancy in two winter hardy cultivars (Yellowhead and Peace) using a new indoor screening method. We compared the reduced dormancy populations with their respective initial cultivars for fall dormancy, yield, and winter survival at four sites across Canada. During the establishment and the first production years, plants of the reduced dormancy populations were generally taller in the fall than their respective cultivar, which resulted in a one unit increase of their fall dormancy class. Under field conditions, plants of the reduced dormancy populations had a similar winter survival than those of the initial cultivars. Under simulated winter conditions, freezing tolerance was not affected by selection for reduced dormancy in Peace, whereas a decrease from - 24.0 to - 21.5 degrees C was observed in Yellowhead. However, in this cultivar, we noted a 37% yield increase under field conditions and a 40% more vigorous regrowth under simulated winter conditions in the reduced dormancy population. These results showed that the indoor selection method effectively reduced fall dormancy and that indirect responses for yield and winter survival were dependent on the genetic background used as selection material. This selection method could therefore be promising to develop alfalfa cultivars adapted to northern latitudes with high winter hardiness and improved late season yield.

Purpose The increase in frequency of freeze–thaw episodes with the diminution of snow cover protection due to climate change compromises the winter survival of alfalfa ( Medicago sativa L.). Symbiosis with cold-tolerant rhizobial strains can improve the ability of alfalfa to survive and grow under stressful conditions. Methods Six strains of Sinorhizobium (Ensifer) meliloti were tested in combination with two alfalfa populations bred to differ in their levels of freezing tolerance. Plants of each different combination were grown for eight weeks in a growth chamber before being exposed to temperatures promoting their acclimation to cold. Plants were then exposed to a freezing stress (-11ºC) and regrown for three weeks. Shoot, root and nodule biomass were measured before cold acclimation and three weeks after the freezing stress. Results After freezing stress, the alfalfa population A-TF7 had shoot and root biomasses that were respectively 19% and 15% larger than cultivar A-TF0. Alfalfa plants inoculated with strain NRG34 showed both a larger shoot biomass and a higher nodule dry weight than plants inoculated with any other strains. Assessment of freezing damages on nodules showed that plants inoculated with NRG34 had the largest proportion of undamaged nodules or of nodules with a regeneration zone. Conclusion This study shows for the first time a relationship between nodule and shoot regrowth after a freezing stress, the latter being linked with the proportion of nodules showing less freezing damage. Our results demonstrated that both the choice of alfalfa populations and S. meliloti strains adapted to stress are complementary to increasing alfalfa persistence .

Highlights Juice extraction resulted in a decrease in the nutritive value of the bagasse as compared with the initial biomass. Silages made from the second pressing bagasse were well conserved. Sweet sorghum silage has a better nutritive value than sweet pearl millet. Abstract . Pressing the biomass of sweet sorghum and sweet pearl millet in-field is one of the suggested options for bioethanol production. The extracted juice can be delivered to an ethanol plant, and the bagasse (pressing residue) can be used for ruminant feeding. Efficient carbohydrate extraction is highly important for good ethanol yield. However, enough carbohydrates must remain in the bagasse for its adequate conservation as silage. In this study, the ensilability and the chemical composition of the second pressing bagasse of sweet sorghum and sweet pearl millet were investigated. The bagasse was obtained following a second pressing of the first pressing bagasse after its impregnation with water based on three water:bagasse ratios (0.5, 1, and 1.5). Results indicated that water:bagasse ratio did not affect water-soluble carbohydrate (WSC) extraction for both crops. The second pressing bagasse of sweet sorghum and sweet pearl millet contained 80.5 ±4.6 and 60 ±4.6 g of WSC kg-1 dry matter (DM), respectively. The second pressing bagasse of both crops had reduced nutritive value compared to the initial biomass, i.e., higher neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations along with lower non-structural carbohydrate (NSC) concentration, in vitro true digestibility of DM (IVTD), and in vitro NDF digestibility (NDFd). The second pressing bagasses of both crops also showed good ensilability, but sweet sorghum bagasse silages were of better nutritive value than sweet pearl millet bagasse silages (ADF = 446.2 ±3.7 vs. 463.2 ±3.7 g kg-1 DM, IVTD = 813.8 ±3.4 vs. 708.8 ±6.8 g kg-1 DM, and NDFd = 741.8 ±4.8 vs. 596.2 ±8.5 g kg-1 NDF, respectively). The water:bagasse ratio used for bagasse impregnation before the second pressing only affected the NDF concentration of silages, as a higher NDF concentration was obtained with a water:bagasse ratio of 1.5. Sweet sorghum and sweet pearl millet can be considered dual-purpose crops; the extracted juice can be fermented into ethanol, and the second pressing bagasse can be used to make good-quality silage. Keywords: Bagasse impregnation, Nutritive value, Silage, Sweet pearl millet, Sweet sorghum, Water-soluble carbohydrates.

Compelling evidence recently demonstrated that plants can take up nitrogen (N) as organic molecules. Yet, very little research addressed this issue in the context of organic horticulture, where N is provided as organic residues. Organic N and carbon (C) transported from roots to shoots could contribute significantly to the plant C and N accumulation. We posited that the type (organic or mineral) and amount of N fertilization affect the soluble organic N and C content of the growing medium, in turn influencing xylem sap N and C and fruit soluble solids content (SSC). To test this hypothesis, we collected growing medium, xylem sap, and fruit samples in a greenhouse cucumber crop grown in a peat-based growing medium and fertilized with organic (blood and feather meals) or mineral (ammonium nitrate) N fertilizers. The organic N source reduced growing medium concentrations of soluble mineral and organic N relative to the mineral source through microbial immobilization. Xylem sap C and N were positively linked to the soluble C and N contents of the growing medium, contributing to higher fruit SSC. A causal model is proposed, in which 62.6% of the variance observed in fruit SSC is explained by variation in mineral soluble N and soluble organic C in the growing medium and dissolved organic C and amino acids in xylem sap. Our results provide in situ indications that organic molecules in the growing medium are taken up by cucumber plants and contribute to fruit soluble solids in a context relevant to greenhouse horticulture.

High concentration of nonstructural carbohydrates (NSC) in forages improves ruminant N utilization and performance. The present study evaluated the direct and indirect effects of one cycle of divergent phenotypic selection for NSC in alfalfa along with the diurnal and seasonal stability of the trait. For this purpose, divergent NSC populations were developed (NSC+ and NSC-) and two field trials were established in Quebec, Canada. Forage samples were collected twice a day (morning and afternoon) and three times a year (spring, summer and autumn) and analysed for NSC, crude protein (CP), fibre concentration, digestibility and yield. The NSC+ population maintained greater NSC concentrations than the NSC- population over 2 establishment years (+18%, 129 vs. 109 g/kg) and three production years (+8%, 126 vs. 116 g/kg). Time of cutting and period of harvest had significant effects on alfalfa NSC concentration and other nutritive attributes, but they did not affect the response to selection for NSC concentration. Phenotypic selection for NSC concentration can therefore be used in a recurrent phenotypic selection approach to improve alfalfa nutritive value.