The hard texture and poor palatability of straw are important factors that hinder its application in feed. Expansion is a technology that can improve the utilization of biomass, but few studies have comprehensively revealed how to change physicochemical characteristics to improve nutritional value. In this study, mechanical and chemical methods were combined to study the texture properties, rheological properties, and physicochemical structures of straw, and its utilization value was evaluated by in vitro rumen digestion. Expansion caused hemicellulose degradation, cellulose separation, and lignin redistribution, resulting in a decrease in crystallinity. The hardness and chewiness of expanded straw were reduced by 55% to 66%, significantly improving palatability. The compressive stress could be reduced by 54–73%, and the relaxation elasticity was reduced by 5% when expanded straw was compressed. The compression deformation of expanded straw was doubled compared to feedstock, and the compacting degree was improved. Expanded straw significantly improved digestibility and gas production efficiency, which was due to the pore structure increasing the attachment of rumen microorganisms; besides that, the reduction of the internal structural force of the straw reduced energy consumption during digestion. The lignin content decreased by 10%, the hardness decreased further in secondary expansion, but the digestibility did not improve significantly.

To investigate the yeast population dynamics during air exposure in total mixed ration (TMR) silage containing sweet potato residue. TMR were ensiled in laboratory silos (1 kg) with or without two lactic acid bacteria strains, Lactobacillus plantarum (LP), and Lactobacillus amylovorus (LA). Fermentation characteristics were measured and yeast population was investigated by ITS1 region gene sequencing using Illumina MiSeq platform. All treatments were well ensiled, and L. amylovorus improved aerobic stability. During aerobic exposure, Pichia kudriavzevii was detected with increased relative abundance in all treatments and more relative abundant in LP. Pichia fermentans was more relative abundant in control. Higher relative abundance of Pichia anomala was detected in deteriorating LP. The relative abundance of Pichia ohmeri increased during later aerobic exposure in the control and LA, with a significant increase in the count of yeast population. Despite Cryptococcus was detected more relative abundant during early stage of aerobic exposure, the yeast population was below the detection limit. Aerobic deterioration was characterized by an increase in operational taxonomic units of Pichia. High relative abundance of P. anomala and P. kudriavzevii made aerobic deterioration easier. Inhibition of P. fermentans might be an effective strategy for improving the aerobic stability to some instance.

Applying microbial organic fertilizer (MOF) effectively improves soil tilth and microbial diversity. However, there were few studies about the changes incurred in the physicochemical properties and bacterial diversity in the farmland of North China at a large-scale following MOF application. This study aimed to investigate the soil physicochemical properties and bacterial community following MOF application. A total of 910 t MOF was used on 173 hectares of degraded soil, and the results indicated increased nutrients in the top plough layer. Compared to controls, the treated samples had significant higher organic matter, total nitrogen, available phosphorus, potassium, and hydrolyzed nitrogen (p < 0.05). Furthermore, MOF application also induced a slight increase in the soil bacterial richness, but a significant decrease in the evenness was observed, where Firmicutes, Actinobacteria, and Bacteroidetes were enriched in the treated group, with Bacillus and Arthrobacter being the dominant genera, accounting for 0.291 and 0.136, respectively. Similarly, an increase in the proportion of Pseudomonas and Psychrobacillus was also observed at up to 0.038 and 0.034, respectively. The MOF treatment improved complex carbon metabolism and nitrogen reduction functions, inhibiting nitrogen oxidation as represented by nitrification. Redundancy and correlation analyses showed that total nitrogen, available phosphorus, and pH were the main factors driving the soil microbial community. This study concluded that MOF application could improve the soil’s physicochemical properties and enhance the abundance and function of soil microbes, which is an effective method for improving the soil tilth and ecology of farmland in north China.

Oxytropis glabra (OG) is a leguminous forage that is potentially valuable for solving the shortage of feed for livestock production, while, in large quantities, it may be toxic because of its swainsonine (SW) content. In this study, OG was ensiled with whole-plant corn (Zea mays L.) at 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, and 0:10 ratios on a fresh matter basis, and, after 60 d of ensiling, the chemical composition, fermentation characteristic, SW removal rate, lactic acid bacteria (LAB) populations, and their capabilities for SW removal were analyzed. As the proportion of corn in the silage increased, the pH, as well as the propionic acid, ammonia-N, dry matter, crude protein, and SW contents, decreased linearly, while the lactic acid, neutral detergent fiber, and residual water-soluble carbohydrate contents increased linearly. Lactobacillus plantarum was the most common microorganism present in all mixture silages. Lactobacillus amylovorus and Lactobacillusbrevis were prevalent at lower ratios of corn to OG. Meanwhile, the LAB strains belong to L. amylovorus and L. plantarum had a higher SW removal rate. Our results suggested that ensiling OG with whole-plant corn improves fermentation and decreases SW content, and that 5:5 is the optimal ratio, so this type of mixed silage could make OG useable for ruminant production.

Objective: This study investigated a method of preparing corn stover for Irpex lacteus (I. lacteus) treatment to improve its in vitro rumen degradability under non-sterile conditions.Methods: Corn stover was inoculated with Lactobacillus plantarum (L. plantarum), Lactobacillus buchneri (L. buchneri), and an equal mixture of these strains, and ensiled for 0, 3, 7, 14, and 28 days. After each period, a portion of the silage was sampled to assess the silage quality, and another portion of the silage was further treated with I. lacteus at 28°C for 28 d. All the samples were analyzed for fermentation quality, chemical composition, and in vitro gas production (IVGP) as a measure of rumen fermentation capacity.Results: Lactic acid bacteria (LAB) was found to improve the silage quality of the corn stover, and the corn stover silage inoculated with L. plantarum produced more lactic acid and higher IVGP than other silage groups. The I. lacteus colonies flourished in the early stage of corn stover silage, especially on the 3-d corn stover silage inoculated with both L. plantarum and L. buchneri. This led to an 18% decrease in the acid detergent lignin content, and a 49.6% increase in IVGP compared with the raw stover.Conclusion: The combination of ensiling with the mixed LAB inoculation and I. lacteus treatment provided a cost-effective method for the improvement of the IVGP of corn stover from 164.8 mL/g organic matter (OM) to 246.6 mL/g OM.