Effects of sodium diacetate on the fermentation profile, chemical composition and aerobic stability of alfalfa silage

Xianjun Yuan,AiYou Wen,Seare T. Desta,Jian Wang,Tao Shao 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: The objective of this study was to evaluate the effect of sodium diacetate (SDA) on fermentation profile, chemical composition and aerobic stability of alfalfa (Medicago sativa L.) silage. Methods: Fresh alfalfa was ensiled with various concentrations of SDA (0, 3, 5, 7, and 9 g/kg of fresh forage). After 60 days of the ensiling, the samples were collected to examine the fermentative quality, chemical composition and aerobic stability. Results: The application of SDA significantly (p<0.05) decreased silage pH with the lowest value in silage with 7 g/kg of SDA. The proliferations of enterobacteria, yeasts, molds and clostridia were inhibited by SDA, resulted in lower ethanol, propionic and butyric acid concentrations and dry matter loss in SDA treated silages than control. The increasing SDA linearly decreased free amino acid N (p<0.001), ammonia N (p = 0.018) and non-protein N (p<0.001), while linearly increased water soluble carbohydrate (p<0.001) and peptide N (p<0.001). It is speculated that SDA accelerated the shift from homofermentative to heterofermentative lactic acid bacteria during the silage fermentation, indicated by lower lactic acid production in SDA-9 than SDA-7 silages after 60 days of ensiling. Alfalfa silages treated with SDA at 7 g/kg had highest Flieg’s point and remained stable more than 9 d during aerobic exposure under humid and hot conditions in southern China. Conclusion: SDA may be used as an additive for alfalfa silages at a level of 7 g/kg.

Improvement of Fermentation and Nutritive Quality of Straw-grass Silage by Inclusion of Wet Hulless-barley Distillers' Grains in Tibet

Yuan, Xianjun,Yu, Chengqun,Shimojo, M.,Shao, Tao Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.4

In order to develop methods that would enlarge the feed resources in Tibet, mixtures of hulless-barley straw and tall fescue were ensiled with four levels (0, 10%, 20%, and 30% of fresh weight) of wet hulless-barley distillers' grains (WHDG). The silos were opened after 7, 14 or 30 d of ensiling, and the fermentation characteristics and nutritive quality of the silages were analyzed. WHDG addition significantly improved fermentation quality, as indicated by the faster decline of pH, rapid accumulation of lactic acid (LA) (p<0.05), and lower butyric acid content and ammonia-N/total N (p<0.05) as compared with the control. These results indicated that WHDG additions not only effectively inhibited the activity of aerobic bacteria, but also resulted in faster and greatly enhanced LA production and pH value decline, which restricted activity of undesirable bacteria, resulting in more residual water soluble carbohydrates (WSC) in the silages. The protein content of WHDG-containing silages were significantly higher (p<0.05) higher than that of the control. In conclusion, the addition of WHDG increased the fermentation and nutritive quality of straw-grass silage, and this effect was more marked when the inclusion rate of WHDG was greater than 20%.

Subgingival microbiome in periodontitis and type 2 diabetes mellitus: an exploratory study using metagenomic sequencing

Xianjun Lu,Tingjun Liu,Jiani Zhou,Jia Liu,Zijian Yuan,Lihong Guo 대한치주과학회 2022 Journal of Periodontal & Implant Science Vol.52 No.4

Purpose: To explore differences in the subgingival microbiome according to the presence of periodontitis and/or type 2 diabetes mellitus (T2D), a metagenomic sequencing analysis of the subgingival microbiome was performed. Methods: Twelve participants were divided into 4 groups based on their health conditions (periodontitis, T2D, T2D complicated with periodontitis, and generally healthy). Subgingival plaque was collected for metagenomic sequencing, and gingival crevicular fluids were collected to analyze the concentrations of short-chain fatty acids. Results: The shifts in the subgingival flora from the healthy to periodontitis states were less prominent in T2D subjects than in subjects without T2D. The pentose and glucuronate interconversion, fructose and mannose metabolism, and galactose metabolism pathways were enriched in the periodontitis state, while the phosphotransferase system, lipopolysaccharide (LPS) and peptidoglycan biosynthesis, bacterial secretion system, sulfur metabolism, and glycolysis pathways were enriched in the T2D state. Multiple genes whose expression was upregulated from the red and orange complex bacterial genomes were associated with bacterial biofilm formation and pathogenicity. The concentrations of propionic acid and butyric acid were significantly higher in subjects with periodontitis, with or without T2D, than in healthy subjects. Conclusions: T2D patients are more susceptible to the presence of periodontal pathogens and have a higher risk of developing periodontitis. The pentose and glucuronate interconversion, fructose and mannose metabolism, galactose metabolism, and glycolysis pathways may represent the potential microbial functional association between periodontitis and T2D, and butyric acid may play an important role in the interaction between these 2 diseases. The enrichment of the LPS and peptidoglycan biosynthesis, bacterial secretion system, and sulfur metabolism pathways may cause T2D patients to be more susceptible to periodontitis.

Characteristics of isolated lactic acid bacteria and their effects on the silage quality

Siran Wang,Xianjun Yuan,Zhihao Dong,Junfeng Li,Gang Guo,Yunfeng Bai,Junyu Zhang,Tao Shao 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: Four lactic acid bacteria (LAB) strains isolated from common vetch, tall fescue and perennial ryegrass on the Tibetan Plateau were characterized, and their effects on the fermentation quality of Italian ryegrass (Lolium multiflorum Lam.) silage were studied. Methods: The four isolated strains and one commercial inoculant (G, Lactobacillus plantarum MTD-1) were evaluated using the acid production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. The five LAB strains were added to Italian ryegrass for ensiling at three different temperatures (10°C, 15°C, and 25°C). Results: All isolated strains (LCG3, LTG7, I5, and LI3) could grow at 5°C to 20°C, pH 3.0 to 8.0 and NaCl (3.0%, 6.5%). Strains LCG3, LTG7, I5, and LI3 were identified as Lactobacillus plantarum, Pediococcus acidilactici, Lactobacillus paraplantarum, and Lactobacillus casei by sequencing 16S rDNA, respectively. All LAB inoculants significantly (p<0.05) increased lactic acid (LA) contents and ratios of lactic acid to acetic acid, and reduced pH and ammonia nitrogen/ total nitrogen (AN/TN) compared with uninoculated silages at various temperatures (10°C, 15°C, and 25°C). Compared to the commercial inoculant G, I5, and LI3 showed similar effects on improving the silage quality of Italian ryegrass at 10°C and 15°C, indicated by similar pH, LA content and AN/TN. Conclusion: All inoculants could improve the silage fermentation quality at various temperatures (10°C, 15°C, and 25°C). At the temperature of 10°C and 15°C, strain I5 and LI3 had similar effects with the commercial inoculant G on improving the silage quality of Italian ryegrass.

Effects of calcium propionate on the fermentation quality and aerobic stability of alfalfa silage

Dong, Zhihao,Yuan, Xianjun,Wen, Aiyou,Desta, Seare T.,Shao, Tao Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.9

Objective: To assess the potency of calcium propionate (CAP) used as silage additive, an experiment was carried out to evaluate the effect of CAP on the nitrogen transformation, fermentation quality and aerobic stability of alfalfa silages. Methods: Alfalfa was ensiled with four levels of CAP (5, 10, 15, and 20 g/kg of fresh weight [FW]) in laboratory silos for 30 days. After opening, the silages were analyzed for the chemical and microbiological characteristics, and subjected to an aerobic stability test. Results: The increasing proportion of CAP did not affect pH, lactic acid (LA) concentrations and yeast counts, while linearly decreased counts of enterobacteria (p = 0.029), molds (p<0.001) and clostridia (p<0.001), and concentrations of acetic acid (p<0.001), propionic acid (p<0.001), butyric acid (p<0.001), and ethanol (p = 0.007), and quadratically (p = 0.001) increased lactic acid bacteria counts. With increasing the proportion of CAP, the dry matter (DM) loss (p<0.001), free amino acid N (p<0.001), ammonia N (p = 0.004), and non-protein N (p<0.001) contents were linearly reduced, whereas DM (p = 0.048), water soluble carbohydrate (p<0.001) and peptide N (p<0.001) contents were linearly increased. The highest Flieg's point was found in CAP10 (75.9), represented the best fermentation quality. All silages treated with CAP improved aerobic stability as indicated by increased stable hours compared with control. Conclusion: The addition of CAP can suppress the undesirable microorganisms during ensiling and exposure to air, thereby improving the fermentation quality and aerobic stability as well as retarding the proteolysis of alfalfa silage. It is suggested that CAP used as an additive is recommended at a level of 10 g/kg FW.

Research on Large‑scale Photovoltaic Planning Based on Risk Assessment in Distribution Network

Lei Wang,Minyu Yuan,Fan Zhang,Xuli Wang,Jing Ma,Lei Dai,Xianjun Qi,Rui Bi 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

Risks caused by large amounts of distributed photovoltaic (PV) feeding into distribution networks, have an impact on PV planning, which has become a critical consideration for distribution networks’ operation. In this paper, a large-scale PV planning method is proposed which based on risk assessment in distribution networks. Cluster division is used to group large-scale distributed PVs. A risk assessment is performed on the distribution network, considering the correlation between PVs and loads. The efects of load fuctuations, PV quantity, capacity and location on the operational risk of the distribution network are analyzed and discussed. A large-scale PV planning model is established with the goal of maximizing the comprehensive benefts, considering the penalty cost of node voltage over-limit and branch power fow over-limit risk. Finally, the genetic algorithm is used to solve the planning model. The simulation results demonstrate the efectiveness of the proposed method.

Effect of Applying Molasses and Propionic Acid on Fermentation Quality and Aerobic Stability of Total Mixed Ration Silage Prepared with Whole-plant Corn in Tibet

Chen, Lei,Guo, Gang,Yuan, Xianjun,Shimojo, Masataka,Yu, Chengqun,Shao, Tao Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.3

The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR) silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM) was ensiled with four different treatments: no additive (control), molasses (M), propionic acid (P), and molasses+propionic acid (PM), in laboratory silos (250 mL) and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN), and high lactic acid (LA) content and V-scores. M silage showed the highest (p<0.05) LA content and higher dry matter (DM) recovery than the control and P silages. P silage had lower (p<0.05) LA content than the control silage. During aerobic exposure, lactic acid contents decreased gradually in the control and M silages, while that of P and PM silages increased, and the peak values were observed after 9 d. M silage had similar yeast counts with the control silage (> $10^5$ cfu/g FM), however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (< $10^5$ cfu/g FM) (p<0.05) and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage.

Comparison of nitrogen transformation dynamics in non-irradiated and irradiated alfalfa and red clover during ensiling

Zhihao Dong,Junfeng Li,Lei Chen,Xianjun Yuan,Tao Shao 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.10

Objective: To study the contribution of plant enzyme and microbial activities on protein degradation in silage, this study evaluated the nitrogen transformation dynamics during ensiling of non- and irradiated alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.). Methods: Alfalfa and red clover silages were prepared and equally divided into two groups. One group was exposed to γ-irradiation at a recommended dosage (25 Gky). Therefore, four types of silages were produced: i) non-irradiated alfalfa silage; ii) irradiated alfalfa silage; iii) non-irradiated red clover silage; and iv) irradiated red clover silage. These silages were opened for fermentation quality and nitrogen components analyses after 1, 4, 8, and 30 days, respectively. Results: The γ-irradiation successfully suppressed microbial activity, indicated by high pH and no apparent increases in fermentation end products in irradiated silages. All nitrogen components, except for peptide-N, increased throughout the ensiling process. Proteolysis less occurred in red clover silages compared with alfalfa silages, indicated by smaller (p<0.05) increment in peptide-N and free amino acid N (FAA-N) during early stage of ensiling. The γ-irradiation treatment increased (p<0.05) peptide-N and FAA-N in alfalfa silage at day 1, whereas not in red clover silage; these two nitrogen components were higher (p<0.05) between day 4 and day 30 in non-irradiated silages than the irradiated silages. The ammonia nitrogen and non-protein nitrogen were highest in non-irradiated alfalfa silage and lowest in irradiated red clover silage after ensiling. Conclusion: The result of this study indicate that red clover and alfalfa are two forages varying in their nitrogen transformation patterns, especially during early stages of ensiling. Microbial activity plays a certain role in the proteolysis and seems little affected by the presence of polyphenol oxidase in red clover compared with alfalfaa.