scholarly journals Profiles of Odd- and Branched-Chain Fatty Acids and Their Correlations With Rumen Fermentation Parameters, Microbial Protein Synthesis, and Bacterial Populations Based on Pure Carbohydrate Incubation in vitro

2021 ◽  
Vol 8 ◽  
Author(s):  
Hangshu Xin ◽  
Nazir Ahmad Khan ◽  
Xin Liu ◽  
Xin Jiang ◽  
Fang Sun ◽  
...  

The objectives of this study were to evaluate changes in profiles of odd- and branched-chain fatty acids (OBCFA), including pentadecanoic acid (C15:0), 13-methyltetradecanoic acid (iso-C15:0), 12-methyltetradecanoic acid (anteiso-C15:0), 14-methylpentadecanoic acid (iso-C16:0), heptadecanoic acid (C17:0), 15-methylhexadecanoic acid (iso-C17:0), and 14-methylhexadecanoic acid (anteiso-C17:0) during in vitro fermentation of pure carbohydrates mixtures in the buffer-rumen fluid. The second objective was to correlate the changes in the OBCFA profile to the corresponding changes in ruminal fermentation parameters, microbial crude protein (MCP) synthesis, and bacterial populations. Five pure carbohydrates mixtures containing different cellulose: starch (C:S) ratios, i.e., 0:100, 25:75, 50:50, 75:25, and 100:0, were incubated for 6, 12, 18, and 24 h in vitro. The results showed that there was significant interaction (P < 0.05) between C:S and incubation time for changes in all OBCFA profiles, except iso-C17:0. The highest concentration of total OBCFA (3.94 mg/g dry matter; DM) was observed in the residues after 24 h of fermentation when the C:S was 0:100, while the lowest concentration of OBCFA (1.65 mg/g DM) was produced after 6 h of incubation when the C:S was 50:50. The correlation analysis revealed that the concentration of iso-C16:0 might be a potential marker for the estimation of total volatile fatty acids (ρ = 0.78) and MCP synthesis (ρ = 0.82) in the rumen. Compared to starch degrading bacteria, cellulolytic bacteria had stronger correlations with OBCFA concentrations, and the strongest correlation was found between the population of Ruminococcus flavefaciens with C15:0 concentration (ρ = 0.70). Notably, this is the first paper reporting relationship between OBCFA with rumen fermentation products and microbial protein synthesis based on fermentation of pure carbohydrates mixtures in vitro, and thus avoid confounding interference from dietary protein and fat presence in the in vivo studies. However, more in-depth experiments are needed to substantiate the current findings.

2020 ◽  
Author(s):  
Hangshu Xin ◽  
Xin Liu ◽  
Xin Jiang ◽  
Chunlong Liu ◽  
Shuzhi Zhang ◽  
...  

Abstract Background: The objectives of this study were to evaluate the profiles of odd- and branched-chain fatty acids (OBCFA; including C15:0, iso-C15:0, anteiso-C15:0, iso-C16:0, C17:0, iso-C17:0 and anteiso-C17:0) during pure carbohydrates incubation in vitro and whether they correlated with ruminal fermentation parameters, microbial crude protein (MCP) synthesis, and bacterial populations. The pure substrates containing five different ratios of fiber and starch (F:S; 0:100, 25:75, 50:50, 75:25 and 100:0) were incubated for 6 h, 12 h, 18 h and 24 h. Results: Except iso-C17:0, OBCFA concentrations were interacted by F:S and incubation time. The highest concentration of total OBCFA was found in the fermented mixture after 24 h of incubation when the F:S = 0:100; while the lowest level was 1.65 mg/g DM produced after 6 h of incubation with F:S = 50:50. The concentrations of total volatile fatty acids (TVFA) and MCP remarkably decreased linearly as the inclusion of fiber in the substrates increased, as expected. The proportions of investigated cellulolytic bacteria in our study were increased linearly (or linearly and quadratically) while those of R. amylophilus and S. bovis were decreased as fiber inclusion increased. The correlation analysis indicated that iso-C16:0 concentration might have potential as a marker of productions of TVFA and MCP with ρ being 0.78 and 0.82 respectively. Compared to starch degrading bacteria, cellulolytic bacteria had more correlations with OBCFA profiles, and the strongest association was found on the population of R. flavefaciens with C15:0 concentration (ρ = 0.70). Conclusions: Our study shows there might be scope for iso-C16:0 to predict rumen productions of VFA and MCP. Notedly, this is the first paper reporting linkage of OBCFA with rumen function based on pure carbohydrate in vitro incubation, which would avoid confounding interference from dietary protein and fat presence. However, more in-depth experiments are needed to substantiate the current findings.


Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1019 ◽  
Author(s):  
Keyuan Liu ◽  
Yang Li ◽  
Guobin Luo ◽  
Hangshu Xin ◽  
Yonggen Zhang ◽  
...  

The purpose of this research was to evaluate whether relationships exist between odd- and branched-chain fatty acids (OBCFAs) originating from milk fat and the corresponding data of ruminal fermentation parameters, microbial populations, and base contents that were used to mark microbial protein in rumen. Nine lactating Holstein dairy cows with similar body weights and parity were selected in this study, and the samples of rumen and milk were collected at the early, middle, and late stages, respectively. The rumen and milk samples were collected over three consecutive days from each cow, and the ruminal and milk OBCFA profiles, ruminal fermentation parameters, bacterial populations, and base contents were measured. The results showed that the concentrations of OBCFAs, with the exception of C11:0 and C15:0, were significantly different between milk and rumen (p < 0.05). The concentrations of anteiso-fatty acids in milk were higher than those in rumen, and the contents of linear odd-chain fatty acids were higher than those of branched-chain fatty acids in both milk and rumen. Significant relationships that existed between the concentrations of C11:0, iso-C15:0, anteiso-C15:0, C15:0, and anteiso-C17:0 in rumen and milk (p < 0.05). The total OBCFA content in milk was positively related to the acetate molar proportion but negatively correlated with isoacid contents (p < 0.05). The populations of Ruminococcus albus, R. flavefacients, and Eubacterium ruminantium were significantly related to milk C13:0 contents (p < 0.05). The adenine/N ratio was negatively related to milk OBCFA content (p < 0.05) but positively associated with the iso-C15:0/iso-C17:0 ratio (p < 0.05). Milk OBCFAs were significantly correlated with ruminal fermentation parameters, ruminal bacterial populations, and base contents. Milk OBCFAs had the potential to predict microbial nitrogen flow, and the prediction equations for ruminal microbial nitrogen flow were established for OBCFAs in dairy milk.


2021 ◽  
Author(s):  
Siyu Yi ◽  
Xiumin Zhang ◽  
Min Wang ◽  
Caixia Zou ◽  
Xuezong Chen ◽  
...  

Abstract Background: Starch has faster rate of rumen fermentation than fiber, and always causes a rapid increase in ruminal molecular hydrogen (H2) partial pressure and microbial protein synthesis, which may promote other H2 sinks to compete H2 from methanogenesis. The study was designed to investigate the effects of increasing starch content on methane (CH4), hydrogen gas (gH2) production, rumen fermentation, metabolic hydrogen ([H]) production, microbial protein (MCP) synthesis through in vitro ruminal batch incubation. Methods: Seven different treatments was prepared by replacing corn straw with corn grain, and starch content were 72, 185, 297, 410, 525, 634 and 747 g/kg DM.Results: Elevating starch content increased DM degradation (Plinear < 0.001), and decreased the CH4 (Plinear and Pquadratic < 0.001) and gH2 (Plinear < 0.001) productions relative to DM degraded. Elevating starch content increased VFA concentration (Plinear < 0.001), propionate molar percentage (Plinear < 0.001; Pquadratic = 0.001) and MCP concentration (Plinear and Pquadratic < 0.001), and decreased acetate molar percentage (Plinear < 0.001), acetate to propionate ratio (Plinear < 0.001) and estimated net [H] production relative to DM degraded (Plinear < 0.001). Elevating starch content decreased molar percentage of [H] utilized for CH4 (Pquadratic = 0.003) and gH2 (Plinear < 0.001) production. Conclusion: Increasing starch content alters rumen fermentation pathway from acetate to propionate production with reduction in efficiency of [H] production, promotes H2 utilization with enhanced MCP synthesis and leads to the reduction in efficiency of CH4 and gH2 production.


2003 ◽  
Vol 2003 ◽  
pp. 151-151
Author(s):  
B. Vlaeminck ◽  
V. Fievez ◽  
H. van Laar ◽  
D. Demeyer

Rumen microbes contain a high proportion (20 to 50%) of their fatty acids (FA) as odd and branched chain fatty acids (OBCFA; C15:0, iso C15:0, anteiso C15:0, C17:0; iso C17:0; anteiso C17:0 and C17:1) and different bacterial classes have distinctive OBCFA ‘fingerprints’. As OBCFA make up around 5% of FA in milk, it has been suggested that there is scope for these compounds to be used in on-farm diagnostic milk-based tests in relation to the rumen fermentation pattern. Correlations of milk OBCFA with rumen fermentation pattern were recently shown (Vlaeminck et al., 2002). In the current in vitro study, the potential of rumen OBCFA to predict the production of volatile fatty acids (VFA) was evaluated.


2022 ◽  
Vol 951 (1) ◽  
pp. 012004
Author(s):  
S Nayohan ◽  
K G Wiryawan ◽  
A Jayanegara

Abstract The aim of this study was to determine the effect of coating urea by chitosan at graded levels on ammonia concentration and rumen fermentation in vitro. This study used Factorial Randomized Complete Block Design (RCBD) to test ammonia parameter and Randomized Complete Block Design (RCBD) for pH, microbial protein synthesis, dry matter and organic matter digestibility, and Volatile Fatty Acid (VFA). The treatments tested were: P0 = addition non coating urea 1%; P1 = coating urea by chitosan 1%; P2 = coating urea by chitosan 2%; P3 = coating urea by chitosan 3%. The data obtained were analysed by using ANOVA and continued with Tukey HSD test with SPSS version 25. The results of this study showed that the coating of urea chitosan had no significant effect on pH, dry matter and organic matter digestibility, microbial protein synthesis, and amonia concentration in the rumen. However, it significantly reduced (P <0.05) total VFA concentration. It can be concluded that the application of urea coating by chitosan does not affect on the degradation of urea in the rumen.


Sign in / Sign up

Export Citation Format

Share Document