Volatile Fatty Acid Concentrations Research Articles

Fermentation Products, Microbial Protein Synthesis, and Hydrolytic Enzymes Activity of Rumen Fluids Local Beef Cattle Supplemented by Direct-Fed Microbials and Waru Leaf Flour

The aim of this study was to evaluate the effect of Waru Leaf Flour (WLF) and Direct-Fed Microbials (DFM) supplementation on volatile fatty acid (VFA) and ammonia (N-NH3) concentrations, total protozoa, microbial protein synthesis (MPS), and the specific activity of cellulase, amylase, protease in rumen fluids of local beef cattle. The study was conducted as an experimental investigation using a factorial Completely Randomized Design (FCRD). The first factor were three levels of DFM (P) mixed with rice straw (0%, 0.5%, and 1% dry matter of rice straw). The second factor consisted of three levels of WLF supplementation (D) in concentrates (0%, 0.24%, and 0.48% of dry matter concentrate). This resulted nine treatment groups, each it replicated three times.The diet composition consisted of rice straw and concentrate at 40:60 ratio (% dry matter). The interaction between DFM and WLF had a statistically significant impact (p<0.01) on the rumen fluid's total protozoa, N-NH3, and protein content. However, this interaction was not statistically significant (P>0.05) in relation to VFA, MPS, cellulase, amylase, and protease activity. While no significant interaction were observed for total VFA, cellulase, amylase, and protease, DFM supplementation had a statistically significant effect (P<0.01) on reducing enzymes activity, and total VFA (P<0.05). SDS-PAGE and zymography analyzes showed two protease molecules at all treatments with molecular weight of 144 kDa and 133 kDa, cellulase molecules at 62-67 kDa and 19-21 kDa respectively. The addition of DFM showed a new protease band, they had a measurement of 14 and 25 kDa.This study provides valuable insights into enzyme activities in rumen, particularly protease, cellulase, and amylase. The results suggest that the combination of 0.24% WLF and 0.5% DFM supplementation holds promise for optimizing rumen conditions and improving the performance of local beef cattle.

Responses of nutrient utilization, rumen fermentation and microorganisms to different roughage of dairy buffaloes

Dairy buffaloes are typically fed a high-forage, low-quality diet with high fiber. These conditions result in an inherent energy and protein inefficiency. In order to make full and rational use of feed resources and improve the production level and breeding efficiency of dairy buffaloes, the effects of various roughages on nutrient digestibility, ruminal fermentation parameters, and microorganisms in dairy buffaloes were studied in this experiment. Three ternary hybrid buffaloes, with an average body weight of 365 ± 22.1 kg, were selected and fitted with permanent rumen fistulas. They were fed six different diets, each consisting of 1 kg concentrate supplement and one of six types of roughage, including alfalfa hay (A diet), oat hay (O diet), whole corn silage (W diet), king grass (K diet), sugarcane shoot silage (S diet), and rice straw hay (R diet) according to an incomplete Latin square design of 3 × 6, respectively. The pre-feeding period of each period was 12 d. From day 13 to 15 was the official experimental period. During the prefeeding period, free feed intake for each roughage was determined, and during the experiment, the roughage was fed at 90% of the voluntary feed intake. Digestion and metabolism tests were carried out using the total manure collection method to determine the feed intake and fecal output of each buffalo, and to collect feed and fecal samples for chemical analysis. On day 15, rumen fluid samples were collected two hours after morning feeding to determine rumen fermentation parameters and bacterial 16 S rRNA high-throughput sequencing was performed. The results showed that DM and OM digestibility were greatest for the W diet and lowest for the S diet. The rumen pH of the O diet was significantly greater than that of the W diet. The concentration of rumen fluid NH3-N (mg/dL) increased with increased CP content. The concentration of total volatile fatty acids (mmol/L) in the rumen decreased with increased NDF content but increased with increased NFC content. The relative abundances of Bacteroidetes, Firmicutes, and Spirochaetes were 57.03-74.84%, 14.29-21.86%, and 0.44-1.43% in the different quality roughage groups. Bacteroidetes were mainly Prevotellaceae1 and Rikenellaceae RC_gut_group with relative abundances of 30.17-45.75% and 3.23-7.82%. The relative abundance of Patescibacteria and Spirochaetes decreased with increasing roughage quality. These results provide a theoretical and practical basis for evaluating the nutritional value of dairy buffalo feed, utilizing feed resources, matching rations, feeding scientifically, and protecting animal health.

Comparison of the Effects of Essential Oils from Cannabis sativa and Cannabis indica on Selected Bacteria, Rumen Fermentation, and Methane Production-In Vitro Study.

This study aimed to evaluate the effects of essential oils (EOs) extracted from Cannabis sativa L. and Cannabis indica Lam. on in vitro ruminal fermentation characteristics, selected rumen microbial populations, and methane production. GC-MS analyses allowed us to identify 89 compounds in both EOs. It was found that E-β-caryophyllene predominated in C. sativa (18.4%) and C. indica (24.1%). An in vitro (Ankom) test was performed to analyse the control and monensin groups, as well as the 50 µL or 100 µL EOs. The samples for volatile fatty acids (VFAs), lactate, and microbiological analysis were taken before incubation and after 6 and 24 h. The application of EOs of C. indica resulted in an increase in the total VFAs of acetate and propionate after 6 h of incubation. The applied EOs had a greater impact on the reduction in methane production after 6 h, but no apparent effect was noted after 24 h. Lower concentrations of C. sativa and C. indica had a more pronounced effect on Lactobacillus spp. and Buryrivibrio spp. than monensin. The presented findings suggest that C. sativa and C. indica supplementation can modify ruminal fermentation, the concentrations of specific volatile fatty acids, and methane production.

Effect of acidosis in the late-finishing phase on rumen fermentation in feedlot steers.

The objective was to determine the effects of induced acidosis in the late-finishing phase on rumen fermentation in feedlot steers. Eleven ruminally cannulated steers (body weight [BW] = 795 kg ± 54) were blocked into two groups based on initial BW. For 195 d prior to the start of the study, cattle were consuming a basal finishing diet (60% dry-rolled corn, 15% modified distillers grains, 15% corn silage, and 10% ground corn-based supplement). Steers were randomly assigned to one of the two treatments: control (CON), or induced acidosis (ACD). Both treatments were fasted for 24h then fed the basal finishing diet. Steers on the ACD treatment received 0.05% of BW of wheat starch via rumen cannula at 0800 and 2000 hours on day 1 and ad libitum refeeding following the fast. On days 1 and 2, CON steers were provided 25% of allotted feed every 6h. Rumen fluid was collected every 4h during the challenge period (hours 0 to 48), and 0, 6, and 12h after feeding during the recovery period (hours 54 to 96). Rumen fluid was analyzed for pH, ammonia, volatile fatty acids (VFA), and lactate. Fecal grab samples were collected every 8h to determine fecal pH. A treatment × day interaction (P = 0.03) was observed for dry matter intake during the challenge period with steers on the ACD treatments consuming more on day 1 than CON steers. Intake was not different on day 2 (P = 0.88). A treatment × hour effect (P < 0.01) was observed for ruminal pH during the challenge period with the ACD steers having a lesser pH than CON from hours 12 to 32. Duration of time below a pH of 5.6 during the challenge period was greater (P < 0.01) for ACD steers than CON. During the challenge period, a treatment × time interaction (P = 0.04) was observed for total VFA concentration with ACD steers having greater total VFA concentration from hours 12 to 36. Acetate to propionate ratio (A:P) was affected by treatment × hour (P = 0.04) with CON steers having greater A:P from hours 28 to 48. Rumen ammonia and lactate concentrations did not differ (P ≥ 0.25) between treatments or the interaction with time. Challenge and recovery period fecal pH were not affected (P ≥ 0.13) by treatment, time, or their interaction. Recovery period ruminal pH was not different (P = 0.99) between treatments. For the recovery period, total VFA and ammonia concentration were not affected by treatment, time, or their interaction (P ≥ 0.07). Ruminal pH and VFA were affected in the initial 48h of induced acidosis in the late-finishing phase.

Feeding Astragalus membranaceus Root Improves the Rumen Fermentation Rate in Housed Goats through the Alteration of the Rumen Community Composition.

Although Astragalus membranaceus root (AMR) has been noted as an ingredient in ruminant feed, the impacts of AMR feeding on rumen fermentation and the microbial community structure within the rumen are yet to be evaluated. This study investigated the effects of AMR supplementation on rumen fermentation characteristics and microbial community structures in goats. In two sets of feeding experiments, four Japanese native goats were fed AMR (10 g/kg DM/day/head) for three weeks per experiment. The rumen fluid samples were analyzed using high-performance liquid chromatography for fermentation products and next-generation sequencing for microbial analysis. The rumen fluid samples in the second experiment were also subject to an in vitro anaerobic fermentation test. The results indicated a significant modification, with a higher volatile fatty acid (VFA) content in the rumen fluid of goats in the feeding period than before feeding (p < 0.01). The microbial analysis revealed a significant increase in community diversity (p < 0.05) following AMR feeding, and the rumen bacterial community increased in two families belonging to the order Oscillospirales in Firmicutes (p < 0.05). The phylum Verrucomicrobiota was observed to be significantly less abundant after AMR feeding than during the control period (p < 0.05). Notably, the linear discriminant analysis revealed that the families with largely unknown functions in the rumen (Oscillospiraceae, Rikenellaceae, Muribaculaceae, and vadinBB97) were the determinants of the community split between control and AMR feeding. Increased fermentation rate by AMR feeding was also supported by an in vitro culture experiment, which resulted in faster VFA production without affecting methane production in total gas production. The study demonstrated that AMR can significantly facilitate change in the bacterial community structure in the goat rumen involving a shift of the favoring fibrolytic bacteria towards VFA production. The long-term effects of AMR supplementation and its applicability across different ruminant species, with potential benefits for animal health and productivity, should be addressed.

Effects of nanobubble water on digestate soaking hydrolysis of rice straw

This study investigated the performance of combined nanobubble water (NW) and digestate in the soaking hydrolysis process. Two types of NW (CO2NW and O2NW) with digestate were used to soak rice straw for 1, 2, 3, 5, and 7 days. During soaking process, the volatile fatty acids (VFA) concentration in the treatment with O2NW and digestate for 3 days (O2NW-3 d) reached 7179.5 mg-HAc/L. Moreover, the highest specific methane yield (SMY) obtained in this treatment could reach 336.7 NmL/gVS. Although the addition of NW did not significantly increase SMY from digestate soaking, NW could accelerate the rate of methane production and reduce digestion time of T80. The enrichment of Enterobacter in the soaking process was observed when using CO2NW and O2NW as soaking solutions which played important roles in VFA production. This study provides a new insight into environment-friendly enhanced crop straw pretreatment, combining NW and digestate soaking hydrolysis.

Efeito de um aditivo fúngico multiespécie no perfil de fermentação ruminal, de-gradabilidade e cinética de produção de gases

Two experiments evaluated the effect of a multispecies fungal complex (BP, BIOPREMIX MX®, Ruminal Fermentation Tech, Uruguay). In Experiment 1 (E1), the impact of adding BP to a total mixed ration (TMR) on ruminal fermentation profile and TMR in situ degradation kinetics was assessed. In Experiment 2 (E2), the effect of adding BP to various substrates on in vitro fermentability was examined. In E1, 4 Holstein cows with rumen cannulas were randomly assigned to Control (TMR with forage:concentrate ratio 75:25) or Control + 120 g/cow/d of BP (BP) and received ad libitum TMR for 30 days. Samples of TMR were ruminally incubated to estimate in situ degradation kinetic. Ruminal pH, ammonia, and volatile fatty acids (VFA) concentrations were measured just before feeding, 4 h and 8 h post feeding. In E2, a factorial arrangement included two BP levels (0 -Control or 6.5 g BP per kg dry matter incubated-WBP) and 8 substrates. In vitro gas production kinetics (GPk), dry matter digestibility (IVDMD), methanogenic potential (CH4), partitioning factor (PF), VFA, and microbial crude protein (MCP) were estimated. The BP increased proportion of propionate (P ≤ 0.05) and reduced ketogenic:glucogenic ratio and Lag phase of NDF (P ≤ 0.05). WBP tended to increase IVDMD, and substrate affected GPk, IVDMD, CH4, PF, VFA and MCP (P ≤ 0.01). Overall, BP improved ruminal metabolism favoring a more glucogenic profile, a shortening Lag phase in NDF degradation, and increasing IVDMD.

Effect of Pomegranate Peel or Bread Yeast on Rumen Fermentations Characteristics in Awassi Lambs

This study was conducted to determine the effect of pomegranate peel powder and baking yeast (saccharomyces cerevisiae) on rumen PH, the concentration of volatile fatty acids, the total number of bacteria, and the concentration of ammonia (NH3-N) in the rumen fluid. were selected 20 male iraqiawassi lambs at 3-4 months old, and randomly divided into 4 equal groups. The first group (control) was fed on concentrated dite at a rate of 3% of body weight with green fodder and free grazing, while pomegranate peels were added to the concentrated fodder for the second group (pomegranate peel group) at a rate of 1% of concentration dite, and bread yeast was added to the fodder of the third group (saccharomyces cerevisiae group) at a dose of 4 g for each animal. The control group was added to its diet with 1% pomegranate peel powder and yeast (saccharomyces cerevisiae) at a dose of 4 g per kg of concentrated feed. The results of the study showed a significant increase (P&lt;0.05) in the pH value in the third and fourth groups compared to the control group, and the total count of rumen bacteria was significantly increased (P&lt;0.05) in the three treatment groups compared to the control group, the concentration of volatile fatty acids(VFA) also increased significantly (P&lt;0.05) in the third and fourth groups compared with the control group, while the concentration of rumen ammonia (NH3-N) significantly (P&lt;0.05 ) decreased in the three treated groups compared with the control group. Conclusion: We conclude that adding pomegranate peels and yeast has improved rumen fermentation in terms of increasing the concentration of volatile fatty acids, reducing the concentration of ammonia, and increasing beneficial microorganisms in the rumen fluid.

Effect of Biochar on Anaerobic Co-Digestion of Untreated Sewage Sludge with Municipal Organic Waste under Mesophilic Conditions

Anaerobic digestion (AD) is a biological process that occurs in the limited presence of oxygen. This process involves various difficulties during the operation, such as acidification and increased concentration of volatile fatty acids, which can inhibit methane production. Therefore, in this work, the impact of biochar on the co-digestion of untreated sludge and residual biomass under mesophilic conditions was studied. For the production of biochar, the gasification process was used at different temperatures: 759 °C (BL), 798 °C (BM), and 888 °C (BH). This biochar was added in concentrations of 0 g/L, 3.33 g/L, and 6.67 g/L at the beginning of the co-digestion process. The results showed that a concentration of 6.67 g/L with BH biochar increased the PBM by 18% compared to the control sample and reduced the chemical oxygen demand (COD) by 88%. In addition, there was a reduction of volatile fatty acids (VFA) of 42.75%. Furthermore, FTIR analysis demonstrated that biochar has appropriate functional groups for this process. These data suggest a good interaction of biochar with the mixture of sludge and municipal waste, indicating that biochar can improve the anaerobic co-digestion of untreated sludge and municipal waste.

Short- and long-term effects of different forage types supplemented in preweaning dairy calves on performance and milk production into first lactation

We investigated the short- and long-term effects of different forage types supplemented in preweaning dairy calves on growth performance, blood metabolites, rumen fermentation, bacterial community, and milk production during first lactation. A total of 60 healthy 30-d-old female Holstein calves were blocked by birth date and body weight and randomly assigned to 1 of 3 groups (n = 20): normal milk and pelleted starter feeding (CON), supplemented with chopped oat hay (OAH; 75.0 g/d per calf [DM basis]), or alfalfa hay (ALF; 75.0 g/d per calf [DM basis]). The forage supplementation started when calves were 30 d old (d 1 of the experimental period) and ended when they were 73 d old (d 44 of the experimental period, when calves were weaned). Milk and feed intakes and fecal consistency scores were recorded daily. Growth performance, rumen fluid, and blood samples were collected biweekly. After weaning, all the calves were integrated with the same barn and diets. After calving, the milk production was recorded daily. During the experimental period, the OAH group had greater solid feed and total DM intakes and greater rumen pH than the CON group (P ≤ 0.04), but had lower forage intake and CP digestibility than the ALF group (P ≤ 0.04). The ALF group had higher rumen pH and blood BHB concentration (P ≤ 0.04), lower fecal score (P = 0.02), and greater ether extract digestibility (P = 0.02) than the CON group. The ALF and OAH groups had lower concentrations of ruminal total VFA (P = 0.01). Still, the ALF group had a greater proportion of acetate and a relative abundance of cellulose degradation-related bacteria (Lachnoclostridium_1 and Oribacterium) and a lower relative abundance of inflammation-related bacteria (Erysipelotrichaceae_UCG-009) in the rumen compared with CON. Interestingly, the average milk production from 6 to 200 DIM was greater in the ALF group (P < 0.01), even though no significant effects were found on the rumen fermentation parameters and blood metabolites at 200 DIM. Generally, alfalfa hay supplementation in preweaning dairy calves had positive effects in the short- and long-term for rumen development, health status, and future milk production.

A lysing polysaccharide monooxygenase from Aspergillus niger effectively facilitated rumen microbial fermentation of rice straw.

This study investigated the impact of Aspergillus niger lysing polysaccharide monooxygenase (AnLPMO) on in vitro rumen microbial fermentation of rice straw. AnLPMO was heterologously expressed in Escherichia coli. Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy analyzed the surface structure of rice straw after AnLPMO treatment. Two in vitro experiments, coupled with 16S highthroughput sequencing and quantitative real-time polymerase chain reaction techniques, assessed the influence of AnLPMO on rumen microbial fermentation of rice straw. AnLPMO exhibited peak activity at 40°C and pH 6.5, with a preference for rice straw xylan hydrolysis, followed by Avicel. AnLPMO application led to the fractional removal of cellulose and hemicelluloses and a notable reduction in the levels of carbon elements and C-C groups present on the surface of rice straw. Compared to the control (no AnLPMO), supplementing AnLPMO at 1.1 to 2.0 U significantly enhanced in vitro digestibility of dry matter (IVDMD, p<0.01), total gas production (p<0.01), and concentrations of total volatile fatty acids (VFA, p<0.01), acetate (p<0.01), and ammonia-N (p<0.01). Particularly, the 1.4 U AnLPMO group showed a 14.8% increase in IVDMD. In the second experiment, compared to deactivated AnLPMO (1.4 U), supplementing bioactive AnLPMO at 1.4 U increased IVDMD (p = 0.01), total gas production (p = 0.04), and concentrations of total VFA (p<0.01), propionate (p<0.01), and ammonia-N (p<0.01), with a limited 9.6% increase in IVDMD. Supplementing AnLPMO stimulated the growth of ruminal bacterial taxa facilitating fiber degradation, including Proteobacteria, Spirochaetes, Succinivibrio, Rikenellaceae_RC9_ Gut_Group, Prevotelaceae_UCG-003, Desulfovibrio, Fibrobacter succinogenes, Ruminococcus albus, R. flavefaciens, Prevotella bryantii, P. ruminicola, and Treponema bryantii. These findings highlight AnLPMO's potential as a feed additive for improving rice straw utilization in ruminant production.

Enhancing biomethanation performance through co-digestion of diverse organic wastes: a comprehensive study on substrate optimization, inoculum selection, and microbial community analysis.

A blend of organic municipal solid waste, slaughterhouse waste, fecal sludge, and landfill leachate was selected in different mixing ratios to formulate the best substrate mixture for biomethanation. Individual substrates were characterized, and the mixing ratio was optimized with the help of a response surface methodology tool to a value of 1:1:1:1 (with a C/N ratio of 28±0.769 and total volatile fatty acid (VFA) concentration of 2500±10.53 mg/L) to improve the overall biomethanation. The optimized blend (C/N ratio: 28.6, VFA: 2538 mg/L) was characterized for physicochemical, biological, and microbial properties and subjected to anaerobic digestion in lab-scale reactors of 1000 mL capacity with and without the addition of inoculum. The biogas yield of individual substrates and blends was ascertained separately. The observed cumulative biogas yield over 21 days from the non-inoculated substrates varied between 142±1.95 mL (24.6±0.3 ml/gVS) and 1974.5±21.72 mL (270.4±3.1 ml/gVS). In comparison, the addition of external inoculation at a 5% rate (w/w) of the substrate uplifted the minimum and maximum cumulative gas yield values to 203±9.9 mL (35.0±1.6 mL/gVS) and 3394±13.4 mL (315.3±1.2 mL/gVS), respectively. The inoculum procured from the Defence Research and Development Organisation (DRDO) was screened in advance, considering factors such as maximizing VFA production and consumption rate, biogas yield, and digestate quality. A similar outcome regarding biogas yield and digestate quality was observed for the equivalent blend. The cumulative gas yield increased from 2673±14.5 mL (373.7±2.2 mL/gVS) to 4284±111.02 mL (391.47±20.02 mL/gVS) over 21 days post-application of a similar dosage of DRDO inoculum. The 16S rRNA genomic analysis revealed that the predominant bacterial population belonged to the phylum Firmicutes, with the majority falling within the orders Clostridiales and Lactobacillales. Ultimately, the study advocates the potential of the blend mentioned above for biomethanation and concomitant enrichment of both biogas yield and digestate quality.

Non-targeted facilitation of primary sludge anaerobic fermentation by micro-aeration and the simultaneous nutrients transformations

Anaerobic fermentation is a widely used technology for resource recovery from municipal sludge (e.g., primary sludge). Micro-aeration is an emerging strategy which can be incorporated into this technology. However, the effect of micro-aeration on the anaerobic fermentation performance and the nutrients transformations are not well known. This study investigated the impact of micro-aeration on the production of volatile fatty acids (VFAs) from primary sludge as well as the simultaneous nitrogen (N) and phosphorus (P) transformations in the system. The obtained results indicated that application of micro-aeration improved the microbial activities and facilitated all the hydrolysis, acetogenesis and methanogenesis processes. Hydrogenotrophic methanogen was enriched by micro-aeration while the acetoclastic methanogenesis was still the dominant CH4 production pathway at gene level. The concentration of VFAs was lower with micro-aeration than in the control system, which could be attributed to the enhanced consumption of VFAs. The simultaneous transformations of N and P were observed with different patterns. Micro-aeration led to removal of up to 131.6 mg/L of N, with occurrence of nitrification and denitrification found to be responsible for the N removal. In contrast, the total P content remained unchanged in the reactor. However, micro-aeration was found to inhibit both extracellular organic-P mineralization and intracellular poly-P degradation, resulting in lower soluble PO43−-P and more P distributed in the organic-P fraction in solid phase. This study provides novel insights into the microscopic mechanisms of the micro-aeration on anaerobic fermentation and the simultaneous regulation of N and P release.

PSI-18 Effects of heat treatment and multi-carbohydrase supplementation on the digestibility of phosphorus in field peas fed to growing pigs

Abstract Most plant-based feed ingredients contain about two-thirds of their total P as phytate. Mineral elements are chelated to phytate or entrapped in plant cell walls, and microbial or enzymatic breakdown of cell walls may be able to release entrapped P, thus leading to improvement of the apparent total tract digestibility (ATTD) of P in pigs. Heat treatment is one of the processing methods that improve the digestibility of fiber in various feedstuffs for pigs. Therefore, this study aimed to determine the effects of heat treatment and multi-carbohydrase supplementation on the ATTD and standardized total tract digestibility (STTD) of P in peas fed to growing pigs. A total of 18 pigs (23.9 ± 1.3 kg) were assigned to 1 of 3 diets in a completely randomized design to give 6 replicates per diet. Three experimental diets were formulated: 1) non-heated or 2) heat-treated (pelleted) peas as the sole source of P, and 3) heat-treated peas with multi-carbohydrase supplementation. Pigs were individually housed in metabolism crates for 12 d, including 7 d for adaptation and 5 d for total collection of feces. Pigs were offered their daily ration at 2.8 times their maintenance energy requirement. Samples of ingredients, diets, and feces were analyzed for dry matter, Ca, and P. Fecal samples were analyzed for mixed bacterial mass (MBM) and volatile fatty acids (VFA) concentrations. Data were analyzed using the PROC MIXED of SAS. The statistical model included diet as fixed effect and replicate as random effect. An alpha level of 0.05 was used to determine statistical significance and P ≤ 0.10 was considered a trend. Pigs fed the diet that contained heat-treated peas with carbohydrase supplementation tended to have greater (P &amp;lt; 0.10) ATTD and STTD of P than pigs fed the diet containing heat-treated peas without enzyme. The values of STTD of P were 54.4, 47.3, and 55.0% for diets containing raw peas, heat-treated peas, and heat-treated peas with carbohydrase supplementation, respectively. Heat treatment and enzyme supplementation did not affect the ATTD of Ca in peas fed to growing pigs. No significant differences were observed in fecal MBM-P and VFA concentrations. In conclusion, carbohydrase supplementation tended to increase the digestibility of P in heat-treated peas fed to growing pigs, however, there was no difference in P digestibility between raw and heat-treated peas. Heat treatment and carbohydrase supplementation did not affect fecal MBM-P and VFA concentrations in growing pigs.

80 Substitution of dried distiller’s grains with soybean meal on beef cattle diets: Effects on ruminal ammonia and volatile fatty acid concentrations

Abstract The objective of this study was to evaluate the effects of substitution of dried distiller grains with soybean meal on beef cattle diets in ruminal ammonia and volatile fatty acid (VFA) concentrations. Red Angus steers [n = 4; body weight (BW) = 360 ± 9 kg] with ruminal, duodenal, and ileal cannulas, were used in a 4 × 4 latin square. Diets (TMR) consisted of dry-rolled corn (70%), hay (10%), liquid supplement (5%), and test ingredients (15%). Treatments were [dry matter (DM) basis]: 1) 15.0% DDGS (CON); SBM in replacement of 50% of DDGS (SBM50); SBM in replacement of 75% of DDGS (SBM75), and SBM in replacement of 100% of DDGS (SBM100). Each period lasted 18-d, consisting of a 7-d diet adaptation followed by an 11-d collection period. Rumen fluid was collected at -2, 0, 2, 4, 6, 8, 10, and 12 h post-feeding on d 16. Ruminal digesta was strained through two layers of cheesecloth and two 10-mL aliquots of ruminal fluid were collected and stored at −20°C until further analysis of ammonia and VFA concentrations. Data were analyzed as repeated measures using the MIXED procedure of SAS with treatment, sampling time, and their interaction as fixed effects, and animal and period as random effects. No treatment by day interactions (P ≥ 0.84) were observed for ammonia or VFA. Ammonia concentrations were greater (P ≤ 0.01) for SBM75 compared with SBM100 and CON, with intermediate values observed for SBM50 (Table 1). Moreover, ammonia was greater (P ≤ 0.01) at 0h compared with 6, 8, and 12h post-feeding. Acetate was greater (P ≤ 0.01) for SBM75 and SBM100 compared with CON and SBM50. Concentrations of propionate were greatest (P ≤ 0.01) for SBM100 and least for CON, with SBM50 and SBM75 being intermediate. Further, propionate was greater (P ≤ 0.01) at 16h compared with 0 and 2 h post-feeding, with all other times being intermediate. Isobutyrate was less (P ≤ 0.01) for CON than all other treatments, and greater concentrations (P ≤ 0.01) were observed at -2 compared with 14 and 16 h post-feeding. Butyrate was greatest (P ≤ 0.01) in SBM75, followed by CON and SBM50; SBM50 was similar to SBM100. Butyrate concentrations were similar -2 and 0 h post feeding, which were less (P ≤ 0.01) than all other times. Isovalerate was greater (P ≤ 0.01) for CON than SBM50 and SBM75, and similar to SBM100. Valerate was greatest (P ≤ 0.01) for SBM75 and SBM100 followed by SBM 50 and CON which had the least valerate value. Overall, our results show that SBM75 resulted in greater concentrations of ammonia, acetate, propionate, butyrate, isobutyrate, and valerate compared with CON. These data suggest that 75% substitution of DDGS with SBM has the potential to optimize microbial fermentation. To complement these results, we are currently evaluating rumen protein degradation profiles and amino acid flow to small intestine.

84 Evaluating the effects of hind gut acidosis in sheep on rumen fermentation ex vivo

Abstract The objective was to determine the effect of hindgut acidosis in sheep on rumen fermentation ex vivo. Eleven ruminally and cecally cannulated ewes [body weight (BW) = 49 ± 4 kg] were assigned to one of two treatments: a constant infusion of deionized water (CON; 26 mL/kg BW per 24 h) or starch solution (STA; 3 g wheat starch/kg BW per 24 h) in the cecum to induce hindgut acidosis. Rumen fluid was collected from each ewe on the d before and four d after the start of cecal infusion for an ex vivo fermentation. There were four flasks for each ewe with two flasks per substrate. The two substrates were forage-based (FB; 40% grass hay pellet, 35% whole shell corn, 15% dried distiller’s grain, and 10% alfalfa cubes) and concentrate-based (CB; 75% whole shell corn, 15% dried distiller’s grain, and 10% alfalfa cubes). Flasks contained 2.5 grams of substrate and 150 mL of inoculum (2:1 ratio of McDougall’s buffer and rumen fluid). Four sealed ANKOM F57 bags were filled with 0.25g DM of substrate and placed into flasks to determine in vitro dry matter disappearance (IVDMD). The flasks were incubated at 39°C for 24 h, with sample aliquots collected at h 0, 8, and 24 to determine pH, volatile fatty acids (VFA), and ammonia. Data were analyzed using the MIXED procedure of SAS 9.4. For all response variables, values from the run before cecal infusion initiation were included in the model as a covariate. Ammonia, pH, and VFA were analyzed with the effects of treatment, time, and their interaction. For the CB substrate, there was no effect (P = 0.90) of cecal infusion on ammonia concentration; however, there was a time effect (P = 0.01) with h 24 having a greater ammonia concentration than h 8. For the FB substrate, there was a tendency for STA to have lesser (P = 0.10) ammonia than CON. There was no effect (P ≥ 0.78) of cecal infusion treatment on pH for both substrates; however, there was a time effect (P = 0.01) with pH decreasing over time. In both substrates, there were no effects (P ≥ 0.23) of cecal infusion treatment on IVDMD, VFA concentration, acetate, or propionate molar concentration. However, butyrate molar concentration tended to be less (P = 0.07) for STA ewes for the CB substrate. No treatment differences were observed in butyrate for the FB substrate (P = 0.35). Results indicate that induced hindgut acidosis in sheep did not affect rumen fermentation ex vivo.

PSVI-4 Effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet

Abstract The objective was to characterize the effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet. Cattle entering the feedlot undergo a transition period where the amount of concentrates in the diet is gradually increased to mitigate the risks of ruminal acidosis. Despite a dietary adaptation, rumen acidosis still affects feedlot cattle later in the finishing phase. Ruminally cannulated steers [n = 11; body weight (BW) = 795 kg ± 54) were blocked into 2 groups based on initial BW. Before the start of the study, cattle had been consuming a finishing diet (60% dry rolled corn, 15% modified distiller’s grains, 15% corn silage, and 10% ground corn based supplement) for more than 150 d. Steers were randomly assigned to 1 of 2 treatments: control (CON) or acidosis (ACD). For the experiment, steers were fasted for 24 h and at the conclusion received the same finishing diet. Steers on ACD steers were also ruminally dosed 0.05% BW of wheat starch on h 0 and h 12 to induce acidosis. Rumen fluid was collected every 4 h for 48 h to analyze ruminal pH, ammonia, volatile fatty acids (VFA), and lactate. Fecal grab samples were collected every 8 h for 48 h to determine fecal pH. Data were analyzed with the MIXED procedure of SAS 9.4 with the effects of treatment, time, and their interaction. A treatment × hour (P &amp;lt; 0.01) effect was observed for ruminal pH with the ACD steers having a lower pH than CON from h 12 to 32. Fecal pH was not affected by treatment, time, or their interaction (P ≥ 0.12). Steers fed ACD had greater total VFA concentration than CON (P &amp;lt; 0.01). A treatment × hour interaction (P &amp;lt; 0.01) was observed for acetate molar proportion with CON having greater percentage acetate at h 24 through 32. Additionally, there was a treatment × hour interaction (P &amp;lt; 0.01) for propionate molar proportion with ACD steers having greater propionate at h 28 and 32, and then at h 40 and 44. Butyrate was not affected (P ≥ 0.58) by treatment × hour or treatment. Acetate to propionate ratio (A:P) was affected by treatment × hour (P &amp;lt; 0.01) with CON steers having greater A:P after h 28. Rumen ammonia and lactate concentrations did not differ (P ≥ 0.25) by treatment or the interaction with h. In steers adapted to a high concentrate diet, acidosis only altered ruminal fermentation in regards to ruminal pH and VFA concentrations.

15 Effects of post-MSC DDGS inclusion in gestation diets compared with other fiber sources on in vitro gas and volatile fatty acid production

Abstract In vitro fermentation has been used to characterize hindgut fermentation of fibrous ingredients fed to grower pigs. However, there is little to no work investigating hindgut fermentation of fibrous feedtuffs in gestating sows, who have greater fermentative capacity compared with grower pigs. The objective of this study was to characterize hindgut gas production and volatile fatty acids (VFA) following in vitro fermentation using fecal inoculum collected from the sows when fed either post-protein separation dried-distiller’s grains with solubles (post-MSC DDGS), soyhulls, or sugar beet pulp. Pregnant sows (n = 22; parity 0 to 1; body weigh = 190 ± 10 kg) were allocated to 1 of 6 dietary treatments in a crossover design with two collection periods (period 1 from d 40-59 of gestation and period 2 from d 60-79 of gestation) to attain at least 7 observations per treatment. Two of the six diets were practical corn-soybean meal-based gestation diets with either soyhulls (17.5% inclusion) or post-MSC DDGS (15% inclusion). The remaining four diets included a corn-basal diet and the basal diet plus 30% inclusion of post-MSC DDGS, soyhulls, or sugar beet pulp. Sows were fed experimental diets (2.2 kg/d in a single feeding) in two 20 d collection periods. For in vitro fermentation, fresh fecal samples were collected on d 16 of each collection period, prepared as inoculum, and subjected to the gas production measurement technique through in vitro fermentation. Supernatant residue from the in vitro fermentation was subjected to VFA analysis by gas chromatography. Data were analyzed with ANOVA and fixed to a mixed linear model using treatment as the main effect and collection period as a random variable. Total gas production of the practical diet containing post-MSC DDGS diet was 132 ml/g less (P = 0.03) than the practical soyhull diet. While the total concentration of total VFA did not differ between practical diets, the concentration of isovalerate tended to be greater for the post-MSC DDGS diet compared with the soyhull diet (P = 0.09). Total gas production was 140 and 375 mg/L less for the post-MSC DDGS than soyhulls and sugar beet pulp, respectively (P &amp;lt; 0.01). The concentrations of butyrate and isovalerate (relative to total VFA) were approximately 7 and 2%, respectively, greater for the post-MSC DDGS than in the soyhulls or sugar beet pulp fermentation residues (P &amp;lt; 0.05). Concentrations of other VFA relative to total VFA did not differ between fiber sources. In conclusion, post-MSC DDGS can contribute to sustainable swine production when fed to gestating by lowering total gas production and being a source of volatile fatty acids.

PSI-20 Isobutyrate supplementation improved energy and nitrogen digestibility in prepubertal gilts fed a high insoluble, but not soluble, fiber diet

Abstract Isoacids are short, branched-chain volatile fatty acids produced by microbial degradation of branched-chain amino acids. While there is a lack of information on isoacids supplementation in monogastric animals, in ruminants, isoacids are growth factors for cellulolytic bacteria which leads to improved digestibility of fibrous ingredients. The objective was to determine if feeding isoacids to prepubertal gilts could improve digestibility of high fiber diets. Two groups of 45 prepubertal gilts (body weight = 139.10 ± 0.68 kg) were individually housed and allotted to 1 of 9 dietary treatments for a 28-d trial (n = 10 per treatment). Dietary treatments consisted of a 3 × 3 factorial arrangement with factors of diet type [corn-soybean meal (CSBM), CSBM with 40% inclusion of distiller’s dried grains with solubles (DDGS), or CSBM with 40% inclusion of sugar beet pulp (SBP)] and isoacids inclusion [no isoacid (NO), 0.50% inclusion of isobutyrate (IB), or 0.88% inclusion of an isoacid mixture (isobutyrate, 2-methylbutyrate, isovalerate; 1:1:1 ratio; MX). Isobutyrate inclusion was the same between IB and MX diets. Gilts were limit fed approximately 2.2 kg per day. Overall growth performance, apparent total tract digestibility (ATTD) of energy and nitrogen (N), and fecal volatile fatty acids (VFA) profile (d 26) were determined. Average daily feed intake (ADFI) was reduced and gain:feed ratio (GF) was increased in gilts fed DDGS (2.14 ± 0.07 kg/d and 0.20 ± 0.02 kg/kg, respectively) or SBP (2.07 ± 0.07 kg/d and 0.19 ± 0.02 kg/kg, respectively) compared with gilts fed CSBM (2.30 ± 0.07 kg/d and 0.15 ± 0.02 kg/kg, respectively), regardless of isoacids inclusion (P &amp;lt; 0.05). Gilts fed DDGS-IB had increased energy (86.5 vs. 83.5 ± 0.42%) and N (84.7 vs. 81.3 ± 0.85%) ATTD compared with gilts fed DDGS-NO (P &amp;lt; 0.05). Gilts fed CSBM-MX had reduced energy (86.9 vs. 88.3 ± 0.50%) and N (75.4 vs. 78.7 ± 0.39%) ATTD compared with gilts fed CSBM-NO (P &amp;lt; 0.05). Moreover, gilts fed SBP-NO had increased energy (85.9 vs. 83.6 ± 0.44%) ATTD compared with the other groups and increased N (71.8 vs. 67.2 ± 0.51%) ATTD compared with SBP-IB (P &amp;lt; 0.05). Fecal content of isobutyrate was decreased in NO compared with the other groups (2.10 vs. 3.00 ± 0.31 mM/L), while fecal content of heptanoate was increased in MX compared with NO (0.06 vs. 0.03 ± 0.01 mM/L), regardless of diet type (P &amp;lt; 0.05). Gilts fed SBP-MX had increased fecal content of total VFA compared with gilts fed SBP-NO (108.90 vs. 67.60 ± 11.50 mM/L; P &amp;lt; 0.05). These results suggest that IB may positively impact the digestibility of diets with a high content of insoluble fiber.

Use of Cracker Residue in the Diet of Dairy Heifers: Impacts on Animal Health, Ruminal Fatty Acids Profile, Digestibility, Weight Gain, and Economic Viability.

This study determined whether the isomeric or isoenergetic/isoproteic substitution of corn in the diet of Jersey heifers in the rearing phase with cracker residue would impair growth and health, as well as reducing production costs. Fourteen Jersey females in the growth phase were used, separated into two treatments with seven animals in each lot in collective pens. The experiment used 7-month-old animals (169.8 ± 2.89 kg) and lasted for four months. In Experiment I, the animals were divided into two groups: treatment, with the partial replacement of 40% corn with cracker residue, and control, in which the animals consumed the same diet with 100% corn (isometric diet kg for kg). In Experiment II, the animals with a body weight of 200.2 ± 3.85 kg were divided into two groups: Treatment, replacing 100% of the corn with cracker residue, and control, in which the animals consumed an isoprotein and isoenergetic diet but with 100% of the corn in the formulation. The diet consisted of concentrate, Tifton 85 hay, and corn silage, supplied twice a day individually, with animals contained in their feeders by kennels. There was water ad libitum in the bay. Biweekly weighing and monthly blood analysis were performed, totaling four collections per part for hematologic evaluation, carbohydrate, lipid, and protein metabolism variables. At the end of each experiment, ruminal fluid was collected to measure the volatile fatty acid profile, and feces were collected to determine the apparent digestibility coefficient (ADC). Experiments I and II showed no effect of treatment on body weight, weight gain, average daily weight gain, feed intake, and feed efficiency. There was no effect of treatment on leukocyte, erythrocyte, lymphocyte, neutrophil, monocyte, and eosinophil counts, hematocrit, and hemoglobin concentration (p > 0.05). Experiment I showed a difference between groups for the variables albumin, globulin, total proteins, cholesterol, glucose, and urea, which did not happen in Experiment II. In both experiments, a higher ADC of nutrients was found in the treatment group which had cracker residue (p > 0.05). The concentration of volatile fatty acids in Experiment I was higher in the control group, unlike in Experiment II, where the highest concentration was in the treatment group (p > 0.05). Because experiment I had an isometric substitution, the diets had different bromatological composition, which is the probable cause of the difference between groups; this did not happen in experiment II, in which the diets consumed by the animals was isoproteic and isoenergetic. Based on these data we conclude that the substitution of cracker residue in an isomeric or isoenergetic/isoproteic form does not negatively affect weight gain and animal health, as well as reduces the cost of the concentrate, consequently reducing the cost of production of these animals.