Total Volatile Fatty Acid Production Research Articles

Application of Meta-Analysis and Machine Learning Methods to the Prediction of Methane Production from In Vitro Mixed Ruminal Micro-Organism Fermentation.

Simple SummaryIn vitro gas production systems are regularly utilized to screen feed ingredients for inclusion in ruminant diets. However, not all in vitro systems are set up to measure methane (CH4) production, nor do all papers report in vitro CH4. Therefore, the objective of this study was to develop models to predict in vitro production of CH4, a greenhouse gas produced by ruminants, from in vitro gas and volatile fatty acid (VFA) production data, and to identify the major drivers of CH4 production in these systems. Meta-analysis and machine learning (ML) methodologies were applied to predict CH4 production from in vitro gas parameters. Meta-analysis results indicate that equations containing apparent dry matter (DM) digestibility, total VFA production, propionate, valerate and feed type (forage vs. concentrate) resulted in best prediction of CH4. The ML models far exceeded the predictability achieved using meta-analysis, but further evaluation on an external database would be required to assess their generalization capacity. The models developed can be utilized to estimate CH4 emissions in vitro.In vitro gas production systems are utilized to screen feed ingredients for inclusion in ruminant diets. However, not all in vitro systems are set up to measure methane (CH4) production, nor do all publications report in vitro CH4. Therefore, the objective of this study was to develop models to predict in vitro CH4 production from total gas and volatile fatty acid (VFA) production data and to identify the major drivers of CH4 production in these systems. Meta-analysis and machine learning (ML) methodologies were applied to a database of 354 data points from 11 studies to predict CH4 production from total gas production, apparent DM digestibility (DMD), final pH, feed type (forage or concentrate), and acetate, propionate, butyrate and valerate production. Model evaluation was performed on an internal dataset of 107 data points. Meta-analysis results indicate that equations containing DMD, total VFA production, propionate, feed type and valerate resulted in best predictability of CH4 on the internal evaluation dataset. The ML models far exceeded the predictability achieved using meta-analysis, but further evaluation on an external database would be required to assess generalization ability on unrelated data. Between the ML methodologies assessed, artificial neural networks and support vector regression resulted in very similar predictability, but differed in fitting, as assessed by behaviour analysis. The models developed can be utilized to estimate CH4 emissions in vitro.

A novel strategy for gas mitigation during swine manure odour treatment using seaweed and a microbial consortium

Gas emissions from swine farms have an impact on air quality in the Republic of Korea. Swine manure stored in deep pits for a long time is a major source of harmful gas emissions. Therefore, we evaluated the mitigation of emissions of ammonia (NH3), hydrogen sulfide (H2S) and amine gases from swine manure with biological products such as seaweed (Sargassum horneri) and a microbial consortium (Bacillus subtilis (1.2 × 109 CFU/mL), Thiobacillus sp. (1.0 × 1010 CFU/mL) and Saccharomyces cerevisiae (2.0 × 109 CFU/mL)) used as additives due to their promising benefits for nutrient cycling. Overall, seaweed powder masking over two days provided notable control of over 98%–100% of the gas emissions. Furthermore, significant control of gas emissions was especially pronounced when seaweed powder masking along with a microbial consortium was applied, resulting in a gas reduction rate of 100% for NH3, amines and H2S over 10 days of treatment. The results also suggested that seaweed powder masking and a microbial consortium used in combination to reduce the gas emissions from swine manure reduced odour compared with that observed when the two additives were used alone. Without the consortium, seaweed decreased total volatile fatty acid (VFA) production. The proposed novel method of masking with a microbial consortium is promising for mitigating hazardous gases, simple, and environmentally beneficial. More research is warranted to determine the mechanisms underlying the seaweed and substrate interactions.

Potential of Citrullus colocynthis as herbal feed additive for ruminants

To assess the potential of Citrullus colocynthis as herbal feed additive for ruminants, colocynth fruit as a whole, its seeds and peel-pulp were evaluated at various levels (0, 0.5, 1.0, 1.5, 2.0, 2.5, 4.0%) with total mixed ration (roughage to concentrate ratio: 65:35) as substrate in 3×7 factorial design by in vitro gas production technique. Phytochemical analysis revealed significant variation (P<0.01) in total phenols, non-tannin phenols, true tannins, saponins, flavonoids and vitamin C content among different parts of colocynth fruit. Irrespective of the part used, varying level of Citrullus colocynthis had significant effect on net gas production (NGP; ml/24/g), metabolizable energy (ME) availability, methanogenesis, digestibility of neutral detergent fiber (NDF) and true organic matter (TOM) in comparison to control; however the effect was pronounced at 1% level of supplementation. No significant difference in total volatile fatty acids (TVFA) production and acetate production was observed at varying levels of Citrullus colocynthis except at 4% level when total mixed ration (TMR) was used as substrate. Irrespective of its level, supplementation of Citrullus colocynthis fruit as a whole, seeds and peel-pulp significantly improved NGP (P<0.001) and ME (P<0.01) availability in comparison to control group whereas partitioning factor (PF; P>0.578), digestibility of NDF (P>0.905) and true OM (P>0.228) remained unaffected between different test groups. However, TVFA production, acetate, propionate and butyrate concentration was observed lower (P<0.001) in peel-pulp and seed supplemented group. From above results it can be concluded that supplementation of Citrullus colocynthis fruit at 1% level of substrate had potential to improve rumen fermentation characteristics and reduce methanogenesis, however in vivo assessment on ruminants need to be conducted to evaluate the persistency of effects along with health concerns.

Effect of combinations of feed-grade urea and slow-release urea in a finishing beef diet on fermentation in an artificial rumen system.

This study evaluated the effect of combinations of feed-grade urea and slow-release urea (SRU) on fermentation and microbial protein synthesis within two artificial rumens (Rusitec) fed a finishing concentrate diet. The experiment was a completely randomized, dose-response design with SRU substituted at levels of 0% (control), 0.5%, 1%, or 1.75% of dry matter (DM) in place of feed-grade urea, with four replicate fermenters per dosage. The diet consisted of 90% concentrate and 10% forage (DM basis). The experiment was conducted over 15 d, with 8 d of adaptation and 7 d of sampling. Dry matter and organic matter disappearances were determined after 48 h of incubation from day 9 to 12, and daily ammonia (NH3) and volatile fatty acid (VFA) production were measured from day 9 to 12. Microbial protein synthesis was determined on days 13-15. Increasing the level of SRU quadratically affected total VFA (Q, P = 0.031) and ammonia (Q, P = 0.034), with a linear increment in acetate (L, P = 0.01) and isovalerate (L, P = 0.05) and reduction in butyrate (L, P = 0.05). Disappearance of neutral detergent fiber (NDF) and acid detergent fiber (ADF) was quadratically affected by levels of SRU, plateauing at 1% SRU. Inclusion of 1% SRU resulted in the highest amount of microbial nitrogen associated with feed particles (Q, P = 0.037). Responses in the efficiency of microbial protein synthesis fluctuated (L, P = 0.002; Q, P = 0.001) and were the highest for 1% SRU. In general, the result of this study showed that 1% SRU in combination with 0.6% urea increased NDF and ADF digestibility and total volatile fatty acid (TVFA) production.

Effect of herbal feed additives containing saponins on rumen fermentation pattern

Macrotyloma uniflorum (kulthi) seeds, Asparagus racemosus (shatavari) roots or Acacia concina (shikakai) pods were supplemented to total mixed rations (TMR) @ 0-3% (on DM basis) to assess the impact of herbal feed additives (HFAs) on the in vitro rumen fermentation pattern. The saponin content and 2, 2-diphenyl-1-picrylhydrazyl- hydrate (DPHH) antioxidant activity was highest in A. racemosus than other HFAs. But total phenols, non tannin phenols, true tannins, condensed tannins, vitamin C and flavanoid contents were highest inM. uniflorum and lowest in A. concina. The dose/level of supplementation of HFAs, irrespective of their nature did not affect net gas production (NGP) and availability of metabolizable energy (ME) from TMR, but digestibility of nutrients and partitioning factor (PF) decreased in comparison to the unsupplemented group. The total and individual volatile fatty acids (VFAs) production; and acetate to propionate ratio was improved when the TMR was supplemented with HFAs at 1% level. The methane and ammonia-N production was depressed at 2% level as compared to control group. Irrespective of the dose, the total VFAs, acetate, and propionate production was higher while ammonia-N decreased in M. uniflorum supplemented TMR than other HFAs supplemented groups. Methane production from the TMR was comparable in the diet supplemented with different HFAs, however, diet supplemented with M. uniflorum resulted in lower methane production. Amongst the tested HFAs, M. uniflorum was a richer source of most of the bio-active compounds. Based on in vitro fermentation parameters, M. uniflorum supplemented to TMR @ 2% gave the best results.

Characteristics of In Vitro Fermentation and Nutrient Digestibility of Ration Supplemented with Different Level of Soybean Oil Calcium Soap

The in vitro experiment was aimed to evaluate the effect of soybean oil calcium soap (CaS-soybean) supplementation in ration on fermentability characteristics, microbial population and nutrient digestibility by using rumen fluid of Bali cattle. The experiment was arranged in a completelyrandomized block design with 4 different ration treatments with 3 replicates. The ration treatments were R1: 40% native grass (NG) + 60% concentrate (C), R2 (40% NG + 60% C containing 2.5% CaS-soybean), R3: (40% NG + 60% C containing 5.0% CaS-soybean) and R4 (40% NG + 60% C containing 7.5% CaS-soybean). The measured variables were pH, NH3-N, total volatile fatty acids, total bacteria and protozoa (microbial populations), dry matter and, and organic matter digestibility. The datawere analyzed by using Analysis of Variance and the differences between treatments were examined with Duncan’s Multiple Range Test. The experimental results showed that the different feed treatments did not have any significant effect on pH, ammonia (NH3-N) concentration, total bacteria, protozoa population, dry matter, and organic matter digestibility. However, the treatments significantly affect the total volatile fatty acids (VFA) production. Ration with 7.5% CaS-soybean (R4) had the highest VFA concentration compared to R1 (Control), R2 (control ration + 2.5% CaS-soybean and R3 (control ration contains 5% CaS-soybean).Feed treatment supplemented with 5.0% CaS-soybean (R3) had a higher total VFA concentrationcompare to control rations (R0). In conclusion, supplementation of the different levels of CaS-soybean within concentrate created thenormal of in vitro fermentation characteristics and the total production of VFA.

Dietary lysophospholipids supplementation inhibited the activity of lipolytic bacteria in forage with high oil diet: an in vitro study.

ObjectiveThe objective of this study was to evaluate the effects of lysophospholipids (LPL) supplementation on rumen fermentation, degradability, and microbial diversity in forage with high oil diet in an in vitro system.MethodsFour experimental treatments were used: i) annual ryegrass (CON), ii) 93% annual ryegrass +7% corn oil on a dry matter (DM) basis (OiL), iii) OiL with a low level (0.08% of dietary DM) of LPL (LLPL), and iv) OiL with a high level (0.16% of dietary DM) of LPL (HLPL). An in vitro fermentation experiment was performed using strained rumen fluid for 48 h incubations. In vitro DM degradability (IVDMD), in vitro neutral detergent fiber degradability, pH, ammonia nitrogen (NH3-N), volatile fatty acid (VFA), and microbial diversity were estimated.ResultsThere was no significant change in IVDMD, pH, NH3-N, and total VFA production among treatments. The LPL supplementation significantly increased the proportion of butyrate and valerate (Linear effect [Lin], p = 0.004 and <0.001, respectively). The LPL supplementation tended to increase the total bacteria in a linear manner (p = 0.089). There were significant decreases in the relative proportions of cellulolytic (Fibrobacter succinogenes and Ruminococcus albus) and lipolytic (Anaerovibrio lipolytica and Butyrivibrio proteoclasticus) bacteria with increasing levels of LPL supplementation (Lin, p = 0.028, 0.006, 0.003, and 0.003, respectively).ConclusionThe LPL supplementation had antimicrobial effects on several cellulolytic and lipolytic bacteria, with no significant difference in nutrient degradability (DM and neutral detergent fiber) and general bacterial counts, suggesting that LPL supplementation might increase the enzymatic activity of rumen bacteria. Therefore, LPL supplementation may be more effective as an antimicrobial agent rather than as an emulsifier in the rumen.

Evaluation of the Associative Effects of Rice Straw with Timothy Hay and Corn Grain Using an In Vitro Ruminal Gas Production Technique.

Simple SummaryRice straw is a widely used forage source for ruminants in most Asian countries; thus, it is important to accurately estimate its nutritional value. Rice straw is typically fed to the animals along with other ingredients, and the associative effects of the combined ingredients may alter the nutritional value of rice straw. We found associative effects on the ruminal fermentability (gas production kinetics and rumen parameters), especially when rice straw was co-fermented with timothy hay and corn grain. We conclude that the nutritional value of rice straw increases when used with timothy hay and corn grain, due to the associative effects among feeds, which should be considered in diet formulations.The objective of this study was to evaluate the associative effects of rice straw with timothy hay and corn grain. Using an automated gas production system, in vitro ruminal fermentation was studied for six substrates: 100% rice straw, 100% timothy hay, 100% corn grain, 50% rice straw and 50% timothy hay, 50% rice straw and 50% corn grain, and 50% rice straw, 25% timothy hay, and 25% corn grain. Incubation was performed in three batches with different rumen fluids to assess the in vitro ruminal gas production kinetics and rumen parameters (pH, NH3-N, volatile fatty acid (VFA), and true dry matter digestibility (TDMD)). The associated effects were tested by comparing the observed values of the composited feeds and the weighted means of individual feeds. There was a significant increase in NH3-N when rice straw was fermented with timothy hay, corn grain, or both (p < 0.05). TDMD increased when corn grain was co-fermented, and the total gas and VFA production increased when all three feeds were co-fermented. We conclude that the feed value of rice straw increases when fed to animals along with timothy hay and corn grain.

Ruminal Fermentation, Growth Rate and Methane Production in Sheep Fed Diets Including White Clover, Soybean Meal or Porphyra sp.

Simple SummaryIn ruminant feeding, the use of diets containing seaweeds could be a valuable alternative to conventional diets. The objective of this work was to investigate the ruminal fermentation, growth rate and methane production in sheep fed a diet including Porphyra sp. compared with diets including clover silage or soybean meal. Including Porphyra sp. had little impact on ruminal fermentation and methane production both in vitro and in vivo. Lambs fed Porphyra sp. had a similar growth rate to those fed a diet including soybean meal, confirming previous in vitro and in situ observations on the high-quality protein of Porphyra sp. in ruminant feed.The aim of the present work was to investigate the potential of Porphyra sp. as an alternative source of protein to soybean meal in diets for sheep. Our experimental treatments included a control diet (CON) based on grass silage and crushed oats and three diets containing protein supplements, clover silage (CLO), soybean meal (SOY) or Porphyra sp. (POR) to increase dietary crude protein concentrations. We studied its effects on rumen fermentation, growth rate and methane emissions. Ruminal fermentation characteristics, kinetics of gas production and methane production were studied in vitro by using batch cultures inoculated with rumen inoculum from sheep. There were no differences among diets in total volatile fatty acids (VFA) production or in the VFA profile in vitro. Across treatments, we measured no differences in methane production either in vitro or in vivo, and we saw no noticeable antimethanogenic effect of Porphyra sp. The present in vivo trial with lambs showed no differences in average daily weight gain when fed diets including Porphyra sp. or soybean meal diets (250 and 254 g/d, respectively). We conclude that Porphyra sp. has a protein value similar to high-quality protein sources like soybean meal.

Milk fatty acid composition, rumen microbial population and animal performance in response to diets rich in linoleic acid supplemented with

Context Rumen biohydrogenation is an important way to produce conjugated linoleic acid (CLA), especially the rumenic acid isomer. However, CLA is principally synthesised endogenously in lactating mammals by delta 9-desaturase in breast tissue. Aims The aim of the study was to evaluate milk fatty acid profile, rumen microbial population and animal performance in response to diets containing sunflower oil either supplemented with or without flavonoids and essential oils from Piper betle L. powder (PP) in dairy goats. Method Twelve multiparous Saanen goats (42 ± 1.00 kg; mean ± s.d.) were randomly assigned to two treatment groups in an experiment that lasted for 6 weeks. The two experimental diets formulated as total mixed ration were: control (CTH) diet (containing 0% PP) and DPB diet (CTH diet containing 1.3% PP on a dry-matter basis). Key results Inclusion of flavonoids and essential oils from PP in the diet (DPB) did not affect dry-matter intake but resulted in a greater milk yield and altered the composition of milk. Compared with the control diet (CTH), the DPB diet decreased the saturated fatty acid concentration and increased the unsaturated fatty acid concentration in milk. Inclusion of PP decreased the C18:0 production (P &lt; 0.05), resulting in higher C18:1 trans11 and C18:2 cis9 trans11 (P &lt; 0.05) concentrations. Overall, DPB diet increased the total CLA by 1.5-fold, from 1.77 to 2.62 g/100 g fatty acid. The desaturase rate (except desaturase for carbon 18, P &lt; 0.05), and atherogenic and thrombogenic indices were not affected by inclusion of PP in the DPB diet. Moreover, the DPB diet escalated total volatile fatty acid production and altered the volatile fatty acid profile. Compared with goats fed with CTH diet, PP supplementation increased the presence of ruminal Butyrivibrio fibrisolvens by ~5-fold, but the presence of B. proteoclasticus decreased to about 1/11 of the control. Conclusions The use of sunflower oil at 17.6 g/kg diet and inclusion of a practical dose of flavonoids and essential oils from Piper betle L. leaves in the diet of dairy goats can be an efficient method to improve milk yield and milk composition, including increasing the CLA concentration of milk. Implications These results constitute an alternative strategy to improve milk quality, without negatively affecting animal performance.

Effects of Urtica dioica, Matricaria chamomilla, and Vitex agnus-castus extracts on in vitro rumen fermentation in normal and following acidosis conditions

The aim of this study was to investigate the effects of dry extracts of Urtica dioica, Matricaria chamomilla, and Vitex agnus-castus with high phenolic contents on rumen microbial fermentation as compared with those of monensin, a common ionophore antibiotic, using Rumen Simulation Technique (RUSITEC) under normal and acidosis conditions. The treatments were as follows: negative control (no additive), positive control (5 mg/d monensin), and extracts of U. dioica (500 mg/d), M. chamomilla (500 mg/d), and V. agnus-castus (500 mg/d). Neither the plant extracts nor monensin altered the ruminal pH under normal or acidosis conditions. All the treatments affected total volatile fatty acid (VFA) production, propionate production, and dry matter digestibility (DMD), regardless of the fermentation conditions. All three extracts increased (P&amp;lt;0.05) total VFA production similar to that observed with monensin (P&amp;lt;0.05). M. chamomilla and V. agnus-castus increased propionate production and DMD similar to that obtained with monensin (P&amp;lt;0.05). In contrast to the monensin treatment, all three extracts increased acetate production under normal conditions (P&amp;lt;0.05). Under acidosis conditions, acetate production remained unchanged in the U. dioica and V. agnus-castus treatments, as well as in the monensin treatment. Under both conditions, the acetate-to-propionate (A:P) ratio decreased only in the monensin treatment (P&amp;lt;0.05). U. dioica and M. chamomilla had antiprotozoal effects (P&amp;lt;0.05) similar to those of monensin, regardless of the condition. The NH3-N concentration declined only in the V. agnus-castus treatment under acidosis conditions (P&amp;lt;0.05). Similar to the monensin treatment, lactate concentrations remained unchanged in the V. agnus-castus treatment under both conditions. In conclusion, plant extracts stimulated fermentative activity of rumen microorganisms under normal and acidosis conditions. Although they did not improve ruminal pH, U. dioica and V. agnus-castus extracts had more favorable effects on some fermentation parameters under acidosis conditions.

361 Porcine in vitro degradation and fermentation characteristics of heat pretreated corn whole stillage

Abstract Pre-treatment of whole stillage (WS; slurry material that is dried into DDGS) with heat can improve digestibility of the resulting DDGS by pigs. A study was conducted to identify optimal conditions (time and temperature) for heat pre-treatment of corn WS. Six samples of WS from different sources were divided into 13 sub-samples to give a total of 78 sub-samples. Thirteen treatments were applied to 13 sub-samples from each source (1 sub-sample/treatment). The treatments were untreated WS, and WS that was pre-treated (70 psi) for 10, 20, or 30 minutes and at 100, 120, 140, or 160 °C in a 3 × 4 factorial arrangement. Sub-samples were subjected to in vitro digestion with porcine pepsin and pancreatin, followed by in vitro fermentation for 72 h. Accumulated gas production was recorded and modeled to estimate kinetics of gas production. Volatile fatty acids (VFA) concentration in fermented solutions was also measured. Pre-treatment time and temperature did not interact on in vitro digestibility of DM (IVDDM), and total gas and VFA production. Pre-treatment time did not affect total gas and VFA production. The IVDDM for untreated WS was 73.4%. An increase in pre-treatment temperature from 100 to 160 °C resulted in linear and quadratic increase in IVDDM by 11%. Response surface analysis indicated that maximum IVDDM resulted from relatively long pre-treatment times (20–30 mins) and highest pre-treatment temperature. An increase in pre-treatment temperature from 100 to 160 °C resulted in linear increase in total gas production by 13%; maximum total gas production resulted from relatively short pre-treatment times (10–20 mins) and highest pre-treatment temperature. Total VFA production was unaffected by pre-treatment time. In conclusion, in vitro digestibility and fermentability of WS was improved by heat pre-treatment. Optimal conditions for pre-treatment of WS for combined improved digestibility and fermentability were 160 °C and 20 mins.

Effects of different barley and oat varieties on methane production, digestibility, and fermentation pattern in vitro

The objective of this in vitro study was to determine the effects of different barley and oat varieties on CH4 production, digestibility, and rumen fermentation patterns in dairy cows. Our hypothesis was that oat-based diets would decrease CH4 production compared with barley-based diets, and that CH4 production would differ between varieties within grain species. To evaluate this hypothesis, we conducted an in vitro experiment using a fully automated gas production technique, in which the total gas volume was automatically recorded by the system. The experiment consisted of triplicate 48-h incubations with 16 treatments, including 8 different varieties of each grain. The grain varieties were investigated as a mix with an early-cut grass silage (1:1 ratio of grain to silage on a dry matter basis) and mixed with buffered rumen fluid. We estimated predicted in vivo total gas production and CH4 production by applying a set of models to the gas production data obtained by the in vitro system. We also evaluated in vitro digestibility and fermentation characteristics. The variety of grain species did not affect total gas production, CH4 production, or fermentation patterns in vitro. However, in vitro-determined digestibility and pH were affected by variety of grain species. Grain species affected total gas and CH4 production: compared with barley-based diets, oat-based diets decreased total gas production and CH4 production by 8.2 and 8.9%, respectively, relative to dry matter intake. Grain species did not affect CH4 production relative to in vitro true dry matter digestibility. Oat-based diets decreased digestibility and total volatile fatty acid production, and maintained a higher pH at 48 h of incubation compared with barley-based diets. Grain species did not affect fermentation patterns, except for decreased molar proportions of valerate with oat-based diets. These results suggest that replacing barley with oats in dairy cow diets could decrease enteric CH4 production.

Long-term high-grain diet altered the ruminal pH, fermentation, and composition and functions of the rumen bacterial community, leading to enhanced lactic acid production in Japanese Black beef cattle during fattening.

To increase intramuscular fat accumulation, Japanese Black cattle are commonly fed a high-grain diet from 10 to 30 months of age although it can result in the abnormal accumulation of organic acids in the rumen. We explored the effect of long-term high-concentrate diet feeding on ruminal pH and fermentation, and its effect on the rumen bacterial community in Japanese Black beef cattle during a 20-month fattening period. Nine castrated and fistulated Japanese Black beef cattle were housed with free access to food and water throughout the study period (10-30 months of age). The fattening stages included Early, Middle, and Late stages (10-14, 15-22, and 23-30 months of age, respectively). Cattle were fed high-concentrate diets for the experimental cattle during fattening. The body weight of the cattle was 439 ± 7.6, 561 ± 11.6, and 712 ± 18.5 kg (mean ± SE) during the Early, Middle, and Late stages, respectively. Ruminal pH was measured continuously during the final 7 days of each stage, and rumen fluid and blood samples were collected on day 4 (fourth day during the final 7 days of the pH measurements). The 24-h mean ruminal pH during the Late stage was significantly lower than that during the Early stage. Total volatile fatty acid (VFA) during the Late stage was significantly lower than during the Early and Middle stages, but no changes were noted in individual VFA components. The lactic acid concentration during the Late stage was significantly higher than that during the Early and Middle stages. The bacterial richness indices decreased significantly during the Late stage in accordance with the 24-h mean ruminal pH. Among the 35 bacterial operational taxonomic units (OTUs) shared by all samples, the relative abundances of OTU8 (Family Ruminococcaceae) and OTU26 (Genus Butyrivibrio) were positively correlated with the 24-h mean ruminal pH. Total VFA concentration was negatively correlated with OTU167 (Genus Intestinimonas), and lactic acid concentration was correlated positively with OTU167 and OTU238 (Family Lachnospiraceae). These results suggested that long-term high-grain diet feeding gradually lowers ruminal pH and total VFA production during the Late fattening stage. However, the ruminal bacterial community adapted to feeding management and the lower pH during the Late stage by preserving their diversity or altering their richness, composition, and function, to enhance lactic acid production in Japanese Black beef cattle.

Variability of caecal parameters in rabbits

Three groups of rabbits of different origin (29, 27 and 28 animals; 3 or 4–6 months of age) were slaughtered, their caecal contents analyzed and used for inoculation of in vitro cultures. Whereas the caecal pH, dry matter percentages and acetate molar proportions in caecal volatile fatty acids (VFA) were relatively stable, molar proportions of other VFA varied considerably. In in vitro incubations, caecal parameters varied somewhat less than in vivo. Methane production varied much more than total VFA production. No non-methanogenic rabbit, however, was found. The hydrogen recovery correlated Significantly with the methane production and, in two out of three groups of rabbits, also with the propionate molar percentage. The caecal pH was inversely related to VFA concentration.

Total VFA Production and Protozoa Population with Jengkol (Archidendron jiringa) Peel Powder Supplementation on In Vitro

Jengkol (Archidendron jiringa) peel is a by-product that has not been utilized optimally. Some research reported that jengkol peel had potency as a source of fiber and bioactive compound (saponins and tannins) for ruminant. This experiment was designed to evaluate the effects of jengkol peel powder supplementation on total volatile fatty acid (VFA) production and protozoa population on in vitro ruminal fermentation. The treatments were arranged in a randomized block design with three treatments (2%, 4%, 6% DM) and four replications. The variables observed included total VFA production and protozoa population. Data were tested using Analysis of Variance (ANOVA) and the differences among treatments means were examined by Duncan Multiple Range Test. The results showed that increasing supplementation of jengkol peel powder increased total VFA production (P<0.01) but did not affect protozoa population (P>0.05). It is concluded that supplementation of jengkol (A. jiringa) peel powder until 6% DM potentially improved rumen fermentation.

Rumen In Vitro Fermentation and In Situ Degradation Kinetics of Winter Forage Brassicas Crops.

Simple SummaryWinter brassica crops such as kales and swedes are used to supply feed in times of seasonal shortage. However, to the best of our knowledge, there is little information about the fermentation characteristics of these forages in the rumen. This study assessed the nutrient concentration, in vitro fermentation and in situ rumen degradation characteristics of Brassica oleracea (L.) ssp. acephala (kales) and Brassica napus (L.) ssp. napobrassica (swedes). The kales and swedes both showed different nutrient concentrations and fermented fast and extensively in the rumen. However, in vitro fermentation of swedes resulted in lower acetate and greater proportions of butyrate and propionate. Varieties of swedes showed more differences in terms of degradation and fermentation in the rumen compared to kale varieties.The aim of the present study was to evaluate the nutritional value, the rumen in vitro fermentation, and the in situ degradation of Brassica oleracea (L.) ssp. acephala (kales) and Brassica napus (L.) ssp. napobrassica (swedes) for winter use. Five varieties of each brassica were used in three field replicates and were randomized in a complete block nested design. All forage varieties were harvested at 210 days post-sowing to analyze the chemical composition, in vitro gas production, volatile fatty acid (VFA) production and in situ dry matter (DM) and crude protein (CP) degradability. Kales presented higher DM and neutral detergent fiber (NDF) content (p < 0.01), whereas swedes showed higher CP, metabolizable energy (ME), glucose, fructose, total sugars, NFC, and nonstructural carbohydrate (NSC) content (p < 0.01). The kale and swede varieties differed in their CP and sugar concentrations, whereas the kale varieties differed in their DM and raffinose content. The rates of gas production were higher for swedes than for kales (p < 0.01). No differences between the brassica species (p > 0.05) were observed in the total VFA production, whereas kales had a higher proportion of acetate and swedes had higher proportions of butyrate (p < 0.05). Only the swede varieties showed differences in VFA production (p < 0.05). The soluble fraction “a”, potential and effective in situ DM degradability were higher in swedes (p < 0.01), but kales presented greater DM and CP degradation rates. Differences were observed between brassica species in the chemical composition, degradation kinetics, and ruminal fermentation products, whereas differences among varieties within species were less frequent but need to be considered.

Effects of cinnamon bark meal (Cinnamomum burmanni Ness ex Bl) as protein protection agent on in vitro rumen fermentation characteristic

This experiment aimed to investigate the effect of protein protection on diet contained cinnamon bark meal as cinnamaldehyde source on rumen fermentation characteristics and in vitro gas production kinetics. Five experimental diets (Pennisetum purpureum (60%): wheat pollard (30%): soybean meal (10%)) added with cinnamon bark meal equal to cinnamaldehyde level as much as 0, 200, 400, 600, 800 mg based on dry matter (DM) and each treatment was replicated for 3 times. Fermentation parameters were measured by incubating the sample in a rumen liquor buffer that was taken from a rumen fistulated Bali cattle using Menke and Steingass gas production technique. The gas produced was recorded at 2, 4, 6, 8, 12, 24, 36 and 48 h of the incubation. The kinetics of gas production was analyzed using the Fit Curve. Results of this experiment showed that there were no significant (P>0,05) different among treatments on the rumen fermentation characteristic (pH, NH3, total volatile fatty acid (VFA) production, and molar proportions of the main VFA), total gas production and kinetics of gas production. It was concluded that adding the cinnamon bark meal as cinnamaldehyde source was no adverse effects on rumen fermentation.

In vitro Evaluation of Corn Germ Meal as Ruminant Feed

The present study was taken up to assess the chemical composition and in vitro nutritional worth of corn germ meal (CGM) in comparison to conventional oilseed cakes used in livestock feeding. The CP content of protein sources varied from 18.59% in CGM to 49.41% in soybean meal (SBM). CGM had the highest ether extract (EE) content, neutral detergent fibre (NDF), acid detergent fibre (ADF) and total carbohydrates. However, total ash, acid detergent insoluble crude protein (ADICP) and neutral detergent insoluble crude protein (NDICP) was lowest in CGM. In vitro net gas production in CGM (267.91 ml/g DM/24 h) was higher (P<0.05) than other conventional oil cakes. The digestibility of organic matter varied from 85.12% in DMC (deoiled mustard cake) to 96.19% in SBM. The ME availability was highest (P<0.05) in CGM (9.63 MJ/kg DM). Ammonical nitrogen in CGM was lower (P<0.05) than SBM and GNC (groundnut cake).The total volatile fatty acids (TVFA) production (mM/dl) was highest (P<0.05) in GNC (12.56) and lowest (P<0.05) in CGM (9.31). Methane production was lowest (P<0.05) in CGM than other conventional oil cakes. Hydrogen recovery (%) was higher (P<0.05) in CGM (65.76) and SBM (65.78) than other protein sources tested. Fermentation efficiency (%) was higher (P<0.05) in SBM (77.02) and GNC (76.75) while volatile fatty acids utilization index (VFA UI) was higher (P<0.05) in CGM (2.92) and DMC (2.84) than other protein sources tested. The results revealed that CGM can be used as a potential protein source for ruminants.

Effect of grape (Vitis vinifera L. cv. Pinotage) pomace supplementation on nutrient utilization in finisher lambs

The objective of the study was to evaluate the effects of feeding varying levels of sun–dried red grape pomace (DGP; Vitis vinifera L. cultivar Pinotage) on nutrient digestibility, rumen fermentation, microbial nitrogen (N) supply, N retention and efficiency of N utilization in lambs. Twenty-one Dohne Merino wether lambs (6.0 ± 1.0 months and 51.6 ± 4.70 kg initial body weight) were randomly assigned to three diets containing 0, 100 and 200 g DGP per kg of diet dry matter in pelleted total mixed rations (TMR). The experiment consisted of 14 days for adaptation to the diets and 7 days for data collection. Intake of neutral detergent fiber (aNDFom) and starch decreased linearly (P ≤ 0.05) while ether extract intake increased linearly (P ≤ 0.05) with the addition of DGP. Apparent total tract aNDFom digestibility decreased linearly (P ≤ 0.05) with increasing levels of DGP. Total volatile fatty acids (VFA) production was quadratically (P ≤ 0.05) influenced by DGP addition. Increasing levels of DGP led to a linear decrease (P ≤ 0.05) in concentrations of butyrate and valerate. Allantoin, microbial N supply, total purine derivatives excreted linearly declined (P ≤ 0.05) with DGP addition. Nitrogen retention and the efficiency of N utilization were not influenced by diet (P > 0.05). Overall, addition of DGP in the lamb finisher diets reduced carbohydrate intake, microbial N yield, total purine derivatives excreted and increased total VFA concentration but did not have adverse effect of DGP on N retention and the efficiency of N utilization.