Rumen Fermentation Kinetics Research Articles

In vitro Evaluation of Different Levels of Cashew (Anacardium occidentale) Nut Meal Supplementation on Rumen Fermentation Kinetics and Digestibility

Background: Globally, safeguarding food and nutritional security of ever increasing population demands sustainable crop and livestock production. While urbanization, decrease in cultivable land and stiff feed-fuel-food competition accompanied with skyrocketing price of conventional feedstuffs hinders the sustainable livestock production. Hence, it necessitates search and exploration of alternative feed resources along with judicious utilization of existing feed resources. In this context, Cashew nut meal (CNM) is one such alternative feed resource but the studies pertaining to its optimum level of inclusion in animal diet is scanty. Therefore, the study was conducted to assess the effect of incorporating varying levels of cashew nut meal (CNM) as a supplement on in vitro rumen fermentation kinetics and digestibility. Methods: Seven distinct compounded feed mixtures (CFM) were formulated, with CNM progressively replacing 0 (C0), 10 (C1), 20 (C2), 30 (C3), 40 (C4), 50 (C5), and 60 (C6) per cent of the soybean meal (SBM) protein present in the control CFM. Additionally, seven experimental complete diets (T0 to T6) were prepared by blending these CFM with Super Napier (Pennisetum purpureum x Pennisetum glaucum) hay in a 40:60 ratio. These diets were subjected to rumen in vitro gas production (RIVGP) study with cumulative gas production measured at 0, 2, 4, 6, 8, 12, 16, 24, 36, 48, 60, 72 and 96 h post-incubation. Subsequently, in vitro dry matter digestibility (IVTDMD) and neutral detergent fiber digestibility (NDFD) of the diets were determined using a modified in vitro two-stage technique. Later, total volatile fatty acids (TVFA) were estimated using gas chromatography. Result: Analysis of chemical composition revealed that CNM contains good protein of 256.5 g/kg. The potential gas production (D) and the rate and extent of gas production (c) for diets containing CNM ranged from 54.63 to 60.24 mL and 0.036 to 0.043 h-1, respectively. IVTDMD and NDFD analysis of the seven diets fell within the range of 79.12% to 80.80% and 64.72% to 66.47%, respectively. The estimated TVFA for seven diets ranged from 17.87 to 23.65 mM. Further, the metabolisable energy (ME) of diets ranged from 7.89 to 8.08 MJ/kg DM. Importantly, no significant differences were observed in rumen fermentation kinetics parameters, IVTDMD, NDFD and TVFA among treatments (T0 to T6). In conclusion, cashew nut meal could be used as an alternative to soybean meal in compounded feed mixtures of ruminants up to 30% (w/w) without any adverse effect on rumen fermentation pattern and digestibility.

Effect of calcium soaps from garlic (Allium sativum) and willow (Salix babylonica) extracts on nematode loads, nutrient intake and digestibility, nitrogen balance and rumen fermentation kinetics in dairy goats.

The objective of this study was to determine the effect of dietary calcium soaps from garlic (Allium sativum) and willow (Salix babylonica) extracts on nematode loads, nutrient intake and digestibility, nitrogen balance and rumen fermentation kinetics in dairy goats. Nine adult non-lactating Saanen goats were grouped into a complete randomized block design with 3 treatments (n = 3) over a period of 28 d. Animals were fed a diet based on alfalfa hay and a concentrate that was supplemented (65 g/kg DM) with calcium soaps of safflower (control), garlic or willow. Intake of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) were not affected by dietary calcium soaps. However, the highest digestibility of DM and OM were observed in willow supplemented goats. In vitro gas kinetics and fermentation profile were not affected by diets. Results from fecal egg count indicated a reduction in total count, Haemonchus spp. and Trychostrongylus spp. for both garlic and willow compared to control. Our results suggest that calcium soaps of garlic or willow extracts can be used to reduce gastrointestinal parasites in goats without compromising productive traits or rumen function.

Effect of hydroxypropyl methylcellulose (HPMC) hard capsules on in vitro rumen fermentation kinetics of commonly used feeds in ruminant feeding.

Accurate dosing of feed additives is often required to evaluate their effects on rumen fermentation. This can be done using soluble but nonfermentable hydroxypropyl methylcellulose (HPMC) hard capsules. The aim of the study was to evaluate the effect of HPMC hard capsules on the extent and rate of in vitro gas production in eleven feeds. Six high-fibre feeds and five concentrates, were weighed into syringes either directly or into HPMC capsules and incubated anaerobically in 30mL buffered rumen fluid at 39°C. Data obtained from gas production measurements were fitted using the Gompertz model to obtain kinetic parameters for gas production. HPMC hard capsules had no effect on the gas production of the blank sample and concentrate feeds. In contrast, high-fibre feeds weighed in HPMC showed a significant decrease (p < 0.05) in total gas production and gas produced within 24 h of incubation. The use of HPMC hard capsules was found to be inappropriate for determining gas production kinetics because fermentation subsides at a certain point when peak fermentation is reached (at TMFR), resulting in a decrease in both total potential gas production and gas production within 24 h of incubation. This is particularly evident when high-fibre feeds are incubated.

Differences in Donor Animal Production Stage Affect Repeatability of In Vitro Rumen Fermentation Kinetics.

In vitro gas production techniques (IVGPT) are widely used to screen feeds and feed additives to reduce the number of animals needed for experiments, which in turn, reduces costs and increases animal welfare. However, information about repeatability is scarce. The objective of this study was to evaluate the variation from in vitro gas production fermentations in the same laboratory using the same feed substrate. The source of rumen fluid used in the fermentations was from two different farms with either cannulated lactating dairy cows or cannulated fasting heifers, representing two distinct stages of production (donor types). Seventeen 24 h fermentations, undertaken during a year, were used to evaluate the variation between the following parameters: gas curve parameters, baseline-corrected total gas production (TGP (mL at Standard Temperature and Pressure (STP))/g incubated dry matter (DM)), methane concentration (%) and yield (mL gas at STP/g DM), pH and degraded dry matter (dDM). Significant differences between donor types were found for the pH of the rumen fluid from individual animals and pH of fermented fluid. However, no significant differences were observed within donor type. The means for methane concentration and yield, after 24 h of fermentation, were not significantly different between or within donor types. Rate of early gas production was significantly different between donor types, but baseline-corrected TGP was not significantly different at 24 h. No dDM differences after 24 h of fermentation between or within donor types were detected. Gas production curves were different between donor types, being either a monophasic version of the sigmoidal model or an exponential curve for the heifers and the production animals, respectively. No differences were observed within type. Repeatability of rumen fluid (CVRF), calculated as the coefficient of variation, and the associated parameters, which were investigated, was best for methane yield (CVRFALL = 0.3%) and least for TGP at 3 h (CVRFALL = 3%). Repeatability was dependent on donor type.

Chemical Characterization and In Vitro Gas Production Kinetics of Alternative Feed Resources for Small Ruminants in the Maltese Islands.

The ever-increasing human population, the problem associated with climate change and recent crises-COVID-19 disease and trade conflicts-all impacted on the availability and cost of animal feed raw materials. This is clearly visible in realities which heavily rely on importation such as islands and small states, where producers involved in the agricultural sector were strongly affected by the sharp increase in prices. To deal with these global issues, alternative resources are perceived to replace conventional ingredients. This work aimed at assessing the nutritive value of different resources (sheep feed, mature carob, Maltese bread, wild asparagus, prickly lettuce, and loquat) for small ruminants present in the Maltese Islands, analyzing their chemical composition, gas production kinetics and antioxidant properties. In general, the variation in chemical composition resulted in different rumen fermentation kinetics (p < 0.007). The ratio between GP-24 h and GP-48 h was higher in Maltese bread than other substrates; loquat, prickly lettuce and wild asparagus showed lower fermentation kinetics in accordance with their high NDF and ADF contents. The antioxidant activity may be partially related to the polyphenolic content that was higher in wild asparagus, prickly lettuce and loquat. All feed characteristic confirmed their potential to be included as ingredients in ruminant diets and as a source of fiber.

Mulberry flavonoids modulate rumen bacteria to alter fermentation kinetics in water buffalo.

Mulberry flavonoids can modulate the composition of rumen microbiota in ruminants to improve nutrient digestibility, owing to their strong biological activities. This study aimed to explore the effect of mulberry leaf flavonoids (MLF) on rumen bacteria, fermentation kinetics, and metagenomic functional profile in water buffalo. Forty buffaloes (4 ± 1 lactations) with almost same body weight (av. 600 ± 50 Kg) and days in milk (90 ± 20 d) were randomly allocated to four treatments having different levels of MLF: 0 g/d (control), 15 g/d (MLF15), 30 g/d (MLF30), and 45 g/d (MLF45) supplemented in a basal diet. After 35 days of supplementation, rumen contents were collected to determine rumen fermentation parameters. The 16S rRNA gene sequencing was performed to elucidate rumen bacteria composition. The obtained taxonomic data were analyzed to explore the rumen bacteriome and predict the associated gene functions and metabolic pathways. Results demonstrated a linear increase (p < 0.01) in rumen acetate, propionate, and total VFAs in the MLF45 group as compared to control. No effect of treatment was observed on rumen pH and butyrate contents. Acetate to propionate ratio in the MLF45 group linearly and quadratically decreased (p = 0.001) as compared to MLF15 and control groups. Similarly, MLF45 linearly increased (p < 0.05) the microbial protein (MCP) and NH3-N as compared to other treatments. Treatment adversely affected (p < 0.01) almost all alpha diversity parameters of rumen bacteria except Simpson index. MLF promoted the abundance of Proteobacteria while reducing the relative abundances of Actinobacteria, Acidobacteria, Chloroflexi, and Patescibacteria. The MLF supplementation tended to substantially reduce (0.05 < p < 0.1) the abundance of Actinobacteria, and Patescibacteria while completely eliminating Acidobacteria (p = 0.029), Chloroflexi (p = 0.059), and Gemmatimonadetes (p = 0.03) indicating the negative effect of flavonoids on the growth of these bacteria. However, MLF45 tended to substantially increase (p = 0.07) the abundance (~21.5%) of Acetobacter. The MLF treatment exhibited negative effect on five genera by significantly reducing (Sphingomonas) or eliminating (Arthobactor, unclassified_c__Actinobacteria, norank_c__Subgroup_6, norank_o__Saccharimonadales, and Nocardioides) them from the rumen microbiota. Pearson correlation analysis revealed 3, 5 and 23 positive correlations of rumen bacteria with milk yield, rumen fermentation and serum antioxidant parameters, respectively. A positive correlation of MCP was observed with three bacterial genera (Acetobacter, Enterobacter, and Klebsiella). The relative abundance of Pseudobutyrivibrio and Empedobacter also showed a positive correlation with the ruminal acetate and propionate. The present study indicated 45 g/d as an appropriate dose of MLF which modulated rumen bacteria and its functional profile in water buffalo.

In Vitro Screening of the Foliage of Eucalyptus Species Harvested in Different Seasons for Modulating Rumen Fermentation and Methane Production

The aim of this study was to assess the effects of five eucalyptus species (Eucalyptus camaldulensis, E. leucoxylon, E. astringens, E. sideroxylon, and E. lehmannii), harvested in spring, autumn, or winter from two Tunisian arboretums, on in vitro rumen fermentation and methanogenesis. Batch cultures were performed to determine rumen fermentation kinetics and end-product formation after 24 h of incubation. The foliage of the species E. sideroxylon and E. lehmannii showed the greatest digestibility coefficients, whereas E. leucoxylon was the least digestible. Acetate-to-propionate ratio was reduced when E. sideroxylon and E. lehmannii were incubated, and these species were also the most efficient at reducing methane emission. Foliage harvested in winter showed greater digestibility and an increase in the acetate-to-propionate ratio than in other seasons, without an increase in methane emission. Foliage from E. sideroxylon and E. lehmannii showed a potential to decrease enteric methane production without depressing effects on ruminal fermentation. In vivo studies would be necessary to conclusively validate these effects as the first step towards proposing the inclusion of eucalyptus leaves in ruminant diets.

Effect of different dietary inclusion levels of whole plant green tomato (Physalis philadelphica) silage on nutrient intake and digestibility, and in vitro rumen fermentation kinetics in sheep.

Mexico has many agricultural by-products that can be used for animal feed, and green tomatoes are produced throughout the country and can be an alternative to overcome the high prices of cereal-based feeds. This study determined in vitro fermentation kinetics, production performance, nutrient intake, digestibility, and nitrogen balance from sheep supplemented with whole plant green tomato (GT) on corn silage (CS) based diets. For 21 days, eighteen Suffolk lambs (38 ± 4 kg of live weight) were grouped into three dietary GT inclusion levels to replace CS: a control diet based on 100% CS (GT0, 570 g /kg dry matter, DM), while 100 g/kg DM (GT100) and 200 g/kg DM (GT200) of GT were included as a replacement for CS. A completely randomized design was used to measure in vitro gas production, in vitro rumen fermentation, chemical composition, and in vivo parameters. In vitro gas production, “A” (ml/g DM), fermentation rates “B,” (h−1), and “C” (h−½), were lower for GT200, while DM disappearance (mg/100mg) was lower for GT100 compared with GT0. Compared to GT0, GT100 and GT200 did not affect (P > 0.05) DM and organic matter (OM) intake (g/kgLW0.75). Ether extract intake was higher for GT0 and GT100 (P < 0.001) compared to GT200. Neutral detergent fiber (NDF) intake was higher (P < 0.05) for GT200 compared with GT0. Intake of lignin was higher (P < 0.001) for GT200 than that of GT0 and GT100. Digestibility coefficients for DM, OM, NDF, and Acid detergent fiber (ADF) were lower (P < 0.05) in GT100 than in the rest of the treatments. Nitrogen intake and N excreted in feces and urine were lower (P < 0.001) for GT0. N balance was negative for all treatments, being higher for GT200 (P < 0.05). Overall, the addition of GT at 100 or 200 g/kg DM in sheep diets negatively affects nutrient digestibility and N balance, so their dietary inclusion is not recommended.

Dietary treatment with omega fatty acids mediates in vitro rumen fermentation kinetics and reduce methane emission in water buffalo

Purpose: To investigate the effect of dietary supplementation of two omega fatty acids on in vitro rumen fermentation, microbial populations, total gas and methane (CH4) production．Methods: Both linoleic and linolenic acids were supplemented at 0 (control), 1, 3, 5 and 7 % of dry matter (DM) in a ration with a high roughage to concentrate ratio (70: 30). Total gas and CH4 were measured at 3, 6, 9, 12 and 24 h of fermentation while pH, volatile fatty acids (VFA), and ammonia nitrogen (NH3-N) concentrations were measured at 24 h using buffalo rumen fluid in an in vitro batch culture system. Microbial populations were determined using 16S-rDNA gene primers by RT-PCR.Results: The results revealed that linoleic acid at 3, 5 and 7 % decreased the concentration of NH3-N (p&lt; 0.05) but linolenic acid at 5 and 7 % increased NH3-N (p &lt; 0.05). A linear decrease (p &lt;0.001) in acetate and butyrate, coupled with linear increase (p &lt;0.001) in propionate was observed in response to treatment. Furthermore, supplementation of 3, 5 and 7 % of both fatty acids linearly (p &lt; 0.001) decreased total gas and CH4 production when compared to the control. The addition of linoleic acid linearly (p &lt; 0.001) decreased the number of protozoa without affecting methanogens, while linolenic acid linearly and quadratically (p &lt; 0.001) reduced the population of both protozoa and methanogens (p &lt; 0.05).Conclusion: Linolenic acid is more effective at a 3 % level in reducing methane production (up to 63 %) in high roughage diets.

In vitro nutritional quality and antioxidant activity of three weed species as feed additives for sheep in the Central Highlands of Mexico.

Sheep production is traditional for rural communities in Mexico, based on natural grasslands and semi-stabled feeding. Quality forages are necessary to improve productivity in these systems. Weeds are an alternative to feed ruminants and to manage crops. Also, many plants have secondary metabolites beneficial for livestock. The objective was to assess the nutritive value in vitro and the antioxidant activity of three weeds (Tithonia tubiformis, Cosmos bipinnatus, and Tagetes lucida) and four treatments (T0 = control diet, T1 = diet + 5% T. tubiformis, T2 = diet + 5% C. bipinnatus, and T3 = diet + 5% T. lucida). Nutritive value was determined from chemical composition by standard methods and mineral contents by inductively coupled plasma analyses. Secondary compounds, total phenols (TP), total tannins (TT), condensed tannins (CT), and phenolic compounds, were determined by high-performance liquid chromatography, and total antioxidant activity was determined by measuring the oxygen radical absorbance capacity. Rumen fermentation kinetics and in vitro digestibility of dry matter (IVDMD), organic matter (IVOMD), and neutral detergent fibre (IVNDFD) were determined per species and treatment by in vitro gas production. T. tubiformis had the highest CP and TP contents (P < 0.05), and C. bipinnatus had the highest fibre and CT contents (P < 0.05). Inclusion of T. lucida in the diet resulted in an 18% increase in TP content and a 30% increase in antioxidant activity in comparison to the control diet. No significant differences (P > 0.05) were found in rumen kinetics parameters, IVDMD, IVOMD, IVNDFD, or metabolizable energy, indicating that the tested weeds can be used as additives to increase antioxidant activity in sheep diets without negative effects.

Mathematical models to adjust the parameters of in vitro cumulative gas production of diets containing preserved Gliricidia

ABSTRACT: This study examined the use of the Gompertz, Groot, monomolecular, Richards and two-compartment-logistic mathematical models to investigate the kinetics of in vitro gas production of diets composed of combinations of Gliricidia hay or silage. In addition, the effects of Gliricidia hay or silage inclusion on the in vitro cumulative gas production of these diets were evaluated. Rumen fermentation kinetics were analyzed by the in vitro cumulative gas production methodology. The model parameters were estimated using the Gauss Newton method, with the exception of the Richards model, which was used by Marquardt’s algorithm. Model fit was assessed using the determination coefficient, F test for parameters identity, concordance correlation coefficient, root mean square error of prediction, and decomposition of mean square error of prediction into mean error, systematic bias and random error. The models were compared for accuracy (pairwise mean square error of prediction) and precision (delta Akaike’s information criterion). All model evaluation and comparison statistics were calculated using Model Evaluation System software version 3.2.2. The Groot and Richards models did not differ from each other (P&gt;0.05) and were the most precise and accurate (P&lt;0.05). Therefore, the Groot model was selected due to its better accuracy and precision and easier access to the parameters. The inclusion of Gliricidia silage in the diet resulted in an increase in the time to obtain the maximum rate of degradation and in the time after incubation when half of the asymptotic level was reached. The Groot model is recommended to estimate the average curve. Dietary inclusion of Gliricidia silage alters the gas production curve due to the longer time required for the diet to reach the maximum rate of degradation, this can increase the time the diet remains in rumen and promote a reduction in the consumption.

Effect of different growth stages of rapeseed (brassica rapa L.) on nutrient intake and digestibility, nitrogen balance, and rumen fermentation kinetics in sheep diets

The objective of the present study was to determine the dietary effect of different growth stages of rapeseed (Brassica rapa L.) on nutrient intake and digestibility, nitrogen balance, and rumen fermentation kinetics in sheep. Four dietary treatments were utilised. A basal control diet based on alfalfa hay, oat hay, soybean meal and corn grain. Then alfalfa hay was replaced with 300 g/kg DM of rapeseed forage harvested at three different growth stages: Vegetative, Flowering and Pod. In vitro gas production was determined using three rumen cannulated Suffolk sheep in a completely randomised design, and nutrients intake and digestibility of each diet were determined using four Suffolk sheep in a 4 × 4 Latin square design with 21 d periods consisting of 14 d for diet adaptation and 7 d for sample collection. Feed intake and excretion of faeces and urine were recorded. Dry matter intake was higher for control and Pod compared to Vegetative and Flowering. The digestibility of dry matter, organic matter, neutral detergent fibre and acid detergent fibre were similar among treatments. Nitrogen intake was higher for control and Pod and lower for Vegetative and Flowering. In vitro gas production was similar among treatments (P > .05). In vitro gas yield at 24 h was higher (P < .05) for control than the rest of the treatments. Overall, inclusion of 300 g/kg DM of rapeseed forage harvested at pod stage as a substitute for alfalfa hay is an alternative source of protein without affecting nutrient intake and digestibility. Highlights Effect of different growth stages of rapeseed on nutrient intake and digestibility was determined Nutrient digestibility was similar between growth stages of rapeseed In vitro gas production was similar between growth stages of rapeseed

The Role of Condensed Tannins in the In Vitro Rumen Fermentation Kinetics in Ruminant Species: Feeding Type Involved?

Simple SummaryInoculum from different feeding types of the ruminant species host has unequal tolerance and effects to condensed tannin (CT) due to their respective feeding strategies behavior producing different ruminal microbiota profiles. This paper describes that in long term incubation, CT plant extract addition affects in vitro fermentation kinetics more severely in grazing ruminant than browsing ruminants.Animal feeding behavior and diet composition determine rumen fermentation responses and its microbial characteristics. This study aimed to evaluate the rumen fermentation kinetics of domestic ruminants feeding diets with or without condensed tannins (CT). Holstein dairy cows, Nelore beef cattle, Mediterranean water buffalo, Santa Inês sheep and Saanen goats were used as inoculum donors (three animals of each species). The substrates were maize silage (Zea mays), fresh elephant grass (Pennisetum purpureum), Tifton-85 hay (Cynodon spp.) and fresh alfalfa (Medicago sativa). Acacia (Acacia molissima) extract was used as the external CT source. The in vitro semi-automated gas production technique was used to assess the fermentation kinetics. The experimental design was completely randomized with five inoculum sources (animal species), four substrates (feeds) and two treatments (with or without extract). The inclusion of CT caused more severe effects in grazing ruminants than selector ruminants.

Dose-Response Effect of Exogenous Enzymes Treatment of Tomato and Watermelon Crop Byproducts on In vitro Nutrient Degradability and Rumen Fermentation Kinetics

Dose-Response Effect of Exogenous Enzymes Treatment of Tomato and Watermelon Crop Byproducts on In vitro Nutrient Degradability and Rumen Fermentation Kinetics

Chemical Composition, In Vitro Digestibility and Rumen Fermentation Kinetics of Agro-Industrial By-Products.

Simple SummaryAgro-industrial by-products are the waste from either agricultural crops or vegetable processing industries, and their disposal represents an environmental problem since they are potential pollutants. One of their most promising alternative uses is as feedstuffs in ruminant diets. The aim of this study was to assess the nutritive value of different by-products by analysing their chemical composition, in vitro digestibility and gas production kinetics. The results showed a high variability in chemical composition, in vitro digestibility and rumen fermentation kinetics among different by-products. In addition, samples of the same by-product from a different origin or subjected to different conservation processes showed a certain variability in the evaluated parameters. The variability among by-products was reflected in the results of the cluster analysis, which divided the materials in four groups based on the multivariate analysis. Most by-products showed the potential to be included as alternative ingredients in ruminant rations. They could be used as a source of energy, fibre or protein, replacing part of the ingredients in a conventional diet and therefore, reducing the risk of environmental pollution and contributing to develop a circular economy by recycling these wastes. In addition, their use as feedstuffs might reduce competition between ruminants and humans for food or land.The nutritive value of 26 agro-industrial by-products was assessed from their chemical composition, in vitro digestibility and rumen fermentation kinetics. By-products from sugar beet, grape, olive tree, almond, broccoli, lettuce, asparagus, green bean, artichoke, peas, broad beans, tomato, pepper, apple pomace and citrus were evaluated. Chemical composition, in vitro digestibility and fermentation kinetics varied largely across the by-products. Data were subjected to multivariate and principal component analyses (PCA). According to a multivariate cluster analysis chart, samples formed four distinctive groups (A–D). Less degradable by-products were olive tree leaves, pepper skins and grape seeds (group A); whereas the more degradable ones were sugar beet, orange, lemon and clementine pulps (group D). In the PCA plot, component 1 segregated samples of groups A and B from those of groups C and D. Considering the large variability among by-products, most of them can be regarded as potential ingredients in ruminant rations. Depending on the characteristic nutritive value of each by-product, these feedstuffs can provide alternative sources of energy (e.g., citrus pulps), protein (e.g., asparagus rinds), soluble fibre (e.g., sugar beet pulp) or less digestible roughage (e.g., grape seeds or pepper skin).

In vitro screening of Algerian steppe browse plants for digestibility, rumen fermentation profile and methane mitigation

The aim of this study was to screen the nutritive value and the effects of anti-nutritional secondary compounds (condensed tannins) on in vitro rumen fermentation and methane mitigation of Algerian steppe browse species: Albizia julibrissin (pods), Acacia nilotica (pods), Punica granatum (leaves and pericarp), Vicia faba (leaves), Artemisia herba-alba (aerial part), Attriplex halimus (leaves) and Calligonum azel (bark). Chemical composition, and in vitro digestibility, and rumen fermentation kinetics and end-products accumulation in batch cultures were determined. Polyethylene glycol (PEG), a tannin binding agent was used to measure the biological activity of tannins. Protein content was high for A. julibrissin and V. faba and low for the pericarp of P. granatum and bark of C. azel. The highest concentrations of total extractable phenols and tannins were observed in P. granatum, whereas A. halimus showed the lowest concentrations. A. nilotica, C. azel and A. julibrissin showed the highest and A. halimus and A. herba-alba the lowest total condensed tannin contents. Vicia faba was the most digestible forage. All the browse species used in the current study, with the exception of C. azel bark, can be used as alternative feedstuffs for ruminant nutrition. The most promising forage in terms of reduced methane emissions is Atriplex halimus foliage, because the decreased methane production is not associated to a reduced rumen degradation and fermentation of this forage in the rumen. However, in vivo studies are warranted to confirm its potential to be included in ruminant diets.

Dietary dragon fruit (Hylocereus undatus) peel powder improved in vitro rumen fermentation and gas production kinetics.

Plant phytophenols especially condensed tannins (CT) and saponins (SP) have been demonstrated to impact on rumen fermentation. Dragon fruit (Hylocereus undatus) peel powder (DFPP) contains both CT and SP. The current study aimed to investigate the influence of DFPP and varying levels of concentrate and roughage ratios on gas production kinetics, nutrient degradability, and methane production "using in vitro gas production technique." The dietary treatments were arranged according to a 3 × 5 Factorial arrangement in a completely randomized design. The two experimental factors consisted of the roughage to concentrate (R:C) ratio (100:0, 70:30, and 30:70) and the levels of DFPP supplementation (0, 1, 2, 3, and 4% of the substrate) on DM basis. The results revealed that the R:C ratio at 30:70 had the highest cumulative gas production when compared to other ratios (P < 0.01). The in vitro true dry matter degradability at 12 and 24h was affected by R:C ratio (P < 0.01). Furthermore, volatile fatty acids (VFA) and propionate (C3) were significantly increased by the levels of DFPP, while acetate (C2) and C2:C3 ratios were decreased (P < 0.05). The rumen protozoal population was significantly decreased by DFPP supplementation (P < 0.05). Rumen methane production was significantly impacted by R:C ratios and decreased when the level of DFPP increased (P < 0.01), while NH3-N and ruminal pH were not influenced by the DFPP supplement. It could be summarized that supplementation of DFPP resulted in improved rumen fermentation kinetics and could be used as a dietary source to mitigate rumen methane production, hence reducing greenhouse gas production.

Evaluating rumen fermentation kinetics and nutritive value of sunflower seed meal supplemented with acetonic extract of pomegranate peel using &lt;i&gt;in vitro&lt;/i&gt; gas production technique

This study was conducted to investigate effects of supplementing different levels (0.0, 0.5 and 1.0% of buffered rumen fluid) of acetonic extract of pomegranate peel on rumen fermentation kinetics of sunflower seed meal (SFM), using in vitro gas production technique. The samples were incubated in syringes containing rumen liquor obtained from three cannulated Iranian Ghezel rams for 2, 4, 6, 8, 12, 24 and 36h. Results indicated that, addition of acetonic extract of pomegranate peel resulted in increase in gas production volume in all of incubation times (p &lt; 0.0001). Amount of gas production, also increased by increasing dose of the extract. Amounts of a (the gas production from the immediately soluble fraction), b (the gas production from the insoluble fraction) and a + b (the potential gas production) for pomegranate peel extract supplemented sunflower seed meal were higher (p &lt; 0.05) than that of control meal. Adding pomegranate peel extract resulted in increase estimated short chain fatty acids (SCFA) production as well as digestible organic matter (DOM), metabolizable energy (ME) and net energy for lactation (NEL) content of SFM. Production of SCFA as well as DOM, ME and NEL content of SFM increased (p &lt; 0.05) by enhancing the level of the extract supplementation. In conclusion, it can be suggest that, supplementing acetonic extract of pomegranate peel may be lead to higher ruminal fermentation and better nutritive value of SFM in ruminants.

Effect of Depotash Vinasse on Rumen Fermentation Kinetics in vitro

Effect of Depotash Vinasse on Rumen Fermentation Kinetics <i>in vitro</i>

Forage management intensification and supplementation strategy: Intake and metabolic parameters on beef cattle production

Improving animal performance on pasture requires grazing management that optimizes forage intake in combination with the appropriate supplementation strategy. The objective was to determine the effects of sward canopy height and level of supplementation on forage intake, digestibility, and ruminal fermentation kinetics of Nellore steers in a double Latin square design with repeated measures. Treatments were three sward heights with differing levels of supplementation and included: (1) short height with high supplementation (SH-HS, 15 cm and 0.6% BW); (2) short height with moderate supplementation (SH-MS, 15 cm and 0.3% BW); (3) moderate height with moderate supplementation (MH-MS, 25 cm and 0.3% BW); (4) moderate height with low supplementation (MH-LS, 25 cm and 0.1% BW); (5) tall height with low supplementation (TH-LS, 35 cm and 0.1% BW); and (6) tall height with no supplementation (TH-WS, 35 cm). Intake of crude protein and total digestible nutrients was greater (P < 0.05) with tall swards and moderate supplementation rates. Nutrient digestibility among treatments did not differ (P ≥ 0.21), possibly due to the availability of high-quality forage during the wet season. Likewise, rate of neutral detergent fiber degradability did not differ (P ≥ 0.19) among treatments. Ruminal ammonia nitrogen differed (P = 0.02) among treatments with moderate supplementation having the greatest (SH-MS) and lowest (MH-MS) concentrations (13.6 and 9.7 mg/dL, respectively). Ruminal pH and volatile fatty acid concentrations did not differ (P ≥ 0.18) among treatments. Microbial N flow to the small intestine and efficiency of microbial synthesis exhibited a quadratic response with moderate sward height treatments having greater values. With these treatments and under the conditions of this study, various combinations of sward height and supplementation level did not alter rumen fermentation kinetics.