Search

Ruminant animals constitute major contributors to greenhouse gas (GHG) emissions and play an important part in sustainable agricultural systems. A bioactive compound (BC) with antibacterial properties was utilized to inhibit rumen methanogens and decrease ruminant methane emissions. The bio efficacy of ruminant nutrition was frequently employed using a new technology through microencapsulation technique to produce stable products. The microencapsulated banana flower powder pellet (mBAFLOP) powder was used as a BC in the diets. Consequently, this study aimed to evaluate the effects of mBAFLOP supplementation on in vitro gas production kinetics, rumen fermentation, microbial population, and methane production. A completely randomized design (CRD) was used to randomly assign respective treatments at 0, 1, 2, and 3% of the total dry matter (DM) substrate. Ruminal pH, in vitro dry matter degradability and volatile fatty acid profile both at 12, and 24 h were not negatively affected by supplementation with mBAFLOP. The supplemented mBAFLOP (3% of total DM substrate) resulting in ruminal ammonia-nitrogen concentrations was linearly increased (P < 0.01) different among treatments, while methane production was reduced when compared with other treatment (quadratic effect, P < 0.05). Moreover, Ruminococcus flavefaciens was increased when the proportion of mBAFLOP supplement was increased. Furthermore, there was a linear effect (P < 0.05) of decreasing Methanobacteriales in the rumen with increased levels of mBAFLOP supplementation. Based on this study, the use of mBAFLOP at 3% could enhance NH 3 N concentration and cellulolytic bacteria especially Ruminococcus flavefaciens was increased. Furthermore, supplementation with mBAFLOP decreased methane production. Therefore, a possible dietary plant-based bioactive compound, mBAFLOP supplementation cloud enhances rumen fermentation and mitigates methane production., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The aim of the study was to evaluate the effect of total mixed ration particle size (length) and breed of cow on intake dynamics, animal performance and CH 4 emissions, comparing high yielding Holstein and low yielding Girolando cows. The experimental design was 2 × 2 Latin Square arranged as a crossover factorial scheme with two diets (short particle size, SPS and long particle size, LPS) and the two breed compositions. The design comprised two periods of 26 d each, where all data collection was performed at cow level. No influence of the particle size occurred for the passage rate, neutral detergent fiber digestibility, performance and milk composition, methane emissions or ruminal fermentation parameters. Girolando cows had greater dry matter intake (DMI) when fed SPS, while Holsteins had the same ( P < 0.05). Girolando cows had lower dry matter digestibility when fed LPS compared to SPS, while Holsteins had the opposite effect ( P < 0.05). Also, the digestibility of crude protein and non-fibrous carbohydrates decreased in Girolando cows fed LPS, but not in Holsteins ( P < 0.05). Girolando cows reduced DMI by 10.6% when fed LPS diet ( P < 0.05). Girolando had an increased eating rate (+24 g of DM/min; P < 0.05) compared to Holstein cows, but Holstein cows had a lower CH 4 intensity (by 29.7%: P < 0.05). Girolando cows increased the dry matter intake when fed a diet with short particle size, while the same did not happen in Holsteins. Dry matter digestibility increased in Holsteins when fed long particle size, while the opposite was observed in Girolando cows. Nutrient digestibility was reduced in Girolando cows when fed short particle size. Particle size did not influence eating time, eating rate, feed trough visits, visits with intake, milk yield and composition regardless of the breed. Reducing particle size increased CH 4 intensity in both breeds.

The objectives of this study were to evaluate the levels of supplemental salt on low-quality forage intake, water intake, dry matter (DM) digestibility, and rumen fermentation. Six ruminally cannulated, Angus crossbred heifers (14 mo of age; 449 kg ± 24 kg body weight [BW]) were used in a dual 3 × 3 Latin square design. The heifers were housed in individual stalls with 2 animals assigned to each treatment per period. Salt treatments were mixed into a protein supplement of 50% cracked corn and 50% soybean meal and fed at 0.3% of shrunk BW. Salt treatments consisted of 1) control, no salt (CON), 2) 0.05% of BW salt (LOW), and 3) 0.1% of BW salt (HIGH). Chopped, low-quality (CP = 7.4%; NDF = 64.2%), grass hay was used as the base ration and was provided daily at 120% of the average daily intake of the previous 3 d. Each period included a 14-d diet adaptation, 6 d of sample collection, 1 d collection of rumen fluid samples for ruminal and microbial profiles. Individual forage dry matter intake, water intake, and DM digestibility were measured during the 6-d collection period. Rumen pH, ammonia levels, and volatile fatty acid (VFA) concentrations were measured during the 1-d ruminal profile. Rumen DM and liquid fill were determined with a 5-h post-feeding rumen evacuation. Supplemental salt had no influence on forage intake (P = 0.19) expressed on a kg/d basis yet tended to decrease linearly (P = 0.06) with increasing levels of salt when expressed on a grams/kg BW basis. DM digestibility was not influenced by salt levels (P > 0.05), but DM fill tended to increase linearly with increasing salt levels (P = 0.06). Water intake and liquid fill, however, increased linearly with increasing levels of salt (P < 0.01) with an 18.9% increase in water intake and 17.0% increase in liquid fill compared to control animals. Ruminal pH and ammonia levels both decreased linearly with increasing salt (P < 0.01). Acetate concentration and acetate: propionate ratio increased linearly with increasing levels of salt (P < 0.01). In contrast, isobutyrate and butyrate concentrations decreased linearly with increasing levels of salt (P < 0.01). Our research suggests that increasing levels of salt tends to influence dry matter intake, DM fill, liquid kinetics, and rumen fermentation characteristics. Results from this research provide additional information on how salt-limited supplements may impact beef cattle consuming low-quality forage diets., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

The utilization of polyphenol-modified starch in ruminants has not undergone extensive exploration. This study aimed to investigate the impact of the complex formed between starch and Melastoma candidum D. Don fruit extract on physicochemical properties, phenol release kinetics in various buffers simulating the gastrointestinal tract, methane production, and post-rumen digestibility. The interaction between starch and M. candidum D. Don fruit extract significantly (p < 0.001) increased resistant starch and particle size diameter. The maximum phenolic release from complex between starch and M. candidum D. Don fruit extract, due to gastrointestinal tract-simulated buffers, ranged from 22.96 to 34.60 mg/100 mg tannic acid equivalent. However, rumen and abomasum-simulated buffers released more phenolic content, whereas the intestine-simulated buffer showed higher antioxidant activity (ferric ion-reducing antioxidant power). Furthermore, complex between starch and M. candidum D. Don fruit extract significantly decreased dry matter rumen digestibility (p < 0.001) and maximum methane gas production (p < 0.001)., (© 2024 Japanese Society of Animal Science.)

The present study evaluated the effects of forage sources on dry matter (DM) intake, digestibility, and fermentation parameters in camels vs. sheep. The study was arranged as a 2 × 3 factorial experiment in a completely randomized design by using two animal species (three ruminally cannulated female camels and three male sheep) and three forage sources. The forages were (1) alfalfa hay; 164 and 479 g/kg DM for crude protein (CP) and neutral detergent fiber (NDF), respectively, (2) berseem hay; 121 and 513 g/kg DM for CP and NDF, respectively, and (3) wheat straw (27.5 and 723 g/kg DM for CP and NDF, respectively). Higher DM intake [g/kg body weight (BW)] was noted in sheep compared to camel when alfalfa hay ( p  < 0.05) and berseem hay ( p  < 0.05) were fed but was similar between both species when they were fed wheat straw. Forage type rather than animal species had more effect on metabolic intake. Lower digestibility was noted in sheep with wheat straw ( p  < 0.05). Similar in situ degradability values for crude protein and DM were noted between camels and sheep. In situ degradability of NDF was higher ( p  < 0.05) in camel than sheep. Greater ruminal pH ( p  < 0.05) was noted in sheep vs. camels when berseem hay and wheat straw were fed. Lower ruminal passage rate ( p  < 0.05) was noted in camels and higher total mean retention time. It was concluded that sheep and camels had similar digestion capacities when fed berseem hay and alfalfa hay, however, camels are more efficient than sheep when fed wheat straw.

Background: The objectives of this study were to investigate the effects of taurine on rumen fermentation, rumen bacterial community and metabolomics, nitrogen metabolism and plasma biochemical parameters in beef steers. Six castrated Simmental steers (liveweight 402 ± 34 kg) and three levels of taurine (0, 20, 40 g d -1 ) were assigned in a replicated 3 × 3 Latin square design. Each experimental period included 15 days for adaptation and 5 days for sampling., Results: Supplementing taurine did not affect the ruminal pH or concentrations of ammonia nitrogen and volatile fatty acids (P > 0.10), but linearly increased the ruminal concentrations of taurine (P < 0.001) and microbial crude protein (P = 0.041). Supplementing taurine linearly increased the neutral detergent fiber digestibility (P = 0.018), and tended to linearly increase dry matter digestibility (P = 0.095), tended to increase the fecal nitrogen excretion (P = 0.065) and increased the urinary taurine excretion (P < 0.001). Supplementing taurine quadratically increased the plasma concentration of triglycerides (P = 0.017), tended to linearly decrease growth hormone (P = 0.074), but did not affect other plasma parameters (P > 0.10). Supplementing taurine modified the rumen bacterial community and increased the ruminal concentration of taurine metabolite 2-hydroxyethoxysulfonic acid (P < 0.001)., Conclusion: It was concluded that taurine improved ruminal microbial crude protein synthesis and increased fiber digestibility through modifying rumen bacterial community. It is necessary to clarify the ruminal hydrolysis of taurine in steers. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

The present study investigated the association between fibre degradation and the concentration of dissolved molecular hydrogen (H2) in the rumen. Napier grass (NG) silage and corn stover (CS) silage were compared as forages with contrasting structures and degradation patterns. In the first experiment, CS silage had greater 48-h DM, neutral-detergent fibre (NDF) and acid-detergent fibre degradation, and total gas and methane (CH4) volumes, and lower 48-h H2 volume than NG silage in 48-h in vitro incubations. In the second experiment, twenty-four growing beef bulls were fed diets including 55 % (DM basis) NG or CS silages. Bulls fed the CS diet had greater DM intake (DMI), average daily gain, total-tract digestibility of OM and NDF, ruminal dissolved methane (dCH4) concentration and gene copies of protozoa, methanogens, Ruminococcus albus and R. flavefaciens, and had lower ruminal dH2 concentration, and molar proportions of valerate and isovalerate, in comparison with those fed the NG diet. There was a negative correlation between dH2 concentration and NDF digestibility in bulls fed the CS diet, and a lack of relationship between dH2 concentration and NDF digestibility with the NG diet. In summary, the fibre of CS silage was more easily degraded by rumen microorganisms than that of NG silage. Increased dCH4 concentration with the CS diet presumably led to the decreased ruminal dH2 concentration, which may be helpful for fibre degradation and growth of fibrolytic micro-organisms in the rumen.

This trial was conducted to study the effects of dietary rapeseed cake (RSC) containing high glucosinolates (GLS) on rumen fermentation, nutrient digestion and the rumen microbial community in steers. Eight growing steers and four rations containing RSC (GLS 226·1 μmol/g DM) at 0·00, 2·65, 5·35 and 8·00 % DM were assigned in a replicate 4 × 4 Latin square design. The results indicated that increasing RSC levels increased the ruminal concentration of thiocyanate (SCN) (P < 0·01), decreased the ruminal concentration of ammonia nitrogen (NH3-N) and the molar proportion of isovalerate (P < 0·05), did not affect the ruminal concentration of total volatile fatty acids (P > 0·05), decreased the crude protein (CP) digestibility (P < 0·05) and increased the ether extract (EE) digestibility (P < 0·01). Increasing RSC levels tended to decrease the abundances of ruminal Ruminobacter amylophilus (P = 0·055) and Ruminococcus albus (P = 0·086) but did not affect methanogens, protozoa, fungi and other bacteria (P > 0·05). Increasing RSC levels in the ration did not affect the ruminal bacterial diversity (P > 0·05), but it increased the operational taxonomic units and the bacterial richness (P < 0·05) and affected the relative abundances of some bacteria at the phylum level and genus level (P < 0·05). In conclusion, RSC decreased the ruminal concentration of NH3-N and the CP digestibility, increased the EE digestibility and partly affected the ruminal bacterial community. SCN, as the metabolite of GLS, could be a major factor affecting these indices.

The objective of this study was to investigate the effects of processing index (PI) of barley grain and dietary undigested neutral detergent fiber (uNDF) concentration on dry matter (DM) intake, chewing activity, ruminal pH and fermentation characteristics, total tract digestibility, gastrointestinal barrier function, and blood metabolites of finishing beef heifers. The PI was measured as the density after processing expressed as a percentage of the density before processing, and a smaller PI equates to a more extensively processed. Six ruminally cannulated heifers (average body weight, 715 ± 29 kg) were used in a 6 × 6 Latin square design with three PI (65%, 75%, and 85%) × 2 uNDF concentration (low and high; 4.6% vs. 5.6% of DM) factorial arrangement. The heifers were fed ad libitum a total mixed ration consisting of 10% barley silage (low uNDF), or 5% silage and 5% straw (high uNDF), 87% dry-rolled barley grain, and 3% mineral and vitamin supplements. Interactions (P < 0.01) of PI × uNDF were observed for DM intake, ruminating and total chewing time, and DM digestibility in the total digestive tract. Intake of DM, organic matter (OM), starch, and crude protein (CP) did not differ (P > 0.14) between low and high uNDF diets, but intakes of NDF and acid detergent fiber were greater (P = 0.01) for high uNDF diets regardless of barley PI. Heifers fed high uNDF diets had longer (P = 0.05) eating times (min/d or min/kg DM) and tended (P = 0.10) to have longer total chewing times (min/kg DM) than those fed low uNDF diets. Additionally, heifers sorted (P = 0.01) against long particles (>19 mm) for high uNDF diets but not for low uNDF diets. Altering PI of barley grain did not affect (P > 0.12) total volatile fatty acid (VFA) concentration, molar percentages of individual VFA, or duration of ruminal pH < 5.8 and <5.6. Total VFA concentration was less (P = 0.01), acetate percentage was greater (P = 0.01), and duration of ruminal pH < 5.8 and <5.6 was less (P = 0.05) for high compared with low uNDF diets. Digestibility of DM, OM, and CP was greater (P = 0.02) for low vs. high uNDF diets with PI of 65% and 75%, with no difference between low and high uNDF diets at PI of 85%. Blood metabolites and gastrointestinal tract barrier function were not affected (P ≥ 0.10) by the treatments. These results suggest that increasing dietary uNDF concentration is an effective strategy to improve ruminal pH status in finishing cattle, regardless of the extent of grain processing, whereas manipulating the extent of barley processing did not reduce the risk of ruminal acidosis., (© Her Majesty the Queen in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada, 2021.)

We investigated the effects of wood kraft pulp (KP) feeding on feed digestibility and rumen fermentation of Japanese Black (JB) steer in the middle fattening stage. The feeding experiment was carried out a replicated 3 × 3 Latin square design using six JB steers (16.2 ± 0.8 months of age). Steers were fed rice straw and three concentrated feeds: commercial formula feed (control), formula feed containing 7.5% KP on a dry matter (DM) basis (7.5% KP), and formula feed containing 15% KP on a DM basis (15% KP). Feed digestibility and rumen fermentation parameters were recorded for 3 days during the measurement period, after an adaptation phase of 11 days. There was no significant difference in DM intake per day among diets. A slightly higher digestibility of neutral detergent fiber was observed in steers fed 15% KP, compared with those fed other diets (P = 0.059). The butyric acid ratio in rumen fluid was higher in steers fed KP diets than in steers fed control (P = 0.083). The average ruminal pH was unaffected by KP diets. This study suggests that replacing 15% of concentrated feed with KP has little effect on feed digestibility and rumen fermentation in JB fattening steer., (© 2021 Japanese Society of Animal Science.)

The chemical characteristics associated with different sources of Cu, Zn, and Mn such as sulfate, hydroxychloride, or organic chelate may affect the interaction between the metals and other components present within the gut of a ruminant (i.e., microorganisms and nutrients). The present study aimed to evaluate the effect of different supplemental trace mineral strategies on apparent total-tract digestibility, rumen fermentation, and dairy productivity. Using 52 Holstein cows in a replicated 4 × 4 Latin square design with periods of 21 d, 4 treatments differing in their sources of Cu, Zn, and Mn were tested: sulfate form, hydroxychloride form, a mix of sulfate and organic chelate forms (70 and 30%, respectively), and a mix of hydroxychloride and organic chelate forms (70 and 30%, respectively). Treatments were formulated to provide 15, 40, and 20 mg of supplemental Cu, Zn, and Mn, respectively, per kilogram of dry matter. This level of supplementation, together with the basal level present in forages and feed ingredients, resulted in a total average supply of 19, 79, and 84 mg of Cu, Zn, and Mn, respectively, per kilogram of dry matter. Cows had ad libitum access to a total mixed ration, which provided 15.3% of crude protein, 21.7% of starch, and 35.3% of neutral detergent fiber (NDF). Data were summarized by period with trace minerals and period as fixed effects and the repeated cow as random effect using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Apparent total-tract NDF and crude protein digestibility was reduced (-0.8% and -1.0%, respectively) when organic chelate trace minerals were fed, whereas apparent total-tract NDF digestibility was improved (+0.8%) when sulfate trace minerals were replaced by hydroxychloride trace minerals. Cows supplemented with the hydroxychloride source had lower ruminal butyric acid concentration compared with cows fed sulfate trace minerals (13.3 vs. 14.6%). In addition, fat- and protein-corrected milk and milk fat yields were improved (+1.0 kg/d and +51 g/d, respectively) in multiparous cows when trace minerals were supplemented as hydroxychloride compared with sulfate. These effects were not observed in primiparous cows. These results confirm that trace mineral sources affect apparent total-tract digestibility and indicate that milk productivity may also be affected., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

The study evaluated the effects of soybean oil (SO) and dietary copper levels on nutrient digestion, ruminal fermentation, enzyme activity, microflora and microbial protein synthesis in dairy bulls. Eight Holstein rumen-cannulated bulls (14 ± 0.2 months of age and 326 ± 8.9 kg of body weight) were allocated into a replicated 4 × 4 Latin square design in a 2 × 2 factorial arrangement with factors being 0 or 40 g/kg dietary dry matter (DM) of SO and 0 or 7.68 mg/kg DM of Cu from copper sulphate (CS). The basal diet contained per kg DM 500 g of corn silage, 500 g of concentrate, 28 g of ether extract (EE) and 7.5 mg of Cu. The SO × CS interaction was significant ( p < 0.05) for ruminal propionate proportion and acetate to propionate ratio. Dietary SO addition increased ( p < 0.05) intake and total tract digestibility of EE but did not affect average daily gain (ADG) of bulls. Dietary CS addition did not affect nutrient intake but increased ( p < 0.05) ADG and total tract digestibility of DM, organic matter, crude protein and neutral detergent fibre. Ruminal pH was not affected by treatments. Dietary SO addition did not affect ruminal total volatile fatty acids (VFA) concentration, decreased ( p < 0.05) acetate proportion and ammonia N and increased ( p < 0.05) propionate proportion. Dietary CS addition did not affect ammonia N, increased ( p < 0.05) total VFA concentration and acetate proportion and decreased ( p < 0.05) propionate proportion. Acetate to propionate ratio decreased ( p < 0.05) with SO addition and increased ( p < 0.05) with CS addition. Dietary SO addition decreased ( p < 0.05) activity of carboxymethyl cellulase, cellobiase and xylanase as well as population of fungi, protozoa, methanogens, Ruminococcus albus and R. flavefaciens but increased ( p < 0.05) α-amylase activity and population of Prevotella ruminicola and Ruminobacter amylophilus . Dietary CS addition increased ( p < 0.05) with CS addition. The results indicated that the addition of CS promoted nutrient digestion and ruminal fermentation by stimulating microbial growth and enzyme activity but did not relieve the negative effects of SO addition on ruminal fermentation in dairy bulls.p < 0.05) with CS addition. The results indicated that the addition of CS promoted nutrient digestion and ruminal fermentation by stimulating microbial growth and enzyme activity but did not relieve the negative effects of SO addition on ruminal fermentation in dairy bulls.

Fat-tailed Altay sheep are indigenous to the Altay prefecture and well adapted to severe cold and sparse pasture of poor quality. Hu sheep were introduced to this region in the 1970s and are raised mainly in feedlots. We hypothesized that the dietary energy utilization would differ between breeds and predicted that Altay sheep would be more efficient than Hu sheep, in particular at a low air temperature. To test this prediction, we examined growth performance, apparent digestibilities, rumen fermentation and serum metabolites in Altay (32 ± 2.6 kg) and Hu sheep (31 ± 2.7 kg) at air temperatures of -5 and 20°C. Average daily gain (ADG), feed and metabolizable energy intakes were greater in Altay than in Hu sheep (p < .01), and all were greater at -5°C than 20°C (p < .01). Body mass gain-to-feed intake ratio was higher in Altay than in Hu sheep (p < .001), but was not affected by air temperature (p > .10). Rumen total volatile fatty acid (VFA) concentration was greater in Hu than in Altay sheep (p < .05) and was greater at 20°C than at -5°C (p < .05), while rumen microbial protein concentration was greater in Altay than in Hu sheep (p < .05). Rectal temperature was higher at -5°C than 20°C (p < .05) and was similar between breeds (p > .05). Serum glucose, non-esterified fatty acid (NEFA) and urea-N concentrations were higher in Hu than in Altay sheep (p < .05). It was concluded that Altay sheep are better able to cope with poor quality diets as they had higher digestibility of nutrients, ADG and body mass gain-to-feed intake ratio than Hu sheep., (© 2020 Blackwell Verlag GmbH.)

This study evaluated the effects of rumen-protected folic acid (RPFA) and betaine (BT) on growth performance, nutrient digestion and blood metabolites in bulls. Forty-eight Angus bulls were blocked by body weight and randomly assigned to four treatments in a 2 × 2 factorial design. BT of 0 or 0·6 g/kg DM was supplemented to diet without or with the addition of 6 mg/kg DM of folic acid from RPFA, respectively. Average daily gain increased by 25·2 and 6·29 % for addition of BT without RPFA and with RPFA, respectively. Digestibility and ruminal total volatile fatty acids of neutral-detergent fibre and acid-detergent fibre increased, feed conversion ratio and blood folate decreased with the addition of BT without RPFA, but these parameters were unchanged with BT addition in diet with RPFA. Digestibility of DM, organic matter and crude protein as well as acetate:propionate ratio increased with RPFA or BT addition. Ruminal ammonia-N decreased with RPFA addition. Activity of carboxymethyl cellulase, cellobiase, xylanase, pectinase and protease as well as population of total bacteria, protozoa, Fibrobacter succinogenes and Ruminobacter amylophilus increased with RPFA or BT addition. Laccase activity and total fungi, Ruminococcus flavefaciens and Prevotella ruminicola population increased with RPFA addition, whereas Ruminococcus albus population increased with BT addition. Blood glucose, total protein, albumin, growth hormone and insulin-like growth factor-1 increased with RPFA addition. Addition of RPFA or BT decreased blood homocysteine. The results indicated that addition of BT stimulated growth and nutrient digestion in bulls only when RPFA was not supplemented.

This study aimed to investigate the effects of chitosan and whole raw soybean on nutrient intake, apparent digestibility, nitrogen utilization, microbial protein synthesis, blood metabolites, feeding behavior, ruminal fermentation, digesta kinetics, and reticular flow of nutrients of buffaloes. Four ruminally-cannulated Murrah buffaloes (351 ± 15 kg of initial BW) were randomly assigned according to a 4 × 4 Latin square design. Treatments were arranged as 2 × 2 factorial arrangement: the first factor was whole raw soybean (WRS), and the second factor was chitosan (CHI) with or without their inclusion in diets. Intake and apparent digestibility of ether extract (p < .01; p = .04, respectively), non-fiber carbohydrates intake (p = .03) and apparent ruminal digestibility of dry matter (p = .01) were affected by diets. An interaction effect or tendency was observed for microbial nitrogen (p = .09), concentrations, ruminal ammonia nitrogen (p = .05), total volatile fatty acid (p = .03). Association of chitosan with whole raw soybean has potential effects as a modulator of rumen fermentation; therefore, chitosan can be applied as an alternative non-ionophore for Murrah buffaloes., (© 2020 Japanese Society of Animal Science.)

There is a risk of iron overload in grazing livestock. However, the effects on nutrient absorption and rumen function induced by excessive iron have not been well understood. Therefore, the purpose of present study was to investigate the impact of over-load iron on growth performance, nutrient digestibility, blood biochemistry, rumen fermentation and bacterial communities in sheep. Twenty-four German Mutton Merino cross-bred sheep with weight (42.66 ± 2.34 kg BW) were randomly divided into 4 groups, each with 6 replicates and 1 sheep per replicate. The basal diet consisted of 60% Leymus chinensis hay and 40% concentrate. The sheep in 4 groups were fed the basal diets supplemented with 50 (Control), 500 (T1), 1,000 (T2) and 1,500 (T3) mg Fe/kg as ferrous sulphate monohydrate (FeSO 4 ·H 2 O) respectively. And the actual contents of iron in the diet were determined to be 457.68 (control), 816.42 (T1), 1,256.78 (T2) and 1,725.63 (T3) mg/kg respectively. The experiment lasted 62 days including a 7-day metabolism trial. During the whole experiment, the digestibility of dry matter, organic matter, neutral detergent fibre and acid detergent fibre showed a quadratic increase with increasing over-load iron levels (p < .05), and maximum responses were found with 500 mg/kg supplementation. However, the response of total VFA concentration showed a quadratic decrease, as did the concentrations of propionate, butyrate and valerate (p < .05). Serum total iron-binding capacity on day 30 showed a quadratic decrease with the increase in high-dose iron, while the serum iron content increased linearly at day 60 (p < .05). Excessive iron resulted in the change in bacterial communities. An increase in over-load iron linearly decreased the abundance of bacteria in the phylum Bacteroidetes (p < .05), but linearly increased the Firmicutes (p = .037) and Proteobacteria (p = .018). In addition, there was a quadratic effect (p = .003) on the Fibrobacteres, which was higher in the 500 and 1,000 mg/kg Fe-supplemented groups. At the genus level, there were quadratic effects on the abundances of Selenomonas&#95;1 (p = .023) and Ruminococcaceae&#95;UCG-014 (p = .016). Furthermore, feeding of iron linearly increased the relative abundances of Succiniclasticum and Succinivibrionaceae&#95;UCG-002 (p < .05). These results indicate that increasing ferrous sulphate monohydrate in diets had no negative impact on the growth performance, but it changed nutrient digestibility, blood iron parameters, rumen fermentation and bacterial communities in sheep., (© 2019 Blackwell Verlag GmbH.)

The objective of the present research was to determine the influence of various doses of the pellets containing DR seed meal (PEDEM) on in vitro CH 4 gas production, in vitro digestibility, protozoal count, and ruminal fermentation characteristics. The study was designed as a completely randomized design with eight levels of PEDEM supplementation at 0, 2, 4, 6, 8, 10, 12, and 14 mg DM. Gas production rate constants for the insoluble fraction (c) and cumulative gas production at 96 h were quadratically increased when PEDEM was supplemented (P < 0.05). The concentration of NH 3 -N was linearly increased when the PEDEM concentration (P < 0.05) was increased, whereas the population of protozoa was linearly decreased when the level of PEDEM supplementation (P < 0.05) was increased. The supplementation of PEDEM in substrate quadratically affected the mean values of in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD), and in vitro NDF digestibility (P < 0.05). TVFA, acetic acid (C2), and butyric acid (C4) were not altered by different doses of PEDEM supplementation (P > 0.05). In contrast, the concentration of propionic acid (C3) was quadratically affected with the supplementation of PEDEM (P = 0.05). The inclusion of PEDEM did not change the CH 4 concentration at 6 h of incubation (P > 0.05), whereas the CH 4 concentration at 24 h of incubation and the mean values were linearly reduced with additional doses of PEDEM (P < 0.05). Compared with the control group, the mean CH 4 concentration was reduced at 51.1% with 12 mg PEDEM, whereas 59.6% was reduced with 14 mg PEDEM supplementations. The supplementation of PEDEM at 12 mg has the potential to manipulate rumen fermentation, to manipulate in vitro digestibility and to reduce protozoa and CH 4 production.

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 24 h 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 NH 3 -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.

Tibetan sheep are indigenous to the Qinghai-Tibetan Plateau, graze the grassland all year round without supplementation and are well-adapted to the harsh conditions. Small-tailed Han sheep were introduced to the plateau and are raised mainly in feedlots. Based on their different backgrounds, we hypothesized that the ability to cope with poor diets would be better in Tibetan than in Han sheep. To test our prediction, we examined the effect of dietary energy on apparent digestibilities, rumen fermentation, urinary purine derivatives and serum metabolites by using a 4 × 4 Latin square design in each sheep breed. Four diets were formulated to be low in crude protein (~7%) but to differ in metabolizable energy concentration. Average daily gain was greater in Tibetan than in Han sheep (p < 0.01) and increased linearly with an increase in energy intake (p < 0.001). The digestibilities of dry matter, organic matter, gross energy, and neutral and acid detergent fibres were greater in Tibetan than in Han sheep (p < 0.05). Ruminal pH was lower (p < 0.05), while volatile fatty acids (VFAs), urea-N, ammonia-N and soluble protein-N concentrations were higher (p < 0.05) in Tibetan than in Han sheep. As a molar proportion of total VFA, acetate decreased (p < 0.001) with an increase in dietary energy whereas propionate and butyrate increased (p < 0.05). Urinary purine derivative excretion was greater in Tibetan than in Han sheep (p < 0.01), as was microbial nitrogen production; both parameters increased with dietary energy (p < 0.01). Serum concentrations of glucose, insulin and insulin-like growth factor-1 increased (p < 0.05) as energy level increased, while non-esterified fatty acids and growth hormone decreased (p < 0.05). It was concluded that Tibetan sheep were better able to cope with low-protein, low-energy diets and, consequently, our prediction was supported., (© 2019 Blackwell Verlag GmbH.)

This study aimed to examine the effects of feeding kraft pulp (KP) on the growth performance, feed digestibility, and rumen fermentation of Japanese Black fattening steers. Ten Japanese Black fattening steers (aged 26 months) were randomly divided into control and KP groups. The control group (n = 5) was fed concentrate feed without KP, and the KP group (n = 5) was fed concentrate feed containing 10% KP. Both the groups were provided rice straw as roughage. The experiment was conducted over a period of 12 weeks. There was no significant difference in dry matter intake, daily body weight gain, and nutrient digestibility between both groups. No difference was observed in the ruminal concentrations of volatile fatty acids among the groups. At weeks 8 and 12 after the onset of the experiment, the acetate-to-propionate ratio in the ruminal fluid of the KP group was significantly higher than that of the control group. The average daily pH of ruminal fluid and activity of ruminal lipopolysaccharide did not differ between the groups. Our results suggested that the growth performance and feed digestibility in the Japanese Black fattening steers were not influenced by replacing concentrate feed with KP., (© 2019 The Authors. Animal Science Journal published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Animal Science.)

The objectives of the trial were to study the effects of dietary crude protein (CP) and tannic acid (TA) on rumen fermentation, microbiota and nutrient digestion in beef cattle. Eight growing beef cattle (live weight 350 ± 25 kg) were allocated in a 2 × 2 crossover design using two levels of dietary CP [111 g/kg dry matter (DM) and 136 g/kg DM] and two levels of TA (0 and 16.9 g/kg DM) as experimental treatments. Each experimental period lasted 19 d, consisting of 14-d adaptation and 5-d sampling. The impacts of dietary CP and TA on ruminal microbiota were analysed using high-throughput sequencing of 16S rRNA gene. Results indicated that no interactions between dietary CP and TA were found on rumen fermentation and nutrient digestibility. Increasing dietary CP level from 111 to 136 g/kg DM increased the ruminal concentrations of ammonia nitrogen (NH 3 -N) ( p < 0.01) and improved the CP digestibility ( p < 0.001). Adding TA at 16.9 g/kg DM inhibited rumen fermentation and decreased the digestibility of dietary CP ( p < 0.001), DM ( p < 0.05) and organic matter ( p < 0.01). Increasing the dietary CP level or adding TA did not affect the relative abundances of the major bacteria Firmicutes and Proteobacteria at the phylum level and Prevotella&#95;1 and Christensenellaceae&#95;R-7&#95;group at the genus level, even though adding TA increased the Shannon index of the ruminal bacterial community. TA was partly hydrolysed to pyrogallol, gallic acid and resorcinol in rumen fluid and the inhibitory effects of TA on rumen fermentation and nutrient digestibility could have been resulted from the TA metabolites including pyrogallol, gallic acid and resorcinol as well as the protein-binding effect.

This study was conducted to evaluate the effect of ß-glucan on feed intake, digestibility of nutrients and ruminal fermentation in Thai native beef cattle that were fed low-quality roughage. Four, Thai native beef cattle with initial body weight (BW) of 100 ± 20.0 kg were randomly assigned according to a 4 × 4 Latin square design to receive four treatment by ß-glucan at 0, 1.6, 3.1 and 4.7 g/day respectively. Supplementation of ß-glucan at 0-4.7 g in cattle did not affect the intake of DM, OM, CP, NDF or ADF. However, supplementation with ß-glucan significantly improved rice straw intake (g/kg BW 0.75 ), compared to the nonsupplemented group (p < 0.05), so rice straw intake was higher than in the group without ß-glucan supplementation. In addition, total feed intake increased with the higher level of ß-glucan supplementation. The estimated energy intake was not altered by ß-glucan supplementation (p > 0.05). The experimental diet had no effect (p > 0.05) on the apparent digestibility of DM, OM, NDF or ADF. However, the digestibility of CP was significantly different among treatment and supplementation at 4.7 g/day ß-glucan which was the highest level (63.2%) among all diets. ß-glucan supplementation did not affect rumen pH, temperature or ruminal NH 3 -N concentration. In addition, blood urea-N levels were similar among experimental groups. The population of protozoa at 4 hr post-feeding increased along with ß-glucan supplementation and was highest at 4.7 g of ß-glucan. Based on this experiment, it could be concluded that supplementation of ß-glucan at 4.7 g improved rice straw intake, as well as total intake and digestibility of CP in Thai native beef cattle., (© 2018 Blackwell Verlag GmbH.)

Background: The effects of the dietary oils with differing fatty acid profiles on rumen fermentation, microbial population, and digestibility in goats were investigated. In Experiment I, rumen microbial population and fermentation profiles were evaluated on 16 fistulated male goats that were randomly assigned to four treatment groups: i) control (CNT), ii) olive oil (OL), iii) palm olein oil (PO), and iv) sunflower oil (SF). In Experiment II, another group of 16 male goats was randomly assigned to the same dietary treatments for digestibility determination., Results: Rumen ammonia concentration was higher in CNT group compared to treatment groups receiving dietary oils. The total VFA and acetate concentration were higher in SF and OL groups, which showed that they were significantly affected by the dietary treatments. There were no differences in total microbial population. However, fibre degrading bacteria populations were affected by the interaction between treatment and day of sampling. Significant differences were observed in apparent digestibility of crude protein and ether extract of treatment groups containing dietary oils compared to the control group., Conclusions: This study demonstrated that supplementation of different dietary oils containing different fatty acid profiles improved rumen fermentation by reducing ammonia concentration and increasing total VFA concentration, altering fibre degrading bacteria population, and improving apparent digestibility of crude protein and ether extract.

High-quality protein roughage is an important feed for productive ruminants. This study examined the effects of strategic feeding of lactating cows with cassava (Manihot esculenta) top silage (CTS) on rumen fermentation, feed intake, milk yield, and quality. Four early lactating crossbred dairy cows (75% Holstein-Friesian and 25% Thai) with body weight (BW) 410 ± 30 kg and milk yield 12 ± 2 kg/day were randomly allotted in a 4 × 4 Latin square design to four different supplementation levels of CTS namely, 0, 0.75, 1.50, and 2.25 kg/day of dry matter (DM). Strategic supplementation of CTS significantly affected ruminal fermentation end-products, especially increased propionate production, decreased protozoal population and suppressed methane production (P < 0.05). Increasing the CTS supplementation level substantially enhanced milk yield and the 3.5% FCM from 12.7 to 14.0 kg/day and from 14.6 to 17.2 kg/day (P < 0.05) for non-supplemented group and for the 2.25 kg/day supplemented group, respectively. We conclude that high-quality protein roughage significantly enhances rumen fermentation end-products, milk yield, and quality in dairy cows.

To investigate the effects of polyphenolic extract from Eucommia ulmoides Oliver leaf (PEEU) on growth performance, digestibility, rumen fermentation and antioxidant status of fattening lambs, 30 weaned male Huzhou lambs were equally divided into three treatments and fed the basal diet supplemented with 0 (CON), 5 (PEEU5) or 10 (PEEU10) g/kg PEEU. Dietary PEEU supplementation did not affect growth performance and apparent digestibility of nutrients. Compared with the CON group, lambs in the PEEU10 group had lower ammonia nitrogen concentration (p < .01) and acetic acid to propionic acid ratio (p < .05) and higher the molar proportion of propionate (p < .05) in rumen fluid. Ammonia nitrogen concentration (p < .01) and the molar proportion of propionate (p < .05) were affected by an interaction between PEEU and sampling day. Dietary PEEU supplementation at 10 g/kg increased total antioxidant capacity (p < .05), superoxide dismutase (p < .05) and glutathione peroxidase (p < .01) activities in serum and glutathione peroxidase activity (p < .05) in liver and decreased (p < .05) malondialdehyde content in serum and liver compared with the CON group. In conclusion, dietary PEEU supplementation affected rumen fermentation patterns and improved antioxidant status of fattening lambs., (© 2018 Japanese Society of Animal Science.)

The objectives of this experiment were to evaluate the effect of feeding a culture of Saccharomyces cerevisiae on rumen metabolism and digestibility when cows are fed diets varying in starch content. Four lactating Holstein cows were assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Treatments were low starch (LS; 23% of diet DM) and no yeast culture (YC; LS-control), LS and 15 g of YC/d (LS-YC), high starch (HS; 29% of diet DM) and no YC (HS-control), and HS and 15 g of YC/d (HS-YC). Periods lasted 28 d, with the last 9 d for data collection. Days 20 to 24 were used to determine production, nutrient flow, and digestibility. On d 25, 3 kg of corn grain DM was placed in the rumen 1 h before the morning feeding, and yields of milk and milk components were measured after the challenge. Blood was sampled -1, 3, 7, and 11 h relative to the morning feeding on d 24 and 25. Rumen pH was measured continuously on d 24 and 25. Rumen papillae were collected on d 24 and 28 to quantify mRNA expression of select genes. Supplementing YC increased yields of milk (26.3 vs. 29.6 kg/d), energy-corrected milk (ECM; 26.5 vs. 30.3 kg/d), fat (0.94 vs. 1.08 kg/d), true protein (0.84 vs. 0.96 kg/d), and ECM/dry matter intake (1.15 vs. 1.30) compared with the control but did not affect dry matter intake (22.6 vs. 22.9 kg/d). Cows fed HS had increased milk true protein percentage (3.18 vs. 3.31%) and yield (0.87 vs. 0.94 kg/d) compared with cows fed LS. Feeding HS-YC increased the proportion of dietary N incorporated into milk true protein from 24.9% in the other 3 treatments to 29.6%. Feeding HS increased the concentration of propionate (21.7 vs. 32.3 mM) and reduced that of NH 3 -N (8.3 vs. 6.7 mg/dL) in rumen fluid compared with the control, and combining HS with YC in HS-YC tended to increase microbial N synthesis compared with LS-YC (275 vs. 322 g/d). Supplementing YC to cows fed HS reduced plasma haptoglobin and rumen lactate concentrations, increased mean rumen pH, reduced the time with pH <6.0, and prevented the decrease in rumen neutral detergent fiber digestion caused by HS. Cows fed HS had less total-tract digestion of organic matter (73.9 vs. 72.4%) because of reduced acid detergent fiber (57.6 vs. 51.7%) and neutral detergent fiber (60.9 vs. 56.7%) digestibility. Production performance after the challenge was similar to that before the challenge, and YC improved yield of ECM. After the challenge, supplementing YC tended to reduce rumen lactate concentration compared with the control and reduced haptoglobin in cows fed HS. Feeding HS but not YC increased expression in rumen papillae of genes for receptors (FFAR2 and FFAR3) and transporter (SLC16A3) of short-chain fatty acids but did not affect genes involved in transport of Na + /H + or water or in inflammatory response. Supplementing YC to dairy cows improved lactation performance in diets containing low or high starch, and mechanisms might be partially attributed to improvements in rumen pH, digestion of fiber, microbial N synthesis, and reduction in acute phase response., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The effects of essential oils (EOs) on ruminal nutrient disappearance, rumen fermentation and blood metabolites in fistulated non-lactating dairy cows were studied. Four fistulated non-lactaing dairy cows were used in a 4 × 4 Latin square design; the experiment consisted of four periods of 21 days in each period, with the first 14 days for adaptation followed by 7 days of measurement period. Animals were fed 3 kg/day of 21% crude protein (CP) concentrate and ad libitum corn silage. Treatments were: (i) control; (ii) 2 mL Allicin/cow/day; (iii) 2 mL zingiberene/cow/day; and (iv) 2 mL citral/cow/day. The results demonstrated that EOs increased dry matter and neutral detergent fiber degradabilities at 48 and 72 h, but had no effect on acid detergent fiber and CP degradabilities. EOs did not change ruminal pH, ammonia nitrogen, protozoa, volatile fatty acid concentrations and blood glucose but reduced blood urea nitrogen at 4 h., (© 2017 Japanese Society of Animal Science.)

A meta-analysis based on an individual-cow data set was conducted to investigate the effects of between-cow variation and related animal variables on predicted CH 4 emissions from dairy cows. Data were taken from 40 change-over studies consisting of a total of 637 cow/period observations. Animal production and rumen fermentation characteristics were measured for 154 diets in 40 studies; diet digestibility was measured for 135 diets in 34 studies, and ruminal digestion kinetics was measured for 56 diets in 15 studies. The experimental diets were based on grass silage, with cereal grains or by-products as energy supplements, and soybean or canola meal as protein supplements. Average forage:concentrate ratio across all diets on a dry matter basis was 59:41. Methane production was predicted from apparently fermented substrate using stoichiometric principles. Data were analyzed by mixed-model regression using diet and period within experiment as random effects, thereby allowing the effect of experiment, diet, and period to be excluded. Dry matter intake and milk yield were more repeatable experimental measures than rumen fermentation, nutrient outflow, diet digestibility, or estimated CH 4 yield. Between-cow coefficient of variation (CV) was 0.010 for stoichiometric CH 4 per mol of volatile fatty acids and 0.067 for predicted CH 4 yield (CH 4 /dry matter intake). Organic matter digestibility (OMD) also displayed little between-cow variation (CV = 0.013), indicating that between-cow variation in diet digestibility and rumen fermentation pattern do not markedly contribute to between cow-variation in CH 4 yield. Digesta passage rate was much more variable (CV = 0.08) between cows than OMD or rumen fermentation pattern. Increased digesta passage rate is associated with improved energetic efficiency of microbial N synthesis, which partitions fermented substrate from volatile fatty acids and gases to microbial cells that are more reduced than fermented carbohydrates. Positive relationships were observed between CH 4 per mol of volatile fatty acids versus OMD and rumen ammonia N concentration versus OMD; and negative relationships between the efficiency of microbial N synthesis versus OMD and digesta passage rate versus OMD, suggesting that the effects of these variables on CH 4 yield were additive. It can be concluded that variations in OMD and efficiency in microbial N synthesis resulting from variations in digesta passage contribute more to between-animal variation in CH 4 emissions than rumen fermentation pattern., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The study examined the effects of blend of 80% canola oil and 20% palm oil (BCPO) on nutrient intake and digestibility, growth performance, rumen fermentation and fatty acids (FA) in goats. Twenty-four Boer bucks were randomly assigned to diets containing 0, 4 and 8% BCPO on a dry matter basis, fed for 100 days and slaughtered. Diet did not affect feed efficiency, growth performance, intake and digestibility of all nutrients except ether extract. Intakes and digestibilities of ether extract, unsaturated fatty acids (FA) and total FA were higher (P < 0.05) while digestibility of C18:0 was lower (P < 0.05) in oil-fed goats than the control goats. Total volatile FA, acetate, butyrate, acetate/propionate ratio and methane decreased (P < 0.05) with increasing BCPO but propionate, NH3 -N and rumen pH did not differ between diets. Ruminal concentration of C18:0, n-3 FA and total FA increased (P < 0.05) while C12:0, C14:0, C15:0 and n-6 FA decreased with increasing BCPO. Analysis of the FA composition of Triceps brachii muscle showed that concentrations of C16:0, C14:0 and C18:2n-6 were lower (P < 0.05) while C18:1n-9, C18:3n-3 and C20:5n-3 were higher in oil-fed goats compared with control goats. Dietary BCPO altered muscle lipids without having detrimental effects on nutrient intake and digestibility and growth performance in goats., (© 2015 Japanese Society of Animal Science.)

The objective of this experiment was to determine effects of Leucaena silage (LS) feeding on feed intake, nutrient digestibility, and rumen fermentation in dairy steers. Four rumen fistulated dairy steers, 167 ± 12 kg body weight (BW), were randomly assigned to receive dietary treatments according to a 4 × 4 Latin square design. Treatments were as follows: T1 = 100 % untreated rice straw (RS), T2 = 70 % RS + 30 % LS, T3 = 40 % RS + 60 % LS, and T4 = 100 % LS, respectively. All animals were fed rice straw and LS ad libitum with concentrate mixture supplemented at 0.2 % BW. The results found that dry matter intake and nutrient digestibility were the highest in dairy steers fed 60 % LS (P < 0.05). Ruminal temperature and pH were not affected by LS feeding (P > 0.05) while ruminal ammonia nitrogen and blood urea nitrogen concentration were linearly increased with increasing levels of LS feeding (P < 0.01). On the other hand, total volatile fatty acids and propionate (C3) were improved by LS feeding especially in steers fed 60 % LS (P < 0.05) whereas acetate (C2) production and C2/C3 ratio were decreased. Moreover, methane production was reduced together with increasing LS feeding level (P < 0.05). Based on this study, it could be concluded that 60 % LS feeding could enhance feed intake, digestibility, and rumen fermentation end-product while reducing methane production in dairy steers. This study suggested that LS could be used as high-quality roughage for ruminant feeding in the tropical region.

The objective of this experiment was to test the effect of a Met analog, 2-hydroxy-4-methylthio-butanoic acid (HMTBa), on ruminal fermentation and microbial protein synthesis, nutrient digestibility, urinary N losses, and performance of dairy cows. Eight multiparous lactating Holstein dairy cows were assigned to 4 levels of HMTBa [0 (control), 0.05, 0.10, and 0.15% (dry matter basis)] in a replicated 4×4 Latin square trial. Experimental periods were 28 d, including 21 d for adaptation. Ruminal ammonia and microbial N were labeled through a 6-d intraruminal infusion of (15)NH4Cl, and microbial protein synthesis in the rumen was estimated using the reticular sampling technique. Treatment had no effect on dry matter intake (28.4 to 29.8kg/d), milk yield (44.1 to 45.3kg/d), feed efficiency, and milk composition. Total-tract apparent digestibility of nutrients was generally not affected by treatment, except digestibility of crude protein and starch decreased quadratically with HMTBa supplementation. Fecal, but not urinary, and total excreta N losses were increased quadratically by HMTBa. Ruminal pH, ammonia concentration, protozoal counts, and the major volatile fatty acids were not affected by treatment. Microbial N outflow from the rumen was linearly increased by HMTBa. 2-Hydroxy-4-methylthio-butanoic acid linearly increased the proportion of Fecalibacterium and quadratically decreased the proportion of Eubacterium in ruminal contents. Of the individual bacterial species, HMTBa increased or tended to increase Prevotella loescheii and Prevotella oralis. 2-Hydroxy-4-methylthio-butanoic acid linearly increased the concentration (and yield) of 15:0 in milk fat. In the conditions of this crossover experiment, HMTBa had no effect on feed intake and performance of dairy cows, decreased dietary crude protein digestibility, and increased microbial N outflow from the rumen., (Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The objectives of the trial were to compare the effects of supplementing rare earth elements (REE) lanthanum (La), cerium (Ce) and praseodymium (Pr) on rumen fermentation, nutrient digestion, methane (CH4) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged 12 months, with initial average liveweight of 333 ± 9 kg and fitted with rumen cannulas, were fed with a basal ration composed of concentrate mixture and maize silage. Animals received a basal ration without adding REE (Control) or three treatments, i.e. supplementing LaCl3, CeCl3 or PrCl3 at 204 mg/kg DM to the basal ration, respectively, which were allocated in a 4 × 4 Latin square design. Each experimental period lasted 15 d, consisting of 12 d for pre-treatment and three subsequent days for sampling. Results showed that all tested levels of REE tended to increase neutral detergent fibre digestibility (p = 0.064) and tended to decrease rumen CH4 production (p = 0.056). Supplementing LaCl3 and CeCl3 decreased total N excretion and urinary N excretion, increased N retention (p < 0.05), tended to increase total urinary purine derivatives (PD) (p = 0.053) and microbial N flow (p = 0.095), whereas supplementing PrCl3 did not affect N retention, urinary PD and microbial N flow. No differences were found in the effects of nutrient digestibility, CH4 production and plasma biochemical parameters among LaCl3, CeCl3 and PrCl3. Further trials using graded levels of LaCl3, CeCl3 and PrCl3 in a wide range are needed to obtain more pronounced results for comparing effects of La, Ce and Pr on rumen fermentation and nutrient digestion in beef cattle.

Physiological consequences of adaptation to and continued feeding of a high-energetic diet were studied in eight non-pregnant, non-lactating dairy Holstein cows over a period of 16 weeks. The first six weeks served as an adaptation period from the low energetic straw-based diet (3.8 MJ NEL/kg DM) to the high-energetic ration (7.5 MJ NEL/kg DM). Intake of dry matter (DM) increased with dietary energy concentration from 9 to 20 kg/d up to week 9 to 12 and decreased thereafter. The initial live weight (LW) of 550 ± 60 kg was increased linearly and corresponded to an average daily LW gain of 2.3 ± 0.3 kg. Energy balance increased approximately nine-fold to a maximum of 114 MJ NEL/d in week 10. Ruminal fermentation pattern was completely changed from an acetate dominating profile to a propionate based one, which was paralleled by a marked increase in the rumen fluid endotoxin concentration. Unlike blood glucose concentration, which increased continuously, that of cholesterol and triglycerides started to increase after an initial stagnation. In conclusion, both ruminal adaptation to a high-energetic diet and the continued feeding of such a diet induced digestive and metabolic adaptations in non-pregnant, non-lactating cows characterised by a progressing positive energy balance.

Simple Summary: This study explored the effects of different caffeine doses on nutrient digestion and fermentation in a simulated rumen environment. The main goal was to improve our understanding of how caffeine might influence these important metabolic processes in the rumen when a lactating cow diet is used. Here, we report that a dose of caffeine (50 ppm) improved the digestibility of dry/organic matter and starch while reducing the protozoa numbers and ammonia concentration, which are related to ruminal protein metabolism. However, higher caffeine doses (above 50 ppm) began to negatively impact these parameters. Our observations suggest that caffeine, a naturally occurring compound in several plants such as coffee, cacao, and tea, could potentially be used to enhance digestion and fermentation in ruminants. This research is valuable to our understanding of anaerobic fermentation in the rumen as it demonstrates the use of this plant secondary metabolite to enhance nutrient utilization and milk production and other benefits to management and the environment. Caffeine is a plant secondary metabolite, commonly known for its bioactivity properties. This molecule increases microbial activity during anaerobic digestion. The aim of this study was to determine the effects of caffeine doses on the rumen fermentation profile and nutrient digestibility when continuous culture fermenters were fed a lactating cow's diet. We hypothesize that adding caffeine doses into continuous culture fermenters with a rumen fluid inoculum will not affect anaerobic fermentation or nutrient utilization. Fermenters were fed twice a day (at 0800 and 2000 h) with an experimental diet of high-producing dairy cows (53.55 g/DM day; Forage:Concentrate ratio, F:C of 40:60). Four levels of caffeine (0 ppm, 50 ppm, 100 ppm, and 150 ppm) were added to the diets as a treatment. The experiment was arranged in a randomized complete block design. Two blocks of four fermenters were run in two replicated periods of ten days. Statistical analyses were conducted in SAS version 9.4 for Windows (SAS Institute Inc., Cary, NC, USA) using the GLIMMIX procedure. The addition of caffeine at a 50 ppm dose on continuous culture fermentation decreased the protozoal counts (Diplodinium spp.) (p = 0.03) and ammonia concentrations (p < 0.05). A treatment of 50 ppm of caffeine increased the DM, OM, and starch digestibility (p < 0.05). When caffeine doses increased further than 50 ppm, the OM, DM, and starch digestibility decreased linearly (p = 0.01). The total volatile fatty acids and fatty acid proportions were unaffected. However, the acetate-to-propionate ratio (A:P) tended to decrease linearly among treatments (p = 0.07). The means of pH measurements and maximum pH had a significantly linear decrease effect (p < 0.01). Caffeine may represent a potential rumen fermentation modifier for use in lactating cow diets. [ABSTRACT FROM AUTHOR]

This study investigates the impact of varying concentrate levels in the diets of Angus beef cattle on their performance, nutrient digestion, and metabolism during the growth (7 to 12 months) and fattening (13 to 30 months) phases. Fifteen Angus steers were continuously fed and divided into low-concentrate (L) and high-concentrate (H) groups based on the fattening period and dietary formulations. Throughout each 9-week trial phase, a comprehensive range of parameters was systematically measured, including dry matter intake (DMI), average daily gain (ADG), gain-to-feed ratio (G/F), blood parameters, rumen fluid composition, and microbial diversity. In the fattening phases, an increase in concentrate levels resulted in a significant rise in the cattle's DMI. Although there was a minor increase in ADG compared to the growing phases, this increase was not statistically significant. The efficiency of nitrogen (N) utilization in the cattle decreased, accompanied by a significant reduction in the apparent digestibility of nutrients. Ruminal fermentation produced more energy substances; however, there was a notable decrease in the abundance of fiber-decomposing microbes (such as the NK4A214_group, Ruminococcus, Papillibacter, and Acetitomaculum) and a significant increase in the abundance of starch-degrading microbes (including Bacteroidota and Prevotellaceae). Additionally, there was a significant reduction in the abundance of immune system-related functional pathways. This suggests that high-concentrate fattening does not necessarily lead to improved growth performance and may negatively affect metabolic health and nutrient digestion. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the effects of guanidinoacetic acid (GAA) supplementation on the growth performance, rumen fermentation, blood indices, nutrient digestion, and nitrogen metabolism of Angus steers. In a 130-day feeding experiment, steers receiving GAA at a conventional dose (0.8 g/kg) and a high dose (1.6 g/kg) exhibited significantly higher average daily weight gain and improved feed conversion efficiency compared to the control group without GAA. GAA supplementation also influenced rumen fermentation, with lower acetate levels, higher propionate levels, and higher acetate: propionate ratio in GAA groups. Blood analyses revealed elevated concentrations of urea, blood ammonia, GAA, creatine, and catalase, indicating improved creatine metabolism and antioxidant activity. A subsequent 3-day digestive metabolism experiment confirmed that the GAA-supplemented groups had increased dry matter and crude protein digestibility, as well as increased N retention and improved organismal nitrogen metabolism. In summary, dietary GAA supplementation at a 0.8 g/kg and 1.6 g/kg DM basis positively influenced growth performance, rumen fermentation, blood indices, nutrient digestion, and nitrogen metabolism in Angus steers, emphasizing its potential as a nutritional strategy. Guanidinoacetic acid (GAA) functions as a precursor for creatine synthesis in the animal body, and maintaining ample creatine reserves is essential for fostering rapid growth. This study aimed to explore the impact of GAA supplementation on growth performance, rumen fermentation, blood indices, nutrient digestion, and nitrogen metabolism in Angus steers through two experiments: a feeding experiment (Experiment 1) and a digestive metabolism experiment (Experiment 2). In Experiment 1, thirty-six Angus steers (485.64 ± 39.41 kg of BW) at 16 months of age were randomly assigned to three groups: control (CON), a conventional dose of GAA (CGAA, 0.8 g/kg), and a high dose of GAA (HGAA, 1.6 g/kg), each with twelve steers. The adaptation period lasted 14 days, and the test period was 130 days. Weighing occurred before morning feeding on days 0, 65, and 130, with rumen fluid and blood collected before morning feeding on day 130. Experiment 2 involved fifteen 18-month-old Angus steers (575.60 ± 7.78 kg of BW) randomly assigned to the same three groups as in Experiment 1, with a 7-day adaptation period and a 3-day test period. Fecal and urine samples were collected from all steers during this period. Results showed a significantly higher average daily gain (ADG) in the CGAA and HGAA groups compared to the CON group (p = 0.043). Additionally, the feed conversion efficiency (FCE) was significantly higher in the CGAA and HGAA groups than in the CON group (p = 0.018). The concentrations of acetate and the acetate:propionate ratio were significantly lower in the CGAA and HGAA groups, while propionate concentration was significantly higher (p < 0.01). Serum concentration of urea (UREA), blood ammonia (BA), GAA, creatine, and catalase (CAT) in the CGAA and HGAA groups were significantly higher than in the CON group, whereas malondialdehyde (MDA) concentrations were significantly lower (p < 0.05). Digestibility of dry matter (DM) and crude protein (CP) and the nitrogen retention ratio were significantly higher in the CGAA and HGAA groups than in the CON group (p < 0.05). In conclusion, dietary addition of both 0.8 g/kg and 1.6 g/kg of GAA increased growth performance, regulated rumen fermentation and blood indices, and improved digestibility and nitrogen metabolism in Angus steers. However, higher doses of GAA did not demonstrate a linear stacking effect. [ABSTRACT FROM AUTHOR]

This study evaluated the impacts of a-amylase (AM) and coated a-amylase (CAM) on bull performance, nutrient digestibility, and ruminal fermentation. This study randomized 60 Holstein bulls of 365 ± 11.5 days of age and 457.5 ± 9.35 kg body weight into three groups: without AM addition, adding AM 0.6g/kg dry matter (DM), and adding CAM 0.6gAM/kg DM, separately. This whole experimental period was 80 days, including a 20-day adaptation period and a 60-day data and sample acquisition period. In comparison with the unsupplemented control, dry matter intake (DMI) was unaltered; however, average daily gain (ADG) and feed efficiency (FE) were greater for AM or CAM addition. Bulls receiving AM or CAM supply had greater total-tract nutrient digestibility, ruminal total volatile fatty acids (VFA) content, propionate molar proportion, cellulolytic enzyme and AM activities, and the number of microorganisms. In addition, the activities of AM and trypsin in the jejunum and ileum and glucose, albumin, and total protein concentrations in serum were greater for AM or CAM addition compared to the control. When comparing the supplementation mode of AM, bulls receiving CAM addition had greater ADG and FE. The crude protein and starch digestibility and intestinal AM and trypsin activity were higher, while acid detergent fiber (ADF) digestibility was lower for CAM addition than for AM addition. The lower propionate molar proportion and cellobiase and carboxymethyl cellulase activities, together with Ruminococcus albus, Ruminococcus flavefaciens, and Fibrobacter succinogenes populations were observed for CAM addition compared with AM addition. However, there were greater glucose, albumin, and total protein concentrations in serum after adding CAM. According to the data, the supply of AM improved ADG, nutrient digestion, and rumen fermentation. Notably, the optimum supplementation mode was in the form of CAM in bulls. [ABSTRACT FROM AUTHOR]

Simple Summary: Global temperatures are on the rise, and this poses a significant threat to animal farming. However, there are certain nutritional strategies that can help mitigate the harmful effects of heat stress, particularly for the growing heifer calves who play a crucial role in the future profitability and sustainability of a dairy farm. In this study, growing calves experiencing heat stress consumed more feed and digested nutrients more efficiently when offered diets with moderate content of dietary fiber and shorter alfalfa hay particle size. Feeding a diet with a moderate level of fiber resulted in better growth, lower rectal temperature, and longer lying behavior, an indication of better animal comfort. Our findings highlight the importance of dietary fiber level and forage particle size in shaping calf performance and behavior under challenging environmental conditions. This experiment was designed to investigate the effects of feeding diets with different fiber content and forage particle size on the performance, health, nutrient digestion, rumen fermentation, and behavioral and sorting activity of Holstein dairy calves kept under elevated environmental temperature. Sixty weaned Holstein female calves (age = 96.7 ± 7.62 days old; body weight = 82.4 ± 10.4 kg) were randomly assigned to one of 4 treatments arranged in a 2-by-2 factorial design in a 70-day experiment. Dietary forage content (moderate, 22.5%; or high, 40.0% on DM basis) and alfalfa hay particle size (short, 4.39 mm; or long, 7.22 mm as geometric mean) were the experimental factors, resulting in the following combinations: (1) high-fiber (HF) diets with forage-to-concentrate ratio of 40:60 and long particle-sized alfalfa hay (LPS; HF-LPS); (2) HF diets with short particle-sized alfalfa hay (SPS; HF-SPS); (3) moderate-fiber (MF) diets with forage-to-concentrate ratio of 22.5:77.5 with LPS (MF-LPS); and (4) MF diets with SPS (MF-SPS). The temperature–humidity index averaged 73.0 ± 1.86, indicating that weaned calves experienced a moderate extent of heat stress. Fiber level and AH particle size interacted and affected dry matter intake, with the greatest intake (4.83 kg/d) observed in MF-SPS-fed calves. Final body weight was greater in calves receiving MF vs. HF diets (164 vs. 152 kg; p < 0.01). Respiration rate decreased when SPS vs. LPS AH was included in HF but not MF diet. Lower rectal temperature was recorded in calves fed MF vs. HF diet. Digestibility of dry matter and crude protein was greater in calves fed MF than HF diets, resulting in lower ruminal pH (6.12 vs. 6.30; p = 0.03). Fiber digestibility was greater in calves fed SPS compared with those fed LPS alfalfa hay. Feeding HF compared with MF diet increased acetate but lowered propionate molar proportions. The inclusion of SPS vs. LPS alfalfa hay decreased lying time in HF diet (920 vs. 861 min; p < 0.01). Calves fed MF vs. HF diets spent less time eating but more time lying, which is likely indicative of better animal comfort. Dietary fiber level and forage particle size interacted and affected sorting against 19 mm particles, the extent of which was greater in HF-SPS diet. Overall, dietary fiber level had a stronger effect than forage particle size on the performance of weaned calves exposed to a moderate degree of heat stress as feeding MF vs. HF diet resulted in greater feed intake, final body weight, structural growth measures, nutrient digestion, as well as longer lying behavior. The inclusion of SPS alfalfa hay in MF diets increased feed consumption. [ABSTRACT FROM AUTHOR]

Meat digestion and intestinal flora fermentation characteristics are closely related to human dietary health. The present study investigated the effect of different cooking treatments, including boiling, roasting, microwaving, stir-frying, and deep-frying, on the oxidation of chicken protein as well as its structural and digestion characteristics. The results revealed that deep-fried and roasted chicken exhibited a relatively higher degree of protein oxidation, while that of boiled chicken was the lowest (p < 0.05). Both stir-frying and deep-frying led to a greater conversion of the α-helix structure of chicken protein into a β-sheet structure and resulted in lower protein gastrointestinal digestibility (p < 0.05), whereas roasted chicken exhibited moderate digestibility. Further, the impact of residual undigested chicken protein on the intestinal flora fermentation was assessed. During the fermentation process, roasted chicken generated the highest number of new intestinal flora species (49 species), exhibiting the highest Chao 1 index (356.20) and a relatively low Simpson index (0.88). Its relative abundance of Fusobacterium was the highest (33.33%), while the total production of six short-chain fatty acids was the lowest (50.76 mM). Although stir-fried and deep-fried chicken exhibited lower digestibility, their adverse impact on intestinal flora was not greater than that of roasted chicken. Therefore, roasting is the least recommended method for the daily cooking of chicken. The present work provides practical advice for choosing cooking methods for chicken in daily life, which is useful for human dietary health. [ABSTRACT FROM AUTHOR]

In order to explore the enhancement effect of biochar on anaerobic digestion, oxytetracycline residue was used as the substrate for anaerobic digestion, and biochar was added to solve the problems of low efficiency and weak stability of traditional anaerobic digestion. The strengthening effects of biochar and zero-valent iron modified biochar were illustrated by the changes of gas production, stability and microbial community. The results show that adding biochar alone and nano-scale zero-valent iron modified biochar can reduce the concentration of ammonia nitrogen in the system, reduce the influence of ammonia inhibition on anaerobic digestion, promote the transformation and consumption of VFAs, and improve the stability of the system. The gas production efficiency increased by 20.74% and 15.49% respectively, reaching above 115.20 mL/g. In addition, biochar can also strengthen the removal of residual oxytetracycline, and its removal efficiency is increased by 2.37% and 4.82% respectively compared with the control group, and the content of residual oxytetracycline in the final system can be reduced to below 10 mg/L. After adding zero-valent iron to biochar, the abundance of acid-producing bacteria and methano-genic archaea increased in different degrees, thus strengthening the process of anaerobic digestion and methanogenesis. [ABSTRACT FROM AUTHOR]

Wholegrains contain both fibre and phenolic acids (PAs), and their gastrointestinal modifications are critical for their bioavailability and bioactivity. We evaluated the modifications on the PA profile and gut microbiota composition of selected Nigerian wholegrains, following cooking and gastrointestinal digestion. Red fonio, red millet, red sorghum, and white corn were cooked, digested, and fermented using an in vitro colonic model. A total of 26 PA derivatives were quantified in soluble and bound fractions using Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) analysis. DNA samples were analysed using 16S rRNA amplicon sequencing to profile the microbiota composition. The results show that cooking and digestion significantly affected the levels of PAs in all grains (p ≤ 0.05) compared to raw grains. Colonic fermentation resulted in a peak of total soluble PAs at 4–6 h for red sorghum and white corn and at 24 h for red millet and red fonio. Enterobacteriaceae genera were the most abundant at 24 h in all grains studied. 3-hydroxybenzaldehyde correlated positively with the relative abundance of Dorea and the mucus-degrader bacteria Akkermansia (p ≤ 0.05), whereas hydroferulic acid and isoferulic acid levels correlated negatively with Oscillospira and Ruminococcus (p ≤ 0.05), respectively. Our data indicate that cooking, digestion, and colonic fermentation affect the release of bound PAs from wholegrains and, consequently, their metabolic conversion. Furthermore, PA fermentation in the gut is associated with potentially relevant changes in the microbiota. This in vitro study provides the basis for the design of an in vivo human intervention study that can confirm the trends herein observed but also assess the impact on health outcomes. [ABSTRACT FROM AUTHOR]

Sheep with a relatively low methane yield were observed to have shorter fluid and particle mean retention times (MRT). Because the application of pilocarpine, a saliva stimulant, was successful in reducing retention times in ruminants in previous studies, we applied this substance to sheep, expecting a reduction in MRT and methane yield. Three non‐pregnant sheep (74 ± 10 kg) were fed a hay‐only diet in a 3 × 3 Latin square design with oral doses of 0, 2.5 and 5 mg pilocarpine/kg body weight and day. Measurements included feed and water intake, MRT of liquid and particulate phases in the reticulorumen (RR) and total gastrointestinal tract (GIT), ruminal microbial yield (via urinary purine bases and metabolic faecal nitrogen), total tract methane emission, apparent nutrient digestibility and rumen fluid parameters. Data were investigated for linear and quadratic effects using orthogonal polynomial contrasts. The MRT of liquid and small particles in the RR and total GIT, and the short‐chain fatty acid concentration in rumen fluid, linearly declined with increasing pilocarpine dosage, while no quadratic relationship was detected. Intake of feed DM and water, apparent nutrient digestibility, methane yield and microbial yield were not affected by pilocarpine. When combining the sheep data with that of a similar experiment in cattle, we found that the MRT of the liquid phase was positively associated with estimated NDF digestibility and with methane production per digested NDF, but was not associated with microbial yield or the ratio of acetate to propionate. The ratio between MRT of the particulate and the liquid phase was smaller for sheep than that for cattle, and was not affected by treatment. Differences in this ratio might explain why species reacted differently to the saliva‐inducing agent, which might help to explain the discrepancy between species in the effect of induced saliva flow on digestive parameters. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tomato plant waste (TPW) is a significant agricultural byproduct that has been often underutilized. Recent studies have shown that its use to obtain methane in an anaerobic digestion (AD) process is viable. However, there is not much information available on studies to improve methane production from this substrate using statistical methods for optimization processes such as central composite design (CCD). For this investigation, CCD was adopted to analyze the effect of S/I ratio (substrate/inoculum ratio) (0.32–1.12), temperature (27–43 °C), and inoculum concentration (10.35–20.95 g VS/L) on methane generation and volatile solids (VS) removal in a batch AD system mono-digestion of TPW. The highest average value of methane yield was found to be 210.8 mL CH4/g VS (S/I ratio 0.48, 40 °C, and 18.80 g VS/L), and the highest average value of VS removal was found to be 36.9% (S/I ratio 1.12, 35 °C, and 15.65 g VS/L). We obtain a model with a better fit for the VS removal (R2 = 0.9587) than for the methane production (R2 = 0.9156). Temperature and S/I ratio were the factors most important for methane production and VS removal, respectively. [ABSTRACT FROM AUTHOR]

Dynamics of starch digestion in dairy cows fed extruded pellets differing in physical functional properties were investigated by measuring starch digestibility, post‐prandial rumen fermentation patterns, and post‐prandial duodenal starch appearance. Additionally, starch digestion effects on neutral detergent fiber (NDF) digestibility and methane (CH4) emission were studied. Pure barley was extruded to produce three treatments having pellets of either low‐density (LD), medium‐density (MD) or high‐density (HD). The experiment was conducted in a 3 × 3 Latin square design using three lactating Danish Holstein cows fitted with ruminal, duodenal and ileal cannulas. After the allocation of experimental concentrate directly into the rumen through the rumen cannula, cows were fed a basal diet low in starch. Eight samples were collected on equal time intervals (9 h) from duodenal digesta, ileal digesta and feces (grab sample) to determine digestibility. For post‐prandial rumen fermentation patterns, four sample sets of rumen dorsal, medial and ventral fluid were taken from each cow, whereas for post‐prandial duodenal starch appearance, 14 samples of duodenal chyme were obtained from each cow relative to morning feeding of experimental concentrate at 07:00 h. Ruminal, small intestinal, hindgut and total tract digestibility of starch did not differ among treatments. Similarly, NDF digestibility and CH4 emission also remained unaffected by treatments. However, compared with the LD and MD treatments, the HD treatment showed higher acetate: propionate ratio at all positions in the rumen and a higher post‐prandial duodenal starch appearance. This indicates lower ruminal starch degradation (RSD) and higher starch flow into the small intestine for HD treatment. In conclusion, the current study indicates that pellets' physical properties can manipulate RSD, where pellets with high density and fluid stability can partly shift starch digestion from the rumen to the small intestine. Indeed, further investigations are needed. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to determine the chemical composition and in vitro ruminal fermentation capacity of potato pulp (PP), potato pulp with peel (PPp) and potato peel (Pp), i.e. potato starch by-products. PP and PPp were applied at 5.0, 7.5 and 10.0% (on a dry matter basis) instead of corn flake and barley grain in dairy cow total mixed ration (TMR). The volumes of in vitro total gas and methane production, and metabolisable energy (ME) values of PP and PPp were higher compared to Pp (P < 0.001). The in vitro true dry matter digestion (tDMd) and in vitro true organic matter digestion (tOMd) values of PP using at 7.5% and 10% rates in TMR were decreased linearly according to that of control TMR value (P < 0.05). Therefore, the use of potato starch by-products in ruminant diet can be suggested due to the high and rapid fermentation potential, especially of potato pulp without peel. The study showed that PP could be applied at up to 5% and PPp at a level of up to 10% in dairy cattle TMR (on a DM basis). Further in vitro studies should be carried out using dried potato starch by-products. [ABSTRACT FROM AUTHOR]

Anaerobic fungi have long been in the attention for their well-known potential in roughages degradation and ruminant nutrition. Although numerous studies have given new insights into anaerobic fungi in lignocellulosics digestion owing to their decisive fibrolytic activity, however, little is known about their role in carbohydrate fermentation. Furthermore, very limited information is available on the newly discovered genera of anaerobic rumen fungi, their mechanism of ruminal digestion, and their application as feed additives in ruminants. Therefore, this review aims to represent the current new understanding of various anaerobic fungal genera and their secretory fibrolytic enzymes, role in lignocellulosic digestion, volatile fatty acids (VFAs) formation and productivity in different ruminant species. This article further reviewed the use of superior anaerobic fungi like Neocallimastix sp., Orpinomyces sp., Piromyces sp. and Anaeromyces sp. as probiotic-feed additives and their role in improving digestibility, fermentation, VFAs production and productivity of ruminants. However, there is very less research focussed on the newly discovered anaerobic fungi and their fermentation profile. In addition, our review will lead to greater understanding of interactions between anaerobic rumen fungi and ruminal fermentation, which will help in devising a new, economical fungal based probiotic feeding system for better livestock productivity. [ABSTRACT FROM AUTHOR]

In order to improve the performance of methane production from agro-waste, a batched four-stage–two-phase anaerobic digestion (4S2P-AD) system was designed to combine the advantages of both anaerobic co-digestion (co-AD) and two-phase AD. The initial separation of two phases was performed using rice straw (RS) as a feedstock in acidogenic phase and cow manure (CM) in methanogenic phase at low inoculum/substrate (I/S) ratios of 0.5 and 0.2 and a high organic loading of 60 g volatile solid (VS)/L. The periodic round-trip reflux of leachate during the 4S2P-AD process facilitated re-inoculation throughout the four stages. The results showed that this round-trip reflux also dispersed toxic ammonia, balanced the carbon/nitrogen ratio, unified the microbial community structure, and led to the selection of Methanosarcina (relative abundance > 80%) as the dominant methanogens. With the abilities to overcome volatile fatty acid accumulation, shorten lag times, improve biodegradability, and foster synergistic effects, it was verified that the 4S2P-AD process can maintain efficient and stable methanogenesis from high-solid lignocellulosic feedstock. The averaged methane production throughout the four stages of 4S2P-AD was 234 mL/g VS. This result is 96% higher than the averaged methane production obtained from the four one-step AD groups using mono-feedstock, and 91% higher than that obtained using co-feedstock. This study provides a scientific reference for the development of new processes of bio-methane production from agro-waste with a high fermentation capacity and stability in the future. [ABSTRACT FROM AUTHOR]

Both in vitro and animal studies indicated that a higher dilution rate is related to a more efficient microbial synthesis and a lower methane (CH4) yield. The latter could be a consequence of the former, as an increase in microbial cell synthesis offers an alternative hydrogen sink competing with methanogenesis. To test this assumption in live animals, we applied a saliva stimulant, pilocarpine, to modify liquid flow rate in cattle. Four non‐lactating cows (750 ± 71 kg) were fed forage only (restricted to constant intake) in a 4 × 4 Latin square design with oral doses of 0, 1, 2.5 and 5mg pilocarpine/kg body weight and day. We quantified feed and water intake, ruminal and total tract mean retention time (MRT) of solute and particle markers, ruminal microbial yield (via urinary purine bases or metabolic faecal nitrogen), CH4 emission, digestibility, chewing behaviour, reticular motility and rumen fluid parameters. The effect of induced saliva flow was evident by visibly increased salivation and water intake. Increasing the pilocarpine dosages resulted in a linearly decreased MRT of fluid and small particles (p < 0.001 and p< 0.05, respectively) and methane yield as related to digested DM (p < 0.05), the latter at a magnitude of 5%. No effect of treatment was found on ruminal microbial yield estimated via purine derivates. Metabolic faecal N as an indicator of microbial growth linearly correlated with pilocarpine dosages (p < 0.05). No significant relationship was found between pilocarpine dosages and large particle MRT, nutrient digestibility, ruminal pH and short‐chain fatty acids. In conclusion, different from some in vitro studies, there was little indication of a reciprocal effect of CH4 and microbial biomass production in cows fed a forage‐only diet. [ABSTRACT FROM AUTHOR]