An in vitro evaluation of fat-extracted pongamia seedcake in barley-based feedlot diets

Highly digestible forages are associated with anin vitrolow-methane (CH4) rumen fermentation profile and thus the possibility of reducing CH4emissions from forage-based systems. We aimed to assess thein vitroruminal fermentation profile, including CH4production, of the top stratum of Kikuyu grass (Cenchrus clandestinus - Hochst. ex Chiov) harvested at different sward heights (10, 15, 20, 25, and 30 cm). Herbage samples (incubating substrate) were analyzed for their chemical composition,in vitroorganic matter digestibility (IVOMD), and morphological components.In vitroincubations were performed under a randomized complete block design with four independent runs of each treatment. Gas production (GP),in vitrodry matter digestibility (IVDMD), CH4production, total volatile fatty acid (VFA) concentration, and their acetate, propionate, and butyrate proportions were measured following 24 and 48 h of incubation. Herbage samples had similar contents of organic matter, neutral detergent fiber, and crude protein for all treatments. However, a higher acid detergent fiber (ADF) content in taller sward heights than in smaller sward heights and a tendency for metabolizable energy (ME) and IVOMD to decrease as sward height increased were found. Similarly, the stem + sheath mass tended to increase with increasing sward height. Amongst the nutrients, ME (r= −0.65) and IVDMD (r= −0.64) were negatively correlated with sward height (p< 0.001) and ADF was positively correlated with sward height (r= 0.73,p< 0.001). Both the GP and IVDMD were negatively related to the sward height at both incubation times. Sward heights of Kikuyu grass below 30 cm display anin vitroprofile of VFAs high in propionate and low in acetate, with a trend toward lower methane production of CH4per unit of IVDMD. These findings are important to aid decision-making on the optimal sward height of Kikuyu grass and manage animal grazing with the opportunity to reduce CH4production.

Highly digestible forages are associated with an in vitro low-methane (CH4) rumen fermentation profile and thus the possibility of reducing CH4 emissions from forage-based systems. We aimed to assess the in vitro ruminal fermentation profile, including CH4 production, of the top stratum of Kikuyu grass (Cenchrus clandestinus - Hochst. ex Chiov) harvested at different sward heights (10, 15, 20, 25, and 30 cm). Herbage samples (incubating substrate) were analyzed for their chemical composition, in vitro organic matter digestibility (IVOMD), and morphological components. In vitro incubations were performed under a randomized complete block design with four independent runs of each treatment. Gas production (GP), in vitro dry matter digestibility (IVDMD), CH4 production, total volatile fatty acid (VFA) concentration, and their acetate, propionate, and butyrate proportions were measured following 24 and 48 hours of incubation. Herbage samples had similar contents of organic matter, neutral detergent fiber, and crude protein for all treatments. However, a higher acid detergent fiber (ADF) content in taller sward heights than in smaller sward heights and a tendency for metabolizable energy (ME) and IVOMD to decrease as sward height increased were found. Similarly, the stem + sheath mass tended to increase with increasing sward height. Amongst the nutrients, ME (r = –0.65) and IVDMD (r = –0.64) were negatively correlated with sward height (p < 0.001) and ADF was positively correlated with sward height (r = 0.73, p < 0.001). Both the GP and IVDMD were negatively related to the sward height at both incubation times. Sward heights of Kikuyu grass below 30 cm display an in vitro profile of VFAs high in propionate and low in acetate, with a trend toward lower methane production of CH4 per unit of IVDMD. These findings are important to aid decision-making on the optimal sward height of Kikuyu grass and manage animal grazing with the opportunity to reduce CH4 production.

Highly digestible forages are associated with an in vitro low-methane (CH4) rumen fermentation profile and thus the possibility of reducing CH4 emissions from forage-based systems. We aimed to assess the in vitro ruminal fermentation profile, including CH4 production, of the top stratum of Kikuyu grass (Cenchrus clandestinus - Hochst. ex Chiov) harvested at different sward heights (10, 15, 20, 25, and 30 cm). Herbage samples (incubating substrate) were analyzed for their chemical composition, in vitro organic matter digestibility (IVOMD), and morphological components. In vitro incubations were performed under a randomized complete block design with four independent runs of each treatment. Gas production (GP), in vitro dry matter digestibility (IVDMD), CH4 production, total volatile fatty acid (VFA) concentration, and their acetate, propionate, and butyrate proportions were measured following 24 and 48 hours of incubation. Herbage samples had similar contents of organic matter, neutral detergent fiber, and crude protein for all treatments. However, a higher acid detergent fiber (ADF) content in taller sward heights than in smaller sward heights and a tendency for metabolizable energy (ME) and IVOMD to decrease as sward height increased were found. Similarly, the stem + sheath mass tended to increase with increasing sward height. Amongst the nutrients, ME (r = –0.65) and IVDMD (r = –0.64) were negatively correlated with sward height (p < 0.001) and ADF was positively correlated with sward height (r = 0.73, p < 0.001). Both the GP and IVDMD were negatively related to the sward height at both incubation times. Sward heights of Kikuyu grass below 30 cm display an in vitro profile of VFAs high in propionate and low in acetate, with a trend toward lower methane production of CH4 per unit of IVDMD. These findings are important to aid decision-making on the optimal sward height of Kikuyu grass and manage animal grazing with the opportunity to reduce CH4 production.

Highly digestible forages are associated with an in vitro low-methane (CH4) rumen fermentation profile and thus the possibility of reducing CH4 emissions from forage-based systems. We aimed to assess the in vitro ruminal fermentation profile, including CH4 production, of the top stratum of Kikuyu grass (Cenchrus clandestinus - Hochst. ex Chiov) harvested at different sward heights (10, 15, 20, 25, and 30 cm). Herbage samples (incubating substrate) were analyzed for their chemical composition, in vitro organic matter digestibility (IVOMD), and morphological components. In vitro incubations were performed under a randomized complete block design with four independent runs of each treatment. Gas production (GP), in vitro dry matter digestibility (IVDMD), CH4 production, total volatile fatty acid (VFA) concentration, and their acetate, propionate, and butyrate proportions were measured following 24 and 48 hours of incubation. Herbage samples had similar contents of organic matter, neutral detergent fiber, and crude protein for all treatments. However, a higher acid detergent fiber (ADF) content in taller sward heights than in smaller sward heights and a tendency for metabolizable energy (ME) and IVOMD to decrease as sward height increased were found. Similarly, the stem + sheath mass tended to increase with increasing sward height. Amongst the nutrients, ME (r = –0.65) and IVDMD (r = –0.64) were negatively correlated with sward height (p < 0.001) and ADF was positively correlated with sward height (r = 0.73, p < 0.001). Both the GP and IVDMD were negatively related to the sward height at both incubation times. Sward heights of Kikuyu grass below 30 cm display an in vitro profile of VFAs high in propionate and low in acetate, with a trend toward lower methane production of CH4 per unit of IVDMD. These findings are important to aid decision-making on the optimal sward height of Kikuyu grass and manage animal grazing with the opportunity to reduce CH4 production.

The objective was to determine the effects of induced hindgut acidosis in sheep on cecal pH, ruminal fermentation, and gut permeability. Eleven ruminally and cecally cannulated ewes (49 ± 4 kg) were assigned to one of two treatments: control (CON; n = 5) or induced hindgut acidosis (HGA; n = 6). To induce hindgut acidosis, 3 g wheat starch/kg BW per 24 h was continuously infused via the cecal cannula for 4 d. Control ewes received a constant infusion of deionized water. Ewes were fed a common diet at a set level of intake based on body weight. Chromium EDTA was dosed once daily via the cecal cannula as a marker of gut permeability. Rumen, cecal, and fecal samples were collected to determine pH and volatile fatty acids (VFA). Rumen fluid was collected on day 4 for an ex vivo fermentation to determine pH, VFA, ammonia, and in vitro dry matter digestibility (IVDMD). On day 5, sucralose was infused through the cecal cannula and blood was collected from a mesenteric catheter under anesthesia. Transepithelial electrical resistance (TEER) was determined in the ileum, cecum, and colon in Ussing chambers. There was a treatment × time effect (P = 0.05) for cecal pH, with HGA ewes having lesser cecal pH after day 1. By day 4, cecal pH had dropped to 5.07 for HGA ewes compared to 6.40 for CON ewes. A treatment × time interaction was observed (P < 0.01) for fecal pH and followed the same trend as cecal pH. Total fecal VFA concentration was greater (P < 0.01) in HGA ewes than CON. Rumen pH was not affected (P = 0.87) by the interaction of treatment × time, but was affected (P < 0.01) by treatment, as ewes on the HGA treatment had a lesser rumen pH than CON ewes. Control ewes had lesser ruminal VFA and ammonia concentrations than HGA ewes (P < 0.01). Despite this, the ex vivo fermentation did not indicate any differences in pH, VFA, or IVDMD (P ≥ 0.11). Urinary Cr recovery was not affected by the interaction of treatment × time, or treatment (P ≥ 0.13). There were no effects (P ≥ 0.22) of treatment, time, or their interaction on mesenteric plasma sucralose concentration. In cecal tissue, TEER tended (P = 0.09) to be lesser, indicating increased permeability in HGA ewes compared with CON ewes. In contrast, TEER was not different (P ≥ 0.83) in ileal or colonic tissues between treatment groups. A cecal infusion of starch induced hindgut acidosis and affected hindgut fermentation. Hindgut acidosis still had systemic effects on rumen conditions despite varied responses in gut permeability.

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.

An in vitro gas production technique was used in this study to elucidate the effect of two strains of active live yeast on methane (CH4) production in the large intestinal content of pigs to provide an insight to whether active live yeast could suppress CH4 production in the hindgut of pigs. Treatments used in this study include blank (no substrate and no live yeast cells), control (no live yeast cells) and yeast (YST) supplementation groups (supplemented with live yeast cells, YST1 or YST2). The yeast cultures contained 1.8×1010 cells per g, which were added at the rates of 0.2 mg and 0.4 mg per ml of the fermented inoculum. Large intestinal contents were collected from 2 Duroc×Landrace×Yorkshire pigs, mixed with a phosphate buffer (1:2), and incubated anaerobically at 39°C for 24 h using 500 mg substrate (dry matter (DM) basis). Total gas and CH4 production decreased (p<0.05) with supplementation of yeast. The methane production reduction potential (MRP) was calculated by assuming net methane concentration for the control as 100%. The MRP of yeast 2 was more than 25%. Compared with the control group, in vitro DM digestibility (IVDMD) and total volatile fatty acids (VFA) concentration increased (p<0.05) in 0.4 mg/ml YST1 and 0.2 mg/ml YST2 supplementation groups. Proportion of propionate, butyrate and valerate increased (p<0.05), but that of acetate decreased (p<0.05), which led to a decreased (p<0.05) acetate: propionate (A: P) ratio in the both YST2 treatments and the 0.4 mg/ml YST 1 supplementation groups. Hydrogen recovery decreased (p<0.05) with yeast supplementation. Quantity of methanogenic archaea per milliliter of inoculum decreased (p<0.05) with yeast supplementation after 24 h of incubation. Our results suggest that live yeast cells suppressed in vitro CH4 production when inoculated into the large intestinal contents of pigs and shifted the fermentation pattern to favor propionate production together with an increased population of acetogenic bacteria, both of which serve as a competitive pathway for the available H2 resulting in the reduction of methanogenic archaea.

The effects of different inclusion rates of Poncirus trifoliata (PT) extract on in vitro ruminal fermentation parameters were investigated. Six dose levels were referred to as follows: PT0, control (without PT); PT1, (3 mg/L); PT3, (9 mg/L); PT5, (15 mg/L); PT7, (21 mg/L); PT9, (27 mg/L), each incubated with 50 mL of buffered rumen fluid and 300 mg of timothy hay as a substrate for 72 h of incubation using an in vitro batch culture system. The in vitro dry matter digestibility (IVDMD) was significantly affected by the PT dose, except after 6 and 48 h of incubation. Total volatile fatty acids (VFAs) increased quadratically (12 h of incubation) within the range of PT1–PT7, whereas decreased at PT9 dose. Methane (CH4) production and the proportion of CH4 in the total gas produced decreased linearly after 12 h of incubation. The relative abundance of Ruminococcus albus and Ruminoccocus flavefaciens was greater at the doses PT1 than PT0, whereas that of Fibrobacter succinogenes was greater at PT0 than at PT9 after 24 h of incubation. Methanogenic archaea decreased linearly with increasing PT dose after 12 h of incubation. The abundance of ciliate-associated methanogens decreased linearly over 24 h of incubation under PT7 and PT9 treatments. These results suggest that the dose of PT can modulate ruminal fermentation to alter VFA concentration and reduce CH4 production by altering ruminal bacterial abundance. Highlights This study evaluated the dose-response effects of Poncirus trifoliata as a methane mitigation agent in ruminants. Inclusion of Poncirus trifoliate lowered in vitro dry matter digestibility and total volatile fatty acid concentration. Inclusion of Poncirus trifoliata extract reduced methane production after 12 h of incubation but did not maintained. Inclusion of Poncirus trifoliata extract reduced methanogenic archaea and ciliate-associated methanogens abundance

ObjectiveThe objective of this study was to investigate the effects of essential oil mixture (EOM) supplementation on rumen fermentation characteristics and microbial changes in an in vitro.MethodsThree experimental treatments were used: control (CON, no additive), EOM 0.1 (supplementation of 1 g EOM/kg of substrate), and EOM 0.2 (supplementation of 2 g EOM/kg of substrate). An in vitro fermentation experiment was carried out using strained rumen fluid for 12 and 24 h incubation periods. At each time point, in vitro dry matter digestibility (IVDMD), neutral detergent fiber digestibility (IVNDFD), pH, ammonia nitrogen (NH3-N), and volatile fatty acid (VFA) concentrations, and relative microbial diversity were estimated.ResultsAfter 24 h incubation, treatments involving EOM supplementation led to significantly higher IVDMD (treatments and quadratic effect; p = 0.019 and 0.008) and IVNDFD (linear effect; p = 0.068) than did the CON treatment. The EOM 0.2 supplementation group had the highest NH3-N concentration (treatments; p = 0.032). Both EOM supplementations did not affect total VFA concentration and the proportion of individual VFAs; however, total VFA tended to increase in EOM supplementation groups, after 12 h incubation (linear; p = 0.071). Relative protozoa abundance significantly increased following EOM supplementation (treatments, p<0.001). Selenomonas ruminantium and Ruminococcus albus (treatments; p<0.001 and p = 0.005), abundance was higher in the EOM 0.1 treatment group than in CON. The abundance of Butyrivibrio fibrisolvens, fungi and Ruminococcus flavefaciens (treatments; p< 0.001, p<0.001, and p = 0.005) was higher following EOM 0.2 treatment.ConclusionThe addition of newly developed EOM increased IVDMD, IVNDFD, and tended to increase total VFA indicating that it may be used as a feed additive to improve rumen fermentation by modulating rumen microbial communities. Further studies would be required to investigate the detailed metabolic mechanism underlying the effects of EOM supplementation.

Inclusion of psyllium in milk replacer for neonatal calves. 2. Effects on volatile fatty acid concentrations, microbial populations, and gastrointestinal tract size

Laboratory-scale experiments have shown that treatment with selective lignin-degrading white-rot fungi improves the nutritional value and ruminal degradability of lignocellulosic biomass (LCB). However, the lack of effective field-applicable pasteurization methods has long been recognized as a major obstacle for scaling up the technique for fungal treatment of large quantities of LCB for animal feeding. In this study, wheat straw (an LCB substrate) was subjected to four field-applicable pasteurization methods - hot-water, formaldehyde fumigation, steam, and hydrated lime - and cultured with Pleurotus ostreatus grain spawn for 10, 20, and 30 days under solid-state fermentation. Samples of untreated, pasteurized but non-inoculated and fungus-treated straws were analyzed for chemical composition, aflatoxin B1 (AFB1 ), and in vitro dry matter digestibility (IVDMD), in vitro total gas (IVGP), methane (CH4 ), and volatile fatty acid (VFA) production. During the 30-day fungal treatment, steam and lime pasteurized straws had the greatest loss of lignin, resulting in marked improvements in crude protein (CP), IVDMD, IVGP, and total VFAs. Irrespective of the pasteurization method, the increase in IVDMD during fungal treatment was linearly (R2 = 0.77-0.92) related to lignin-loss in the substrate during fungal treatment. The CH4 production of the fungus-treated straw was not affected by the pasteurization methods. Aflatoxin B1 was within the safe level (<5 μg kg-1 ) in all pasteurized, fungus treated straws. Steam and lime were promising field-applicable pasteurization techniques to produce nutritionally improved fungus-treated wheat straw to feed ruminants. Lime pasteurization was more economical and did not require expensive energy inputs. © 2023 Society of Chemical Industry.

Tannins added to animal diets may have a positive effect on energy and protein utilisation in the rumen. The objective of this study was to examine the impact of different sources and concentrations (20, 50, 100, 150 and 200 g kg⁻¹ dry matter (DM)) of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen microbial fermentation in vitro. The experiment also included a negative control with no tannins (control) and a positive control with monensin (10 mg L⁻¹). In vitro gas production and total volatile fatty acid (VFA) concentration decreased as tannin concentration increased. Addition of acacia, chestnut or valonea tannins at ≥ 50 g kg⁻¹ or quebracho tannins at ≥ 100 g kg⁻¹ resulted in a decrease (up to 40%) in methane (CH₄) production compared with the control. Valonea tannins were the only tannin source that reduced (-11%) CH₄ production at 50 g kg⁻¹ without affecting VFA concentration. Tannin treatments reduced ammonia (NH₃) and branched-chain VFA concentrations, indicating a reduction in ruminal protein degradation. Monensin reduced CH₄ production (-37%) and NH₃ concentration (-20%) without affecting total VFA concentration. Supplying acacia, chestnut or valonea tannins at 50 g kg⁻¹ has the potential to reduce CH₄ production and ruminal protein degradation with minimum detrimental effects on efficiency of ruminal fermentation.

The objective of this study was to evaluate the molasses based raw spent wash as an alternative energy feed substitute in heifers. The study was conducted in two phases. In phase I, effect of replacement of 0, 5, 10, 15 and 20% of substrate with raw spent wash was studied on in vitro DM digestibility (IVTDMD), in vitro OM digestibility (IVTOMD), pH, in vitro gas production, partitioning factor (PF), total volatile fatty acid (TVFA), ammonia nitrogen (NH3-N) and microbial biomass production (MBP). Results revealed that there was no significant effect of incorporation of different levels raw spent wash on gas production, TVFA production and NH3-N. IVTDMD and IVTOMD digestibility and MBP showed positive correlation with raw spent wash levels. In phase II, eighteen heifers were randomly allocated into three groups (n=6) for a period of 150 d on body weight basis. Feeding regimen was similar in all the groups except that the 10 and 20% barley grains of concentrate mixture were replaced with raw spent wash (RSW). Inclusion of 10 and 20% RSW did not alter feed intake, growth performance and nutrient digestibility among groups. The levels of haemoglobin, packed cell volume, total protein, globulin, alanine transaminase, aspartate amino transferase, alkaline phosphatase, plasma urea nitrogen, Ca, P, Mg, ferric reducing antioxidant power assay and non esterified fatty acids. A higher (P<0.05) concentration of white blood cells, albumin, cholesterol, glucose and immunoglobulin was detected in RSW included groups. In conclusion, upto 10% barley grain could be replaced by raw spent wash without any adverse effect on nutrients intake, nutrient utilization and blood metabolites.

Garlic (Allium sativum) contains secondary compounds known to modify rumen fermentation parameters and decrease methane (CH4) emissions; however, results from previous research on the effects of garlic-byproduct supplementation are quite variable. The objective of this experiment was to evaluate the effects of increasing inclusion levels and processing methods of dried raw garlic on in vitro ruminal fermentation and CH4 production. The experiment was designed as a randomized complete block design, where 24 h incubations were conducted on three separate days, with corn silage and gin trash (80:20, respectively) used as basal substrate. Treatments were arranged in a 3 × 3 factorial with garlic inclusion (0, 2.5, and 5% of the diet) and processing method (freeze-dried, oven-dried, and autoclaved) as factors. Three ruminally cannulated steers were fed ad libitum a corn silage and gin trash diet, for at least 35 d prior to collection of ruminal fluid used as inoculum. Final pH, concentration of volatile fatty acids (VFA) and ammonia nitrogen (NH3-N), in vitro organic matter digestibility (IVOMD), total gas production, and CH4 concentrations were determined at the end of incubation. Data were analyzed using the Mixed procedure of SAS. Final pH and concentration of total VFA were not affected (P &amp;gt; 0.05) by the processing method nor inclusion level of garlic. Increasing garlic inclusion decreased NH3-N concentration (P &amp;lt; 0.05), reduced (P &amp;lt; 0.05) the proportion of acetate, tended to increase (P &amp;lt; 0.10) the proportion of propionate, and tended to decrease (P &amp;lt; 0.10) the acetate:propionate ratio. Neither garlic inclusion level nor processing methods modified IVOMD, total gas production, or CH4 concentration. Modifications in VFA molar proportions and NH3-N concentration may be related to differences in N concentration in the incubated substrates. In conclusion, neither processing method nor garlic level inclusion modified CH4 production or nutrient digestibility.

Changes in in vitro gas and methane production from rumen fluid from dairy cows during adaptation to feed additives in vivo