Molar Proportion Of Acetate Research Articles

Interaction of replacing corn silage with soyhulls as a roughage source with or without 3% added wheat straw in the diet: impacts on intake, digestibility, and ruminal fermentation in steers fed high-concentrate diets.

Six ruminally cannulated steers [475.0 ± 49.6 kg initial body weight (BW)] were used in a 6 × 3 incomplete Latin square design (six treatments and three periods), to evaluate the impacts replacing of corn silage with pelleted soyhulls as roughage in high-concentrate finishing diets containing 30% modified distillers grains with solubles. Treatments were based on increasing dietary inclusion of soyhulls and consisted of: (1) Control (0), roughage supplied by dietary inclusion of 20% corn silage [dry matter (DM) basis]; (2) 50% replacement of corn silage with soyhulls (50); (3) 100% replacement of corn silage with soyhulls (100), and the same three treatments repeated with 3% added wheat straw (DM basis) replacing corn in the diet (0S, 50S, and 100S, respectively). Absolute dry matter intake (DMI; kg/d basis) tended to decrease both linearly and quadratically (P ≤ 0.09) and proportional DMI (% of BW) decreased linearly (P = 0.04) with increasing soyhull inclusion but was not affected by the addition of straw in the diet (P = 0.68). Total tract digestibility of organic matter and crude protein were not affected by soyhull inclusion or added straw (P ≥ 0.32). Ruminal pH did not differ (P = 0.65) with increasing soyhull inclusion but increased with the addition of straw (P < 0.01; 5.9 vs. 6.1 for no straw and straw, respectively). Molar proportions of acetate and butyrate decreased while propionate increased with increased soyhull inclusion (P ≤ 0.03; linearly and quadratically, respectively). Ruminal fluid kinetics were unaffected by either rate of replacement of corn silage with soyhulls or wheat straw inclusion (P ≥ 0.13). Decreases in DMI observed in this study would likely decrease finishing cattle performance and underscores the need for additional research before recommending this practice to cattle feeders.

Effects of cyclic monensin feeding on ruminal function in cannulated beef steers consuming low-quality forage

The aim of this research was to evaluate the effects of cyclically feeding monensin (Rumensin 90, Elanco Animal Health) to ruminally cannulated steers (12 Bos taurus; 260 kg of BW) consuming low-quality forage (4.9% CP) on measures of intake, digestion, and ruminal function. Twelve steers were randomly assigned to 1 of 3 treatments in a completely randomized design: (1) no monensin (CON); (2) 200 mg·head−1·d−1 monensin (MON); or (3) 200 mg·head−1·d−1 monensin for 14 d and 0 mg·head−1·d−1 monensin for the subsequent 14 d (CYC; recurrent cycle). Hay and ort samples were collected d 10 through 13 for intake determination during each of the four 28-d replicated cycles. Rumen fluid was collected with a suction strainer 0, 2, 4, 8, and 12 h after feeding on d 14 for pH and VFA analysis. Data were analyzed using the MIXED procedure of SAS 9.4 (SAS Institute Inc.). Treatment × cycle interactions or treatment effects were not observed for any measure of intake (OM intake, NDF intake; P ≥ 0.17) or pH (P = 0.13). A tendency for a treatment × cycle interaction was observed (P = 0.08) for OM digestion but not for NDF digestion (P = 0.37). Treatment × cycle interactions were observed (P < 0.01) for molar proportions of acetate, propionate, and acetate:propionate ratio. Because these treatment × cycle interactions occurred, treatment × hour interactions, treatment effects, and hour effects were evaluated within cycles for these parameters. Treatment × hour interactions (P ≤ 0.02) occurred for molar proportion of propionate in cycle 1 and propionate and acetate:propionate ratio in cycle 3, and there was a tendency (P = 0.09) for a treatment × hour interaction for acetate:propionate in cycle 4. Although treatment effects were observed for molar proportions of acetate, propionate, and acetate:propionate ratio in cycle 1 (P ≤ 0.01), these effects had diminished by cycle 4 (P ≥ 0.39). An effect of hour after feeding was observed (P ≤ 0.02) in all 4 cycles for acetate, propionate, acetate:propionate, and ruminal pH. Further evaluation of monensin feeding methods that vary duration of feeding and withdrawal periods may be warranted. Additionally, further study concerning differences in the effect of these methods on a diet bases on concentrate versus low-quality forage warrant investigation.

Effects of a mixture of phytobiotic-rich herbal extracts on growth performance, blood metabolites, rumen fermentation, and bacterial population of dairy calves

Forty-eight newborn Holstein dairy calves [40 ± 3.4 (SD) of kg of body weight (BW); 24 females and 24 males] were used in a completely randomized design to investigate the effects of a mixture of phytobiotic-rich herbal extract (Immunofin, IMPE) incorporated into milk on performance, ruminal fermentation, bacterial population, and serum biochemical metabolites during the preweaning period. Calves had free access to calf starter and clean water from d 6 until weaning. The treatments were the control (CON; without additive) and IMPE at 4, 8, and 12 mL/d. The treatments had no significant effect on total dry matter intake, weight gain, and BW at weaning. The incidence of diarrhea was lower in calves fed 8 mL of IMPE/d compared with CON. At weaning, body measurements (except for front leg circumference) were not affected by IMPE treatment. Relative to the CON group, front leg circumference was significantly decreased by IMPE supplementation. Serum IgG concentration was not significantly increased by IMPE supplementation compared with the CON group. Triglyceride concentration decreased in calves receiving 4, 8, and 12 mL/d of IMPE compared with the CON groups. In contrast to the CON group, serum albumin and total serum protein concentrations increased with IMPE supplementation. Calves receiving 4 mL/d of IMPE had a greater abundance of total bacteria, Ruminococcus albus, Ruminococcus flavefaciens, and Fibrobacter succinogenes compared with the other treatments. Molar proportions of acetate increased in calves fed IMPE (at 12 mL/d) compared with calves fed CON. Ruminal N-NH3 concentrations decreased linearly with the increase in IMPE supplementation. The results of the present study suggest that the addition of IMPE to milk may improve some health and immunity conditions, blood metabolite concentrations, and increase the abundance of some cellulolytic bacteria in the rumen of Holstein dairy calves. The use of IMPE may be an alternative to feeding antibiotics at subtherapeutic concentrations to improve calf health and immunity status.

Effects of rumen-protected leucine on production performance and starch digestion in the small intestine of lactating goats

This study was conducted to evaluate the effects of rumen-protected leucine (RP-Leu) on production performance and starch digestion in the small intestine of lactating goats. Thirty lactating goats (body weight: 43.07 ± 5.06 kg; first parity, day in milk: 135 ± 15 days; milk yield: 2.06 ± 0.44 kg/d) were randomly assigned into one of the following dietary treatments: (1) CON: basal diet and (2) RPL: basal diet + 10.6 g/d RP-Leu. The experiment lasted 65 days, 15 days for adaption, 45 days for treatment, and 5 days for measurement. Goats fed the diet supplemented with RP-Leu had higher (P < 0.05) average daily gain than those fed the CON diet, but no significant difference (P > 0.05) was observed in milk yield and milk composition. The addition of RP-Leu did not affect dry matter intake, apparent total tract digestibility of starch, and rumen fermentation parameters in lactating goats (P > 0.05). The feces of goats fed the diet supplemented with RP-Leu had reduced molar proportion of butyrate and increased pH and molar proportion of acetate compared with that of goats fed the basal diet (P < 0.05). Dietary supplementation of RP-Leu increased the relative abundance of Christensenellaceae, Christensenellaceae_R-7, Ruminococcaceae, and Ruminococcus in feces, while reducing the relative abundance of Lachnospiraceae and Anaerostipes (P < 0.05). Serum low-density lipoprotein and free leucine were greater (P < 0.05) for goats fed the RPL diet than those of goats fed the CON diet. In addition, the concentrations of total cholesterol and high-density lipoprotein in goats fed the RPL diet tended to be higher (0.05 ≤ P < 0.10) than those of goats fed the CON diet. In conclusion, dietary supplementation of RP-Leu probably improved starch digestibility in the small intestine of lactating goats showing as reduced hindgut starch fermentation and unchanged starch intake, apparent total tract digestibility of starch and rumen fermentation parameters.

Effects of Pistacia atlantica gum essential oil on ruminal methanogen, protozoa, selected bacteria species and fermentation characteristics in sheep

The objective of the current research was to investigate the effects of Pistacia atlantica subspecies Kurdica gum essential oil (PAKEO) on ruminal methanogen, protozoa, selected bacteria species, feed intake, and ruminal microbial fermentation in sheep. Six rumen-cannulated male Sanjabi sheep (average BW = 49 ± 2.4 kg) were used in a crossover design with two periods and 2 treatments: control (CON, without additive) and PAKEO (1.2 ml/sheep/day of PAKEO). Voluntary feed intake and ruminal ammonia-N concentration were not affected, but ruminal pH decreased by PAKEO. Total VFA concentration (P = 0.06) and propionate molar proportion (P < 0.05) increased, but acetate molar proportion not affected in PAKEO treatment compared to the CON. Also, PAKEO supplementation decreased the acetate: propionate ratio (P = 0.05). Results showed that PAKEO supplementation increased (P < 0.01) the relative abundance of total bacteria and Ruminococcus flavefaciens, and decreased (P < 0.05) Fibrobacter succinogenes abundance, but not influenced Ruminococcus albus. The ruminal relative population of methanogens was dramatically decreased by PAKEO (P < 0.01). Protozoa population was not affected by the addition of PAKEO. Results suggest that PAKEO could have the potential as feed additives to change the rumen microbial population and subsequently improve the ruminal fermentation characteristics. The decrease in ruminal methanogens and enhanced production of the gluconeogenesis precursor, propionic acid, demonstrated that PAKEO could be used to improve ruminal fermentation.

Evaluating the effect of finely ground, dry-rolled, and crumbled corn grain on performance, feeding behavior, and starch digestion in Holstein dairy heifers

Corn processing methods including finely ground (FGC), dry rolled (DRC), and crumbled corn (CRC) were evaluated to determine their effects on average daily gain (ADG), structural growth, starch digestibility, feeding behavior, and blood metabolites of young dairy heifers. In this study, 36 Holstein heifers [91 ± 4 d of age, 105 ± 6.5 kg of body weight (BW); mean ± standard deviation] housed in 9 pens (4 heifers per pen) were fed diets (dry matter basis) containing 20% forage (wheat straw) and 80% corn-based concentrate for 60 d. Pens were randomly assigned to 1 of 3 dietary treatments based on the type of corn grain used for the diets: (1) ground corn (FGC; fine: 1.11 ± 0.52 mm); (2) dry-rolled corn (DRC; 2.30 ± 0.68 mm); and (3) crumbled corn (CRC; 2.54 ± 0.70 mm). Heifers had ad libitum access to diets and water throughout the experiment and the feed intake was measured daily. Animals were weighed at the beginning (91 d of age) and end (151 d of age) of the study. The ADG (kg of BW/d) was calculated at the end of experiment at an individual level. Feeding behavior was recorded based on direct observation by monitoring each heifer every 5 min during a 22-h period at 150 d of age. The CRC and DRC tended to increase feed intake compared with FGC, whereas heifers fed CRC tended to have a greater withers height compared with other treatments. Feed efficiency was not affected; however, ADG and final BW increased in heifers fed the CRC diet compared with other diets. Feeding CRC increased total-tract starch digestibility compared with FGC and DRC diets (97.8 vs. 93.1 and 89.5%, respectively). Compared with FGC diet, feeding DRC and CRC tended to increase rumination time. The molar proportion of propionate was greater, and the molar proportion of acetate and acetate-to-propionate ratio were lower in heifers fed CRC than in those fed DRC. The blood glucose and insulin-like growth factor concentrations increased in heifers fed CRC compared with feeding DRC; however, blood urea concentrations decreased by CRC feeding. In conclusion, thermal processing (CRC diet) improved total-tract starch digestibility, ADG, feed intake, and skeletal growth, but had no effect on feed efficiency during the experimental period. Our results indicated that the thermal processing of corn grain improved growth performance of weaned heifers; however, the performance of heifers over a 60-d period did not differ between mechanical processing methods (grinding and dry rolling).

Synchronization of rumen degradable protein with non-fiber carbohydrate on microbial protein synthesis and dairy ration digestibility.

Background and Aim:Dairy ration formulations should consider the synchronization of the rumen degradable protein (RDP) to rumen undegradable protein (RUP) ratio (RDPR) with non-fiber carbohydrate (NFC) to achieve optimum microbial protein synthesis (MPS), reduce feed costs, and reduce N excretion to the environment. This study aimed to investigate the effect of RDPR and NFC synchronization on in vitro digestibility, fermentability, and MPS.Materials and Methods:The experiment used a 3×3 factorial randomized block design with four replications. The first factor was RDPR (RDPR1=50:50; RDPR2=55:45; RDPR3=60:40) and the second factor was NFC levels (NFC1=30%, NFC2=35%, NFC3=40%). The experimental diets were evaluated using a two-stage in vitro method. The examined parameters included rumen pH, NH3 concentration, total volatile fatty acid (VFA) concentration, the molar proportion of VFAs, rumen microbes (protozoa and total bacteria population), and MPS. Data were analyzed using ANOVA, followed by the Duncan test.Results:The results show that neither RDPR nor NFC affected rumen pH, NH3, total VFA, and the rumen microbe population. The interaction between RDPR and NFC affected the molar proportion of acetate, iso-butyrate, and n-valerate. The combination of RDPR1 and NFC1 produced a lower molar proportion of acetate (49.73%) than the other treatment combinations (>54%). The acetate to propionate ratio was influenced by the NFC levels, in which NFC2 and NFC3 produced the highest ratio (p<0.05). MPS was affected by RDPR and NFC, but not by their interaction. Treatments NFC2 and RDPR3 produced the highest MPS. NFC affected the dry matter and organic matter digestibility (DMD and OMD), with treatment NFC3 resulting in the highest DMD and OMD.Conclusion:The combination of a 60:40 RDPR with 35% NFC resulted in the best synchronization of protein and energy available for MPS and digestion activity in the rumen.

Effects of Dietary Barley Starch Contents on the Performance, Nutrient Digestion, Rumen Fermentation, and Bacterial Community of Fattening Hu Sheep.

The objective of this experiment was to investigate the effects of substituting corn starch (CS) with barley starch (BS) on the growth performance, nutrient digestion, rumen fermentation, and bacterial community of fattening Hu sheep. Seventy-two Hu lambs with similar initial body weight (BW, 29.70 ± 1.70 kg) were randomly assigned to four treatments, with 18 lambs per group. The four experimental diets have identical starch contents but with different starch sources as 100% starch from corn (BS-0), 33% starch from barley and 67% starch from corn (BS-33), 67% starch form barley and 33% starch from corn (BS-67), and 100% starch from barley (BS-100). All lambs were reared in individual units and fed high-concentrate diets (85% concentrate in diets based on dry matter [DM]). The experimental period included 7 days for adaptation and 63 days for data collection. Sixteen ruminal cannulated Hu sheep were divided into 4 groups and received the four experimental diets to determine the dynamics of ruminal pH. The average daily gain (ADG), and BW gain of lambs linearly decreased (p < 0.05), whereas the feed to gain ratio linearly increased (p < 0.05) with increasing dietary proportions of BS. Digestibility of DM, organic matter, neutral detergent fiber, acid detergent fiber, starch, and gross energy (GE) decreased (p < 0.05) with increasing dietary BS contents. Ruminal mean pH decreased (p < 0.05) with increasing proportions of dietary BS, accompanied with linearly increased (p < 0.05) time and area of ruminal pH below 5.80 or 5.60. Increasing dietary proportions of BS linearly decreased (p < 0.05) the molar proportion of acetate, but linearly increased (p < 0.05) the molar proportion of propionate. Sheep of the BS-0 and BS-33 treatments had a less (p < 0.05) relative abundance of Selenomonas ruminantium than that of sheep of the BS-67 treatment, but a greater (p < 0.05) relative abundance of Ruminococcus albus than that of sheep of the BS-100 treatment (p < 0.05). In conclusion, feeding a high-concentrate corn-based diet for fattening Hu sheep improved the performance and rumen fermentation parameters when compared to the barley-based diet.

In vitro feed fermentation with the rumen liquor of buffaloes fed on diet supplemented with phyto-feed additives

A study on in vitro feed fermentation with the rumen liquor of the buffaloes (12–15 months of age with average body weight 164±4.0kg) supplemented phyto-feed additives (FAs) was conducted to evaluate the long term feeding of the additives for its sustainability of inhibiting methane production. Monthly (for 6 months) in vitro experiments were performed using the rumen liquor of buffalo calves fed on diet supplemented with no additive (T0 control), with FA I (blend of garlic bulb, ajwain seed, harad seed pulp and soapnut berries mixed in 1:1:1:1 ratio) @ 1% of DMI (T1), with FA II (ajwain oil) @ 1ml of per kg dry matter intake (T2) and with FA I and FA II switched alternatively after every 15 days (T3). There was reduction (P<0.05) in total gas and methane production irrespective of the period and this inhibition was maximum (22.2 and 46.56 percent) with the rumen liquor of T3 group. There were no effects of feed additives on in vitro true digestibility, total volatile fatty acids and molar proportion of acetate, propionate, butyrate, A:P ratio and ammonia-N at any period. However, significant increase was noticed in partitioning factor in T3 treatment. Alternate supplementation of the two feed additives had no additional advantage. Further, the results revealed that the feed additives did not lose their anti-methanogenic characteristic as there was methane inhibition till the end of the experiment.

Dried distiller´s grains plus solubles supplementation improves low-quality tropical grass utilization on beef steers

ABSTRACT: This study was designed to evaluate the effect of corn dried distiller´s grains (DDGS) supplementation on feed intake, total tract digestibility, and ruminal fermentation of beef steers fed low-quality Guinea grass (Megathyrsus maximus, cv. Gatton panic). Twelve Braford crossbred steers were housed in individual pens (n = 4 steers/treatment), provided with three levels of DDGS supplement: 0%, 0.6%, or 1.2% BW. Steers were blocked by live weight and randomly assigned to treatments within the block. Corn DDGS supplementation increased total OM intake (21.55, 40.23, and 56.69 g/kg BW0.75) and tract OM digestibility (46.33, 49.03, and 72.39 % DM). Total tract digestible OM, CP, NDF and EE intake also increase in response to DDGS supplementation. Forage OM intake decreased when supplementation level reached 1.2 % BW. Also, ruminal pH decreased with DDGS supplementation level (6.88, 6.47, and 6.27). No differences were observed in total volatile fatty acids (VFA) concentration; however, the molar proportion of acetate decreased (77.98, 73.90, and 67.29 % Total VFA) as well as acetate: propionate ratio (4.38, 3.48, and 2.74). On the contrary, propionate proportions increased (18.32, 21.86, and 24.81 % Total VFA). Levels of ammonia and lactate were within suggested values for optimal fermentation and bacterial growth. Low-quality grass supplementation with corn DDGS increased total OM intake and digestibility. Also, DDGS inclusion favorably altered volatile fatty acids profile by reducing the acetate to propionate ratio regarding forage-only diets.

Effects of partially replacing dietary corn with molasses, condensed whey permeate, or treated condensed whey permeate on ruminal microbial fermentation

Corn is a feedstuff commonly fed to dairy cows as a source of energy. The objective of this study was to evaluate whether partially replacing dietary corn with molasses or condensed whey permeate, in lactating dairy cow diets in a dual-flow continuous culture system, can maintain nutrient digestibility by ruminal microorganisms. Furthermore, this study evaluated whether treating condensed whey permeate before feeding could aid the fermentation of the condensed whey permeate in the rumen. Eight fermentors were used in a 4 × 4 replicated Latin square with 4 periods of 10 d each. The control diet (CON) was formulated with corn grain, and the other diets were formulated by replacing corn grain with either sugarcane molasses (MOL), condensed whey permeate (CWP), or treated condensed whey permeate (TCWP). Diets were formulated by replacing 4% of the diet dry matter (DM) in the form of starch from corn with sugars from the byproducts. Sugars were defined as water-soluble carbohydrates (WSC) in the rations. The fermentors were fed 52 g of DM twice daily of diets containing 17% crude protein, 28% neutral detergent fiber, and 45% nonfiber carbohydrates. Liquid treatments were pipetted into each fermentor. After 7 d of adaptation, samples were collected for analyses of volatile fatty acids (VFA), lactate, and ammonia, and fermentors' pH were measured at time points after the morning feeding for 3 d. Pooled samples from effluent containers were collected for similar analyses, nutrient flow, and N metabolism. Data were statistically analyzed using Proc MIXED of SAS version 9.4 (SAS Institute Inc.); fixed effects included treatment and time, and random effects included fermentor, period, and square. The interaction of treatment and time was included for the kinetics samples. The TCWP and MOL treatments maintained greater fermentor pH compared with CWP. Total VFA concentration was increased in CWP compared with MOL. The acetate:propionate ratio was increased in TCWP compared with CON, due to tendencies of increased acetate molar proportion and decreased propionate molar proportion in TCWP. Lactate concentration was increased in MOL. Digestibility of WSC was increased in the diets that replaced corn with byproducts. The partial replacement of 4% of DM from corn starch with the sugars in byproducts had minimal effects on ruminal microbial fermentation and increased pH. Treated CWP had similar effects to molasses.

Increasing dietary crude protein levels attenuates the effects of caecotrope deprivation in growing rabbits

The effect of caecotrope deprivation on growth, caecal metabolism and Volatile Fatty acid (VFA) production was studied in rabbits fed varying levels of dietary protein during a 42-days feeding trial. Fourty-eight mixed breed rabbits (average initial weight = 875±25 g) were divided into two groups viz; caecotrope consuming (CC) and caecotrope-deprived (CD) groups. Rabbits in the 2 groups were divided equally and assigned to 3 diets containing different crude protein (CP) levels (12, 15 and 18%) in a 2 × 3 factorial arrangement. The result revealed that increasing dietary CP improved (P&lt;0.05) the proximate composition of the caecotrope. The live weight, weight gain, feed conversion ratio, nitrogen utilization and VFA production in CD rabbits fed diets containing 18% CP were comparable (P&lt;0.05) with those of CC fed diets with 15% CP. Nitrogen utilization increased (P&lt;0.05) following increasing dietary crude protein level. Molar proportions of acetate, butyrate, and propionate were higher (P&lt;0.05) in CC rabbit compared to CD. Lactobaccilus acidophilus was isolated from the caecum of CC rabbits. It was concluded that caecotrope deprivation has detrimental effect on growth, nitrogen metabolism, VFA production and caecal bacteria and this effect can be attenuated by increasing the dietary protein level in growing rabbits.

Amla (Phyllanthus emblica) fresh fruit as new feed source to enhance ruminal fermentation and milk production in lactating dairy cows

This study sought to determine the effect of feeding three levels of the novel feedstuff fresh Phyllanthus emblica (amla) fruit on nutrient digestibility, fermentation parameters, and milk production of lactating dairy cows. Eight ruminally cannulated mid-lactation dairy cows were randomly assigned to two treatment groups in a repeated crossover design. There was a 14-d adaptation phase followed by the start of period 1. In this period, the first group of 4 cows received the control diet, whereas the other group was supplemented with FAF at increasing levels (200, 400, 600 g/d), sequentially, at 14-d intervals. Each period consisted of a cow as the main plot, with three different amla doses representing subplots. In period 2, the control and supplemented groups were exchanged. For each sub-period, the first ten days were adjusted for diet adaptation, and the last four days were assigned to sample milk, feed, rumen, and feces. Supplementation of FAF had no effect (P = 0.92) on feed intake. While, the lowest (P < 0.01) rumen protozoa count was recorded at 400 g/d FAF dose compared to other groups. However, total VFA concentrations varied in a quadratic manner (P = 0.04) with increasing FAF doses. The molar proportion of acetate (P = 0.01) and propionate (P < 0.01) were altered (cubic effect). The effects of FAF supplementation on NH3-N concentration (P < 0.001) were dose-dependent, with the concentration decreasing by 54.9% at 200 g/d and increasing by 29.8% at 600 g/d when compared to controls. There was a quadratic effect of FAF on milk yield (P = 0.02), with the 200 and 400 g/d groups producing higher milk yields than the 600 g/d groups. The inclusion of 400 g/d FAF in the diet led to greater milk protein yield (P < 0.01) and milk nitrogen efficiency (P < 0.01) compared to cows fed 200 g/d FAF. Moreover, the concentration of milk urea nitrogen (MUN) was reduced (P < 0.001) with 200 or 400 g/d FAF supplementation compared with control or 600 g/d FAF. When cows were supplemented with a 400 g/d FAF dose, both ruminal protozoa counts and MUN were reduced, but milk protein and nitrogen efficiency were increased with no reduction in milk production. These results suggest that FAF can be used as an alternative natural feed source up to 400 g/d on an as-fed basis, but beyond that there may have anti-nutritional factors that limit the levels of amla supplementation.

Effect of Whole or Ground Flaxseed Supplementation on Fatty Acid Profile, Fermentation, and Bacterial Composition in Rumen of Dairy Cows.

Flaxseed is rich in α-linolenic acid (ALA) and can increase omega-3 polyunsaturated fatty acid in the milk of dairy cows. However, the response of rumen fermentation to different forms of flaxseed supplementation is unknown. This study aimed to investigate the effect of different forms of flaxseed on the fatty acid profile, fermentation, and composition of bacteria in the rumen of dairy cows. In total, 30 Holstein dairy cows were selected and randomly assigned into three groups (10/group). Cows were fed a basal diet (control check; CK) or basal diets supplemented with either 1,500 g per day whole flaxseed (WF) or 1,500 g per day ground flaxseed (GF). The WF group had the highest ALA content in rumen fluid, whereas no difference was found between the CK and GF groups. However, the molar proportion of acetate increased in the WF and GF groups and was the highest in the GF group, and a similar trend was shown by propionate, isobutyrate, butyrate, isovalerate, and valerate (CK < WF < GF). The abundance of Ruminococcaceae_NK4A214_group, Christensenellaceae_R-7_group, and Eubacterium_coprostanoligenes_group also showed the same trend (CK < WF < GF). Different forms of flaxseed release ALA by different mechanisms in the rumen, and the molar proportions of volatile fatty acids and the bacterial composition were potentially influenced mainly by the amount of ALA released into the rumen.

Effects of Dietary Supplementation With Clostridium butyricum on the Amelioration of Growth Performance, Rumen Fermentation, and Rumen Microbiota of Holstein Heifers.

In China, the use of antibiotics growth promoters as feed additives has been banned. The goal of raising dairy heifers is to gain a relatively high body weight on a high-fiber diet at first mating or calving, thus increasing economic benefits. The objective of this experiment was to explore the effects of supplemental Clostridium butyricum (C. butyricum) on growth performance, rumen fermentation and microbiota, and blood parameters in Holstein heifers. Twenty Holstein heifers [mean ± standard deviation (SD); age = 182 ± 4.20 d, body weight = 197.53 ± 5.94 kg, dry matter intake (DMI) = 6.10 ± 0.38 kg] were randomly assigned to one of two diets group for a 42-day feeding period: (1) basal diet (an untreated control group, i.e., the CON group) or (2) basal diet plus daily 2 × 108 (colony-forming unit, CFU) of C. butyricum per kg of DMI per heifer (the CB group). The results demonstrated that C. butyricum supplementation increased the average daily gain from d 21 to 42 and DMI compared to the control group. Supplementation with C. butyricum significantly decreased the molar proportion of acetate and the acetate to propionate ratio but increased the molar proportion of butyrate and propionate. Compared with the control group, the relative abundance of Butyrivibrio fibrisolvens, Ruminococcus albus, Ruminobacter amylophilus, Ruminococcus flavefaciens, and Streptococcus bovis increased during the trial period in the CB group. However, C. butyricum had no significant effect on the blood parameters in Holstein heifers. In conclusion, these results show that feeding C. butyricum can improve growth performance and rumen fermentation without any negative impact on blood parameters in Holstein heifers.

Changes in Carbohydrate Composition in Fermented Total Mixed Ration and Its Effects on in vitro Methane Production and Microbiome.

The purpose of this experiment was to investigate the changes of carbohydrate composition in fermented total mixed diet and its effects on rumen fermentation, methane production, and rumen microbiome in vitro. The concentrate-to-forage ratio of the total mixed ration (TMR) was 4:6, and TMR was ensiled with lactic acid bacteria and fibrolytic enzymes. The results showed that different TMRs had different carbohydrate compositions and subfractions, fermentation characteristics, and bacterial community diversity. After fermentation, the fermented total mixed ration (FTMR) group had lower contents of neutral detergent fiber, acid detergent fiber, starch, non-fibrous carbohydrates, and carbohydrates. In addition, lactic acid content and relative abundance of Lactobacillus in the FTMR group were higher. Compared with the TMR group, the in vitro ammonia nitrogen and total volatile fatty acid concentrations and the molar proportion of propionate and butyrate were increased in the FTMR group. However, the ruminal pH, molar proportion of acetate, and methane production were significantly decreased in the FTMR group. Notably, we found that the relative abundance of ruminal bacteria was higher in FTMR than in TMR samples, including Prevotella, Coprococcus, and Oscillospira. At the same time, we found that the diversity of methanogens in the FTMR group was lower than that in the TMR group. The relative abundance of Methanobrevibacter significantly decreased, while the relative abundances of Methanoplanus and vadinCA11 increased. The relative abundances of Entodinium and Pichia significantly decreased in the FTMR group compared with the TMR group. These results suggest that FTMR can be used as an environmentally cleaner technology in animal farming due to its ability to improve ruminal fermentation, modulate the rumen microbiome, and reduce methane emissions.

Tannic Acid-Steeped Corn Grain Modulates in vitro Ruminal Fermentation Pattern and Microbial Metabolic Pathways.

This study investigated the effects of tannic acid (TA)-treated corn on changes in ruminal fermentation characteristics and the composition of the ruminal bacterial community in vitro. Ruminal fluid was obtained from three rumen-fistulated goats fed a 60:40 (forage/concentrate) diet. The batch cultures consisted of 25 ml of strained rumen fluid in 25 ml of an anaerobic buffer containing 0.56 g of ground corn, 0.24 g of soybean meal, 0.10 g of alfalfa, and 0.10 g of oat grass. Ground corn (2 mm) was steeped in an equal quantity (i.e., in a ratio of 1:1, w/v) of water alone (Con), 15 (TA15), 25 (TA25), and 35 g/l (TA35) TA solution for 12 h. After incubation for 24 h, TA-treated corn linearly increased (P <0.05) ruminal pH and the molar proportion of acetate, but linearly reduced (P <0.05) total volatile fatty acids and the molar proportion of butyrate compared with the Con treatment. Illumina MiSeq sequencing was used to investigate the profile changes of the ruminal microbes. A principal coordinates analysis plot based on weighted UniFrac values revealed that the structure of the ruminal bacterial communities in the control group was different from that of the TA-treated corn groups. The results of changes in the rumen bacterial communities showed that TA-treated corn linearly enriched (P <0.05) Rikenellaceae_RC9_gut_group, but linearly reduced (P <0.05) Ruminococcaceae_NK4A214_group, Ruminococcus_2, and unclassified_o__Clostridiales. Functional prediction of ruminal microbiota revealed that the TA-treated corn linearly decreased ruminal microbiota function of utilizing starch through pyruvate metabolism. In conclusion, TA-treated corn can modulate the rumen fermentation characteristics, microbial composition, and metabolic pathways, which may be potentially useful for preventing the occurrence of ruminal acidosis.

Modified Nano-Montmorillonite and Monensin Modulate In Vitro Ruminal Fermentation, Nutrient Degradability, and Methanogenesis Differently.

Simple SummaryNatural montmorillonite (NM) is the most common clay used as a feed additive in ruminant diets. Under normal pH conditions, it can adsorb hydrogen and may affect methane (CH4) formation; however, it possesses less efficiency than other clays. Due to NM’s negative charge flat surface and positive charge edges, its physicochemical properties can be modified by cationic or anionic surfactants. Therefore, two types of modified nano-montmorillonite (MNM) were developed by ion-exchange reactions using cationic and anionic surfactants. Comparisons were made with monensin as a rumen modulator to reduce CH4 emission from ruminants. The results indicated that the physicochemical properties of both MNM types were enhanced (e.g., cation-exchange capacity and zeta potential). All MNM clays and monensin successfully reduced rumen CH4 production and ammonia concentration; however, clay modified by cationic surfactant was more efficient than what was modified by anionic surfactant in modulating in vitro rumen fermentation propertiesTwo types of modified nano-montmorillonite (MNM) were developed by ion-exchange reactions using two different surfactants; sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CETAB), to prepare MNMSDS and MNMCETAB, respectively. Both MNM types were on the nano-scale and had higher cation-exchange capacity values than NM clay. The MNMCETAB had the highest zeta potential (−27 mV) compared with the other clays. Effects of MNM types on in vitro ruminal batch culture fermentation, nutrient degradability, and methane (CH4) emission compared with monensin were evaluated in vitro using a semi-automatic gas production system. The experimental treatments were the control (0 supplementations), monensin (40 mg/kg DM), and NM (5 g NM/kg DM), and two levels of MNMSDS and MNMCETAB were supplemented at 0.05 (low) and 0.5 (high) g/kg DM to the control basal feed substrate. Among the experimental treatments, the high dose of both MNM types reduced (p < 0.01) CH4 production and ammonia concentrations compared with the control, while only MNMCETAB treatment tended to increase (p = 0.08) the truly degraded organic matter compared with monensin. All MNM treatments increased (p < 0.01) acetate molar proportions compared with monensin. The high MNMCETAB increased (p < 0.01) the in vitro ruminal batch culture pH compared with the control and monensin. The MNMCETAB supplemented at 0.5 g/kg DM is the most efficient additive to reduce CH4 emission with the advantage of enhancing the in vitro nutrient degradability of the experimental feed substrate. These results indicated that MNM could modulate the in vitro ruminal fermentation pattern in a dose- and type-dependent manner.

Long-Term Mootral Application Impacts Methane Production and the Microbial Community in the Rumen Simulation Technique System.

Methane emissions by ruminants contribute to global warming and result in a loss of dietary energy for the animals. One possibility of reducing methane emissions is by dietary strategies. In the present trial, we investigated the long-term effects of Mootral, a feed additive consisting of garlic powder (Allium sativum) and bitter orange extracts (Citrus aurantium), on fermentation parameters and the microbial community in the rumen simulation technique (RUSITEC) system. The experiment lasted 38 days and was divided into three phases: an equilibration period of 7 days, a baseline period (BL) of 3 days, and experimental period (EP) of 28 days. Twelve fermentation vessels were divided into three groups (n = 4): control (CON), short-term (ST), and long-term (LT) application. From day 11 to day 27, 1.7 g of Mootral was added to the ST vessels; LT vessels received 1.7 g of Mootral daily for the entire EP. With the onset of Mootral application, methane production was significantly reduced in both groups until day 18. Thereafter, the production rate returned to the initial quantity. Furthermore, the short chain fatty acid fermentation profile was significantly altered by Mootral application; the molar proportion of acetate decreased, while the proportions of propionate and butyrate increased. Metabolomic analysis revealed further changes in metabolite concentrations associated with the Mootral supplementation period. The methyl coenzyme-M reductase gene copy number was reduced in the liquid and solid phase, whereas the treatment did not affect the abundance of bacteria. At the end of the BL, Methanomicrobia was the most abundant archaeal class. Mootral supplementation induced an increase in the relative abundance of Methanomassiliicoccales and a reduction in the relative abundance of Methanomicrobia, however, this effect was transient. Abundances of bacterial families were only marginally altered by the treatment. In conclusion, Mootral has the transient ability to reduce methane production significantly due to a selective effect on archaea numbers and archaeal community composition with little effect on the bacterial community.

Meta-analysis of the effects of dietary inclusion of sericea lespedeza (Lespedeza cuneata) forage on performance, digestibility, and rumen fermentation of small ruminants

For more than 20 years, the nutraceutical forage sericea lespedeza ‘AU-grazer’ (SL; Lespedeza cuneata) has been used as an alternative to anthelmintic drugs for controlling gastrointestinal parasites in small ruminants, but with little attention to animal performance. Thus, the objective of this study was to evaluate the effects of dietary inclusion of SL on performance, digestibility, and rumen fermentation of small ruminants using a meta-analytic approach. A total of 24 peer-reviewed manuscripts (sheep = 6 and goats = 18) from 2000 to 2020 met the inclusion criteria for the analysis. Raw mean differences between dietary SL and control treatments weighted by inversed variance were compared with a robust variance estimation. Diet characteristics like crude protein content, NDF content, condensed tannin (CT) content, and inclusion level of SL in the diet (0% to 100%) were used as covariates in a metaregression and subgrouping analysis. Compared to the control, dietary inclusion of SL decreased (P < 0.05) total-tract digestibility by 12% (DMD) and average daily gain (ADG) by 17.7%, but no effects were observed in dry matter intake. Likewise, dietary SL reduced (P < 0.05) molar proportion of acetate (68.88 vs 71.8%), but increased butyrate (10.3 vs 9.2%) and propionate (17.9 vs 16.8%) molar proportions in the rumen. Consequently, dietary SL reduced CH4 emissions by 38% compared to the control. Despite the high heterogeneity in the response variables (I2 > 50), no significant bias was detected (funnel test; P > 0.05). The dose-response analysis revealed that SL-based diets should not include more than 60% in the diet to prevent negative effects in DMD and ADG. Likewise, low inclusion level of SL in the diet (from 30 to 40%) linearly increased propionate concentrations in the rumen but reduced CH4 emissions. In addition to the nutraceutical benefits of this forage, SL inclusion improved rumen fermentation (increased propionate, reduced CH4) at low rates of inclusion, but reduced ADG in small ruminants at higher rates, with these effects minimized if dietary inclusion rate for SL is 60% or less. Further research is needed to determine the optimum inclusion rate to balance nutritional and pharmaceutical effects of SL in the diet of small ruminants.