Ruminal Fermentation Parameters Research Articles

Effects of Different Technological Forms of the Perilla frutescens in the Diet on Ruminal Fermentation, Milk and Plasma Fatty Acid Composition, Ruminal Biohydrogenation and Milk Quality in Dairy Goats.

Fatty acids can be protected by changing their structure or form against microbial activity, and the different forms of fatty acids can modulate the ruminal biohydrogenation rate and contribute to the desired fatty acid profile in milk fat. The study investigated the effects of perilla (Perilla frutescens) dietary supplementation in the diet in different technological forms (seed, oil and formaldehyde-treated oil) on milk, plasma and ruminal fatty acid composition, and milk quality in lactating goats. The four dietary treatments consisted of (1) no supplementation, basal diet (CON); (2) perilla supplementation as seed at 44.7g/kg (consisting of 20g/kg oil (PS)); (3) perilla supplementation as oil at 20g/kg (PO); (4) perilla supplementation as formaldehyde treated oil at 20g/kg (protected perilla oil [PPO]). The experiment was implemented in a double 4×4 Latin square trial design, and sampling was carried out for 7 days after 21 days of adaptation. Performance parameters were not affected by P. frutescens supplementation to the diet. PO decreased milk fat, whereas PPO increased milk fat. Milk cholesterol was not affected by P. frutescens dietary supplementation. Perilla oil supplementation in different forms to the diet did not affect ruminal pH, VFA and methane production. Perilla oil supplementation in different forms to the diet did not also affect the concentration of blood serum glucose, cholesterol and non-esterified fatty acids. Perilla supplementation to the diet increased the milk conjugated linoleic acid (CLA), C18:3n-3, C22:5n-3, C20:5n-3, C22:6n-3 and polyunsaturated fatty acid (PUFA) concentrations, and PPO group showed the greatest values. Ruminal palmitic (C16:0) acid was decreased, and in perilla groups, stearic acid (C18:0) concentration had the lowest, and ruminal c-9, t-11 CLA concentration had the highest value in PPO. It has been found that the most effective form of perilla oil in increasing milk quality is that with formaldehyde treatment (protected form). Perilla oil, which is a rich source of omega 3 in the diet, can be used to increase milk quality in goats without adversely affecting performance, ruminal fermentation and blood parameters.

Effects of Oregano on Lactation Performance, Nutrient Digestibility, Ruminal Fermentation Parameters, and Methane Emissions in Dairy Cows: A Meta-Analysis

Growing concerns regarding antibiotic use in livestock, due to antibiotic resistance and potential human transmission, have led to increased interest in herbs and their derivatives, including essential oils, which possess antimicrobial properties that may enhance overall productivity and serve as a strategy for methane mitigation. The objective of this meta-analysis was to investigate the effects of adding oregano to the diet in different forms (essential oils, plant materials, or leaves) on the dry matter intake (DMI), milk yield (MY), milk components, nutrient digestibility, ruminal fermentation parameters, and methane (CH4) emissions of dairy cows. A literature search was conducted to identify papers published from 2000 to 2023. Effect size for all outcomes was reported as a standardized means difference (SMD) and raw means difference with 95% confidence intervals. Heterogeneity was determined using the Q test and I2 statistic. The results of the meta-analysis indicated that adding oregano had no effect on DMI (SMD = 0.081; p = 0.507) and MY (SMD = 0.060; p = 0.665). Milk fat percentage, milk protein percentage, and milk lactose percentage were not affected by oregano. The addition of oregano to the diet significantly decreased dry matter digestibility (SMD = −0.502; p = 0.013), crude protein digestibility (SMD = −0.374; p = 0.040), and neutral detergent fiber digestibility (SMD = −0.505; p = 0.014). Ruminal pH (SMD = −0.122; p = 0.411), total volatile fatty acids concentration (SMD = −0.038; p = 0.798), acetate (SMD = −0.046; p = 0.757), propionate (SMD = 0.007; p = 0.960), and butyrate (SMD = 0.037; p = 0.801) proportion were not affected by oregano. The addition of oregano to the diet tended to decrease CH4/DMI (SMD = −0.275; p = 0.095) but did not affect CH4 production (SMD = −0.156; p = 0.282). Heterogeneity (Q and I2) was non-significant for all parameters. We conclude that the inclusion of oregano in various forms (essential oils, plant materials, or leaves) in the diet of dairy cows reduces nutrient digestibility but does not significantly affect DMI, MY, milk components, ruminal fermentation parameters, or CH4 production. Future research should focus on optimizing the dosage of oregano (both EOs and plant materials) and exploring the impact of its form on lactation, nutrient digestibility, ruminal fermentation, and CH4 emissions in dairy cows.

The effect of increasing canola oil and soybean oil addition to beef cattle rations based on corn silage and barley grain on the in vitro ruminal gas production and rumen fermentation

AbstractThe purpose of the current experiment was to determine the effects of ruminal fermentation parameters of the additions of canola or soybean oils at different rates (4, 8 and 12%) to beef cattle total mix rations (TMR), based on corn silage and barley grain. The addition of 4% soybean oil to TMR positively affected in vitro gas production, net energy lactation (NEL), metabolic energy (ME), and organic matter digestion (OMd). The additions of 8% and 12% of soybean oil to TMR linearly decreased ME, NEL and OMd (p < 0.05). The additions of 4, 8 and 12% canola oil to the TMR linearly decreased the in vitro gas production and estimated fermentation values (ME, NEL and OMd) (p < 0.05). All doses of soybean or canola oils in TMR reduced the molarities of total short‐chain fatty acids (tSFCA), acetic (AA), butyric (BA), propionic (PA), valeric (VA), iso‐valeric (IVA) and iso‐butyric acids (IBA) for in vitro fermentation fluid (p < 0.05). There was a negative correlation between the increasing dietary stearic, oleic and linoleic acid and the end‐products of in vitro rumen fermentation. However, increasing dietary α‐linolenic acids had no adverse effect on in vitro ruminal fermentation end‐products. As a result, 4% addition of the soybean oil, which included a higher rate of α‐linolenic acid and saturated fatty acids and a lower rate of oleic, linoleic acids according to those of canola oil, to the TMR positively affected in vitro ruminal fermentation. In addition, the ≥8% addition of canola or soybean oil adversely affected the in vitro fermentation values.

Effect of Replacing Corn Grain and Soybean Meal with Field Peas at Different Levels on Feed Intake, Milk Production, and Metabolism in Dairy Cows under a Restrictive Grazing.

This study assessed the effects of replacing soybean meal (SBM) and corn grain with field peas in the concentrate of grazing dairy cows on milk production, intake, ruminal fermentation, and blood indicators. Twelve multiparous lactating Holstein-Friesian cows were utilized in a replicated 3 × 3 Latin square design, comprising three periods and three treatments: (1) Pea-0 (Control diet): 6 kg dry matter (DM) of fresh pasture, 7.2 kg DM of grass silage, and 7 kg DM of a concentrate containing 0% pea; (2) Pea-30: Control diet with the concentrate composed of 30% pea; (3) Pea-60: Control diet with the concentrate composed of 60% pea. The effect of treatments on productive and metabolic parameters was evaluated using linear-mixed models. Pasture and total DM intake, milk production, and composition were unaffected by treatments. Despite the concentrates being isonitrogenous and isoenergetic, crude protein (CP) intake was slightly higher in Pea-30 and significantly higher in Pea-60 due to higher pasture CP content in the pasture grazed by these groups, leading to higher milk urea content, though within recommended ranges. Blood parameters showed no significant changes, except for plasma β-hydroxybutyrate, which was lowest in the Pea-60 treatment; however, all values were within ranges not indicative of subclinical ketosis. Ruminal fermentation parameters were similar across treatments. These findings support the use of field peas as a viable alternative to replace SBM and corn grain in concentrates, enabling similar milk production and composition in grazing dairy cows.

The Effect of Humic Acid Supplementation on Selected Ruminal Fermentation Parameters and Protozoal Generic Distribution in Cows

The objective of this study was to examine the effect of humic acid (HA) supplementation on the rumen fermentation and protozoal community in the rumen. For this purpose, four ruminally cannulated Simmental cows were randomly assigned in a replicated 4 × 4 Latin square design experiment to study the effect of HA dietary supplementation on feed utilization, rumen fermentation, and protozoal community for 84 days. The basal diet (BD) was composed of meadow hay (68.2% of dry matter [DM]), maize silage (17% of DM), and granulated feed mixture (14.9% of DM). There were four treatments, including the BD without additives (control diet, H0), the BD supplemented with 50 g HA/cow/day (H50 treatment), the BD supplemented with 100 g HA/cow/day (H100 treatment), and the BD supplemented with 200 g HA/cow/day (H200 treatment). HA supplementation did not affect the total or individual volatile fatty acid concentrations, the total protozoa, or the ruminal pH. However, HA at the dosage of 50 g/cow/day increased the NH3-N concentration and fecal nitrogen compared to the control (p < 0.001). HA supplementation also significantly impacted the abundance of individual protozoal genera in the rumen. The results of this study suggest that HA has potential in ruminants as a natural feed additive and may play a role in nitrogen metabolism and stabilizing the protozoal community without adverse effects on rumen fermentation.

PSIX-19 Effect of protein and starch level on N balance and ruminal fermentation parameters in steers consuming low-quality forage: Bos taurus taurus

Abstract Globally cattle convert low-quality forage to beef and milk; therefore, understanding protein utilization in Bos taurus taurus is critical to enhancing sustainability as over and under-supplementation of protein are economically and environmentally costly. Low-quality forage lacks the N necessary for proper utilization and metabolic function. Supplemental protein improves low-quality forage utilization and is expected to increase N absorption and retention. Supplement starch can increase volatile fatty acid (VFA) production and energy supplied to the animal; however, too much starch decreases ruminally available N and pH potentially decreasing fibrolytic activity. Accordingly, our objective was to determine the effect starch supplementation on N balance and ruminal fermentation parameters in Bos taurus steers. Ruminally cannulated Angus steers [n = 5; body weight (BW) = 375 ± 45 kg] were used in a 4 × 4 Latin square to evaluate the effect of decreasing supplemental starch when consuming King Ranch Bluestem hay (3.5% CP, 73% NDF). Steers received four isonitrogenous (130 mg N/kg BW) supplements providing increasing levels of starch (2% starch = 100% soybean meal; 20% starch = 26.3% corn, 73% soybean meal, 0.7% urea; 38% starch = 51.6% corn, 47% soybean meal, 1.4% urea; 56% starch = 78.6% corn, 19% soybean meal, 2.4% urea). Five 14-d periods were conducted, consisting of 9 d adaptation and 4 d to measure intake and digestion, and 1 d for ruminal fermentation. Supplemental N intake decreased linearly (P < 0.01) with increasing starch as the crude protein content of the soybean was underestimated. Forage and total N intake were not affected by starch level (P ≥ 0.17). Fecal and total urinary N excretion were not different between starch levels (P ≥ 0.43). Urinary ammonia-N and urea-N averaged 6.6 and 16.8% of total urinary N excretion, respectively, but no differences between starch levels were observed (P ≥ 0.39). Level of starch supplementation had no effect on N retention and absorption (P ≥ 0.50). There was a treatment × time interaction observed for ruminal ammonia concentration (P < 0.01). All treatments, except 2% starch, peaked at 4 h post feeding, 20 and 38% treatments gradually decreased following four, but the concentration of ruminal ammonia decreased by 80% between 4 h and 8 h after feeding in the 56% starch treatment. Starch level had no effect total VFA concentration, VFA molar proportions, or ruminal pH (P ≥ 0.10). In conclusion, providing supplemental starch did not affect N balance or VFA production when fed to steers consuming low-quality forage. Nitrogen balance and VFA production likely were not affected because all supplements provided sufficient ruminally available N and, therefore, exerted minimal effects on forage utilization.

Effects of protein grass hay as alternative feed resource on lamb's fattening performance and meat quality

Protein grass hay (PGH) was used as a new feed source for lambs to study its effect on fattening performance and meat quality. Fifty-six male lambs were allotted to four experimental groups and fed for eight weeks either alfalfa hay (AH)-based diet (control) or diets in which AH was replaced with 33 %, 66 %, or 99 % PGH. The inclusion of PGH did not affect final body weight, dry matter intake, average daily gain, feed conversion ratio, or carcass weight. Moreover, substituting AH with PGH at any level did not influence the ruminal fermentation or serum biochemical parameters, meat color, water holding capacity, shear force, or amino acid profile. However, relative liver weight was increased with 66 % substitutions. Furthermore, replacing 99 % AH with PGH decreased the meat's pH at 24 h. Higher levels of C18:3n-3, C20:5n-3, and total n-3 PUFA and a lower ratio of n-6: n-3 PUFA were also observed in meat from lambs fed PGH at 99 %. These findings suggest that PGH could be incorporated into the lamb's diet up to 99 % without compromising fattening performance and body health while improving their meat n-3 PUFA deposition.

The Effects of Different Doses of 3-NOP on Ruminal Fermentation Parameters, Methane Production, and the Microbiota of Lambs In Vitro

The Effects of Different Doses of 3-NOP on Ruminal Fermentation Parameters, Methane Production, and the Microbiota of Lambs In Vitro

Effects of Different Starch Sources Used at High Levels in Cattle on Ruminal Fermentation Properties and Some Blood Parameters

In this study, it was aimed to determine the effects of different starch sources on ruminal fermentation and in situ digestibility characteristics and some blood parameters in cows. In the study, three different total mixed rations (TMR) with similar energy, protein and starch contents were prepared and these TMR’s formed the groups of the ex-periment. The main starch sources of the TMR’s were from the barley, wheat, and corn grains, respectively. The study was carried out as two consecutive trails using 3 non-lactating Holstein female cattle with rumen cannulate within a 3 × 3 Latin square trial design. These TMRs were fed at ad libitum and then nutrient intakes, ruminal fermentation (pH, acetic, propionic, butyric, and lactic acids), some serum (urea, glucose, total protein, albumin, triglyceride) and blood gas parameters (pH, pCO2, pO2, HCO3-, Na+, K+, Ca++, Cl-, anion gap, lactate) were determined. Also, in situ dry matter and starch degradability were carried out in these animals. Nutrient intakes of cows fed different TMRs were similar (P>0.05), except neutral detergent fiber (NDF) intake (P<0.05). Both ruminal fermentation, serum and blood gas pa-rameters did not change among treatment groups (P>0.05). As a result, it was determined that there were no serious changes in the ruminal fluid, serum, and blood gas parameter values of the subjects due to the content difference of the trial TMR’s. On the other hand, it was determined that in situ dry matter (DM) and starch degradability of barley and wheat were significantly different among cereal grains, ruminal DM and starch degradability of corn followed a slower, stable, and gradual increase.

Integrating 16S rRNA Sequencing and LC-MS-Based Metabolomics to Evaluate the Effects of Dietary Crude Protein on Ruminal Morphology, Fermentation Parameter and Digestive Enzyme Activity in Tibetan Sheep.

The dietary crude protein level could affect ruminal fermentation parameters and the microflora of ruminants. The present study's aim was to investigate the effects of different protein level diets on ruminal morphology, fermentation parameters, digestive enzyme activity, microflora and metabolites of Tibetan sheep. Ninety weaned lambs (initial weight of 15.40 ± 0.81 kg, 2 months old) were selected and randomly divided into three groups (six pens/treatment, five rams/pen). Dietary treatments were formulated with 13.03% (high protein, HP), 11.58% (moderate protein, MP) and 10.20% (low protein, LP), respectively. Compared with LP, both papillae length and papillae width were significantly promoted in HP and MP (p < 0.05). The concentrations of ammonia nitrogen, total VFAs, propionic acids and butyric acids in HP were significantly increased compared to those in MP and LP (p < 0.05). The activities of protease and α-amylase in HP were significantly greater than those of LP (p < 0.05). For the ruminal microbial community, higher proportions of phylum Prevotella 1 and Succiniclasticum and genus Rikenellaceae RC9 gut group and Ruminococcus 1 were observed in HP (p < 0.05). A total of 60 differential metabolites (DMs) (28 up, 32 down) between HP and MP; 73 DMs (55 up, 18 down) between HP and LP; and 65 DMs (49 up, 16 down) between MP and LP were identified. Furthermore, four pathways of the biosynthesis of unsaturated fatty acids, tryptophan metabolism, bile secretion and ABC transporters were significantly different (p < 0.05). The abundance of phylum Prevotella 1 was negatively associated with stearic acid and palmitic acid but positively associated with the taurine. The abundance of genus Ruminococcus 1 was negatively associated with stearic acid, oleic acid, erucic acid, Indole-3-acetamide and palmitic acid but positively associated with 6-hydroxymelatonin. In conclusion, a 13.03% CP level improved ruminal morphology, fermentation parameters and digestive enzyme activities through modulating the microbial community and regulating metabolism in Tibetan sheep.

Effects of probiotic-supplemented milk replacer on growth, blood biochemistry, fermentation, digestibility, and carcass traits in lambs

The objective of this study was to investigate the effects of feeding cow's milk replacer and probiotic supplementation on growth performance, blood metabolites, ruminal fermentation parameters, and nutrient digestibility in male lambs, with ewe's milk serving as the control treatment. Eighteen male lambs with an average initial body weight of 5.0 ± 1.2 kg and age of 15 ± 4 days were randomly assigned to three experimental groups: ewe's milk, cow's milk replacer, and cow's milk replacer with probiotic supplementation. The experiment was conducted using a completely randomized design. Lambs fed ewe's milk showed significantly higher average daily gain (218.4 g/day) compared to those fed cow's milk replacer (183.7 g/day) or cow's milk replacer with probiotic (209.1 g/day). Similarly, dry matter intake was highest in the ewe's milk group (585.6 g/day) compared to the cow's milk replacer (435.9 g/day) and cow's milk replacer with probiotic (510.5 g/day) groups. Blood glucose levels were higher in the ewe's milk group (75.3 mg/dL) compared to the cow's milk replacer (70.3 mg/dL) and cow's milk replacer with probiotic (72.1 mg/dL) groups. Probiotic supplementation resulted in increased blood urea nitrogen (15.6 mg/dL) and total protein (7.3 g/dL) levels compared to the other groups. Furthermore, the ewe's milk group showed higher apparent dry matter (76.1%) and crude protein (68.5%) digestibility compared to the other treatments. The fecal score on day 30 was higher in the cow's milk replacer group (2.34) compared to the ewe's milk (1.24) and cow's milk replacer with probiotic (1.45) groups. There were no significant differences in the carcass traits of the experimental lambs. In conclusion, based on the results of this study, it seems that feeding cow's milk + probiotic as a replacement for ewe's milk did not significantly affect the performance, carcass traits, and blood and fermentation parameters in infant lambs.

Responses of nutrient utilization, rumen fermentation and microorganisms to different roughage of dairy buffaloes

Dairy buffaloes are typically fed a high-forage, low-quality diet with high fiber. These conditions result in an inherent energy and protein inefficiency. In order to make full and rational use of feed resources and improve the production level and breeding efficiency of dairy buffaloes, the effects of various roughages on nutrient digestibility, ruminal fermentation parameters, and microorganisms in dairy buffaloes were studied in this experiment. Three ternary hybrid buffaloes, with an average body weight of 365 ± 22.1 kg, were selected and fitted with permanent rumen fistulas. They were fed six different diets, each consisting of 1 kg concentrate supplement and one of six types of roughage, including alfalfa hay (A diet), oat hay (O diet), whole corn silage (W diet), king grass (K diet), sugarcane shoot silage (S diet), and rice straw hay (R diet) according to an incomplete Latin square design of 3 × 6, respectively. The pre-feeding period of each period was 12 d. From day 13 to 15 was the official experimental period. During the prefeeding period, free feed intake for each roughage was determined, and during the experiment, the roughage was fed at 90% of the voluntary feed intake. Digestion and metabolism tests were carried out using the total manure collection method to determine the feed intake and fecal output of each buffalo, and to collect feed and fecal samples for chemical analysis. On day 15, rumen fluid samples were collected two hours after morning feeding to determine rumen fermentation parameters and bacterial 16 S rRNA high-throughput sequencing was performed. The results showed that DM and OM digestibility were greatest for the W diet and lowest for the S diet. The rumen pH of the O diet was significantly greater than that of the W diet. The concentration of rumen fluid NH3-N (mg/dL) increased with increased CP content. The concentration of total volatile fatty acids (mmol/L) in the rumen decreased with increased NDF content but increased with increased NFC content. The relative abundances of Bacteroidetes, Firmicutes, and Spirochaetes were 57.03-74.84%, 14.29-21.86%, and 0.44-1.43% in the different quality roughage groups. Bacteroidetes were mainly Prevotellaceae1 and Rikenellaceae RC_gut_group with relative abundances of 30.17-45.75% and 3.23-7.82%. The relative abundance of Patescibacteria and Spirochaetes decreased with increasing roughage quality. These results provide a theoretical and practical basis for evaluating the nutritional value of dairy buffalo feed, utilizing feed resources, matching rations, feeding scientifically, and protecting animal health.

Effects of Palm Oil Deodorizer Distillate on the Ruminal Environment of Sheep.

This study aimed to assess the impact of palm oil deodorizer distillate (POD) on the ruminal environment, including (i) microbial community, (ii) ruminal degradability, and (iii) apparent digestibility in sheep. The data used were derived from twenty rumen-cannulated sheep fed five isoproteic and isofiber diets based on elephant grass (Pennisetum purpureum Schum. cv. Roxo) silage supplemented with 0, 25, 50, 75, or 100 g kg-1 POD on a dry matter (DM) basis. Rumen fluid samples were collected three hours after feeding directly from the ventral sac of the rumen via a cannula and then subjected to DNA extraction, which was subsequently used for 16S rDNA amplification, followed by sequencing and diversity analysis. In this study, the microbial diversity was dominated by Bacteroidetes and Firmicutes, followed by Euryarchaetoa, Actinobacteria, and Tenericutes, in the ruminal environment, and was slightly modified when supplemented with the POD up to 100 g/kg (10%), leading to only a slight decrease in the diversity index. The ruminal degradability, ruminal fermentation parameters, and apparent digestibility were slightly compromised by the inclusion of up to 25 g of POD per kg of DM, and larger inclusions interfered with the ruminal degradability of fibrous fractions and the apparent digestibility of dry matter. This lipid supplement showed good results for feeding sheep and is an inexpensive and abundant alternative in the regional market.

Sainfoin can be included up to 40% in the concentrate of finishing lambs without impairing their performance, rumen fermentation, and carcass quality

Sainfoin (Onobrychis viciifolia) is an excellent forage legume to be included in sheep diets as fresh forage, but its inclusion in concentrates fed to indoor lambs reared has been scarcely studied. This study evaluated the effects of including different levels of dehydrated sainfoin in the concentrates fed to light lambs during the finishing period on animal performance, ruminal fermentation, and carcass traits. Twenty–six weaned male Rasa Aragonesa lambs (14.0 ± 0.49 kg body weight) were randomly grouped and individually fed ad libitum with isoproteic and isoenergetic pelleted concentrates containing 0% (0SF; n=9), 20% (20SF; n=9) or 40% sainfoin (40SF; n=8) for 40 days, from weaning to slaughter. In addition, an in vitro assay was carried out to evaluate the concentrates. The 40SF lambs had a higher dry matter intake (P < 0.01) and tended to show an improvement in average daily gain (P < 0.10). The diet had no effect on carcass weight, dressing percentage, rectus abdominis color or subcutaneous caudal fat color (P > 0.05). Regarding the rumen study, the diet did not affect most ruminal fermentation parameters (P > 0.05), except for pH, which was greater in 40SF lambs than in 20SF lambs (P < 0.05), and the proportion of acetic acid and the acetic:propionic ratio, both of which were higher in 40SF and 20SF lambs than in 0SF lambs (P < 0.01). The results from the in vitro assay showed that the 40SF diet decreased the in vitro dry matter degradability, increased propionic, and decreased butyric proportion compared to 0SF concentrate (P < 0.05), but no effect was obtained for gas, methane, total volatile fatty acids, and ammonia formation among diets (P > 0.05). The lack of detrimental effects on lamb performance and carcass traits suggests that the inclusion of up to 40% sainfoin in the concentrate of light lambs reared indoors would be advisable to promote the use of local forages.

Effects of yeast culture on in vitro ruminal fermentation and microbial community of high concentrate diet in sheep.

This research aimed to investigate effects of different yeast culture (YC) levels on in vitro fermentation characteristics and bacterial and fungal community under high concentrate diet. A total of 5 groups were included in the experiment: control group without YC (CON), YC1 (0.5% YC proportion of substrate dry matter), YC2 (1%), YC3 (1.5%) and YC4 (2%). After 48h of fermentation, the incubation fluids and residues were collected to analyze the ruminal fermentation parameters and bacterial and fungal community. Results showed that the ruminal fluid pH of YC2 and YC4 groups was higher (P < 0.05) than that of CON group. Compared with CON group, the microbial protein, propionate and butyrate concentrations and cumulative gas production at 48h of YC2 group were significantly increased (P < 0.05), whereas an opposite trend of ammonia nitrogen and lactate was observed between two groups. Microbial analysis showed that the Chao1 and Shannon indexes of YC2 group were higher (P < 0.05) than those of CON group. Additionally, YC supplementation significantly decreased (P < 0.05) Succinivibrionaceae_UCG-001, Streptococcus bovis and Neosetophoma relative abundances. An opposite tendency of Aspergillus abundance was found between CON and YC treatments. Compared with CON group, the relative abundances of Prevotella, Succiniclasticum, Butyrivibrio and Megasphaera elsdenii were significantly increased (P < 0.05) in YC2 group, while Apiotrichum and unclassified Clostridiales relative abundances were decreased (P < 0.05). In conclusion, high concentrate substrate supplemented with appropriate YC (1%) can improve ruminal fermentation and regulate bacterial and fungal composition.

Response to Incremental Replacement of Palm Oil with Fish Oil in Starter Diet on Growth Performance, Plasma Metabolites, Ruminal Fermentation, and Behavior of Dairy Calves.

The objective of this study was to evaluate the effects of the incremental levels of n-3 fatty acids (FA) in starter feed (SF) on growth and metabolic performance of milk-fed calves. From day 3 of age, 30 female calves (39.4 ± 3.1 kg of body weight) were randomly assigned to one of three dietary treatments: (1) SF supplemented with 3.3% palm fatty acids (PO), (2) SF supplemented with 1.7% of PO and 1.9% fish oil (PFO), or (3) SF supplemented with 3.9% fish oil (FO). Chopped straw (7.5% of DM) was included in the SF of all treatments as total mixed ration (TMR). Diets had similar energy and protein contents. Total n-3 FA (% of total FA) and n-6/n-3 of PO, PFO, and FO were 1.90, 6.80, and 11.8 and 15.5, 4.50, and 2.70, respectively. The BW was greater for calves receiving FO (60.2 ± 0.3 kg) compared with PFO (58.7 ± 0.3 kg; p = 0.007) and tended to be greater for calves receiving FO vs. PO (59.0 ± 0.3 kg; p = 0.050). Because there was no interaction effect between diet × week of experiment, the greater BW of FO could not be attributed to the dietary treatment. Accordingly, average daily gain, total dry matter intake (DMI), starter DMI, and gain to intake ratio (G:FI) did not differ among dietary treatments during the entire period of the study (p > 0.05). Dietary treatments did not impact body size parameters such as body length, body girth, withers height, heart girth, hip height, and width (p > 0.05). Neither ruminal fermentation parameters nor blood variables were influenced by supplementing the types of oil at different time points. Calves' behavioral parameters, such as standing, lying, eating, and ruminating, were not influenced by different dietary treatments (p > 0.05). The number of days with abnormal fecal score was not different among dietary groups (p > 0.05). Overall, our findings suggest that changing the n-6/n-3 ratio in starter feed by incremental replacement of palm fatty acid with fish oil at a moderate supplemental level of ~3% of DM may not affect the growth and metabolic performance of young calves under non-challenged conditions.

Ruminal inocula with distinct fermentation profiles differentially affect the in vitro fermentation pattern of a commercial algal blend.

The in vitro rumen batch technique is widely used for screening novel feed sources; however, it remains unclear to what extent the in vitro fermentability of non-conventional feed sources is affected by non-adapted ruminal inocula. Thus, in this study, we evaluated the effects of distinct ruminal inocula on the in vitro fermentation parameters of a sustainable non-conventional feed, a commercially available algal blend composed of microalgae (Chlorella vulgaris and Nannochloropsis oceanica) and seaweeds (Ulva sp. and Gracilaria gracilis). First, four late-lactation Holstein cows were fed four forage-based diets varying only in the proportions of basal forage (100% corn silage, 70% corn silage and 30% haylage, 30% corn silage and 70% haylage, and 100% haylage) in a 4 × 4 Latin square design with the last square omitted. After 3 weeks of adaptation, haylage-based diets resulted in ruminal fermentation parameters distinct from those promoted by corn silage-based diets, as reflected in increased pH, ammonia-N contents, and acetate proportions. Individual ruminal fluids derived from each of the four diets were further used as inocula in in vitro incubations. Here, a 1:1 mixture of corn silage and haylage was supplemented with 0, 5, 10, or 15% algal blend and incubated with each inoculum for 24 h in a 4 × 4 factorial design. Total gas and methane production decreased with inocula from cows fed haylage-based diets and with increasing algal blend supplementation levels. The fermentation pH increased and the ammonia-N contents decreased with inocula from cows fed haylage-based diets; however, these parameters were not affected by algal blend inclusion levels. The interaction between the ruminal inoculum source and the algal blend supplementation level affected the total volatile fatty acids (VFA) and the proportions of most individual VFA. Total VFA production decreased with increasing algal supplementation levels, particularly with inocula from cows fed 30% corn silage and 70% haylage; the acetate, propionate, and valerate proportions were only affected by algal blend levels under incubation with 100% corn silage inocula. Overall, our findings highlight the importance of the ruminal inoculum source when assessing the fermentability of non-conventional feed as well as the potential of the algal blend as a natural modulator of ruminal fermentation.

79 Dietary buffer comparison and tannins supplementation modulating subacute ruminal acidosis and fermentation in beef cattle

Abstract As the demand of nutrients by the population will continue to grow over the years, efficient practices are required in the food chain to satisfy the demand. This practice involves the intensification of production systems. Moreover, intensification can potentially harm the animal or environment if the resources are used to the limit. The latter, product of pushing to the limit the ruminal environment. Dietary buffers and tannins offer a key role addressing issues related to intensification. This study aimed to evaluate the effects of two dietary buffers and tannins. Ruminal fermentation parameters, in vitro methane production, ruminal pH, in vitro organic matter digestibility were measured. Eight ruminally cannulated steers were used in a duplicated 4 x 4 Latin square design. Steers were fed with a basal diet comprised of 35.5% corn silage, 18.7% protein supplement, 21.5% corn grain, 22% bermuda hay, 1% mineral supplement (DM basis). Four treatments were used: BICARB (Basal diet + 1.2% DM Sodium Bicarbonate), BRIC-050 (Basal diet + 1.2% DM BRIC), BRIC-150 (Basal diet + 1.2% DM BRIC + 0.15 % DM Tannins), TAN (Basal diet + 0.15% DM Tannins). Steers were housed in individual pens and received every morning a TMR and water ad libitum. The experiment consisted of 4 periods with 16 days total, composed by 3 d of covariates, 7 d of treatment adaptation, 1 d of 50% feed restriction, 1 d SARA challenge, 4 d of recovery, and 20 d of washout between periods. Two in vitro batch culture were performed in every period at the last day of covariates and last day of recovery, collecting ruminal fluid from each animal. Treatments with BICARB promoted a higher pH than TAN during the adaptation at 4 h after feeding (P = 0.01). Moreover, BRIC-150 showed similar results with a tendency to increase (P = 0.07) when compared with TAN. During the feed restriction BRIC-150 showed a greater pH (P = 0.01) when compared with TAN. While, for BICARB and BRIC-050 pH tended to be greater (P = 0.06) than TAN. During the SARA challenge and the recovery, treatments with buffer tended to have greater pH (P &amp;lt; 0.1). A significant reduction ammonia nitrogen was observed for BICARB and TAN compared with BRIC-050 and BRIC-150 (P &amp;lt; 0.01). Overall, the three buffers tested showed similar results in terms of maintaining a greater pH than treatment without buffer.

In vitroruminal fermentation, core nutrient, fatty acids and mineral matter of pennyroyal (Mentha pulegium L.) herbage at different phenological stages.

In ruminants, fibrous feedstuffs must be included in the ration to ensure normal rumen physiology and to prevent the occurrence of rumen-related metabolic diseases. In addition to being a source of fibrous feedstuffs, they contain energy depending on the level of digestion and protein, minerals, fatty acids, minerals, and secondary compounds. This study aimed to determine the nutrient matter, fatty acid, mineral and in vitro rumen fermentation values of the pennyroyal (Mentha pulegium L.) plant. The pennyroyal plant samples were collected at different phenological stages (vegetative, full flowering, and seed bulking) from the natural meadow. The samples were analysed for core nutrients, condensed tannins, minerals, fatty acids, and in vitro ruminal fermentation parameters. The calcium (Ca) and iron (Fe) contents and in vitro ruminal fermentation parameters (total gas production and methane production, organic matter digestion (OMd), and the ammonia-nitrogen) decreased with increasing phenological stage (p < 0.05). The percentages of linoleic, α-linolenic, ω-3, ω-6 and polyunsaturated fatty (PUFA) acids of the pennyroyal plant linearly increased with the phenological stages (p < 0.05). However, butyric acid (BA) concentration in the in vitro ruminal fermentation fluid in the full flowering stage was lower than that of other stages (p < 0.05). Pennyroyal plant is a functional plant in terms of high values of ether extract (EE), α-linolenic acid, linoleic acid, ∑ω-3 fatty acids, Ca, Fe and Zn contents. For this plant to be used as animal feed, the stage when it has the highest values for Ca, Mg, S and Zn minerals and in vitro OMd were vegetative and full flowering. The stage with good potential as animal feed for ∑ω-3 and ∑ω-6 fatty acids and core nutrients (CP and EE) is the seed bulking stage.

The Effect of Saponite Clay on Ruminal Fermentation Parameters during In Vitro Studies.

Reducing the emission of global warming gases currently remains one of the strategic tasks. Therefore, the objective of our work was to determine the effect of saponite clay on fermentation in the rumen of cows. The pH, total gas production, CH4, and volatile fatty acid (VFA) production in ruminal fluid was determined in vitro. Saponite clay from the Tashkiv deposit (Ukraine) has a high content of silicon, iron, aluminum, and magnesium. The addition of 0.15 and 0.25 g of saponite clay to the incubated mixture did not change the pH but reduced the total production (19% and 31%, respectively) and CH4 (24% and 46%, respectively) in the ruminal fluid compared to the control group and had no significant effect on the total VFA levels, but propionic acid increased by 15% and 21% and butyric acid decreased by 39% and 32%, respectively. We observed a decrease in the fermentation rates, with a simultaneous increase in the P:B ratio and an increase in the fermentation efficiency (FE) in the groups fermented with saponite clay, probably a consequence of the high efficiency in the breakdown of starch in the rumen. Therefore, further in vivo studies to determine the effective dose and effect of saponite clay on cow productivity and the reduction of gas emissions are promising and important.