Ruminal Ammonia Nitrogen Concentration Research Articles

Meta-analysis of dietary supplementation with flavonoids in small ruminants: Growth performance, antioxidant status, nutrient digestibility, ruminal fermentation, and meat quality

This study aimed to evaluate the effects of dietary supplementation with flavonoids on growth performance, antioxidant status, nutrient digestibility, ruminal fermentation, and meat quality of small ruminants through a meta-analytic approach. The data used in the meta-analysis were extracted from 29 scientific articles identified through systematic searches following the PRISMA methodology. Der-Simonian and Laird, random effects models, were used to assess effect sizes using weighted mean differences. Dietary supplementation with flavonoids increased (P < 0.05) dry matter intake, average daily gain, hot carcass weight, hot carcass yield, Longissimus dorsi muscle area, and backfat thickness. In contrast, the feed conversion ratio decreased (P < 0.05) in response to dietary flavonoid supplementation. Dietary supplementation with flavonoids increased (P < 0.001) the serum concentration of superoxide dismutase, catalase, glutathione peroxidase, and total antioxidant capacity but decreased (P < 0.001) the serum concentration of malondialdehyde (MDA). The digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber increased (P < 0.05) in response to dietary flavonoid supplementation. Dietary supplementation with flavonoids decreased (P < 0.001) the ruminal concentration of ammonia nitrogen and increased (P < 0.001) the ruminal concentration of total volatile fatty acids and acetate. Dietary supplementation with flavonoids decreased (P < 0.001) cooking loss, shear force, and MDA in meat. In conclusion, dietary supplementation with flavonoids can be used as a nutritional strategy to improve growth performance, antioxidant status in blood serum, nutrient digestibility, ruminal fermentation, and meat quality in small ruminants.

Advantageous effects of rumen-protected phytonutrients from tropical plant extracts on rumen fermentation efficiency and methane mitigation using in vitro fermentation technique.

Tropical plants are composed of phytonutrients (PTNs) and are utilized for their capacity to manipulate rumen fermentation characteristics and methane production. The aim of this experiment was to determine the impact of microencapsulated phytonutrients-extracted from lemongrass and mangosteen peel (M-LEMANGOS), as well as crude protein levels on nutrient degradability, rumen ecology, microbial population, and methane emission in an in vitro study. The treatments were randomly assigned in a 2 × 4 Factorial arrangement in a Completely randomized design. The two factors consisted of crude protein (CP) percentage in the concentrate diet (16% and 18% CP) and the levels of M-LEMANGOS addition (0%, 2%, 4%, and 6% of the total substrate). The results showed that nutrient degradability both 12 and 24 h were significantly increased with M-LEMANGOS at 4% total substate. In part of volatile fatty acids (VFAs), particularly propionate and total VFA, these were enhanced by %CP and M-LEMANGOS combination. The %CP increased ruminal ammonia-nitrogen concentration (NH3-N), while M-LEMANGOS supplementation reduced such concentration. Methane production and Methanobacteriales population at 12 and 24 h were reduced when supplemented with M-LEMANGOS at 4% total substate. The population of Fibrobacter succinogenes, Ruminococcus flavefaciens, and Megasphaera elsdenii were increased with the interaction between %CP and M-LEMANGOS addition. M-LEMANGOS indicates promising potential as a plant-based PTN for dietary modulation of rumen fermentation and mitigation of methane production.

Meta-Analysis of Dietary Supplementation with Seaweed in Dairy Cows: Milk Yield and Composition, Nutrient Digestibility, Rumen Fermentation, and Enteric Methane Emissions

This study used a meta-analytic approach to evaluate the effects of dietary supplementation with seaweed on milk yield, milk composition, nutrient digestibility, ruminal fermentation, and enteric methane (CH4) emissions of dairy cows. Data used in statistical analyses were obtained from 23 peer-reviewed scientific articles. Effect size was assessed using weighted mean differences (WMD) between seaweed-supplemented and control treatments. Dietary supplementation with seaweed decreased (p &lt; 0.05) dry matter intake, milk protein content, milk urea nitrogen, and somatic cell count. In contrast, milk fat content, milk lactose content, and milk iodine increased (p &lt; 0.05) in response to dietary supplementation with seaweed. Dietary supplementation with seaweed did not affect (p &gt; 0.05) nutrient digestibility, total volatile fatty acids, acetate, and propionate. Dietary supplementation with seaweeds increased (p &lt; 0.05) ruminal pH and ruminal concentration of butyrate and valerate. In contrast, lower (p &lt; 0.05) ruminal ammonia nitrogen concentration, acetate/propionate ratio, daily CH4 emission, CH4 yield, and CH4 intensity were observed in response to dietary supplementation with seaweeds. In conclusion, dietary supplementation with seaweed modifies milk composition, improves ruminal fermentation, and decreases enteric methane emissions without negatively affecting milk yield or feed efficiency.

Effects of quebracho–chestnut tannin extract supplementation on production performance, nitrogen partitioning, and rumen fermentation patterns in early-lactating Holstein cows

Tannins have been extensively studied to decrease nitrogen excretion, however, the effects of tannins on animal production were inconsistent. The objective was to evaluate the effects of a mixture of quebracho-chestnut tannin extract (QCTE) supplementation on the production performance, nutrient digestibility, rumen fermentation patterns, and N partitioning in dairy cows. Sixty multiparous Holstein cows (mean ± standard deviation; average 717 ± 51 kg of body weight, 2.5 ± 0.2 of parity, 47 ± 1.9 kg/d of milk production, 78 ± 3.2 d of days in milk were randomly divided into four groups. Cows in different groups were provided QCTE at doses of 0, 10, 20, and 30 g/d per cow for 56 d. Although QCTE supplementation did not affect dry matter intake (DMI) and total-tract apparent digestibility of nutrients, milk yield and milk protein yield increased linearly (P = 0.01), and a trend for a linear (P = 0.07) increase in milk/DMI were observed with increasing QCTE supplementation. Increasing QCTE supplementation decreased the milk urea-N concentration and somatic cell count linearly (P < 0.05), tended to linearly (P < 0.1) decrease the concentration of blood urea-N and ruminal ammonia nitrogen, linearly (P < 0.05) increased levels of total antioxidant capacity and superoxide dismutase, and the molar proportions of ruminal propionate. Additionally, total N excretion was not affected by QCTE treatments, but QCTE supplementation linearly (P = 0.04) increased N utilization efficiency and tended to linearly (P = 0.1) decrease urea-N excretion in the urine. In conclusion, feeding QCTE at a dose of 30 g/d per head to cows in early lactation could increase antioxidant enzyme activities, improve production performance, and decrease environmentally labile urinary N excretion under the conditions of the study.

Capsaicin as a Dietary Additive for Dairy Cows: A Meta-Analysis on Performance, Milk Composition, Digestibility, Rumen Fermentation, and Serum Metabolites.

This study aimed to evaluate the effects of dietary supplementation with capsaicin (CAP) on productive performance, milk composition, nutrient digestibility, ruminal fermentation, and serum metabolites of dairy cows using a meta-analytical approach. The database included 13 studies, from which the response variables of interest were obtained. Data were analyzed using a random effects model, and results were expressed as weighted mean differences between treatments supplemented with and without CAP. Dietary supplementation with CAP increased (p < 0.05) dry matter intake, milk yield, feed efficiency, milk fat yield, and milk fat content. However, CAP supplementation did not affect (p > 0.05) milk protein and lactose yield, milk urea nitrogen, or milk somatic cell count. Greater (p < 0.05) apparent digestibility of dry matter and crude protein was observed in response to the dietary inclusion of CAP. Likewise, supplementation with CAP increased (p < 0.05) the rumen concentration of total volatile fatty acids. In contrast, CAP supplementation did not affect (p > 0.05) ruminal pH or the ruminal concentration of ammonia nitrogen, acetate, propionate, and butyrate. In blood serum, CAP supplementation increased (p < 0.05) the glucose concentration and decreased (p < 0.05) the concentration of non-esterified fatty acids. However, CAP supplementation did not affect (p > 0.05) the serum concentration of urea and beta-hydroxybutyrate. In conclusion, capsaicin can be used as a dietary additive to improve the productive performance, milk composition, and nutrient digestibility in dairy cows and, at the same time, improve the ruminal concentration of total volatile fatty acids and serum levels of glucose and non-esterified fatty acids.

Exploring rumen fermentation and microbial populations in Dhofari goats fed a chitosan-added diet

The use of chitosan (CHI) in ruminant diets is a promising natural modifier for rumen fermentation, capable of modulating both the rumen pattern and microbial activities. The objective of this study was to explore the rumen fermentation and microbial populations in Dhofari goats fed a diet supplemented with CHI. A total of 24 Dhofari lactating goats (body weight, 27.32 ± 1.80 kg) were assigned randomly into three experimental groups (n = 8 ewes/group). Goats were fed a basal diet with either 0 (control), 180 (low), or 360 (high) mg CHI/kg of dietary dry matter (DM) for 45 days. Feeding high CHI linearly increased (p < 0.05) the propionate level and reduced the acetate, butyrate, and total protozoa count (p < 0.05). Ruminal ammonia nitrogen (NH3–N) concentrations and the acetate:propionate ratio decreased linearly when goats were fed CHI (p < 0.05). The abundances of both Spirochetes and Fibrobacteres phyla were reduced (p < 0.05) with both CHI doses relative to the control. Both low and high CHI reduced (p < 0.05) the relative abundances of Butyrivibrio hungatei, Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens, Selenomonas ruminantium and Neocallimastix californiae populations. Adding CHI significantly decreased (p < 0.05) the abundances of Ascomycota, Basidiomycota, and Bacillariophyta phyla compared to the control. Adding CHI to the diet reduces the abundance of fibrolytic-degrading bacteria, however, it increases the amylolytic-degrading bacteria. Application of 360 mg of CHI/kg DM modified the relative populations of ruminal microbes, which could enhance the rumen fermentation patterns in Dhofari goats.

Investigation of the effect of different additives on the qualities, &lt;i&gt;in vitro&lt;/i&gt; degradation, and rumen fermentation profile of indigo waste silage

&lt;abstract&gt; &lt;p&gt;Natural indigo dye production produces indigo waste as a by-product. Our purpose of this study was to examine the effects of calcium hydroxide (Ca(OH)&lt;sub&gt;2&lt;/sub&gt;), cellulase (CE), molasses (MO), and their combinations on the silage quality, &lt;italic&gt;in vitro&lt;/italic&gt; degradability, and rumen fermentation parameters of indigo waste silage. A completely randomized design (CRD) was used for the experiment. Indigo waste was chopped and ensiled in a small-scale silo with no additive (control), Ca(OH)&lt;sub&gt;2&lt;/sub&gt;, MO, CE, Ca(OH)&lt;sub&gt;2&lt;/sub&gt;:MO, Ca(OH)&lt;sub&gt;2&lt;/sub&gt;:CE, MO:CE, and MO:CE:Ca(OH)&lt;sub&gt;2&lt;/sub&gt;. After 30 days of storage, the silages were tested for quality and chemical composition, as well as an &lt;italic&gt;in vitro&lt;/italic&gt; fermentation. The ruminal fluid inoculum was collected from two beef cattle with a body weight (BW) of 200±10 kg, and the inoculum had been pre-heated before being transported to the laboratory. Silage with MO, CE, or their combination increased the amount of lactic acid (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01). The silage pH was lowest in MO:CE (4.5) and was highest in Ca(OH)&lt;sub&gt;2&lt;/sub&gt;:CE (10.6) in indigo waste (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01). In comparison to the control (19.5% CP), the CP content of all additives increased by 20.7% to 21.5% (&lt;italic&gt;p&lt;/italic&gt; = 0.02). The addition of Ca(OH)&lt;sub&gt;2&lt;/sub&gt;:MO and Ca(OH)&lt;sub&gt;2&lt;/sub&gt;:CE resulted in a reduction of NDF content by 60.7% and 59.4%, respectively, in comparison to the control group (72.4%) (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01). Silage with additives had no effect on the cumulative gas production or gas kinetics, except that the constant rate of gas production for the insoluble fraction (c) was higher in MO (&lt;italic&gt;p&lt;/italic&gt; = 0.03). &lt;italic&gt;In vitro&lt;/italic&gt; dry matter degradability (IVDMD) was higher in CE and MO and highest in MO:CE-treated silage (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01). The &lt;italic&gt;in vitro&lt;/italic&gt; organic matter degradability (IVOMD) increased in Ca(OH)&lt;sub&gt;2&lt;/sub&gt;:MO compared with the control (&lt;italic&gt;p&lt;/italic&gt; = 0.03). The additives alone or in their two combinations in silage reduced the ruminal ammonia-nitrogen (NH&lt;sub&gt;3&lt;/sub&gt;-N) concentration (28.0 to 31.5 mg/dL) when compared to the control (32.7 mg/dL) (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01). In addition, the highest total volatile fatty acid (VFA) level was found in the silage of the MO (92.9 mmol/L) compared with the control (71.3 mmol/l) (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01). The proportion of propionic acid and butyric acid increased (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01) whereas acetic acid decreased (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.01) in the rumen of silage with MO and CE. In summary, the addition of MO and CE has the potential to be used in the silage of indigo waste.&lt;/p&gt; &lt;/abstract&gt;

Immunity, rumen metagenomics, ruminal variables, and growth performance of calves fed milk with sage (Salvia officinalis) essential oil.

The study aimed to determine the effect of sage (Salvia officinalis) essential oil (EO) to the drinking milk until the weaning stage of Holstein calves on the growth performance, body measurements, ruminal fermentation, rumen metagenomic profile, proinflammatory cytokines [interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and IL-1β], immune globulins (IgG, IgM, and IgE), and acute phase proteins (serum amyloid-A, SAA). In the study, 24 Holstein calves were divided into three groups as 0 μL (SAG0; control group), 100 μL (SAG100), or 200 μL (SAG200) of sage EO to the milk per calf per day. The addition of sage EO to the milk linearly increased the live weight, feed intake, and daily body weight gain (P < 0.05). The addition of sage EO to the milk in calves linearly increased serum IgG titter dose dependently (P < 0.05), but serum IgM and IgE titters did not change (P > 0.05). The concentrations of serum TNF-α, IL-1β, and IL-6 in the weaned calves linearly decreased by the sage aromatic oil addition to the milk (P < 0.05). The serum SAA concentrations of calves did not differ among the control and treatment groups (P > 0.05). Probiotic Bifidobacterium and Acidaminococcus genusin calf rumen fluid canincrease bysage EO addition to milk. The relative abundance of genus Prevotella, Prevotellaceae_NK3B31_group, and Prevotella_9 increase with sage EO. The ruminal ammonia-nitrogen (NH3-N) concentration and total short chain fatty acid (T-SCFA) molarity decreased by sage EO addition to the drinking milk (P < 0.05). Themolarities of iso butyric (IBA) and iso valeric acids (IVA) in rumen fluid of the weaned calves linearly reduced by the increasing sage EO dose to the milk (P < 0.05). The butyric acid (BA) and iso caproic acid (ICA) molarities in rumen fluid did not change by the sage EO addition (P > 0.05). Consequently, it has been observed that sage EO addition to the milk of calves positively affected the immune system variables and performance parameters.Sage EO additionof calves before weaning may support the immune system in the eventual immunosuppression at the weaning stage.

Effects of Neem (Azadirachta indica) Leaf Powder Supplementation on Rumen Fermentation, Feed Intake, Apparent Digestibility and Performance in Omani Sheep.

The objective of the present study was to evaluate the potential of the dietary addition of neem (Azadirachta indica) leaf powder (NLP) when compared to monensin (MON) on ruminal fermentation, feed intake, digestibility, and performance of growing lambs. Eighteen Omani lambs (22.8 ± 2.18 kg of body weight (BW)) were equally divided into three groups (n = 6 lambs/group) for 90 days. Animals were fed an ad lib basal diet consisting of Rhodes grass (Chloris gayana) hay (600 g/kg) and a concentrated mixture (400 g/kg) offered twice daily. Experimental treatments were control (basal diet without supplements); MON (control plus 35 mg/kg DM as a positive control); and NLP (control plus 40 g/kg DM). Lambs fed NLP had reduced ruminal ammonia nitrogen concentrations, protozoal counts, total volatile fatty acid, and blood urea nitrogen concentrations compared to the control. Compared to MON, lambs fed NLP had increased ruminal acetate and decreased propionate proportions. Inclusion of NLP in the diet increased blood total protein, globulin, and liver enzyme concentrations in comparison with the control, which was similar to MON. The lamb's final BW and average BW gain were also increased with the NLP relative to the control. Further, adding NLP to the diet increased the digestibility of crude protein compared to the control diet. In conclusion, adding NLP to the diet with 40 g/kg DM could be used as a promising phytogenic supplement for growing lambs with no detrimental effects on the ruminal fermentation profile, nutrient intake, or digestibility.

Essential Oils as a Dietary Additive for Small Ruminants: A Meta-Analysis on Performance, Rumen Parameters, Serum Metabolites, and Product Quality.

Simple SummaryEssential oils can be used to improve animal performance as well as the health and quality of livestock products. The aim of this study was to evaluate the effects of essential oil supplementation on animal performance, ruminal fermentation, blood metabolites, and meat and milk quality of small ruminants through a meta-analysis. Supplementation with essential oils improved weight gain, milk production and composition, oxidative stability of meat, and blood serum antioxidant enzyme activity. Additionally, essential oils decreased methane emissions. This suggests that the inclusion of essential oils in the diets of small ruminants could be used to improve animal performance and the quality of meat and milk, in addition to reducing the environmental impact and oxidative stress of the animals.There is an increasing pressure to identify natural feed additives that improve the productivity and health of livestock, without affecting the quality of derived products. The objective of this study was to evaluate the effects of dietary supplementation with essential oils (EOs) on productive performance, rumen parameters, serum metabolites, and quality of products (meat and milk) derived from small ruminants by means of a meta-analysis. Seventy-four peer-reviewed publications were included in the data set. Weighted mean differences (WMD) between the EOs treatments and the control treatment were used to assess the magnitude of effect. Dietary inclusion of EOs increased (p < 0.05) dry matter intake (WMD = 0.021 kg/d), dry matter digestibility (WMD = 14.11 g/kg of DM), daily weight gain (WMD = 0.008 kg/d), and feed conversion ratio (WMD = −0.111). The inclusion of EOs in small ruminants’ diets decreased (p < 0.05) ruminal ammonia nitrogen concentration (WMD = −0.310 mg/dL), total protozoa (WMD = −1.426 × 105/mL), methanogens (WMD = −0.60 × 107/mL), and enteric methane emissions (WMD = −3.93 L/d) and increased ruminal propionate concentration (WMD = 0.726 mol/100 mol, p < 0.001). The serum urea concentration was lower (WMD = −0.688 mg/dL; p = 0.009), but serum catalase (WMD = 0.204 ng/mL), superoxide dismutase (WMD = 0.037 ng/mL), and total antioxidant capacity (WMD = 0.749 U/mL) were higher (p < 0.05) in response to EOs supplementation. In meat, EOs supplementation decreased (p < 0.05) the cooking loss (WMD = −0.617 g/100 g), malondialdehyde content (WMD = −0.029 mg/kg of meat), yellowness (WMD = −0.316), and total viable bacterial count (WMD = −0.780 CFU/g of meat). There was higher (p < 0.05) milk production (WMD = 0.113 kg/d), feed efficiency (WMD = 0.039 kg/kg), protein (WMD = 0.059 g/100 g), and lactose content in the milk (WMD = 0.100 g/100 g), as well as lower somatic cell counts in milk (WMD = −0.910 × 103 cells/mL) in response to EOs supplementation. In conclusion, dietary supplementation with EOs improves productive performance as well as meat and milk quality of small ruminants. In addition, EOs improve antioxidant status in blood serum and rumen fermentation and decrease environmental impact.

The effect of vegetable and animal oils added to different forages and concentrates on the in vitro fermentation parameters in ruminants

ABSTRACT This study aimed to determine the effects of fermentation parameters of sunflower oil, vegetable oil blend, palm oil and chicken oil addition to sunflower meal, wheat grain, alfalfa herbage and corn silage at different rates (4% and 6%, dry matter basis). The oil supplementation up to 6% rate to the alfalfa herbage and corn silage did not adversely affect the level of in vitro gas production, metabolic energy (ME), net energy lactation (NEL), organic matter digestion (OMD) and molarities of acetic, propionic, butyric, iso-valeric, iso-butyric and valeric acids and number of total protozoa (P > 0.05). The oil supplementation to alfalfa herbage increased molarities of butyric, iso-valeric, iso-butyric and valeric acids and number of total protozoa (except sunflower oil) in rumen fluid (P < 0.05). Palm oil decreased the in vitro gas production, ME, NEL and OMD values of sunflower meal (P < 0.05). Supplementation of vegetable oil blend to wheat grain increased ME, NEL and OMD values and butyric acid molarity in rumen fluid (P < 0.05). The in vitro ruminal ammonia–nitrogen concentrations of alfalfa herbage and corn silage increased by vegetable oil blend, palm oil and chicken oil up to 6% (P < 0.05). As a result, the nutrient content of the feedstuffs used changed the in vitro ruminal fermentation values of the oil additive to be added. The addition of sunflower oil, vegetable oil blend, palm oil and chicken oil at 4% and 6% rates to corn silage, alfalfa herbage, sunflower meal and wheat grain feed found to differ on in vitro ruminal fermentation parameters.

Effect of daily or intermittent addition of fenugreek (Trigonella foenum graecum L.) seeds to concentrate on intake, digestion, and growth performance of Barbarine lamb

An 82-day experiment was carried out to determine the response of growing lambs to the intermittent administration of fenugreek (FG) seeds (Trigonella foenum graecum L.) into concentrate. Twenty-Four 3-month-old Barbarine lambs (initial body weight 16.6 ± 0.42 kg) were divided into four equal groups (n = 6). All lambs received 600 g alfalfa pellets and 250 g concentrate containing or not 12% ground FG seeds. Control concentrate (CC) was composed (as fed) of barley (200 g), faba bean (40 g) and mineral and vitamin supplement (MVS, 14 g). The experimental concentrate (CE) contained barley (200 g), FG seeds (30 g) and MVS (14 g). The two concentrates have the same crude protein content. The control group (FG-0) received CC while groups FG-D, FG-2D and FG-4D received CE daily, or in alternation with concentrate CC at 2 or 4-day intervals (FG-2D or FG-4D, respectively). The feeding trial was followed by a 5-day in vivo digestibility trial. The frequency of distribution of FG-containing concentrate (CE) had no effect (P > 0.05) on diet intake and diet apparent digestibility of dry matter, organic matter, crude protein and cell wall (NDFom), nitrogen balance and the concentrations of urea, total protein and glucose in sheep plasma. The intermittent supply of FG seeds in concentrate tended to increase (P = 0.087)the average daily gain in FG-2D and FG-4D lambs and the microbial nitrogen synthesis (P = 0.052)with the FG administration. However, it decreased (P < 0.001) ruminal protozoa count by 33%, 44% and 66% in the FG-D, FG-2D and FG-4D lambs, respectively compared to FG-0 group. Similarly, the intermittent administration of FG seeds decreased ruminal ammonia nitrogen (NH3-N) concentrations (P < 0.001) by 28%, 31% and 35% in the FG-D, FG-2D and FG-4D, respectively. The antiprotozoal activity of FG seeds could have been induced by secondary compounds like saponins. This activity was more efficient when the frequency of incorporation of FG seeds into the concentrate is wider. It is concluded that the intermittent administration of 120 g/kg to concentrate (DM basis), had an antiprotozoal effect but failed to improve diet digestibility and growth performance of Barbarine lambs. Therefore, there is a need to emphasize further investigation to identify the active components responsible for the antiprotozoal activity of FG seeds.

A Meta-Analysis of Essential Oils Use for Beef Cattle Feed: Rumen Fermentation, Blood Metabolites, Meat Quality, Performance and, Environmental and Economic Impact

The objective of this study was to see how dietary supplementation with essential oils (EOs) affected rumen fermentation, blood metabolites, growth performance and meat quality of beef cattle through a meta-analysis. In addition, a simulation analysis was conducted to evaluate the effects of EOs on the economic and environmental impact of beef production. Data were extracted from 34 peer-reviewed studies and analyzed using random-effects statistical models to assess the weighted mean difference (WMD) between control and EOs treatments. Dietary supplementation of EOs increased (p &lt; 0.01) dry matter intake (WMD = 0.209 kg/d), final body weight (WMD = 12.843 kg), daily weight gain (WMD = 0.087 kg/d), feed efficiency (WMD = 0.004 kg/kg), hot carcass weight (WMD = 5.45 kg), and Longissimus dorsi muscle area (WMD = 3.48 cm2). Lower (p &lt; 0.05) ruminal concentration of ammonia nitrogen (WMD = −1.18 mg/dL), acetate (WMD = −4.37 mol/100 mol) and total protozoa (WMD = −2.17 × 105/mL), and higher concentration of propionate (WMD = 0.878 mol/100 mol, p &lt; 0.001) were observed in response to EOs supplementation. Serum urea concentration (WMD = −1.35 mg/dL, p = 0.026) and haptoglobin (WMD = −39.67 μg/mL, p = 0.031) were lower in cattle supplemented with EOs. In meat, EOs supplementation reduced (p &lt; 0.001) cooking loss (WMD = −61.765 g/kg), shear force (WMD = −0.211 kgf/cm2), and malondialdehyde content (WMD = −0.040 mg/kg), but did not affect pH, color (L* a* and b*), or chemical composition (p &gt; 0.05). Simulation analysis showed that EOs increased economic income by 1.44% and reduced the environmental footprint by 0.83%. In conclusion, dietary supplementation of EOs improves productive performance and rumen fermentation, while increasing the economic profitability and reducing the environmental impact of beef cattle. In addition, supplementation with EOs improves beef tenderness and oxidative stability.

Effects of replacing grain feed with rumen-protected fat on feedlot performance, ruminal parameters and blood metabolites in growing Merino lambs’ diets during the hot season

In this study, the effects of rumen-protected fat (RPF) were evaluated as an energy source for partial replacement of grain feed in the diets of Merino male lambs during the hot season. Fourteen six months old Merino male lambs weighing average of 29.59 kg were randomly allocated into two groups: control diet (CON) and diets supplemented with 30 g/kg RPF. Live weight (LW), dry matter intake (DMI) and average daily gain (ADG) were recorded, and the feed conversion ratio (FCR) was then calculated. The ruminal pH, the ruminal ammonia nitrogen concentrations (NH3-N) value, the molar proportion of volatile fatty acid (VFA), blood serum as well as hematological parameters were determined and protozoa numbers were counted. While the live weight and daily gain of the lambs were not influenced by dietary treatments, DMI was increased with RPF supplementation. The ruminal pH, VFA and ruminal NH3-N concentrations were unchanged, but the protozoa numbers decreased significantly by RPF supplementation (P&amp;lt;0.05). RPF supplementation significantly affected some serum and hematological parameters in comparison to the control group. In conclusion, RPF may be added to concentrate mixture lamb feed at the level of 30 g/kg to enhance the diet energy density without negatively changing the animal’s performance.

Rumen fermentation and metabolic profile of rams fed with diets amended cottonseed cake.

The aim of the study was to evaluate the addition of increasing cottonseed cake contents in the diet. The diets were composed of corn silage (500gkg-1) and concentrate feed (500gkg-1) on a dry matter (DM) basis. The treatments consisted of the substitution of 0, 140, 280, and 420gkg-1 soybean meal to cottonseed cake in the DM of concentrate feed. Four rams of the Santa Inês breed, average age of 12months and average weight of 27.77 ± 3.87kg, were distributed in a Latin square design (4 × 4) in a split-split-plot design, with diets in the plots and as subplots were 5days of collection and the collection times. The results were subjected to analysis of variance and regression at 5% probability. The soybean meal substitution contents by cottonseed cake in the concentrate increased linearly the pH (P = 0.019). Ruminal ammonia-nitrogen concentration decreased linearly by 0.0137mg dL-1 at each 10g/kg of substitution and the time after feeding promoted the same effect (P < 0.001) decreased linearly by 0.6204mg dL-1 at each hour after feeding. There was an increased linearly of 0.0116mmolmL-1 at the concentration of propionic (P = 0.008) and a reduction of 0.0062mmolmL-1 at the concentration of butyric (P = 0.009) with cottonseed cake content; however, the substitution did not influence the others short-chain fatty acids. Replacement of soybean meal with cottonseed cake in the sheep feed did not significantly alter the blood parameters, promoting minor changes in the ruminal parameters mainly in the ruminal ammonia-nitrogen without affecting the animal's health.

PSXIV-6 País grape marc (Vitis vinifera, País) inclusion in concentrate diets reduces ammonia nitrogen but not methane production in an in vitro batch culture

Abstract País Grape (Vitis vinifera L.) is an ancestral variety used in Chilean wine industry. It has a higher content of proanthocyanidins than commercial varieties such as Carmenère or Pinot Noir, resulting in País grape marc (PGM) with high contents of condensed tannins. As such, PGM inclusion in ruminant diets would have the potential to reduce enteric methane (CH4) emissions and decrease urinary N excretion. The objective of this study was to evaluate the effects of substitution of mixed hay (MH) with PGM in a high concentrate diet [65% dry matter (DM)] on in vitro dry matter disappearance (IVDMD), ruminal fermentation parameters, gas and CH4 production. Treatments were: T1 (Control) = 20% MH, 15% corn silage, 65% concentrate; T2 = 10% MH, 10% PGM, 15% corn silage, 65% concentrate; T3 = 20% PGM, 15% corn silage, 65% concentrate. The study was a randomized complete design with 3 treatment and 3 replicates, incubated for 24 h at 39º C. Data were compared by Tukey test and polynomial contrasts. There was a linear reduction in NH3-N (P = 0.001) as dietary PGM increased. Inclusion of PGM reduced NH3-N by 50% when added at 10% DM, and 71.7% at 20% DM. However, there also was 4% reduction in IVDMD (P ≤ 0.001) and gas production (P = 0.012) in the 20% GM diet. There were no treatment effects (P ≥ 0.05) on CH4 production or yield. Fermentation efficiency determined by the partition factor increased linearly (P = 0.013) as PGM inclusion increased, suggesting that it increases organic matter to be degraded. Based on this study it could be concluded that PGM is an alternative source of fiber for ruminants on concentrate diets, as it can result in improved rumen fermentation efficiency and a substantial reduction in ruminal ammonia nitrogen concentration (NH3-N).

Feed Intake and Nutrient Digestibility, Rumen Fermentation Profiles, Milk Yield and Compositions of Lactating Dairy Cows Supplemented by Flemingia macrophylla Pellet

Feed intake and nutrient digestibility, rumen fermentation profiles, milk yield and compositions of lactating dairy cows fed with Flemingia macrophylla pellet (FMP) were evaluated. Four crossbred dairy cows in early lactation were randomly allocated into a 2×2 factorial arrangement in a 4×4 Latin square design (LSD). The first factor was protein level of concentrate mixtures consisted of two levels, i.e., 14% and 16%. The second factor was supplementation levels of FMP consisted of two levels, i.e., 0 and 150 g/cow/d. There were no interactions between the protein level of concentrate and FMP supplementation on feed intake and digestibility, rumen fermentation profiles, milk yield and composition of lactating dairy cows. The findings revealed that both factors significantly impacted feed intakes. They also significantly increased the digestibility of CP and neutral detergent fiber (NDF). Ruminal ammonia nitrogen and propionate (C3) concentrations were improved (p&lt;0.05), while rumen acetate (C2), the ratio of C2:C3, estimated methane (CH4) production, and protozoal counts were subsequently reduced (p&lt;0.05). Crude protein level and FMP supplementation additionally improved nitrogen absorption and utilization, as well as microbial nitrogen synthesis. Milk production was significantly increased by the FMP feeding. In conclusion, a concentrated mixture with 16% CP along with supplementation of FMP at a dose of 150 g/cow/d could significantly increase rumen fermentation end-products, microbial protein synthesis, mitigated rumen CH4 production, and milk production in lactating dairy cows fed with rice straw.

Estimating in vitro ruminal ammonia-N using multiple linear models and artificial neural networks based on the CNCPS nitrogenous fractions of cattle rations with low concentrate/roughage ratios.

The objectives of this study were to investigate the relationship between the in vitro ruminal ammonia nitrogen (NH3 -N) concentration and the Cornell Net Carbohydrate and Protein System (CNCPS) N-fractions of feeds for cattle and further compare the performance of developing multiple linear regression (MLR) and artificial neural network (ANN) models in estimating the NH3 -N concentration in rumen fermentation. Two data sets were established, of which the training data set containing forty-five rations for cattle with concentrate/roughage ratios of 50:50, 40:60, 30:70, 20:80 and 10:90 used for developing models and the test data set containing ten other rations with the same concentrate/roughage ratios with the training data set were used for validating of models. The NH3 -N concentrations of feed samples were measured using an in vitro incubation technique. The CNCPS N-fractions (g), for example PB1 (rapidly degraded true protein), PB2 (neutral detergent soluble nitrogen), PB3 (acid detergent soluble nitrogen) of rations, were calculated based on chemical analysis. Statistical analysis indicated that the NH3 -N concentration (mg) was significantly correlated with the CNCPS N-fractions (g) PB1 , PB2 and PB3 in a multiple linear pattern: NH3 -N=(130.70±33.80) PB1 +(155.83±17.89) PB2 - (85.44±37.69) PB3 +(42.43±1.05), R2 =0.77, p<0.0001, n=45. The results indicated that both MLR and ANN models were suitable for predicting in vitro NH3 -N concentration of rations using CNCPS N-fractions PB1 , PB2 , and PB3 as independent variables while the neural network model showed better performance in terms of greater r2 , CCC and lower RMSPE between the observed and predicted values.

Live Bacillus subtilis natto Promotes Rumen Fermentation by Modulating Rumen Microbiota In Vitro.

Simple SummaryAlthough there is much research on the applications of Bacillus subtilis natto in dairy cows, the regulation of it on rumen microorganisms and the mechanisms of microbiota that affect rumen fermentation is still unclear, such as the mechanism of improving ruminal ammonia nitrogen concentration and the pathway of increasing propionic acid production. In this study, we explored the effects of live and autoclaved B. subtilis natto on rumen microbiota in vitro by 16S rRNA gene sequencing to clarify the ruminal microbial composition and diversity and their underlying mechanisms.Previous studies have shown that Bacillus subtilis natto affects rumen fermentation and rumen microbial community structure, which are limited to detect a few microbial abundances using traditional methods. However, the regulation of B. subtilis natto on rumen microorganisms and the mechanisms of microbiota that affect rumen fermentation is still unclear. This study explored the effects of live and autoclaved B. subtilis natto on ruminal microbial composition and diversity in vitro using 16S rRNA gene sequencing and the underlying mechanisms. Rumen fluid was collected, allocated to thirty-six bottles, and divided into three treatments: CTR, blank control group without B. subtilis natto; LBS, CTR with 109 cfu of live B. subtilis natto; and ABS, CTR with 109 cfu of autoclaved B. subtilis natto. The rumen fluid was collected after 0, 6, 12, and 24 h of fermentation, and pH, ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acids (VFAs) were determined. The diversity and composition of rumen microbiota were assessed by 16S rRNA gene sequencing. The results revealed LBS affected the concentrations of NH3-N, MCP, and VFAs (p < 0.05), especially after 12 h, which might be attributed to changes in 18 genera. Whereas ABS only enhanced pH and NH3-N concentration compared with the CTR group (p < 0.05), which might be associated with changes in six genera. Supplementation with live B. subtilis natto improved ruminal NH3-N and propionate concentrations, indicating that live bacteria were better than autoclaved ones. This study advances our understanding of B. subtilis natto in promoting ruminal fermentation, providing a new perspective for the precise utilization of B. subtilis natto in dairy rations.

Effect of increasing doses of neem (Azadirachta indica) seed oil on feed intake, nutrients digestibility, ruminal fermentation and nitrogen utilization of Omani sheep

This study was conducted to examine the effects of neem (Azadirachta indica) seed oil (NSO) on feed intake, ruminal fermentability, feed digestibility, nitrogen balance, and blood parameters in Omani sheep. Nine Omani male sheep (BW; 54.44 ± 8 kg/sheep) were used in a replicated 3 × 3 Latin Square design with three dietary treatments and three periods, with each period lasting 21 days. The animals were randomly assigned into three treatment groups: basal diet without NSO (control); 20 mL/sheep per day NSO (low dose) or 40 mL/sheep per day NSO (high dose). Sheep fed with high dose presented lower (p < 0.05) intake, fiber digestibility, and excreted N in urine. However, diet supplemented with high NSO dose had a lower (p < 0.05) ruminal acetate proportion, while increased (p < 0.05) ruminal propionate compared to the control group. Moreover, sheep offered with NSO showed a linear decrease (p = 0.052) in ruminal ammonia nitrogen (NH3-N) concentration. The high dose increased (p < 0.05) blood glucose and cholesterol, while decreased urea nitrogen concentrations. Emission of predicted methane (CH4) reduced (p = 0.007) by 13% for high dose compared to the control group. In conclusion, these results suggested that NSO is a potential feed additive with up to 20 ml/kg of DM alters rumen fermentation profile, decreased CH4 production, feed digestibility, and nitrogen metabolism for sheep.