Influence of Yucca shidigera extract on ruminal ammonia concentrations and ruminal microorganisms

The Effect of Yucca schidigera Extract on Serum Metabolites of Angus Crossbreed Steers with Metabolomics

This study was conducted to explore the potential effect of Yucca schidigera extract (YSE) on the metabolism of beef cattle. Thirty Angus crossbreed steers were selected, with an initial mean body weight of 506.6 ± 33.3 kg, and assigned to two treatments: a diet with no additives (CON group) and a diet supplemented with 1.75 g/kg of YSE (YSE group) (on a dry matter basis). The experiment lasted for 104 days, with 14 days for adaptation. The results showed that adding YSE could significantly improve the average daily gain (ADG) from 1 to 59 d (15.38%) (p = 0.01) and 1 to 90 d (11.38%) (p < 0.01), as well as dry matter digestibility (DMD) (0.84%) (p < 0.05). The contents of alanine aminotransferase, aspartate aminotransferase, and bilirubin and the total antioxidant capacity were increased and blood urea was reduced in the YSE group, compared to the CON group (p < 0.05). Both the glycerophospholipids and bile acids, including phosphocholine, glycerophosphocholine, PC(15:0/18:2(9Z,12Z)), PE(18:0/20:3(5Z,8Z,11Z)), PE(18:3(6Z,9Z,12Z)/P-18:0), LysoPC(15:0), LysoPC(17:0), LysoPC(18:0), LysoPC(20:5(5Z,8Z,11Z,14Z,17Z)), deoxycholic acid, glycocholic acid, and cholic acid, were upregulated by the addition of YSE. In summary, YSE may improve the ADG by increasing the blood total antioxidant capacity and glycerophospholipid synthesis, maintaining steers under a healthy status that is beneficial for growth. Furthermore, YSE may also increase the expression of bile acid synthesis, thereby promoting DMD, which, in turn, offers more nutrients available for growth.

Anti-methanogenic potential of seaweeds and seaweed-derived compounds in ruminant feed: current perspectives, risks and future prospects

With methane emissions from ruminant agriculture contributing 17% of total methane emissions worldwide, there is increasing urgency to develop strategies to reduce greenhouse gas emissions in this sector. One of the proposed strategies is ruminant feed intervention studies focused on the inclusion of anti-methanogenic compounds which are those capable of interacting with the rumen microbiome, reducing the capacity of ruminal microorganisms to produce methane. Recently, seaweeds have been investigated for their ability to reduce methane in ruminants in vitro and in vivo, with the greatest methane abatement reported when using the red seaweed Asparagopsis taxiformis (attributed to the bromoform content of this species). From the literature analysis in this study, levels of up to 99% reduction in ruminant methane emissions have been reported from inclusion of this seaweed in animal feed, although further in vivo and microbiome studies are required to confirm these results as other reports showed no effect on methane emission resulting from the inclusion of seaweed to basal feed. This review explores the current state of research aiming to integrate seaweeds as anti-methanogenic feed additives, as well as examining the specific bioactive compounds within seaweeds that are likely to be related to these effects. The effects of the inclusion of seaweeds on the ruminal microbiome are also reviewed, as well as the future challenges when considering the large-scale inclusion of seaweeds into ruminant diets as anti-methanogenic agents.

Effect of feeding Yucca schidigera extract and a live yeast on the rumen microbiome and performance of dairy cows fed a diet excess in rumen degradable nitrogen

Nitrogen (N) loss from livestock agriculture via ammonia and nitrous oxide can reduce feed efficiency, production and negatively affect the environment. One option to reduce N loss is to add dietary supplements such as Yucca schidigera extract which has ammonia-binding properties and contains antimicrobial steroidal saponins, or Saccharomyces cerevisiae yeast, which can stabilise rumen pH and promote fibre degradation, increasing microbial growth and demand for degradable N. To determine the effect of Yucca schidigera extract when fed alone or in combination with a live yeast on the performance, rumen metabolism, microbiome and N balance, six rumen cannulated dairy cows were fed a mixed ration (C), mixed ration with Y. schidigera extract (De-Odorase®, Alltech®; 5 g/cow/day; D), or mixed ration with Y. schidigera extract (5 g/day) and Saccharomyces cerevisiae (Yea-Sacc®, Alltech®, 1 g/cow per day; DY), in a 3 × 3 Latin rectangle design study with three periods of 49-day duration. Digesta samples were collected via the ruminal cannula during the final week of each period and separated into liquid (LPD) and solid (SPD) phases for microbiome analysis using 16S rRNA amplicon sequencing. DM intake was 0.8 kg/d lower (P < 0.05) in cows fed DY than C or D, with milk protein concentration 1.7 g/kg higher in C than D or DY. There was a beta diversity (Bray Curtis) clustering of the LPD in cows fed D or DY compared to C (P < 0.05), driven by an increase in Prevotella ruminicola-related operational taxonomic units (OTUs), and a decrease in P. brevis and P. bryantii OTUs. A methanogen OTU, Methanobrevibacter olleyae, was decreased in cows fed D or DY and an unclassified species of Gammaproteobacteria was increased in DY (LDA > 2.0, P < 0.05) compared to C. Rumen pH, ammonia and total VFA concentration were not affected by treatment (P > 0.05) but the concentration of propionate and iso-butyrate were lower at 1700 and 2000 h in cows fed DY compared to C (P < 0.05). Measurements of N balance were unaffected by supplementation with D or DY, and there was no effect of treatment on slurry pH. In conclusion, supplementing with an extract of Yucca schidigera either alone or in combination with a live yeast had only a small effect on performance, with Yucca schidigera altering species associated with carbohydrate and protein metabolism, and reduced Methanobrevibacter olleyae which is involved in methanogenesis.

A Review of Effect of Saponins on Ruminal Fermentation, Health and Performance of Ruminants

Saponins are steroid, or triterpene glycoside, compounds found in plants and plant products, mainly legumes. However, some plants containing saponins are toxic. Saponins have both positive and negative roles in animal nutrition. Saponins have been shown to act as membrane-permeabilizing, immunostimulant, hypocholesterolaemic, and defaunating agents in the rumen for the manipulation of ruminal fermentation. Moreover, it has been reported that saponins have impair protein digestion in the gut to interact with cholesterol in the cell membrane, cause cell rupture and selective ruminal protozoa elimination, thus improving N-use efficiency and resulting in a probable increase in ruminant animal performance.

Effects of Different Levels of Yucca Supplementation on Growth Rates, Metabolic Profiles, Fecal Odor Emissions, and Carcass Traits of Growing Lambs

Sixty male Awassi lambs were used to investigate the effects of dietary Yucca schidgera extract (YS) on the production, fecal and urinary odor emissions, and carcass traits of growing lambs fed complete pellets. Lambs were fed either a complete pelleted diet without yucca (control) or supplemented with 300 or 600 mg YS/kg dry matter (DM) during the 84-day experiment. The weights and feed consumption of the lambs were measured weekly. Blood samples were taken on days 1, 28, 58, and 84, and ruminal fluid samples were collected on day 70. On day 90, the odor emissions from feces and urine were measured. On day 84, 12 lambs were slaughtered for the evaluation of carcass and meat quality. The final values for bodyweight, bodyweight gain, and feed efficiency of lambs fed the YS₃₀₀ diet were 3.40%, 6.64%, and 6.17%, respectively, higher (p < 0.05) than those fed the YS₆₀₀ diet. Additionally, the percentage of dressing, myofibril fragmentation index, and ruminal isovalerate percentage of lambs treated with YS₆₀₀ were higher than those treated with YS₃₀₀. Compared with the control, the addition of yucca reduced odor emissions from feces and urine. In conclusion, dietary YS₃₀₀ had no additional benefits on growth rate, feed efficiency, and carcass traits, while dietary YS₆₀₀ improved fecal and urinary odors.

Inclusion of Yucca schidigera extract into finishing diets: impacts on ruminal, physiological, and productive responses of feedlot cattle

This experiment compared ruminal, physiological, and productive responses of feedlot cattle receiving Yucca schidigera extract to replace or fed in conjunction with monensin + tylosin. Angus-influenced steers (n = 120) were ranked by body weight (BW; 315 ± 3 kg) and allocated to 4 groups of 30 steers each. Groups were housed in 1 of 4 drylot pens (30 × 12 m) equipped with GrowSafe feeding systems (4 bunks/pen) during the experiment (day -14 to slaughter). On day 0, groups were randomly assigned to receive a diet containing (2 × 2 factorial): 1) no inclusion or inclusion of monensin + tylosin (360 mg and 90 mg/steer daily, respectively) and 2) no inclusion or inclusion of Y. schidigera extract (4 g/steer daily). Steers were slaughtered in 3 groups balanced by treatment combination (36 steers on day 114, 36 steers on day 142, and 48 steers on day 169). Blood was sampled on days 0, 28, 56, and 84, and the day before shipping to slaughter. On day 41, eight rumen-cannulated heifers (BW = 590 ± 15 kg) were housed with steers (1 pair/pen). Pairs rotated among groups every 21 d, resulting in a replicated 4 × 4 Latin square (n = 8/treatment combination) with 14-d washout intervals. Heifers were sampled for blood and rumen fluid at the beginning and end of each 21-d period. Monensin + tylosin inclusion decreased (P < 0.01) feed intake and improved (P = 0.02) feed efficiency of steers, but did not alter (P ≥ 0.17) steer BW gain or carcass merit traits. Inclusion of Y. schidigera extract did not impact (P ≥ 0.30) steer performance and carcass characteristics. Plasma glucose, insulin, insulin-like growth factor-I, and urea-N concentrations were not affected (P ≥ 0.16) by monensin + tylosin, nor by Y. schidigera extract inclusion in steers and heifers. Ruminal pH in heifers was increased (P = 0.04) by monensin + tylosin, and also by (P = 0.03) Y. schidigera extract inclusion. Rumen fluid viscosity was reduced (P = 0.04) by Y. schidigera extract, and rumen protozoa count was increased (P < 0.01) by monensin + tylosin inclusion. The proportion of propionate in the ruminal fluid was increased (P = 0.04) by monensin + tylosin, and tended (P = 0.07) to be increased by Y. schidigera extract inclusion. Hence, Y. schidigera extract yielded similar improvements in rumen fermentation compared with monensin + tylosin, but without increasing performance and carcass quality of finishing cattle. No complimentary effects were observed when combining all these additives into the finishing diet.

Effects of Dietary Capsaicin and Yucca schidigera Extracts as Feed Additives on Rumen Fermentation and Microflora of Beef Cattle Fed with a Moderate-Energy Diet

Capsaicin (CAP) and Yucca schidigera extract (YSE) are two types of plant extracts that can change rumen fermentation. This study was conducted to investigate whether supplementation of beef cattle diets with CAP and YSE for 90 days would affect rumen fermentation and microflora. Forty-five healthy Angus steers (initial body weight = 510.54 ± 41.27 kg) were divided into three groups: control (CON), CAP, and YSE. Ammonia nitrogen (NH3-N) and total volatile fatty acid (TVFA) concentrations were significantly higher in the YSE group than in the CON group and significantly lower in the CAP group than in the CON group. At the phylum level, YSE increased the relative abundances of Bacteroidota and Patescibacteria and reduced that of Bacillota. At the genus level, CAP and YSE both increased the relative abundances of genera subordinate to Bacteroidota and decreased the relative abundances of genera subordinate to Bacillota. Our study shows that YSE and CAP have different effects on rumen fermentation and microflora after long-term supplementation.

Effects of Allium mongolicum Regel ethanol extract on three flavor-related rumen branched-chain fatty acids, rumen fermentation and rumen bacteria in lambs

The objective of this study was to evaluate the effect of Allium mongolicum Regel ethanol extract (AME) on the concentration of three branched-chain fatty acids (BCFAs) related to flavor, fermentation parameters and the bacteria and their correlations in the rumen of lambs. A total of thirty 3-month-old male, Small-tailed Han sheep (33.60 ± 1.23 kg) were randomly distributed into 2 groups as follows: control group (CON) was fed a basal diet and AME group was fed a basal diet supplemented with 2.8 g⋅lamb–1⋅d–1A. mongolicum Regel ethanol extract. AME supplementation decreased (P = 0.022) 4-methyloctanoic acid (MOA) content and tended to lower (P = 0.055) 4-methylnonanoic acid (MNA) content in the rumen. Compared to CON group, the ruminal concentrations of valerate and isovalerate were higher (P = 0.046 and P = 0.024, respectively), and propionate was lower (P = 0.020) in the AME group. At the phylum level, the AME group had a lower abundance of Bacteroidetes (P = 0.014) and a higher abundance of Firmicutes (P = 0.020) than the CON group. At the genus level, the relative abundances of Prevotella (P = 0.001), Christensenellaceae_R-7_group (P = 0.003), Succiniclasticum (P = 0.004), and Selenomonas (P = 0.001) were significantly lower in the AME group than in the CON group, while the relative abundances of Ruminococcus (P &lt; 0.001), Quinella (P = 0.013), and Lachnospiraceae_XPB1014_group (P = 0.001) were significantly higher. The relative abundances of Prevotella (P = 0.029, R = 0.685; P = 0.009, R = 0.770), Christensenellaceae_R-7_group (P = 0.019, R = 0.721; P = 0.029, R = 0.685), and Succiniclasticum (P = 0.002, R = 0.842; P = 0.001, R = 0.879) was positively correlated with MOA and MNA levels, and the relative abundance of Lachnospiraceae_XPB1014_group (P = 0.033, R = −0.673) was negatively correlated with MOA. The relative abundance of Christensenellaceae_R-7_group (P = 0.014, R = −0.744) and Prevotellaceae_UCG-003 (P = 0.023, R = −0.706) correlated negatively with the EOA content. In conclusion, these findings suggest that the AME affected the concentration of BCFAs, fermentation parameters and the rumen bacteria in the rumen of lambs.

Effects of Yucca schidigera Based Feed Additive on In Vitro Dry Matter Digestibility, Efficiency of Microbial Production, and Greenhouse Gas Emissions of Four Dairy Diets

The present study evaluated the effects of a feed additive (synthesized from Yucca schidigera) on some fermentation variables. In the first of two experiments, seven concentrations of the feed additive were evaluated using the in vitro batch culture technique to determine the optimum dose to use in the second experiment. The substrates used were a total mixed ration (TMR) and alfalfa hay. The levels of inclusion were 0 (control), 0.5, 1, 2, 4, 6, and 8 g/head/d. After this initial evaluation, 2 g/head/d was selected for the second experiment. For the second study, four dietary substrates (two corn silages and two TMR; collected from different dairy farms in the Piedmont, North Carolina, area) were used. Incubation times were 3, 6, and 24 h and treatments were 0 (control) and 2 g/head/d of the feed additive. Inclusion of the feed additive did not affect (p > 0.05) in vitro dry matter disappearance. Additionally, the feed additive had no effect (p > 0.05) on short-chain fatty acid concentrations, microbial mass, and efficiency of microbial production. Methane production was reduced by 22.7% with feed additive inclusion. Similarly, lower (p = 0.013; 18%) carbon dioxide concentration was observed in the feed additive treatment. Ammonia and hydrogen sulfite concentrations were similar (p > 0.05) for both treatments. Inclusion of the feed additive at 2 g/head/d decreased methane and carbon dioxide concentrations in most of the diets. The energy saved by reducing the amount of methane produced was not partitioned into valuable products such as short-chain fatty acids and microbial mass.

Transcriptome analysis of the effect of high-temperature on nutrient metabolism in juvenile grass carp (Ctenopharyngodon idellus)

To investigate the variations in gene expression in grass carp under high-temperature stress, two libraries were constructed from a high-temperature treatment group (T33) and a control group (T27) and sequenced using Illumina sequencing technology. The results showed that sequencing generated a total of 279,398,348 raw reads, approximately 40.7-51.8 M clean reads were obtained from each library, and the percentage of uniquely mapped transcripts ranged from 80.13 to 84.58%. A total of 260 differentially expressed genes (DEGs) were identified under high-temperature stress, among which 84 genes were upregulated and 176 genes were downregulated. Ten DEGs were randomly selected for quantitative RT-PCR (qRT-PCR) analysis, and the results confirmed that the transcriptome analysis was reliable. Furthermore, the DEGs were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and the results showed that most of the DEGs were involved in protein, lipid and carbohydrate metabolism. Moreover, plasma urea nitrogen (Urea) and triglyceride (TG) contents were significantly lower in the high-temperature treatment group than in the control group (P < 0.01). In summary, these results indicated that high-temperature stress could inhibit protein synthesis, decrease fatty acid synthesis, and weaken carbohydrate metabolism in juvenile grass carp.

Micro-Aid Liquid 10 Promotes Growth Performance and Health Status of White Shrimp, Litopenaeus vannamei

An experiment was conducted to evaluate the effects of the Micro-Aid Liquid 10 (MAL10) (DPI Global, Porterville, CA, USA), a product made from yucca extract, on growth performance, gut microbiota, and resistance of white shrimp, Litopenaeus vannamei against infectious disease caused by Vibrio alginolyticus. MAL10 was added to shrimp rearing water at different levels of 0 (control), 0.25 mL m3−1 (W0.25), 0.5 mL m3−1 (W0.5), 1 mL m3−1 (W1), and 5 mL m3−1 (W5), respectively, once per week for 70 days. Growth performances, including final body weight, specific growth rate, average daily growth and percentage of weight gain, were significantly improved by adding the MAL10 at levels up to 5 mL m3−1, which may be due to the proliferation of B cells in hepatopancreas of MAL10-treated shrimp. No significant differences in the total viable count and Vibrio-like count in the gut of shrimp were recorded by spread plate method. In the challenge test, shrimp reared in the water supplemented with MAL10 at levels of 1–5 mL m3−1 had significantly lower cumulative mortality after a challenge test with V. alginolyticus compared to shrimp reared in the control, W0.25 and W0.5 groups. Next-generation sequencing indicated that the relative distribution of phylum Proteobacteria in control (80.4%) was higher than the W (77.4%). The proportion of Vibrio was primarily dominant genera in the shrimp intestine and highest in the control group compared to the W group, followed by Spongiimonas, Motilimonas, Demequina, and Shewanella genera. Although there was no statistically significant difference, higher α-diversity indices were recorded in the W5-treated group than in the control group. Therefore, it is considered that MAL10 could be used as a natural alternative in shrimp aquaculture to reduce the risk of infectious disease caused by pathogenic Vibrio and improve the growth performance of white shrimp.

Effects of dietary inclusion of Moringa oleifera leaf meal on nutrient digestibility, rumen fermentation, ruminal enzyme activities and growth performance of buffalo calves

This study was conducted to investigate the impact of dietary inclusion of Moringa oleifera leaf meal (MLM) as a substitution for soybean meal on nutrient digestibility, rumen fermentation, rumen enzyme activity, blood metabolites, growth-related hormones, and growth performance of buffalo calves. Thirty buffalo calves eight to nine months of age with an average body weight of approximately 153.7 ± 0.97 kg were randomly distributed through three dietary treatments (ten calves/treatment). MLM inclusion rates were 15% (M15) and 20% (M20), replacing soybean meal by 50 and 75% in the concentrate mixture, respectively. The results indicated that, digestibility of dry matter, organic matter (OM), and crude fiber (CF) increased significantly (p < 0.05) with MLM inclusion, while the digestibility of crude protein (CP) and ether extract (EE) reduced significantly (p < 0.05) with MLM addition. Dietary supplementation with MLM significantly affected (p < 0.001) rumen fermentation by reducing ruminal enzymes, ruminal ammonia-N, total protozoa, and acetate/propionate ratio and increasing acetic, propionic, and butyric acids and total volatile fatty acid concentrations (p < 0.001). Furthermore, dietary inclusion of 15% MLM significantly improved (p < 0.001) final body weight, dry matter intake of feed, daily weight gain, feed conversion efficiency, blood metabolites, and plasma insulin growth factor-I (IGF-I). It can be concluded that MLM is a multi-purpose protein supplement that provides some nutritional and therapeutic advantages when replacing 50% of soybean meal. Dietary supplementation of 15% MLM improved rumen fermentation, growth performance, blood metabolites, plasma IGF-I and mitigated ammonia and methane without any adverse effects in growing buffalo calves.

Supplementing Yucca schidigera extract to mitigate frothy bloat in beef cattle receiving a high-concentrate diet

This experiment compared incidence of frothy bloat, as well as ruminal, physiological, and performance responses of beef heifers receiving a bloat-provoking diet and supplemented with Yucca schidigera extract. Sixteen ruminally cannulated Angus-influenced heifers were ranked by body weight (BW) and assigned to 4 groups of 4 heifers each. Groups were enrolled in a replicated 4 × 4 Latin square design containing 4 periods of 28 d, and a 21-d washout interval between periods. Groups were assigned to receive no Y. schidigera extract (CON), or Y. schidigera extract at (as-fed basis) 1 g/heifer daily (YS1), 2 g/heifer daily (YS2), or 4 g/heifer daily (YS4). During each period, heifers (n = 16/treatment) were housed in individual pens, and fed a sorghum (Sorghum bicolor L.)-based bloat-provocative diet at 2% of their BW. Diet and treatments were individually fed to heifers, twice daily in equal proportions (0700 and 1600 hours). Heifers were assessed for bloat score (0 to 5 scale, increasing according to bloat severity) 3 hr after the morning feeding. Blood samples were collected on days 0, 7, 14, 21, and 28 prior to (0 hr) and at 3, 6, and 9 hr relative to the morning feeding. Rumen fluid samples were collected at the same time points on days 0 and 28. Orthogonal contrasts were tested to determine whether inclusion of Y. schidigera extract (0, 1, 2, or 4 g/heifer daily) yielded linear or quadratic effects, and explore an overall effect of Y. schidigera extract supplementation (CON vs. YS1 + YS2 + YS4). Rumen fluid viscosity was impacted quadratically by Y. schidigera extract inclusion (P = 0.02), being greatest in YS1, followed by YS2, and equivalent between CON and YS4 heifers. Heifers receiving Y. schidigera extract had greater (P ≤ 0.05) rumen propionate, iso-valerate, and valerate concentrations, as well as less (P < 0.01) acetate : propionate ratio compared with CON heifers. Inclusion of Y. schidigera extract linearly increased (P ≤ 0.04) average daily gain and feed efficiency. No other treatment effects were noted (P ≥ 0.19) including bloat score (1.07 ± 0.03 across treatments), ruminal protozoa count, plasma concentrations of cortisol, haptoglobin, urea N, total protein, and rumen concentration of total volatile fatty acids. Supplementing Y. schidigera extract up to 4 g/d favored rumen propionate concentrations and linearly increased growth and feed efficiency but failed to mitigate incidence of frothy bloat in beef heifers consuming a grain-based bloat-provocative diet.

Astragalus membranaceus root supplementation improves average daily gain, rumen fermentation, serum immunity and antioxidant indices of Tibetan sheep

The use of antibiotics as supplements in animal feed is restricted due to possible health hazards associated with them. Consequently, there is increasing interest in exploiting natural products to improve health and production of livestock with no detrimental side effects. In this study, we examined the effect of Astragalus membranaceus root (AMT) supplementation on DM intake, growth performance, rumen fermentation and immunity of Tibetan sheep. Twenty-four male Tibetan sheep (31 ± 1.4 kg; 9 months old) were assigned randomly to one of four dietary treatments with different levels of AMT: 0, 20, 50 and 80 g/kg DM (A₀, A₂, A₅ and A₈, respectively) in addition to their basal diets. A₀ acted as a control group, and measurements were recorded over a 56-d feeding period. Sheep fed with AMT had a higher average daily gain and a lower feed:gain ratio than controls (P < 0.001). Rumen concentrations of NH₃-N (P < 0.001), total volatile fatty acids (P = 0.028), acetate (P = 0.017) and propionate (P = 0.031) in A₅ and A₈ were higher than those in A₀. The addition of AMT in the feed significantly increased serum antioxidant and immunity factors of the sheep and increased the concentrations of serum interleukin, immunoglobulin and tumour necrosis factor-α (P = 0.010). We concluded that AMT can be used as a feed additive to improve growth performance and rumen fermentation and enhance the immunity of Tibetan sheep. Some responses exhibited a dose-dependent response, whereas other did not exhibit a pattern, with an increase in AMT. The addition of 50 and 80 g/kg AMT of total DM intake showed the most promising results.

Combination Effects of Plant Extracts Rich in Tannins and Saponins as Feed Additives for Mitigating in Vitro Ruminal Methane and Ammonia Formation

The objective of this experiment was to test the effects of combining plant extracts rich in tannins and saponins at varying proportions on in vitro ruminal methane and ammonia formation. Tannins were extracted from Swietenia mahogani leaves and saponins from Sapindus rarak fruits with various solvents. The extracts obtained with the most efficient solvents (tannins: 75% water and 25% methanol; saponins: pure methanol) were then used in vitro. The treatments consisted of two substrate types (high-forage (HF) or high-concentrate (HC) diets) and five extract combinations (tannins: saponins, 1:0, 3:1, 1:1, 1:3, and 0:1) added at 2 mg/mL in incubation liquid. In vitro incubation was performed in four runs, with each treatment being represented with two replicates per run. The addition of plant extracts rich in tannins and saponins, either individually or in combination, decreased the methane proportion of total gas in both the HF (p < 0.05) and HC (p < 0.05) diets. The effects of the plant extracts rich in tannins and saponins were generally additive in mitigating methane emissions. Favorable associative effects between the extracts were observed in the ammonia concentration, both in the HF (p < 0.001) and HC (p < 0.01) diets and in the methane proportion of total gas, with a 1:3 mixture of tannins and saponins added to the HC diet (p < 0.05).

Effect of Yucca schidigera extract on the growth performance, intestinal antioxidant status, immune response, and tight junctions of mirror carp (Cyprinus carpio)

The current study was designed to evaluate the effect of Yucca schidigera extract (YSE) on the growth performance, intestinal antioxidant status, immune response, and tight junctions of mirror carp (Cyprinus carpio). A total of 450 mirror carp (45.21 ± 0.43 g) were fed diets supplemented with 0, 200, or 400 mg/kg YSE for 8 weeks. Compared with the control (0 mg/kg), the final body weight and weight gain rate were significantly higher in the 400 mg/kg YSE group (P < 0.05), and the serum ammonia concentration was significantly lower in both YSE groups (P < 0.05). Additionally, the total antioxidant capacity was significantly higher in the 400 mg/kg YSE group (P < 0.05), and the malondialdehyde content was significantly lower in both YSE groups (P < 0.05). Complement 3 and 4 contents were significantly higher in the 400 mg/kg YSE group (P < 0.05), and lysozyme was significantly higher in both YSE groups compared to the control group (P < 0.05). The relative mRNA levels of copper zinc superoxide dismutase, catalase, glutathione peroxidase1a, and nuclear factor erythroid 2-related factor 2 as well as transforming growth factor β were significantly higher in both YSE supplemented groups compared to the control (P < 0.05), whereas the relative mRNA level of Kelch-like ECH-associated protein 1 was significantly lower in both YSE supplemented groups (P < 0.05). The relative mRNA levels of interleukin 1β and interleukin 6 were significantly lower in the 400 mg/kg YSE supplemented group compared to the control (P < 0.05). Additionally, both YSE levels decreased the relative mRNA expression of tumour necrosis factor-α (P < 0.05). The relative mRNA levels of ZO-1 and claudin 11 were significantly higher in both YSE supplemented groups (P < 0.05), and the relative mRNA level of occludin was significantly higher in the 200 mg/kg YSE group than the control and 400 mg/kg YSE groups (P < 0.05). In conclusion, dietary supplementation with 400 mg/kg YSE improved the growth, intestinal antioxidant status, immune response, and tight junctions of mirror carp.

Origin of the extremely high elasticity of bulk emulsions, stabilized by Yucca Schidigera saponins

We found experimentally that the elasticity of sunflower oil-in-water emulsions (SFO-in-W) stabilized by Yucca Schidigera Roezl saponin extract, is by >50 times higher as compared to the elasticity of common emulsions. We revealed that strong specific interactions between the phytosterols from the non-purified oil and the saponins from the Yucca extract lead to the formation of nanostructured adsorption layers which are responsible for the very high elasticity of the oil-water interface and of the respective bulk emulsions. Remarkably, this extra high emulsion elasticity inhibits the emulsion syneresis even at 65 vol% of the oil drops - these emulsions remain homogeneous and stable even after 30 days of shelf-storage. These results demonstrate that the combination of saponin and phytosterols is a powerful new approach to structure oil-in-water emulsions with potential applications for formulating healthier functional food.

Effects of Licorice Extract Supplementation on Feed Intake, Digestion, Rumen Function, Blood Indices and Live Weight Gain of Karakul Sheep

Simple Summary

The aim of this study was to investigate the effects of licorice extract supplementation on feed intake and digestibility, rumen function, blood indices and live weight gain of Karakul sheep. The results indicated that licorice extract supplementation in the diet at 4.5% of dry matter level had limited impact on rumen function but improved blood immunoglobulin and anti-oxidative status of Karakul sheep, without impairment of feed conversion efficiency or live weight gain.

Abstract

This study was designed to investigate the effects of licorice extract supplemented to a cottonseed hull-based diet on rumen function, blood indices and growth of Karakul sheep. Twelve rumen-fistulated 1.5-year-old sheep were blocked in pairs by live weight. Sheep within pairs were randomly allocated to feed either on a cottonseed hull basal diet (control group) or on a basal diet containing 4.5% of licorice extract on dry matter (DM) basis (supplemented group). Sheep were housed individually and fed for 60 days, with a 15-day adaptation period and a 45-day measurement period. Feed intake and live weight gain were quantified. Rumen and blood samples were taken during the measurement period. The DM intake was lower for the supplemented group than for the control group. The mean ruminal concentrations of total volatile fatty acid (VFA) and acetate and the ratio of acetate to propionate were lower, while the levels of propionate and butyrate were higher for the supplemented group than for the control group. Average daily live weight gain, digestible energy intake, apparent nutrient digestibility and feed conversion efficiency did not differ between the two treatments. The serum concentrations of immunoglobulin A and G were 2.1 and 1.8 times greater, and total antioxidant and superoxide dismutase increased by 1.8 and 1.2 times in the supplemented group compared with the control group. These results indicated that licorice extract supplementation in the diet at 4.5% of DM had a limited impact on rumen function but improved blood immunoglobulin and anti-oxidative status of Karakul sheep, without impairment of feed conversion efficiency or live weight gain.

Ferric citrate, nitrate, saponin and their combinations affect in vitro ruminal fermentation, production of sulphide and methane and abundance of select microbial populations

AIMS

This study investigated the effects of ferric citrate, nitrate and saponin, both individually and in combination, on sulphidogenesis, methanogenesis, rumen fermentation and abundances of select microbial populations using in vitro rumen cultures.

METHODS AND RESULTS

Ferric citrate (50 mg l^-1 ), Quillaja saponin (0·6 g l^-1 ) and sodium nitrate (5 mmol l^-1 ) were used in in vitro ruminal fermentation. Ferric citrate alone, its combination with saponin and/or nitrate lowered the aqueous sulphide concentration and total sulphide production. Methane production was suppressed by nitrate alone (by up to 32·92%), its combination with saponin (25·04%) and with both saponins with nitrate (25·92%). None of the treatments adversely affected feed digestion or rumen fermentation. The population of sulphate-reducing bacteria was increased by nitrate and saponin individually, while that of total Archaea was decreased by nitrate alone and the combination of the three inhibitors.

CONCLUSIONS

Nitrate and its combination with saponin or both ferric citrate and saponin substantially decreased methane production. Most importantly, the decreased methane production was not at the expense of feed digestion or fermentation. Sulphidogenesis from the sulphate present in the high-sulphur diets can be suppressed competitively by ferric citrate, although it was elevated by saponin and nitrate.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study demonstrated that combinations of certain methane inhibitors, which have different mechanisms of antimethanogenic actions or inhibit different guilds of microbes involved in methane production and sulphate reduction, can be more effective and practical than individual inhibitors, not only in mitigating enteric methane emission but also in lowering the risk of sulphur-associated polioencephalomalacia in feedlot cattle fed high sulphur diets.

Ensiling characteristics, in vitro rumen fermentation, microbial communities and aerobic stability of low-dry matter silages produced with sweet sorghum and alfalfa mixtures

BACKGROUND

Silages produced with grass and legume mixtures may have positive associative effects on silage quality and animal performance when ruminants are fed the silages. The present study aimed to determine the preservation characteristics, in vitro rumen fermentation profile and microbial abundance of silages, produced with mixtures of sweet sorghum (SS) and alfalfa (AF) in different ratios: 100:0 (Control), 75:25 (SA25), 50:50 (SA50), 25:75 (SA75) and 0:100 (SA100) on a fresh weight basis.

RESULTS

As the proportion of AF increased in the silages, pH, acetic acid, ammonia nitrogen and crude protein (CP) concentrations, and aerobic stability increased (P < 0.05), whereas lactic acid and neutral detergent fibre (NDF) and acid detergent fibre (ADF) concentrations decreased (P < 0.05). Increasing the proportion of AF in the silages, increased (P < 0.05) the in vitro degradability of dry matter and CP, as well as the proportions of genus Prevotella, but decreased (P < 0.05) the in vitro degradability of NDF (IVNDFD) and ADF (IVADFD) and proportions of Butyrivibrio fibrisolvens. Compared to the Control silage, SA25 silage had greater (P < 0.05) proportions of Fibrobacter succinogenes and Ruminococcus flavefaciens, IVNDFD, IVADFD, ruminal short chain fatty acids and microbial protein concentrations, as well as lower (P < 0.05) methane production.

CONCLUSION

The silage produced with the SS to AF ratio of 75:25 was the most suitable for ruminants use as a result of the optimal balance of fermentation quality, feed-nutritional value and aerobic stability. © 2018 Society of Chemical Industry.

Productive and physiological responses of feeder cattle supplemented with Yucca schidigera extract during feedlot receiving

This experiment evaluated the effects of supplementing a saponin-containing feed ingredient, manufactured from purified extract of Yucca schidigera [Micro-Aid (MA); DPI Global; Porterville, CA], on performance, health, and physiological responses of receiving cattle. A total of 105 recently weaned Angus x Hereford calves (75 steers and 30 heifers), originating from eight cow-calf operations, were obtained from an auction facility on day -2 and road transported (800 km; 12 h) to the experimental facility. Immediately after arrival on day -1, shrunk BW was recorded and calves were grouped with free-choice access to grass hay, mineral supplement, and water. On day 0, calves were ranked by sex, source, and shrunk BW, and allocated to one of 21 pens (5 calves/pen; being one or two heifers within each pen). Pens were assigned to receive a total mixed ration (TMR) and one of three treatments (as-fed basis): (1) 1 g/calf daily of MA (M1; n = 7), (2) 2 g/calf daily of MA (M2; n = 7), or (3) no MA supplementation (CON; n = 7). Calves received the TMR to yield 15% (as-fed basis) orts, and treatments were top-dressed from days 0 to 59. Calves were assessed for bovine respiratory disease (BRD) signs and TMR intake was recorded for each pen daily. Calves were vaccinated against BRD pathogens on days 0 and 21. Final shrunk BW was recorded on day 60, and blood samples were collected on days 0, 2, 6, 10, 14, 21, 28, 34, 45, and 59. ADG was greater (P = 0.03) in M2 vs. M1 and CON (1.53, 1.42, and 1.42 kg/day, respectively), and similar (P = 0.95) between M1 and CON calves. No treatment effects were detected for TMR intake (P = 0.52), whereas feed efficiency was greater (P ≤ 0.05) in M2 vs. M1 and CON calves (213, 200, and 204 g/kg, respectively) and similar (P = 0.40) between M1 and CON calves. No treatment effects were detected (P = 0.39) for diagnosis of BRD signs. The number of antimicrobial treatments required upon BRD diagnosis was greater (P ≤ 0.01) in CON vs. M1 and M2 (1.40, 1.05, and 1.10 treatments, respectively), and similar (P = 0.60) between M1 and M2 calves. No other treatment effects were detected (P ≥ 0.23), including circulating concentrations of hormones and metabolites, serum antibody titers to BRD pathogens, and mRNA expression of innate immunity genes in whole blood. Collectively, results from this experiment suggest that MA supplementation at 2 g/animal daily enhances performance and response to BRD treatment in high-risk cattle during feedlot receiving.

Effect of supplementation of saponin containing herbs on in vitro methane production under different feeding systems

This study was taken up to assess the effect of herbal feed additives [HFAs; kulthi (Dohichos biflorus), patha (Cissampelos pareria), aritha (Sapindus trifoliatus)] supplemented at 0–3% on DM basis of total mixed rations (TMR) on the in vitro methane production and nutrient fermentation in a 3 × 4 factorial design. TMR with different roughage to concentrate ratio (R:C) of 80:20, 75:25, 70:30 and 65:35 on DM basis were formulated. The roughage portion was made up of wheat straw and maize green fodder in 70:30 ratio. The chemical analysis of HFAs revealed that aritha had the highest concentration of both water and methanol soluble saponins; and condensed tannins (Leucocyanidin). Patha followed by kulthi had the highest concentration of vitamin C, flavonoids, total phenols and true tannins. The digestion kinetic parameters revealed that with the increase in level of concentrate in the diet, irrespective of type and level of supplementation of HFAs, the lag phase for fermentation of diet decreased linearly. The data conclusively revealed that the best response with respect to net gas production (NGP), digestibility of nutrients, methane production, volatile fatty acid (VFA) production, ME availability and other fermentation parameters from TMRs with different R:C ratios was observed in kulthi and patha supplemented at the rate of 2% of TMR with R:C ratio of 65:35 on DM basis.

Saponins from Quillaja saponaria and Quillaja brasiliensis: Particular Chemical Characteristics and Biological Activities

Quillaja saponaria Molina represents the main source of saponins for industrial applications. Q. saponaria triterpenoids have been studied for more than four decades and their relevance is due to their biological activities, especially as a vaccine adjuvant and immunostimulant, which have led to important research in the field of vaccine development. These saponins, alone or incorporated into immunostimulating complexes (ISCOMs), are able to modulate immunity by increasing antigen uptake, stimulating cytotoxic T lymphocyte production (Th1) and cytokines (Th2) in response to different antigens. Furthermore, antiviral, antifungal, antibacterial, antiparasitic, and antitumor activities are also reported as important biological properties of Quillaja triterpenoids. Recently, other saponins from Q. brasiliensis (A. St.-Hill. & Tul.) Mart. were successfully tested and showed similar chemical and biological properties to those of Q. saponaria barks. The aim of this manuscript is to summarize the current advances in phytochemical and pharmacological knowledge of saponins from Quillaja plants, including the particular chemical characteristics of these triterpenoids. The potential applications of Quillaja saponins to stimulate further drug discovery research will be provided.

Yucca schidigera can mitigate ammonia emissions from manure and promote poultry health and production

Mojave yucca (Yucca schidigera) is widely grown in the deserts. This herb is commercially used because it is rich in saponins and phenolic compounds with antioxidant effect. Y. schidigera or its derivatives are included as nontoxic food supplements, in cosmetics, and in the pharmaceutical industry. Saponins originated from Y. schidigera have anti-inflammatory, antioxidant, immunostimulatory, growth promoter, hypocholesterolemic, and hypoglycemic effects. To date, the key role of Y. schidigera or its products in animal nutrition is to reduce the ammonia content in the atmosphere and fecal odor in poultry excreta. Mitigating ammonia by using this plant could be achieved by the modification of gut microbiota, enhancement in digestion, and absorption of nutrients, leading to a better growth and production performance of animals and poultry. Various methods were applied to mitigate the emission of odor from the litter by different strategies including biofilters, litter treatments, air scrubbers, neutralizing agents, windbreak walls, etc., but these techniques are expensive. This article provides a new insight to scientists and poultry breeders to use Y. schidigera plant or its products as inexpensive and safe sources of a feed supplement to overcome the ammonia and fecal odor problems, as well as reduce environmental pollution in poultry houses.

Phytochemicals as antibiotic alternatives to promote growth and enhance host health

There are heightened concerns globally on emerging drug-resistant superbugs and the lack of new antibiotics for treating human and animal diseases. For the agricultural industry, there is an urgent need to develop strategies to replace antibiotics for food-producing animals, especially poultry and livestock. The 2nd International Symposium on Alternatives to Antibiotics was held at the World Organization for Animal Health in Paris, France, December 12-15, 2016 to discuss recent scientific developments on strategic antibiotic-free management plans, to evaluate regional differences in policies regarding the reduction of antibiotics in animal agriculture and to develop antibiotic alternatives to combat the global increase in antibiotic resistance. More than 270 participants from academia, government research institutions, regulatory agencies, and private animal industries from >25 different countries came together to discuss recent research and promising novel technologies that could provide alternatives to antibiotics for use in animal health and production; assess challenges associated with their commercialization; and devise actionable strategies to facilitate the development of alternatives to antibiotic growth promoters (AGPs) without hampering animal production. The 3-day meeting consisted of four scientific sessions including vaccines, microbial products, phytochemicals, immune-related products, and innovative drugs, chemicals and enzymes, followed by the last session on regulation and funding. Each session was followed by an expert panel discussion that included industry representatives and session speakers. The session on phytochemicals included talks describing recent research achievements, with examples of successful agricultural use of various phytochemicals as antibiotic alternatives and their mode of action in major agricultural animals (poultry, swine and ruminants). Scientists from industry and academia and government research institutes shared their experience in developing and applying potential antibiotic-alternative phytochemicals commercially to reduce AGPs and to develop a sustainable animal production system in the absence of antibiotics.

Effects of naturally-produced lovastatin on feed digestibility, rumen fermentation, microbiota and methane emissions in goats over a 12-week treatment period

Twenty male Saanen goats were randomly assigned to four levels of lovastatin supplementation and used to determine the optimal dosage and sustainability of naturally produced lovastatin from fermentation of palm kernel cake (PKC) with Aspergillus terreus on enteric methane (CH₄) mitigation. The effects on ruminal microbiota, rumen fermentation, feed digestibility and health of animal were determined over three measuring periods (4-, 8- and 12-weeks) and the accumulation of lovastatin in tissues was determined at the end of the experiment. The diets contained 50% rice straw, 22.8% concentrates and 27.2% of various proportions of untreated or treated PKC to achieve the target daily intake level of 0 (Control), 2, 4 or 6 mg lovastatin/kg body weight (BW). Enteric CH₄ emissions per dry matter intake (DMI), decreased significantly (P<0.05) and equivalent to 11% and 20.4%, respectively, for the 2 and 4 mg/kg BW groups as compared to the Control. No further decrease in CH₄ emission thereafter with higher lovastatin supplementation. Lovastatin had no effect on feed digestibility and minor effect on rumen microbiota, and specifically did not reduce the populations of total methanogens and Methanobacteriales (responsible for CH₄ production). Similarly, lovastatin had little effect on rumen fermentation characteristics except that the proportion of propionate increased, which led to a decreasing trend (P<0.08) in acetic: propionate ratio with increasing dosage of lovastatin. This suggests a shift in rumen fermentation pathway to favor propionate production which serves as H⁺ sink, partly explaining the observed CH₄ reduction. No adverse physiological effects were noted in the animals except that treated PKC (containing lovastatin) was less palatable at the highest inclusion level. Lovastatin residues were detected in tissues of goats fed 6 mg lovastatin/kg BW at between 0.01 to 0.03 μg/g, which are very low.

Does intra-ruminal nitrogen recycling waste valuable resources? A review of major players and their manipulation

Nitrogenous emissions from ruminant livestock production are of increasing public concern and, together with methane, contribute to environmental pollution. The main cause of nitrogen-(N)-containing emissions is the inadequate provision of N to ruminants, leading to an excess of ammonia in the rumen, which is subsequently excreted. Depending on the size and molecular structure, various bacterial, protozoal and fungal species are involved in the ruminal breakdown of nitrogenous compounds (NC). Decelerating ruminal NC degradation by controlling the abundance and activity of proteolytic and deaminating microorganisms, but without reducing cellulolytic processes, is a promising strategy to decrease N emissions along with increasing N utilization by ruminants. Different dietary options, including among others the treatment of feedstuffs with heat or the application of diverse feed additives, as well as vaccination against rumen microorganisms or their enzymes have been evaluated. Thereby, reduced productions of microbial metabolites, e.g. ammonia, and increased microbial N flows give evidence for an improved N retention. However, linkage between these findings and alterations in the rumen microbiota composition, particularly NC-degrading microbes, remains sparse and contradictory findings confound the exact evaluation of these manipulating strategies, thus emphasizing the need for comprehensive research. The demand for increased sustainability in ruminant livestock production requests to apply attention to microbial N utilization efficiency and this will require a better understanding of underlying metabolic processes as well as composition and interactions of ruminal NC-degrading microorganisms.

Effects of Leymus chinensis replacement with whole-crop wheat hay on blood parameters, fatty acid composition, and microbiomes of Holstein bulls

This study investigated the replacement of Leymus chinensis (LC) with whole-crop wheat hay (WCWH) in the diets of Holstein bulls in the fattening stage and examined the potential effects on blood parameters, fatty acids in rumen fluid and serum, and the rumen microbiomes. In this study, 12 Holstein bulls in the fattening period (body weight = 485.0 ± 40.8 kg) were assigned to 1 of 4 dietary treatments using a 4 × 4 Latin square design. Each experimental period consisted of a 17-d adaptation period and a 5-d collection period. The dietary treatments consisted of 4 proportions of WCWH (0, 33, 67, and 100%) as a substitute for LC (designated as WCWH0, WCWH33, WCWH67, and WCWH100, respectively). On d 18 and 22 of each experiment period, blood and rumen content samples were collected for analysis, respectively. Real-time quantitative PCR was used to analyze the rumen microbiomes. The results from this study revealed no differences in the saturated, monounsaturated, and polyunsaturated long-chain fatty acid proportions of rumen liquid among the treatments. It was observed in the present trial that rumen microbiotal flora were not significantly different in the bulls fed LC compared with the bulls fed WCWH. Additionally, blood sample analysis demonstrated that the concentration of urea nitrogen in the WCWH100 group was higher than that observed in the other groups. Meanwhile, no differences were detected for other serum parameters. There were no differences in the proportions of serum saturated, monounsaturated, and polyunsaturated long-chain fatty acids among the treatments. In conclusion, our data revealed that LC can be replaced with WCWH in the diet of Holstein bulls in the fattening stage with no negative effects on the blood indicators, fatty acids, and microbiomes.

Yucca schidigera can promote rabbit growth, fecundity, affect the release of hormones in vivo and in vitro, induce pathological changes in liver, and reduce ovarian resistance to benzene

This study evaluated the effect of Yucca schidigera (YS) extract on the physiological, reproductive, and endocrine indexes of New Zealand White rabbit does. Six-week-old rabbit does were fed a standard diet (control group) or a diet enriched with 5 or 20g of Y powder extract per 100-kg feed mixture for 350days. The does were artificially inseminated after induction of superovulation. Weight gain; conception and kindling rate; viability of pups and mothers; histopathological state of liver and muscle; plasma levels of progesterone (P4), oxytocin (OT), and prostaglandin F (PGF); and the release of P4, insulin-like growth factor I (IGF-I), OT, and PGF by isolated ovarian fragments and their response to the addition of benzene were analyzed. YS extract supplementation promoted weight gain and induced histopathological changes in the liver (creased vacuolization and occurrence of fuchsinophile inclusions in hepatocytes, liver fibrosis, hyperemia, occurrence of Kupffer cells, signs of necrosis and inflammation). YS consumption was not associated with changes in muscle (occurrence of fuchsinophile inclusions and signs of atrophy, interstitial edema, and inflammation), although Y2 increased muscle vascularization. YS supplementation increased conception and kindling rates but did not affect viability of pups or adult animals. Moreover, it enhanced plasma OT and PGF levels; plasma P4 concentration was increased by low-dose YS, but decreased by high-dose YS. Cultured ovarian fragments isolated from YS-fed does released more P4 and PGF and less IGF-I than ovarian fragments of control animals. However, YS supplementation did not affect ovarian OT release. Benzene alone did not influence the release of hormones by ovaries of control does. YS supplementation induced the inhibitory effect of benzene on the release of PGF, but not on other ovarian hormones. Collectively, these results suggest that dietary supplementation of YS extract can stimulate rabbit performance (growth and fecundity), which may be due to the promotion of P4, OT, and PGF release. It could, however, induce some pathological changes in the liver and reduce resistance of ovaries to the environmental contaminant benzene.

In vitro screening of natural feed additives from crustaceans, diatoms, seaweeds and plant extracts to manipulate rumen fermentation

BACKGROUND

Eight natural products from animal, unicellular algae, brown seaweed and plant origins were chosen according to their theoretical antimicrobial activity: Diatomaceous earths (DE), insoluble chitosan (ICHI), soluble chitosan (CHI), seaweed meal (SWM), Ascophyllum nodosum (ASC), Laminaria digitata (LAM), neem oil (NOIL) and an ivy fruit extract rich in saponins (IVY). Dose-response incubations were conducted to determine their effect on rumen fermentation pattern and gas production, while their anti-protozoal activity was tested using (14) C-labelled bacteria.

RESULTS

DE, SWM, NOIL and ICHI had very small effects on rumen function when used at inclusion rate up to 2 g L(-1) . ASC had anti-protozoal effects (up to -23%) promoting a decrease in gas production and methanogenesis (-15%). LAM increased VFA production (+7%) and shifted from butyrate to acetate. CHI also shifted fermentation towards propionate production and lower methane (-23%) and protozoal activity (-56%). IVY decreased protozoal activity (-39%) and ammonia concentration (-56%), as well as increased feed fermentation (+11% VFA concentration) and shifted from acetate to propionate production.

CONCLUSIONS

ASC, LAM, CHI and IVY showed promising potential in vitro as feed additives to improve rumen function, thus more research is needed to investigate their mode of action in the rumen microbial ecosystem. © 2015 Society of Chemical Industry.

Inclusion of Yucca schidigera extract in diets with different protein levels for dogs

This study evaluated the effects of inclusion of Yucca schidigera extract (YSE) in two diets with different levels of crude protein (CP) for dogs on facal odour, nutrient digestibility, ammonia concentration in feces and hematological and serum biochemical profiles. Twenty adults Beagles were used, distributed in a randomized block design in a 2 × 4 factorial design (two diets, 25% and 34% CP, and four YSE levels: 0, 250, 500 and 750 mg/kg) with five replicates, obtained during two experimental periods. The fecal odour reduced (P < 0.05) when 500 mg/kg of YSE was used in diets with higher CP. The inclusion of YSE reduced (P < 0.05) fecal ammonia, and the inclusion of 250 and 500 mg/kg YSE reduced intestinal gas. The inclusion of 750 mg/kg YSE increased the mean corpuscular hemoglobin (MCH), alanine aminotransferase (ALT) activity and tended to increase the serum cholesterol concentration, regardless of the protein level of the diets. There was no effect on the digestibility of nutrients, fecal consistency, nitrogen balance and thickness of the intestinal wall. The inclusion of 500 mg/kg YSE is effective in reducing fecal odour in dogs receiving diets with 34% of CP. Regardless of the protein content, YSE reduces fecal ammonia, but may cause adverse effects if included at higher doses.

Effects of twenty percent alkaline-treated corn stover without or with yucca extract on performance and nutrient mass balance of finishing steers fed modified distillers grains-based diets

Two experiments were conducted with 192 steers each (during the winter [November to May] or summer [June to October]) to evaluate 3 diets with or without Yucca schidigera extract in a 3 × 2 factorial on steer growth performance and N mass balance. One factor was diet (DM basis): 1) 5% untreated corn stover, 51% corn, and 40% modified distillers grains plus solubles (MDGS; CON); 2) 20% calcium oxide-treated corn stover (CaO added at 5% of stover DM), 40% MDGS, and 36% corn (TRT); or 3) 20% untreated corn stover, 40% MDGS, and 36% corn (NONTRT). The other factor was dietary extract at 0 (NOYE) or 1.0 g/d per steer (YE). No interaction between diet and YE was detected (P > 0.51) for growth performance and carcass traits in winter and only for DMI in summer. Final BW, ADG, DMI, or G:F were not different (P ≥ 0.28) between cattle fed CON and TRT, whereas cattle fed NONTRT had lesser ADG, HCW, and G:F compared to CON and TRT in the winter experiment. During the summer, final BW and ADG tended to be greater (P ≥ 0.07) for CON compared to TRT. Cattle fed TRT had reduced (P < 0.01) G:F compared to CON. No difference was observed (P ≥ 0.36) between YE and NOYE in the winter experiment for performance or carcass traits. In the summer, cattle fed YE had greater (P < 0.02) HCW, ADG, and DMI compared to NOYE. In the summer experiment, cattle fed YE had greater (P < 0.01) N intake, N excretion, and amount of N lost (kg/steer) compared to NOYE, but no difference (P = 0.33) was observed for percentage of N volatilized (% of excretion). Diet had no effect (P > 0.18) on amount (kg/steer) or percentage of N volatized in the winter or summer. All diets had similar amounts (P > 0.13) of DM and OM removed from the pen surface in both summer and winter. Feeding CaO-treated corn stover as a partial grain replacement had no impact on performance in winter but decreased G:F in summer. Although high-fiber diets increased the amount of OM on pen surfaces, they did not impact N volatilized. Feeding a Y. schidigera extract did not affect N balance or manure characteristics.

Meta-analysis on Methane Mitigating Properties of Saponin-rich Sources in the Rumen: Influence of Addition Levels and Plant Sources

Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to ruminant feed. A database was constructed from published literature reporting the addition of saponin-rich sources at various levels and then monitoring ruminal methane emissions in vitro. Accordingly, levels of saponin-rich source additions as well as different saponin sources were specified in the database. Apart from methane, other related rumen fermentation parameters were also included in the database, i.e. organic matter digestibility, gas production, pH, ammonia concentration, short-chain fatty acid profiles and protozoal count. A total of 23 studies comprised of 89 data points met the inclusion criteria. The data obtained were subsequently subjected to a statistical meta-analysis based on mixed model methodology. Accordingly, different studies were treated as random effects whereas levels of saponin-rich source additions or different saponin sources were considered as fixed effects. Model statistics used were p-value and root mean square error. Results showed that an addition of increasing levels of a saponin-rich source decreased methane emission per unit of substrate incubated as well as per unit of total gas produced (p<0.05). There was a decrease in acetate proportion (linear pattern; p<0.001) and an increase in propionate proportion (linear pattern; p<0.001) with increasing levels of saponin. Log protozoal count decreased (p<0.05) at higher saponin levels. Comparing between different saponin-rich sources, all saponin sources, i.e. quillaja, tea and yucca saponins produced less methane per unit of total gas than that of control (p<0.05). Although numerically the order of effectiveness of saponin-rich sources in mitigating methane was yucca>tea>quillaja, statistically they did not differ each other. It can be concluded that methane mitigating properties of saponins in the rumen are level- and source-dependent.

Effect of Gynosaponin on Rumen In vitro Methanogenesis under Different Forage-Concentrate Ratios

The study aimed to investigate the effects of gynosaponin on in vitro methanogenesis under different forage-concentrate ratios (F:C ratios). Experiment was conducted with two kinds of F:C ratios (F:C = 7:3 and F:C = 3:7) and gynosaponin addition (0 mg and 16 mg) in a 2×2 double factorial design. In the presence of gynosaponin, methane production and acetate concentration were significantly decreased, whereas concentration of propionate tended to be increased resulting in a significant reduction (p<0.05) of acetate:propionate ratio (A:P ratio), in high-forage substrate. Gynosaponin treatment increased (p<0.05) the butyrate concentration in both F:C ratios. Denaturing gradient gel electrophoresis (DGGE) analysis showed there was no apparent shift in the composition of total bacteria, protozoa and methanogens after treated by gynosaponin under both F:C ratios. The real-time polymerase chain reaction (PCR) analysis indicated that variable F:C ratios significantly affected the abundances of Fibrobacter succinogenes, Rumninococcus flavefaciens, total fungi and counts of protozoa (p<0.05), but did not affect the mcrA gene copies of methanogens and abundance of total bacteria. Counts of protozoa and abundance of F.succinogenes were decreased significantly (p<0.05), whereas mcrA gene copies of methanogens were decreased slightly (p<0.10) in high-forage substrate after treated by gynosaponin. However, gynosaponin treatment under high-concentrate level did not affect the methanogenesis, fermentation characteristics and tested microbes. Accordingly, overall results suggested that gynosaponin supplementation reduced the in vitro methanogenesis and improved rumen fermentation under high-forage condition by changing the abundances of related rumen microbes.

The effects of thyme and cinnamon essential oils on performance, rumen fermentation and blood metabolites in holstein calves consuming high concentrate diet

Essential oils have been shown to favorably effect in vitro ruminal fermentation, but there are few in vivo studies that have examined animal responses. The objective of this study was to evaluate the effects of thyme (THY) and cinnamon (CIN) essential oils on feed intake, growth performance, ruminal fermentation and blood metabolites in feedlot calves fed high-concentrate diets. Twelve growing Holstein calves (213±17 kg initial BW) were used in a completely randomized design and received their respective dietary treatments for 45 d. Treatments were: 1-control (no additive), 2-THY (5 g/d/calf) and 3-CIN (5 g/d/calf). Calves were fed ad libitum diets consisting of 15% forage and 85% concentrate, and adapted to the finishing diet by gradually increasing the concentrate ratio with feeding a series of transition diets 5 wk before the experiment started. Supplementation of THY or CIN did not affect DMI and ADG, and feed efficiency was similar between treatment groups. There were no effects of additives on ruminal pH and rumen concentrations of ammonia nitrogen and total VFA; whereas molar proportion of acetate and ratio of acetate to propionate decreased, and the molar proportion of propionate increased with THY and CIN supplementation. Rumen molar concentration of butyrate was significantly increased by adding CIN compared to control; but no change was observed with THY compared with control group. No effects of THY, or CIN were observed on valerate, isobutyrate or isovalerate proportions. Plasma concentrations of glucose, cholesterol, triglyceride, urea-N, β-hydroxybutyrate, alanine aminotransferase and aspartate aminotransferase were not changed by feeding THY or CIN. Results from this study suggest that supplementing a feedlot finishing diet with THY or CIN essential oil might be useful as ruminal fermentation modifiers in beef production systems, but has minor impacts on blood metabolites.

Effects of a selection of additives on in vitro ruminal methanogenesis and in situ and in vivo NDF digestibility

The effects of 18 essential oils, yeast, Quebracho tannin and Quillaja saponin on ruminal methane and gas production (GP) were studied in vitro. A lactating cow diet was incubated with rumen inoculum. Doses of the additives (mg/L) were: essential oils = 500; tannin = 67; yeast = 8.35 and 16.7; and saponin = 300. Lemongrass, estragole, eugenol, geraniol, limonen, thyme oil and thymol produced less gas (overall mean 33.8 mL/200 mg dry matter (DM)) than control (43.6 mL/200 mg DM; P < 0.001). Methane produced (mL/200 mg DM) by guaiacol (10.7), lemongrass (9.6), limonene (11.4), thyme oil (10.9) and thymol (2.1) was lower than control (12.5) (P < 0.001). Methane percentage on total GP was lower (P < 0.001) for cinnamic alcohol (25.4), guaiacol (24.5), thymol (19.7) and vanillin (26.3) than control (28.8). In a second experiment, thymol, guaiacol and yeast were added to the diet of dry fistulated cows to determine in situ neutral detergent fiber digestibility (NDFD) of six forages and in vivo dietary NDFD. Thymol and yeast decreased in situ NDFD after 24 h (33.9% and 33.5% vs. 38.1%; P = 0.008). Thymol decreased in vivo total tract NDFD (40.8% vs. 51.4%; P = 0.02). Differences in GP and methane levels were registered within classes of additives. A careful selection of additives may allow for the manipulation of ruminal fermentation.

Effects of extracts of Humulus lupulus (hops) and Yucca schidigera applied alone or in combination with monensin on rumen fermentation and microbial populations in vitro

BACKGROUND

β-Acids in hops (Humulus lupulus) and saponins in yucca (Yucca schidigera) have been found to possess antimicrobial properties similar to that of monensin and could be an alternative to in-feed antibiotics. The effects of monensin (MON) and ethanol extracts of hops (HE) and Y. schidigera (YE) alone and in combination with MON were assessed on ruminal microbial composition and fermentation in vitro of a barley-based diet.

RESULTS

All treatments decreased (P < 0.05) CH4 production (per unit of dry matter), microbial protein (mg), and NH3 -N accumulation. All treatments reduced (P < 0.01) the acetate:propionate (A:P) ratio and molar proportions of butyrate, but increased (P < 0.01) those of propionate, whereas those of acetate decreased (P < 0.001) with addition of MON (10 µg mL(-1)) and combined with HE or YE. Methane produced per unit of true digested dry matter decreased (P < 0.001) with all treatments except YE. Monensin reduced (P < 0.001) proportions of 16S rRNA copies of Ruminococcus flavefaciens, but increased (P < 0.01) those of Selenomonas ruminantium. Hops extract alone or combined with MON reduced (P < 0.01) proportions of R. flavefaciens but combined with MON tended (P < 0.1) to increase those of S. ruminantium. Yucca extract combined with MON increased (P < 0.01) the proportions of R. flavefaciens and S. ruminantium. All treatments except MON (2.5 µg mL(-1)) reduced (P < 0.01) the relative abundance of methanogens.

CONCLUSION

Hops extract and YE altered rumen microbes and fermentation in a manner similar to MON with many responses being additive when applied in combination.

Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact

The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeast, DFM, and Yucca schidigera extract. Ten horses were fed the 2 experimental diets during two 42-d periods in a crossover design. Total fecal and urine collection occurred during the last 14 d of each period. Results indicate no significant differences between Cu, Zn, Mn, and Co concentrations excreted via urine (P > 0.05) due to dietary treatment. There was no difference between fecal Cu and Mn concentrations (P > 0.05) based on diet consumed. Mean fecal Zn and Co concentrations excreted by horses consuming ADD were greater than CTRL (P < 0.003). Differences due to diet were found for selenium fecal (P < 0.0001) and urine (P < 0.0001) excretions, with decreased concentrations found for horses consuming organic selenium yeast (ADD). In contrast, fecal K (%) was greater (P = 0.0421) for horses consuming ADD, whereas concentrations of fecal solids, total N, ammonia N, P, total ammonia, and fecal output did not differ between dietary treatments (P > 0.05). In feces stockpiled to simulate a crude composting method, no differences (P > 0.05) due to diet were detected for particle size, temperature, moisture, OM, total N, P, phosphate, K, moisture, potash, or ammonia N (P > 0.05). Although no difference (P = 0.2737) in feces stockpile temperature due to diet was found, temperature differences over time were documented (P < 0.0001). In conclusion, the addition of certain chelated mineral sources, organic Se yeast, DFM, and Yucca schidigera extract did not decrease most nutrient concentrations excreted. Horses consuming organic selenium as part of the additive diet had lower fecal and urine Se concentrations, as well as greater fecal K concentrations.