Host-mediated effects of phytonutrients in ruminants: A review

The endocannabinoid system in bovine tissues: characterization of transcript abundance in the growing Holstein steer

BACKGROUND

The endocannabinoid system (ECS) is highly integrated with seemingly all physiological and pathophysiological processes in the body. There is increasing interest in utilizing bioactive plant compounds, for promoting health and improving production in livestock. Given the established interaction between phytochemicals and the ECS, there are many opportunities for identification and development of therapies to address a range of diseases and disorders. However, the ECS has not been thoroughly characterized in cattle, especially in the gastrointestinal tract. The objective of this study was to characterize the distribution and transcriptional abundance of genes associated with the endocannabinoid system in bovine tissues.

METHODS

Tissues including brain, spleen, thyroid, lung, liver, kidney, mesenteric vein, tongue, sublingual mucosa, rumen, omasum, duodenum, jejunum, ileum and colon were collected from 10-mo old Holstein steers (n = 6). Total RNA was extracted and gene expression was measured using absolute quantification real time qPCR. Gene expression of endocannabinoid receptors CNR1 and CNR2, synthesis enzymes DAGLA, DAGLB and NAPEPLD, degradation enzymes MGLL and FAAH, and transient receptor potential vanilloids TRPV3 and TRPV6 was measured. Data were analyzed in R using a Kruskal-Wallis followed by a Wilcoxon rank-sum test. Results are reported as the median copy number/20 ng of equivalent cDNA (CN) with interquartile range (IQR).

RESULTS

The greatest expression of CNR1 and CNR2 was in the brain and spleen, respectively. Expression of either receptor was not detected in any gastrointestinal tissues, however there was a tendency (P = 0.095) for CNR2 to be expressed above background in rumen. Expression of endocannabinoid synthesis and degradation enzymes varied greatly across tissues. Brain tissue had the greatest DAGLA expression at 641 CN (IQR 52; P ≤ 0.05). DAGLB was detected in all tissues, with brain and spleen having the greatest expression (P ≤ 0.05). Expression of NAPEPLD in the gastrointestinal tract was lowest in tongue and sublingual mucosal. There was no difference in expression of NAPEPLD between hindgut tissues, however these tissues collectively had 592% greater expression than rumen and omasum (P ≤ 0.05). While MGLL was found to be expressed in all tissues, expression of FAAH was only above the limit of detection in brain, liver, kidney, jejunum and ileum. TRPV3 was expressed above background in tongue, rumen, omasum and colon. Although not different from each other, thyroid and duodenum had the greatest expression of TRPV6, with 285 (IQR 164) and 563 (IQR 467) CN compared to all other tissues (P < 0.05).

CONCLUSIONS

These data demonstrate the complex distribution and variation of the ECS in bovine tissues. Expression patterns suggest that regulatory functions of this system are tissue dependent, providing initial insight into potential target tissues for manipulation of the ECS.

Lactational performance and hematological effects of capsaicin supplementation in dairy cows: A meta-analysis

A meta-analysis was performed to investigate the effects of capsaicin (CAP) on lactational performance and blood chemistry and cell counts in dairy cattle. The database comprised 11 peer-reviewed studies published between 2011 and 2024. The overall effect of CAP, challenge (e.g., ketosis, glucose tolerance, LPS), and dose were considered explanatory variables in the analysis. Lactation performance response variables included DMI, milk yield (MY), ECM yield, feed efficiency (FE), milk components, and BW. Hematological response variables included red and white blood cell counts and blood BHB, total fatty acids, insulin, and glucose concentrations. Data were analyzed using random- and mixed-effect models in the "robumeta" package in RStudio. Milk yield was increased by 2.9% by CAP when compared with control. Capsaicin supplementation increased FE by 3.4% compared with control. Milk fat concentration and yield were also increased by CAP compared with control by 2.6% and 4.0%, respectively. Blood glucose concentrations were decreased 2.5% by CAP supplementation, whereas insulin levels were unaffected. Cows fed CAP during a challenge had higher MY and FE and tended to have lower blood glucose than their control counterparts. Overall, this analysis suggests that CAP supplementation may be directly affecting host physiology by altering glucose metabolism, but further research to define the mechanism is warranted.

Impact of oil type and savory plant on nutrient digestibility and rumen fermentation, milk yield, and milk fatty acid profile in dairy cows

Fat supplements are well known for their multiple beneficial effects on ruminant health, reproduction and productivity, and as a source for certain bioactive compounds in ruminant products. On the other hand, numerous phytochemicals have demonstrated the potential to improve rumen fermentation through modifying the volatile fatty acid (VFA) pattern to favour those with greater energy efficiency, boosting microbial protein synthesis, and decreasing methane emission and ruminal ammonia concentration. Savory is an aromatic plant rich in various phytochemicals (mainly carvacrol and flavonoids) that can alter ruminal metabolism of dietary fatty acids, potentially increasing the production of some bioactive compounds such as conjugated linoleic acids (CLAs). This study aimed to investigate combined effects of oil type (fish oil (FO) versus soybean oil (SO)) and the inclusion of savory (Satureja khuzistanica) plant (SP) in the diet on total tract digestibility of nutrients, rumen fermentation, milk yield and milk fatty acid profile in dairy cattle. Eight multiparous lactating Holstein cows were used in a replicated 4 × 4 Latin square design experiment with four diets and four 21-d periods. During each experimental period consisted of 14 days of adaptation and a 7-day sampling period, cows were randomly assigned to one of the four dietary treatments: the diet supplemented with 2% (DM basis) fish oil (FOD) or soybean oil (SOD), the FOD or SOD plus 370 g DM/d/head SP (FODs, SODs, respectively). The experimental diets were arranged in a 2 × 2 factorial design, with the fat sources as the first and SP as the second factor. The FO-supplemented diets had lower dry matter intake (DMI) and higher total tract digestibility than SO-supplemented diets (P < 0.05), and including SP in the diet improved total tract digestibility of dry matter (DM), organic matter (OM), ether extract (EE), and non-fibrous carbohydrates (NFC) (P < 0.05) without negatively affecting DMI. Rumen pH was lower with SO than with FO diets (P < 0.01) and increased with SP inclusion in the diet (P < 0.05). Total protozoa count and ruminal ammonia concentration decreased, and the branched-chain VFA (BCVFA) proportion increased with SP inclusion in the diet (P < 0.05). Milk production, as well as the concentration and yield of milk components (except lactose concentration) were higher with SO than with FO diets (P < 0.05), but these variables remained unaffected by SP. The milk concentrations of both non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) were lower with SO compared to FO diets, and these variables were reduced by SP (P < 0.01). The proportions of both mono- and polyunsaturated FA (MUFA and PUFA, respectively) in milk were higher with FO than with SO diets (P < 0.01), and their proportions increased by SP at the expense of saturated FA (SFA) (P < 0.01). Including SP in the diet increased the proportions of all the milk n-3 FA (C18:3c, C20:5, and C22:6) by 21%, 40%, and 97%, respectively, and those of conjugated linoleic acids (C18:2 (c9,t11-CLA) and C18:2 (t10,c12-CLA)) by 23% and 62%, respectively. There was no interaction between oil type and SP for the assessed variables. Fish oil, despite reducing milk production and milk components, was more effective than soybean oil in enriching milk with healthy FA. These findings also show promise for SP as a feed additive with the potential to improve total tract digestibility, rumen fermentation and milk FA composition.

Nutritional Strategies to Alleviate Stress and Improve Welfare in Dairy Ruminants

Dairy ruminants provide a major part of the livestock and agriculture sectors. Due to the increase in world population and the subsequent increase in dairy product demands, the dairy sector has been intensified. Dairy farming intensification and the subsequent increase in animal nutritional demands and the increase in the average global temperature as well have subjected animals to various stress conditions that impact their health and welfare. Various management practices and nutritional strategies have been proposed and studied to alleviate these impacts, especially under heat stress, as well as during critical periods, like the transition period. Some of the nutritional interventions to cope with stress factors and ensure optimal health and production are the inclusion of functional fatty acids and amino acids and feed additives (minerals, prebiotics, probiotics, essential oils and herbs, phytobiotics, enzymes, etc.) that have been proven to regulate animals' metabolism and improve their antioxidant status and immune function. Thus, these nutritional strategies could be the key to ensuring optimum growth, milk production, and reproduction efficiency. This review summarizes and highlights key nutritional approaches to support the remarkable metabolic adaptations ruminants are facing during the transition period and to reduce heat stress effects and evaluate their beneficial effects on animal physiology, performance, health, as well as welfare.

Essential oils and capsaicin in the diet of Jersey cows at early lactation and their positive impact on anti-inflammatory, antioxidant and immunological responses

The objective of this work was to determine whether the addition of phytogenic compounds based on essential oils (carvacrol, eugenol, cinnamaldehyde) and resinous pepper oil (capsaicin) to the diet of Jersey cows at the beginning of lactation affects anti-inflammatory, antioxidant and immunomodulatory responses, as well as whether there are effects of EO on blood metabolites, ruminal fermentation, digestibility and milk production and composition. Six primiparous cows (370.00 ± 17 kg body weight (BW); 13.02 kg dry matter intake (DMI); 21 days of lactation and average milk production of 20 ± 2 L per day) were allocated to crossed experimental design (2 × 2) with two experimental periods of 28 days and two treatments. Blood, milk and rumen fluid were collected and, at the end of each period, feed and feces samples were collected to evaluate the apparent digestibility of nutrients. The groups were control (CLT) without supplementation and treated (BEO) with the addition of 150 mg/kg of dry matter of the phytogenic to the concentrated portion of the diet. Cows in the BEO group had lower numbers of leukocytes (P ≤ 0.05) and lymphocytes (P ≤ 0.02), but total protein and globulin levels were higher on days 21 and 28 (P ≤ 0.01). In the BEO group, the levels of immunoglobulin A, immunoglobulin heavy chain and transferrin were higher (P ≤ 0.05). The levels of ceruloplasmin, haptoglobin and C-reactive protein were lower in the BEO group (P ≤ 0.05). Lipid peroxidation levels and protein carbonyl content were lower in the BEO group. The total antioxidant capacity (P ≤ 0.09) and the activity of glutathione S-transferase (P ≤ 0.03) and glutathione peroxidase (P ≤ 0.05) were higher in the BEO group. Cows in the BEO group had lower pH (P ≤ 0.05), acetic acid concentrations (P ≤ 0.01) and higher protozoa counts (P ≤ 0.01). Our results suggest that phytogenic supplementation has positive effects on the health of Jersey cows in early lactation, characterized by immunostimulant, antioxidant and anti-inflammatory effects.

Dietary supplementation of phytoncide and soybean oil increases milk conjugated linoleic acid and depresses methane emissions in Holstein dairy cows

The objective of this study was to determine whether adding phytoncide oil (PO) and soybean oil (SBO) to the dairy cow diet could increase milk conjugated linoleic acid (CLA) and depress methane (CH4) emissions in Holstein dairy cows. Rumen fermentation was conducted at four levels of SBO (0, 1, 2, and 4%, on DM basis) and two levels of PO (0 and 0.1%, on DM basis) with in vitro experiment. To evaluate blood parameters, fecal microbe population, milk yield and fatty acid compositions, and CH4 production, in vivo experiment was conducted using 38 Holstein dairy cows divided into two groups of control (fed TMR) and treatment (fed TMR with 0.1% PO and 2% SBO as DM basis). In the in vitro study (Experiment 1), PO or SBO did not affect rumen pH. However, SBO tended to decrease ruminal ammonia-N (p = 0.099). Additionally, PO or SBO significantly decreased total gas production (p = 0.041 and p = 0.034, respectively). Both PO and SBO significantly decreased CH4 production (p < 0.05). In addition, PO significantly increased both CLA isomers (c9, t11 and t10, c12 CLA) (p < 0.001). Collectively, 0.1% PO and 2% SBO were selected resulting in most effectively improved CLA and decreased CH4 production. In the in vivo study (Experiment 2), 0.1% PO with 2% SBO (PSO) did not affect complete blood count. However, it decreased blood urea nitrogen and magnesium levels in blood (p = 0.021 and p = 0.01, respectively). PSO treatment decreased pathogenic microbes (p < 0.05). It increased milk yield (p = 0.017) but decreased percentage of milk fat (p = 0.013) and MUN level (p < 0.01). In addition, PSO treatment increased both the concentration of CLA and PUFA in milk fat (p < 0.01). Finally, it decreased CH4 emissions from dairy cows. These results provide compelling evidence that a diet supplemented with PSO can simultaneously increase CLA concentration and decrease CH4 production with no influence on the amount of milk fat (kg/day) in Holstein dairy cows.

Lactational performance, enteric methane emission, and nutrient utilization of dairy cows supplemented with botanicals

The objective of this study was to evaluate lactational performance, enteric gas emissions, ruminal fermentation, nutrient use efficiency, milk fatty acid profile, and energy and inflammatory markers in blood of peak-lactation dairy cows fed diets supplemented with Capsicum oleoresin or a combination of Capsicum oleoresin and clove oil. A 10-wk randomized complete block design experiment was conducted with 18 primiparous and 30 multiparous Holstein cows. Cows were blocked based on parity, days in milk, and milk yield (MY), and randomly assigned to 1 of 3 treatments (16 cows/treatment): (1) basal diet (CON); (2) basal diet supplemented with 300 mg/cow per day of Capsicum oleoresin (CAP); and (3) basal diet supplemented with 300 mg/cow per day of a combination of Capsicum oleoresin and clove oil (CAPCO). Premixes containing ground corn (CON), CAP, or CAPCO were mixed daily with the basal diet at 0.8% of dry matter intake (DMI). Supplementation of the diet with CAP or CAPCO did not affect DMI, MY, milk components, and feed efficiency of the cows. Body weight (BW) was increased during the last 2 wk of the experiment by CAP and CAPCO, compared with CON. The botanicals improved BW gain (0.85 and 0.66 kg/d for CAP and CAPCO, respectively, compared with -0.01 kg/d for CON) and CAP enhanced the efficiency of energy utilization, compared with CON (94.5% vs. 78.4%, respectively). Daily CH4 emission was not affected by treatments, but CH4 emission yield (per kg of DMI) and intensity (per kg of MY) were decreased by up to 11% by CAPCO supplementation, compared with CON and CAP. A treatment × parity interaction indicated that the CH4 mitigation effect was pronounced in primiparous but not in multiparous cows. Ruminal molar proportion of propionate was decreased by botanicals, compared with CON. Concentrations of trans-10 C18:1 and total trans fatty acids in milk fat were decreased by CAP and tended to be decreased by CAPCO, compared with CON. Total-tract apparent digestibility of nutrients was not affected by treatments, except for a tendency for decreased starch digestibility in cows supplemented with botanicals. Blood concentrations of β-hydroxybutyrate, total fatty acids, and insulin were not affected by botanicals. Blood haptoglobin concentration was increased by CAP in multiparous but not in primiparous cows. Lactational performance of peak-lactation dairy cows was not affected by the botanicals in this study, but they appeared to improve efficiency of energy utilization and partitioned energy toward BW gain. In addition, CH4 yield and intensity were decreased in primiparous cows fed CAPCO, suggesting a potential positive environmental effect of the combination of Capsicum oleoresin and clove oil supplementation.

Plant polyphenol extract supplementation affects performance, welfare, and the Nrf2-oxidative stress response in adipose tissue of heat-stressed dairy cows

We examined the effects of a supplement of plant polyphenols extracts of green tea, capsicum, and fenugreek, and electrolytes ([Na+, K+]; AXT, Axion ThermoPlus, CCPA, France] during summer heat load on production, welfare, and oxidative stress proteins in adipose tissue (AT) of dairy cows. A total of 42 multiparous mid-lactation cows were divided into 3 groups during summer, and were fed for 2 wk either a standard milking cow diet (CTL, n = 14) or diets supplemented with 100 g/d of AXT (100AXT, n = 14), or 150 g/d of AXT (150AXT, n = 14), while being cooled 5 times a day. Then, half of the cows from each dietary treatment were cooled (CL) or not cooled (NCL) for 2 wk, after which the cooled and uncooled groups were switched for additional 2 wk. Cows were milked 3 times a day, and milk composition was analyzed at the end of each 2-wk period. Vaginal temperature (VT) was measured for 3 consecutive days in each period. Biopsies of subcutaneous AT were taken from 10 NCL cows (5 each of CTL and 150AXT) at the end of the period and examined by liquid chromatography-tandem mass spectrometry proteomics analysis. Data were analyzed with PROC MIXED of SAS (version 9.2, SAS Institute Inc.). The model included the effects of dietary treatment, cooling regimen, period, and their interactions. Protein and mRNA abundances and proteomic data (P ≤ 0.05 and fold change [FC] ± 1.5) were analyzed by t-test. Milk yields and 4% fat-corrected milk (FCM) were higher in 100AXT than in CTL; milk components were not different. Dry matter intake (DMI) was higher in 100AXT than in CTL. The effect of cooling and the interactions of period × cooling were significant for DMI, 4% FCM, energy-corrected milk, and milk/DMI. The proportion of time that VT was >39°C was lower in 100AXT and in 150AXT than in CTL. Daily rumination time was greater in 150AXT than in CTL, and lying time was greater in 100AXT and 150AXT than in CTL. Proteomics of AT demonstrated that 150AXT had increased abundances of peroxidasin (FC = 1.6), microsomal glutathione S-transferase 2 (FC = 2.5), and heme oxygenase 1 (FC = 3.6) compared with CTL. Top enriched canonical pathways included acute phase response signaling, Nrf2-mediated oxidative stress response, and lipopolysaccharide (LPS)/IL-1-mediated inhibition of RXR function. Immunoblots of AT showed a higher abundance of the transient receptor potential vanilloid 1 and of LPS binding protein in AT of 150AXT compared with CTL. Supplementation of AXT increased DMI, milk, and 4% FCM, lowered VT, improved welfare indices, and enriched the AT with Nrf2-oxidative stress response and acute phase response proteins in heat-stressed dairy cows.

Modulation of Swine Gut Microbiota by Phytogenic Blends and High Concentrations of Casein in a Validated Swine Large Intestinal In Vitro Model

Phytogenic feed additives are gaining popularity in livestock as a replacement for antibiotic growth promotors. Some phytogenic blends (PB) positively affect the production performance, inhibit pathogens within the gut microbiota, and improve the overall health of farm animals. In this study, a swine large intestine in vitro model was used to evaluate the effect of two PBs, alone or in combination with casein, on swine gut microbiota. As a result, the combination of casein with PB1 had the most beneficial effects on swine gut microbiota, as it increased the relative abundance of some commensal bacteria and two genera (Lactobacillus and Oscillospiraceae UCG-002), which are associated with greater production performance in pigs. At the same time, supplementation with PBs did not lead to an increase in opportunistic pathogens, indicating their safety for pigs. Both PBs showed fewer changes in swine gut microbiota compared to interventions with added casein. In contrast, casein supplementation significantly increased beta diversity and the relative abundance of commensal as well as potentially beneficial bacteria. In conclusion, the combination of casein with PBs, in particular PB1, had the most beneficial effects among the studied supplements in vitro, with respect to microbiota modulation and metabolite production, although this data should be proven in further in vivo studies.

The Effect of Monensin vs. Neem, and Moringa Extracts on Nutrient Digestibility, Growth Performance, Methane, and Blood Profile of Merino Lambs

Plant secondary compounds are potential rumen modifiers that can improve nutrient utilization in ruminant animals. This study evaluated the effect of Moringa (Moringa oleifera) and Neem (Azadirachta indica) leaf extracts on nutrient digestibility, growth performance, and enteric methane production in South African Mutton Merino lambs. Forty 4-month-old ram lambs with a mean body weight of 35 ± 2.2 kg were blocked by weight and from each block, lambs were randomly allocated into one of the following treatments: (i) diet only (fed a total mixed ration TMR-negative control), (ii) Monensin (fed TMR containing Monensin sodium, 15 mg/kg DM), (iii) Moringa (fed TMR, drenched with Moringa extract 50 mg/kg feed DM intake), and (iv) Neem (fed TMR, drenched with Neem extract 50 mg/kg DM intake). Extracts were administered via oral drenching at a concentration determined based on the previous week's feed intake. There were no differences in dry matter intake, average daily gain, feed conversion efficiency, digestibility, and nitrogen retention across the treatments. However, the extracts tended to reduce methane emitted both in g/head/day (p < 0.08) and g/ kg dry matter intake (p < 0.07). Extracts did not influence any of the blood metabolites in the ram lambs. Although the benefits of utilizing these medicinal plants as rumen modifiers under prolonged feeding conditions is justified, further evaluation is recommended to test Moringa and Neem leaf extracts at higher inclusion levels. Our research group is currently exploring a variety of phytogenic tools for the identification and standardization of key bioactive compounds linked to methane inhibition, in these leaf extracts.

Dried tea residue can alter the blood metabolism and the composition and functionality of the intestinal microbiota in Hu sheep

Ruminant animals face multiple challenges during the rearing process, including immune disorders and oxidative stress. Green tea by-products have gained widespread attention for their significant immunomodulatory and antioxidant effects, leading to their application in livestock production. In this study, we investigated the effects of Dried Tea Residue (DTR) as a feed additive on the growth performance, blood biochemical indicators, and hindgut microbial structure and function of Hu sheep. Sixteen Hu sheep were randomly divided into two groups and fed with 0 and 100 g/d of DTR, respectively. Data were recorded over a 56-day feeding period. Compared to the control group, there were no significant changes in the production performance of Hu sheep fed with DTR. However, the sheep fed with DTR showed a significant increase in IgA (p < 0.001), IgG (p = 0.005), IgM (p = 0.003), T-SOD (p = 0.013), GSH-Px (p = 0.005), and CAT (p < 0.001) in the blood, along with a significant decrease in albumin (p = 0.019), high density lipoprotein (p = 0.050), and triglyceride (p = 0.021). DTR supplementation enhanced the fiber digestion ability of hindgut microbiota, optimized the microbial community structure, and increased the abundance of carbohydrate-digesting enzymes. Therefore, DTR can be used as a natural feed additive in ruminant animal production to enhance their immune and antioxidant capabilities, thereby improving the health status of ruminant animals.

Lactational performance, rumen fermentation, nutrient use efficiency, enteric methane emissions, and manure greenhouse gas-emitting potential in dairy cows fed a blend of essential oils

The objective of this experiment was to investigate the effects of an essential oil (EO) blend on lactational performance, rumen fermentation, nutrient utilization, blood variables, enteric methane emissions and manure greenhouse gas-emitting potential in dairy cows. A randomized complete block design experiment was conducted with 26 primiparous and 22 multiparous Holstein cows. A 2-wk covariate and a 2-wk adaptation periods preceded a 10-wk experimental period used for data and sample collection. Treatments were: (1) basal diet supplemented with placebo (CON); and (2) basal diet supplemented with a blend of EO containing eugenol and geranyl acetate as main compounds. Supplementation with EO did not affect dry matter intake, milk and energy-corrected milk yields, and feed efficiency of cows, compared with CON. Milk fat and lactose concentrations were increased, and milk total solids (TS) concentration and milk fat yield tended to be increased by EO. Multiparous cows supplemented with EO tended to have slightly decreased dry matter and crude protein digestibility compared with CON multiparous cows. There was a tendency for increased ruminal pH by EO, whereas other rumen fermentation variables did not differ between treatments. Daily methane emission was not affected by EO supplementation, but methane emission intensity per kg of milk fat was decreased by 8.5% by EO. Methane emission intensity per kg of milk lactose and milk TS were decreased and methane emission intensity per kg of milk yield tended to be decreased by up to 10% in EO multiparous cows, but not in primiparous cows. The greenhouse gas-emitting potential of manure was not affected by EO supplementation. Compared with CON, fecal nitrogen excretion was increased by EO supplementation in multiparous, but not in primiparous cows, and milk nitrogen secretion (as a % of nitrogen intake) tended to be increased in EO supplemented cows. Blood variables were not affected by EO supplementation in the current study. Overall, dietary supplementation of EO did not affect lactational performance of the cows, although milk fat and lactose concentrations were increased. Most enteric methane emission metrics were not affected, but EO decreased methane intensity per kg of milk fat by 8.5%, compared with the control.

Immunomodulation by cannabidiol in bovine primary ruminal epithelial cells

BACKGROUND

Ruminant livestock experience a number of challenges, including high concentrate diets, weaning and transport, which can increase their risk of disorders such as ruminal acidosis, and the associated inflammation of the ruminal epithelium. Cannabidiol (CBD), a phytochemical from hemp (Cannabis sativa), is a promising target as a therapy for gastrointestinal inflammation, and may be extremely valuable as either a treatment or prophylactic. However, the effects of CBD in the the ruminant gastrointestinal tract have not been explored, in part due to the restrictions on feeding hemp to livestock. Therefore, the objective of this study was to investigate the immunomodulatory properties of CBD using a model of inflammation in primary ruminal epithelial cells (REC). In addition, CBD dose was evaluated for possible cytotoxic effects.

RESULTS

Negative effects on cell viability were not observed when REC were exposed to 10 μM CBD. However, when the dose was increased to 50 μM for 24 h, there was a significant cytotoxic effect. When 10 μM CBD was added to culture media as treatment for inflammation induced with lipopolysaccharide (LPS), expression of genes encoding for pro-inflammatory cytokine IL1B was less compared to LPS exposure alone, and CBD resulted in a down-regulation of IL6. As a pre-treatment, prior to LPS exposure, REC had decreased expression of IL6 and CXCL10 while CBD was present in the media, but not when it was removed prior to addition of LPS.

CONCLUSIONS

Results suggest that CBD may reduce cytokine transcription both during LPS-induced inflammation and when used preventatively, although these effects were dependent on its continued presence in the culture media. Overall, these experiments provide evidence of an immunomodulatory effect by CBD during a pro-inflammatory response in primary REC in culture.

Modulation of feed digestibility, nitrogen metabolism, energy utilisation and serum biochemical indices by dietary Ligularia virgaurea supplementation in Tibetan sheep

Ligularia virgaurea is the most widely functional native herbage in the alpine meadow pastures of the Qinghai-Tibet Plateau (QTP) and has multiple pharmacological and biological activities. The effect of L. virgaurea as a dietary component on the digestion and metabolism of sheep was evaluated by conducting feeding trials in metabolic cages. Thirty-two Tibetan yearling rams (29 ± 1.56 kg BW) were randomly allotted to four groups included in a completely randomised design with eight animals per treatment. Sheep were fed a basal diet (freshly native pasture) without the addition of L. virgaurea (control) or with the addition of L. virgaurea (100, 200, or 300 mg/kg BW per day) for 45 days. Addition of L. virgaurea to the diet of Tibetan sheep was found to influence the average daily gain (quadratic [Q], P < 0.001), feed conversion ratio (Q, P = 0.002), CH4 emissions (linear [L], P = 0.029), DM (Q, P = 0.012), neutral detergent fibre (Q, P = 0.017), acid detergent fibre (ADF) (Q, P = 0.027), and ether extract (EE) intake (Q, P = 0.026). Apparently, different levels of L. virgaurea affected the digestibility coefficients of DM, ADF, and EE (L, P > 0.05; Q, P < 0.05). The nitrogen (N) intake (Q, P = 0.001), retained nitrogen (Q, P < 0.001), and N utilisation efficiency (L, P > 0.05; Q, P ≤ 0.001) were also affected by the dietary inclusion of L. virgaurea. Effects of L. virgaurea feeding were also witnessed on methane energy (CH4-E) (L, P = 0.029), gross energy (GE) (Q, P = 0.013), digestible energy (DE) (Q, P = 0.015), and metabolisable energy (ME) intake (Q, P = 0.015). Energy utilisation efficiency expressed as a proportion of GE intake (DE/GE intake, ME/GE intake, ME/DE intake, FE/GE intake, and CH4-E/GE intake) manifested quadratic changes (P < 0.05) with the increase in the L. virgaurea supplementation level. The addition of L. virgaurea increased the activity of superoxide dismutase (Q, P = 0.026) and glutathione peroxidase activity (Q, P = 0.039) in the serum. Overall, the greatest improvement of feed digestibility, N retention, energy utilisation, and antioxidant capacity of Tibetan sheep was yielded by the inclusion of 200 mg/kg BW per day of L. virgaurea. Therefore, the addition of an appropriate amount of L. virgaurea to the diet of Tibetan sheep is safe and natural, and may enhance the sustainability of small ruminant production systems in QTP areas.

Effects of Supplementation with an Herbal Mixture on the Antioxidant Capacity of Milk

The aim of this study was to assess the effect of the addition of a standardized herbal mixture to the feed ration for Holstein-Friesian cows on the antioxidant capacity of milk. The study was carried out on a farm specialized in breeding dairy cattle. The exact study involved 30 cows in lactation III, which were in the first phase of lactation at the beginning of the experiment (15 cows-control group; 15 cows-experimental group). The nutrition supplied to the cows was based on the TMR (total mixed ration) system, with roughage and concentrate fodder used as the basis of the feed ration. The addition of a standardized blend of dried herbs, i.e., oregano (Origanum vulgare), thyme (Thymus vulgaris), purple coneflower (Echinacea purpurea), and cinnamon bark (Cinnamomum zeylanicum), was the experimental factor. Powdered herbs were administered as a component of the concentrate fodder at the dose of 3% DM ration/day/head. Milk samples were collected four times during the experiment (term 0 after the colostrum period and then after lactation weeks 2, 4, and 6). The following parameters were determined in the milk: the basic chemical composition, i.e., the content of total protein, fat, lactose, and casein; somatic cell count; content of selected whey proteins (α-lactalbumin, β-lactoglobulin, lactoferrin, BSA); and fat-soluble vitamins (A, D₃, E). Additionally, the milk antioxidant capacity (ABTS, FRAP, DPPH) was determined and the degree of antioxidant protection (DAP) was calculated. It was shown that the milk from cows receiving the herbal blend-supplemented fodder had a higher content of casein, compared to the control group. The herbal supplementation contributed to a significant increase in the content of bioactive compounds, i.e., selected whey proteins (β-lactoglobulin, lactoferrin) and lipophilic vitamins (A, E). The milk was also characterized by significantly higher antioxidant potential (regardless of the measurement method) and a higher degree of antioxidant protection (DAP).

Oral administration of Pinus koraiensis cone essential oil reduces rumen methane emission by altering the rumen microbial composition and functions in Korean native goat (Capra hircus coreanae)

This study aimed to investigate Pinus koraiensis cone essential oil (PEO) as a methane (CH₄) inhibitor and determine its impact on the taxonomic and functional characteristics of the rumen microbiota in goats. A total of 10 growing Korean native goats (Capra hircus coreanae, 29.9 ± 1.58 kg, male) were assigned to different dietary treatments: control (CON; basal diet without additive) and PEO (basal diet +1 g/d of PEO) by a 2 × 2 crossover design. Methane measurements were conducted every 4 consecutive days for 17-20 days using a laser CH₄ detector. Samples of rumen fluid and feces were collected during each experimental period to evaluate the biological effects and dry matter (DM) digestibility after PEO oral administration. The rumen microbiota was analyzed via 16S rRNA gene amplicon sequencing. The PEO oral administration resulted in reduced CH₄ emission (eructation CH₄/body weight^0.75, p = 0.079) without affecting DM intake; however, it lowered the total volatile fatty acids (p = 0.041), molar proportion of propionate (p = 0.075), and ammonia nitrogen (p = 0.087) in the rumen. Blood metabolites (i.e., albumin, alanine transaminase/serum glutamic pyruvate transaminase, creatinine, and triglyceride) were significantly affected (p < 0.05) by PEO oral administration. The absolute fungal abundance (p = 0.009) was reduced by PEO oral administration, whereas ciliate protozoa, total bacteria, and methanogen abundance were not affected. The composition of rumen prokaryotic microbiota was altered by PEO oral administration with lower evenness (p = 0.054) observed for the PEO group than the CON group. Moreover, PICRUSt2 analysis revealed that the metabolic pathways of prokaryotic bacteria, such as pyruvate metabolism, were enriched in the PEO group. We also identified the Rikenellaceae RC9 gut group as the taxa potentially contributing to the enriched KEGG modules for histidine biosynthesis and pyruvate oxidation in the rumen of the PEO group using the FishTaco analysis. The entire co-occurrence networks showed that more nodes and edges were detected in the PEO group. Overall, these findings provide an understanding of how PEO oral administration affects CH₄ emission and rumen prokaryotic microbiota composition and function. This study may help develop potential manipulation strategies to find new essential oils to mitigate enteric CH₄ emissions from ruminants.

Blend of Cinnamaldehyde, Eugenol, and Capsicum Oleoresin Improved Rumen Health of Lambs Fed High-Concentrate Diet as Revealed by Fermentation Characteristics, Epithelial Gene Expression, and Bacterial Community

We investigated the effects of CEC on the fermentation characteristics, epithelial gene expression, and bacterial community in the rumen of lambs fed a high-concentrate diet. Twenty-four 3-month-old female crossbred lambs with an initial body weight of 30.37 ± 0.57 kg were randomly allocated to consume a diet supplemented with 80 mg/kg CEC (CEC) or not (CON). The experiment consisted of a 14 d adaptation period and a 60 d data collection period. Compared with the CON group, the CEC group had higher ADG, epithelial cell thickness, ruminal butyrate proportion, and lower ammonia nitrogen concentration. Increases in the mRNA expression of Occludin and Claudin-4, as well as decreases in the mRNA expression of apoptotic protease activating factor-1 (Apaf-1), cytochrome c (Cyt-C), Caspase-8, Caspase-9, Caspase-3, Caspase-7, and toll-like receptor 4 (TLR4), were observed in the CEC group. Moreover, CEC treatment also decreased the concentration of IL-1β, IL-12, and TNF-α. Supplementation with CEC altered the structure and composition of the rumen bacterial community, which was indicated by the increased relative abundances of Firmicutes, Synergistota, Rikenellaceae_RC9_gut_group, Olsenella, Schwartzia, Erysipelotrichaceae_UCG-002, Lachnospiraceae_NK3A20_group, Acetitomaculum, [Eubacterium]_ruminantium_group, Prevotellaceae_UCG-004, Christensenellaceae_R-7_group, Sphaerochaeta, Pyramidobacter, and [Eubacterium]_eligens_group, and the decreased relative abundances of Acidobacteriota, Chloroflexi, Gemmatimonadota, and MND1. Furthermore, Spearman correlation analysis revealed that the altered rumen bacteria were closely correlated with rumen health-related indices. Dietary CEC supplementation improved growth performance, reduced inflammation and apoptosis, protected barrier function, and modulated the bacterial community of lambs fed a high-concentrate diet.

Effects of Chestnut Hydrolysable Tannin on Intake, Digestibility, Rumen Fermentation, Milk Production and Somatic Cell Count in Crossbred Dairy Cows

This study was conducted to determine the effects of chestnut hydrolysable tannin (CHT) on intake, digestibility, rumen fermentation, milk yield and somatic cell count in crossbred dairy cows (>75% Holstein Friesian). Four crossbred dairy cows (467.6 ± 35.2 kg BW) were assigned to be supplemented with one of four levels of CHT according to a 4 × 4 Latin square design. Dietary treatments included the control (without CHT supplementation) and CHT treatments that consisted of supplementation with 3.15, 6.30 and 9.45 g CHT/day. Rice straw was given ad libitum. The results showed that increasing levels of CHT tended to quadratically decrease rice straw intake (p = 0.06). However, total dry matter intake (DMI) and other nutrients were not different (p > 0.05) among the dietary treatments. The apparent digestibility of DM, organic matter (OM) and crude protein (CP) in cows with CHT treatments were higher (p < 0.05) than those of control cows. Milk yield and milk composition were not different (p > 0.05) among treatments. Lactose yield tended to increase linearly (p = 0.09) as CHT supplementation increased. Ruminal pH and ammonia nitrogen (NH3-N) were not different (p > 0.05), but total volatile fatty acids (VFAs) increased linearly (p < 0.05) as CHT levels increased. The somatic cell count (SCC) and somatic cell score (SCS) in the CHT treatments were different (p < 0.01) than those in the control treatment. In conclusion, it appears that CHT supplementation improved feed utilization and influenced SCC in crossbred dairy cows. Long-term research is needed to confirm the benefit of CHT supplementation.

Blood calcium concentration and performance in periparturient and early lactating dairy cows is influenced by plant bioactive lipid compounds

Previous studies ex vivo suggested that plant bioactive lipid compounds (PBLC) can increase ruminal calcium absorption. Therefore, we hypothesized that PBLC feeding around calving may potentially counteract hypocalcemia and support performance in postpartum dairy cows. The corresponding aim of the study was to investigate the effect of PBLC feeding on blood minerals in Brown Swiss (BS) and hypocalcemia-susceptible Holstein Friesian (HF) cows during the period from d -2 to 28 relative to calving and on milk performance until d 80 of lactation. A total of 29 BS cows and 41 HF cows were divided each into a control (CON) and PBLC treatment group. The latter was supplemented with 1.7 g/d menthol-rich PBLC from 8 d before expected calving to 80 d postpartum. Milk yield and composition, body condition score and blood minerals were measured. Feeding PBLC induced a significant breed × treatment interaction for iCa, supporting that PBLC increased iCa exclusively in HF cows; the increase was 0.03 mM over the whole period and 0.05 mM from d 1 to 3 after calving. Subclinical hypocalcemia was seen in one BS-CON and 8 HF-CON cows and 2 BS-PBLC and 4 HF-PBLC cows. Clinical milk fever was detected only in HF cows (2 HF-CON and one HF-PBLC). Other tested blood minerals, such as sodium, chloride, and potassium, as well as blood glucose, were neither affected by PBLC feeding nor breed, nor were their 2-way interactions, except for higher sodium levels in PBLC cows on d 21. Body condition score showed no effect of treatment, except for a lower body condition score in BS-PBLC compared with BS-CON at d 14. Dietary PBLC increased milk yield, milk fat yield, and milk protein yield at 2 consecutive dairy herd improvement test days. As indicated by treatment × day interactions, energy-corrected milk yield and milk lactose yield were increased by PBLC on the first test day only, and milk protein concentration decreased from test d 1 to test d 2 in CON only. The concentrations of fat, lactose, and urea, as well as somatic cell count, were not affected by treatment. The weekly milk yield over the first 11 wk of lactation was 29.5 kg/wk higher for PBLC versus CON across breeds. It is concluded that the applied PBLC induced a small but measurable improvement of calcium status in HF cows in the study period and had additional positive effects on milk performance in both breeds.

Effects of phytonutrients and yeast culture supplementation on lactational performance and nutrient use efficiency in dairy cows

Yeast culture and phytonutrients are dietary supplements with distinct modes of action, and they may have additive effects on the performance of dairy cattle. The objective of this study was to investigate the effects of a preparation of phytonutrients and a yeast culture from Saccharomyces cerevisiae on lactational performance, total-tract digestibility of nutrients, urinary nitrogen losses, energy metabolism markers, and blood cells in dairy cows. Thirty-six mid-lactation Holstein cows (10 primiparous and 26 multiparous) were used in an 8-wk randomized complete block design experiment with a 2-wk covariate period, 2 wk for adaptation to the diets, and a 4-wk experimental period for data and samples collection. Following a 2-wk covariate period, cows were blocked by days in milk, parity, and milk yield and randomly assigned to 1 of 3 treatments (12 cows per treatment): basal diet supplemented with 14 g/cow per day yeast culture (YC; S. cerevisiae), basal diet supplemented with 1.0 g/cow per day phytonutrients (PN; 5.5% cinnamaldehyde, 9.5% eugenol, and 3.5% capsicum oleoresin), or basal diet supplemented with a combination of YC and PN (YCPN). Treatments were top-dressed once daily on the total mixed ration at time of feeding. Dry matter intake, milk yield, and feed efficiency were not affected by treatments. Milk composition and energy-corrected milk yield were also not affected by supplementation of YC, PN, and YCPN. There were no differences in intake or total-tract digestibility of dietary nutrients among treatments. Compared with YC, the PN and YCPN treatments tended to decrease the proportion of short-chain fatty acids in milk fat. There was an additive effect of YC and PN supplementation on urinary urea nitrogen (UUN) excretion relative to total nitrogen intake. Cows fed a diet supplemented with YCPN had lower UUN excretion than cows in YC and tended to have lower UUN excretion compared with PN. Blood monocytes count and percentage were decreased in cows fed PN and YCPN diets compared with YC. Treatments did not affect concentrations of blood β-hydroxybutyrate and total fatty acids. Overall, lactational performance, digestibility of nutrients, energy metabolism markers, and blood cells were not affected by YC, PN, or YCPN supplementation. A combination of PN and YC had an additive effect on nitrogen excretion in dairy cows.

Ruminal fermentation and methane production in vitro, milk production, nutrient utilization, blood profile, and immune responses of lactating goats fed polyphenolic and saponin-rich plant extracts

This study was conducted to evaluate the effect of a composite plant extract (CPE) rich in polyphenolics and saponins from seeds of Dolichos biflorus (horse gram), root of Asparagus racemosus (shatavari), bark of Amoora rohituka (rohitaka), and peel of Punica granatum (pomegranate) on ruminal fermentation and methanogenesis in vitro, milk production, nutrient digestibility, immune response, and blood profiles in lactating Beetal goats fed CPE at 20 g/kg diet. Dose effect of CPE was assessed using different doses (0, 10, 20, 30, and 40 g/kg substrate) to find out an optimum dose for the in vivo study. The in vivo experiment lasted 70 days including a 10-day adaptation period. In the in vitro study, dry matter (DM) and fiber degradability increased linearly (P < 0.05) and methane production and ammonia concentration decreased linearly (P < 0.05) with increasing doses of CPE. Concentrations of total VFA and proportion of propionate increased (P < 0.001) linearly, whereas proportion of acetate and acetate to propionate ratio decreased with a linear effect. Dietary CPE increased milk yield (P = 0.017) and concentrations of protein and lactose (P = 0.045) by CPE, but concentrations of fat and solid not fat in milk were not affected (P > 0.10). Somatic cell counts in milk reduced (P = 0.045) in the CPE-fed goats. Apparent digestibility of DM (P = 0.037) increased significantly and NDF (P = 0.066) tended to increase due to supplementation of CPE. Blood glucose (P = 0.028) and albumin (P = 0.007) concentrations increased, while other liver-marker metabolites and enzyme activities and superoxide dismutase activity were not altered in goats due to feeding of CPE. Concentrations of total amino acids (P = 0.010), total essential amino acids (P = 0.012), and total ketogenic amino acids (P < 0.001) were greater in the CPE-fed goats than the control goats. Cell-mediated immune response improved due to CPE feeding. This study suggests that the CPE rich in both phenolics and saponins could improve ruminal fermentation, milk production, and nutrient utilization in lactating goats with better health status while decreasing methane emission.

Thermoregulation and Performance of Dairy Cows Subjected to Different Evaporative Cooling Regimens, with or without Pepper Extract Supplementation

The objective of this study was to evaluate whether there is an interaction between pepper extract (PE) supplementation and evaporative cooling regimens on the performance, thermal comfort, and metabolism of lactating cows. The experiment was designed as a double 4 × 4 Latin square using eight multiparous Holstein cows (days in milk 147 ± 43.8 days). Treatments were a 2 × 2 factorial arrangement; two evaporative cooling regimens [sprinkler cycles of 30 s on and 4.5 min off (R5) and 30 s on and 9.5 min off (R10)] were combined with no inclusion of pepper extract (CT) or 800 mg/cow daily of PE. The inclusion of PE allowed a greater reduction in the surface temperature of the coat, and the cows remained for longer periods in the feeding area. There was an interaction between the use of PE and the climate regimen for surface temperature, which was lower for PER5. Cows experiencing greater intermittency in the spraying cycles (R10) spent 35% more time at the feeding area. A significant interaction was observed for milk production, with greater production for CTR5 compared to the other treatments. The feed efficiency for R5 was higher than that for R10. The R5 treatment combined with PE reduced water intake. There was no significant difference in serum parameters other than gamma-glutamyl transferase, with an interaction between treatments and greater activity for PER10, and total protein and albumin, which had cooling effects that were higher for R10. The two factors tested interfered in different and dissociated ways. The evaporative cooling strategies were effective, and the R5 treatment resulted in higher feed efficiency and milk production. The inclusion of PE enhanced heat reduction in cows when they were subjected to a cooling regime.

Rumen fermentation, methane concentration, and blood metabolites of cattle receiving dietetical phytobiotic and cobalt (II) chloride

Background and Aim

Ensuring the genetic potential of ruminants through nutrition studies using medicinal plants and trace element metals is an urgent task. This study aimed to study the effect of Artemisia absinthium L. (Asteraceae) herb plant separately and in combination with cobalt (II) chloride (CoCl₂) chelate compounds on the course of metabolic processes in the rumen, methane concentration, and biochemical blood parameters in bulls.

Materials and Methods

Control group (BD: Basal diet); experimental Group I - BD + A. absinthium herb at a dose of 2.0 g/kg dry matter (DM), experimental Group II - BD + A. absinthium herb at a dose of 2.0 g/kg DM + CoCl₂ (1.5 mg/kg), and experimental Group III - BD + CoCl₂ were set (1.5 mg/kg). The study was conducted on 16 beef bulls (Kazakh white-headed breed) aged 13-14 months, with an average live weight of 330-335 kg. Enzymatic processes in the rumen were studied, including the level of volatile fatty acids (using the gas chromatography method), nitrogen and its fractions (using the Kjeldahl method), methane concentration, and morphological and biochemical blood composition.

Results

There was a decrease in the concentration of acetic acid in experimental group I (15.9%) (p < 0.05) and in the III group (60.3%) and propionic acid in all experimental groups by 5.6%-47.3% (p < 0.05). Feeding A. absinthium herb as part of the diet of experimental Group I contributed to a decrease in methane concentration by 17.8% (p = 0.05) and the lowest methane concentration was noted for experimental Group III. It was less than in control by 59.1% (p < 0.05). An increase in the concentration of glucose, total protein, and creatinine was found in the experimental groups (p < 0.05). The digestibility of organic matter (3.5%), crude fiber (3.6%), and hemicellulose (11.0%) increased with the feeding of A. absinthium herb.

Conclusion

Thus, using biocomplexes based on A. absinthium herb and CoCl₂ do not harm the rumen fermentation of cattle. Still, further microbiome studies are required to evaluate the effects of A. absinthium on cattle properly.

Feeding tannins to dairy cows in different seasons improves the oxidative status of blood plasma and the antioxidant capacity of cheese

The aim of the present study was to assess the dietary supplementation of tannins to grazing dairy cows in 2 seasons characterized by a good quality pasture (spring) or a poor-quality pasture (summer). The effects of dietary tannins were assessed on plasma antioxidant status and cytokines profile and on the antioxidant properties of cheese and cheese in vitro digestates. Fourteen lactating dairy cows were divided into 2 homogeneous groups (n = 7): a control group (CON), and an experimental group (TAN) receiving 150 g/head per day of tannins supplementation. The experiment was performed twice, in spring and in summer. The animals were free to graze on spontaneous pasture (spring) or on dry stubble (summer). Blood was sampled at the beginning (d 0), at the midpoint (d 11), and at the end (d 22) of the trial. Individual cheese was produced before the beginning (d -1) and at the end (d 22) of the trial from the milk collected from each cow. On blood plasma, the reactive oxygen metabolites (ROM), biological antioxidant potential (BAP), nonesterified fatty acids quantification, and cytokines profile in terms of IL-10, IL-8, IL-1β, and IFN-γ were determined. Data on ROM demonstrated that tannins supplementation lowered oxidative stress both in spring and in summer. Accordingly, TAN diet increased BAP levels compared with the CON during summer trial. Thus, feeding tannins resulted in lower ratio between ROM and BAP (oxidative stress index) in both spring and summer. Cytokines' profile showed lower IL-1β values in TAN group at d 22 during spring season, with a concomitant higher IL-10 level, during summer season. Moreover, TAN group had a lower level of IFN-γ in plasma than CON group, both in spring and in summer. On cheese samples, the in vitro digestion was performed and on cheese and cheese digestates (gastric and intestinal digestate) the free radical scavenging antioxidant activity was evaluated. The intestinal digestate fraction registered the highest antioxidant activity compared with cheese and gastric digestate, in both spring and summer seasons. Furthermore, an improvement of the antioxidant property of cheese and cheese digestates was found. Present data demonstrated that tannins supplementation contributed to reduce the oxidative stress of lactating dairy cows and showed an increase of anti-inflammatory cytokines ratio.

Garlic-Derived Metabolites Exert Antioxidant Activity, Modulate Gut Microbiota Composition and Limit Citrobacter rodentium Infection in Mice

The garlic-derived compounds propyl propane thiosulfinate (PTS) and propyl propane thiosulfonate (PTSO) are metabolites with putative health benefits against intestinal inflammation that may be related to their antioxidant activity. However, the underlying mechanisms remain unclear, and whether PTS-PTSO can promote gut health by altering the microbiota and exert protection against enteric pathogens needs further investigation. Here, we explored the antioxidant activity of PTS-PTSO in murine macrophages in vitro, and in an in vivo model of bacterial infection with the bacterial pathogen Citrobacter rodentium. PTS-PTSO attenuated reactive oxygen species in lipopolysaccharide-stimulated macrophages in a nuclear factor erythroid factor 2-related factor 2 (Nrf2)-dependent manner, decreased nitric oxide levels both in macrophages in vitro and in the sera of mice fed PTS-PTSO, and had putatively beneficial effects on the commensal gut microbiota. Importantly, PTS-PTSO decreased faecal C. rodentium counts, concomitant with upregulation of Nrf2-related genes in colon tissue. Thus, PTS-PTSO mediates Nrf2-mediated antioxidant activity and modulates gut microbiota, which may protect the host against C. rodentium colonization. Our results provide further insight into how PTS-PTSO and related bioactive dietary compounds may reduce enteric infections.

Effect of Plant Bioactive Compounds Supplemented in Transition Dairy Cows on the Metabolic and Inflammatory Status

(1) Background: This study evaluated the effects of a plant bioactive (Phyto Ax’Cell, Phytosynthese, Mozac, France) on the inflammatory status and health of dairy cows during calving. (2) Methods: 46 Holstein crossbred cows were randomized into a control group (CON, n = 23) and the Phyto Ax’Cell group (PAC, n = 23). PAC received Phyto Ax’Cell at 25 g/cow/day, from 15 days prepartum to 7 days postpartum. Blood analyses were performed weekly from D-7 to D14 to evaluate the energy metabolism and inflammatory status; rectal temperature was measured daily within 14 days from calving day (D0). (3) Results: PAC showed lower serum haptoglobin at D7 (0.55 vs. 0.79 mg/mL; p < 0.05) and D14 (0.44 vs. 0.66 mg/mL; p < 0.05). CON had a higher number of circulating white blood cells and granulocytes on D7 (p < 0.05). Fewer cows from PAC showed hyperthermia (≥39 °C) during the first 2 weeks postpartum (−7%, p < 0.05). Energy metabolism, which was represented by the NEFA/cholesterol ratio, improved (0.21 vs. 0.36 at D0, p < 0.1; 0.19 and 0.15 vs. 0.36 and 0.32, respectively, at D+7 and D+14, p < 0.05) under the plant bioactive supplementation. (4) Conclusions: The results suggest that the anti-inflammatory plant bioactive compound with Brazilian green propolis administered during calving had a beneficial effect on the energy and inflammatory status of dairy cows.

Effects of Turmeric Powder on Aflatoxin M1 and Aflatoxicol Excretion in Milk from Dairy Cows Exposed to Aflatoxin B1 at the EU Maximum Tolerable Levels

Due to the climatic change, an increase in aflatoxin B1 (AFB1) maize contamination has been reported in Europe. As an alternative to mineral binders, natural phytogenic compounds are increasingly used to counteract the negative effects of AFB1 in farm animals. In cows, even low dietary AFB1 concentrations may result in the milk excretion of the genotoxic carcinogen metabolite aflatoxin M1 (AFM1). In this study, we tested the ability of dietary turmeric powder (TP), an extract from Curcuma longa (CL) rich in curcumin and curcuminoids, in reducing AFM1 mammary excretion in Holstein–Friesian cows. Both active principles are reported to inhibit AFM1 hepatic synthesis and interact with drug transporters involved in AFB1 absorption and excretion. A crossover design was applied to two groups of cows (n = 4 each) with a 4-day washout. Animals received a diet contaminated with low AFB1 levels (5 ± 1 µg/kg) for 10 days ± TP supplementation (20 g/head/day). TP treatment had no impact on milk yield, milk composition or somatic cell count. Despite a tendency toward a lower average AFM1 milk content in the last four days of the treatment (below EU limits), no statistically significant differences with the AFB1 group occurred. Since the bioavailability of TP active principles may be a major issue, further investigations with different CL preparations are warranted.

Supplementing a Phytogenic Feed Additive Modulates the Risk of Subacute Rumen Acidosis, Rumen Fermentation and Systemic Inflammation in Cattle Fed Acidogenic Diets

Feeding with high-concentrate diets increases the risk of subacute ruminal acidosis (SARA). This experiment was conducted to evaluate whether supplementing a phytogenic feed additive based on L-menthol, thymol, eugenol, mint oil (Mentha arvensis) and cloves powder (Syzygium aromaticum) (PHY) can amend the ruminal fermentation profile, modulate the risk of SARA and reduce inflammation in cattle. The experiment was designed as a crossover design with nine non-lactating Holstein cows, and was conducted in two experimental runs. In each run, cows were fed a 100% forage diet one week (wk 0), and were then transitioned stepwise over one week (0 to 65% concentrate, wk adapt.) to a high concentrate diet that was fed for 4 weeks. Animals were fed diets either with PHY or without (CON). The PHY group had an increased ruminal pH compared to CON, reduced time to pH < 5.8 in wk 3, which tended to decrease further in wk 4, reduced the ruminal concentration of D-lactate, and tended to decrease total lactate (wk 3). In wk 2, PHY increased acetate, butyrate, isobutyrate, isovalerate, and the acetate to propionate ratio compared to CON. Phytogenic supplementation reduced inflammation compared to CON in wk 3. Overall, PHY had beneficial effects on ruminal fermentation, reduced inflammation, and modulated the risk of SARA starting from wk 3 of supplementation.

A composite polyphenol-rich extract improved growth performance, ruminal fermentation and immunity, while decreasing methanogenesis and excretion of nitrogen and phosphorus in growing buffaloes

The effects of a composite polyphenolic-rich extract (CPRE) on ruminal fermentation, nutrient utilisation, growth performance, excretion of nitrogen and phosphorus and methane emission were studied in growing buffaloes. Four herbal dry extracts prepared from Acacia arabica (babul; bark), Acacia catechu (cutch; bark), Punica granatum (pomegranate; peel) and Eugenia jambolana (Indian blackberry; seeds) were mixed in an equal proportion (1:1:1:1) to prepare the CPRE that contained mainly phenolic compounds (146 g/kg), flavonoids (41.7 g/kg) and saponins (40.5 g/kg). First, in vitro tests were performed for ruminal fermentation and feed degradability using ruminal fluid as inocula and CPRE at 0 to 40 g/kg substrate to decide an optimal dose of CPRE for an in vivo study on buffaloes. In the animal study, 20 buffaloes were randomly assigned to two groups (n = 10)-a control diet and a CPRE diet (control diet added with extra 20 g/kg of CPRE). The in vitro tests suggested that addition of CPRE at 20 g/kg substrate increased degradability of substrate, short-chain fatty acid concentration and propionate proportion, and reduced methane production, acetate proportion, acetate:propionate ratio and ammonia concentration in fermentation media, which were also noted in the rumen of buffaloes. Feeding CRPE to buffaloes did not affect feed intake, but increased daily body weight gain, dry matter and crude protein digestibility and nitrogen and phosphorus retention in the body. Total bacteria, methanogens and protozoal numbers were similar between two groups, but Fibrobacter succinogenes increased in the rumen of buffaloes fed CPRE. Concentrations of total, essential, non-essential and glucogenic amino acids were greater in the plasma of CPRE-fed buffaloes. Cell-mediated immune response improved in the CPRE-fed buffaloes compared with the control group. Estimated methane production and excretion of nitrogen and phosphorus per unit of body weight gain decreased in the CPRE group. The comprehensive results of this study clearly suggested that the composite polyphenol-rich feed additive at 20 g/kg diet improved growth performance, ruminal fermentation, immunity and plasma amino acids profile, whereas it reduced indicators of environmental impacts of buffalo production.

Dose-dependent effect of plants of the Lamiaceae family on the concentration of methane, fatty acids and nitrogen in the ecosystem in vitro

Fermentation processes in the rumen of ruminants determine how much final metabolites and their derivatives will be formed, which are necessary for the full development of the organism, the level of productivity, and also affect the level of formation of endogenous substances, namely, greenhouse gas emissions. These criteria lead us to the search for new feed products that improve the metabolic processes of the rumen and the digestive system as a whole, so phyto-substances can serve as an alternative. The article presents the results of in vitro study of the influence of Salviae folia, Scutellaria baicalensis, Oríganum vulgáre on formation of methane, synthesis of volatile fatty acids and nitrogen, as the main indicator parameters of the enzymatic activity of the rumen of ruminants. It was found that when using phyto- substances: Salviae folia and Scutellaria baicalensis, more acetic and propionic acid was formed, Oríganum vulgare in various dosages shifted towards propionic and valeric acid. Formation of a larger amount of microbial protein (P≤0.05) with use of Salviae folia, Scutellaria baicalensis, Oríganum vulgáre in various dosages was established. Methane production decreased with use of Oríganum vulgáre.

The Role of Polyphenols in Regulation of Heat Shock Proteins and Gut Microbiota in Weaning Stress

Gut microbiota is the natural residents of the intestinal ecosystem which display multiple functions that provide beneficial effects on host physiology. Disturbances in gut microbiota in weaning stress are regulated by the immune system and oxidative stress-related protein pathways. Weaning stress also alters gut microbiota response, limits digestibility, and influences animal productive performance through the production of inflammatory molecules. Heat shock proteins are the molecular chaperones that perform array functions from physiological to pathological point of view and remodeling cellular stress response. As it is involved in the defense mechanism, polyphenols ensure cellular tolerance against enormous stimuli. Polyphenols are nature-blessed compounds that show their existence in plenty of amounts. Due to their wider availability and popularity, they can exert strong immunomodulatory, antioxidative, and anti-inflammatory activities. Their promising health-promoting effects have been demonstrated in different cellular and animal studies. Dietary interventions with polyphenols may alter the gut microbiome response and attenuate the weaning stress related to inflammation. Further, polyphenols elicit health-favored effects through ameliorating inflammatory processes to improve digestibility and thereby exert a protective effect on animal production. Here, in this article, we will expand the role of dietary polyphenol intervention strategies in weaning stress which perturbs gut microbiota function and also paid emphasis to heat shock proteins in gut health. This review article gives new direction to the feed industry to formulate diet containing polyphenols which would have a significant impact on animal health.

An Exploration of the Effects of an Early Postpartum Intravenous Infusion with Carnosic Acid on Physiological Responses of Transition Dairy Cows

The objective of the present study was to evaluate the effects of an antioxidant and anti-inflammatory compound found in rosemary plants (Salvia rosmarinus) named carnosic acid during the transition period of dairy cows. From day 1 to 3 after calving, 16 multiparous Holstein cows received a daily intravenous infusion of either 500 mL of saline (NaCl 0.9%; Saline; n = 8) or carnosic acid at a rate of 0.3 mg/kg of BW supplied in 500 mL of saline (CA; n = 8). Blood samples were taken at –7, 2, 5, 7, 14, and 21 d relative to parturition, then analyzed for metabolites related to energy metabolism, muscle mass catabolism, liver function, inflammation, and oxidative stress. CA infusion tended to improve milk performance; however, DMI was unaffected by treatment. At 2 d relative to parturition, CA cows had lower blood concentrations of haptoglobin, paraoxonase, FRAP, and NO₂^– than saline cows. After treatment infusions, haptoglobin remained lower in CA cows than saline at 5 d relative to parturition. Our results demonstrate that carnosic acid promoted positive responses on inflammation and oxidative stress biomarkers and may promote beneficial effects on lactation performance in peripartal dairy cows.

In vitro nutritional quality and antioxidant activity of three weed species as feed additives for sheep in the Central Highlands of Mexico

Sheep production is traditional for rural communities in Mexico, based on natural grasslands and semi-stabled feeding. Quality forages are necessary to improve productivity in these systems. Weeds are an alternative to feed ruminants and to manage crops. Also, many plants have secondary metabolites beneficial for livestock. The objective was to assess the nutritive value in vitro and the antioxidant activity of three weeds (Tithonia tubiformis, Cosmos bipinnatus, and Tagetes lucida) and four treatments (T0 = control diet, T1 = diet + 5% T. tubiformis, T2 = diet + 5% C. bipinnatus, and T3 = diet + 5% T. lucida). Nutritive value was determined from chemical composition by standard methods and mineral contents by inductively coupled plasma analyses. Secondary compounds, total phenols (TP), total tannins (TT), condensed tannins (CT), and phenolic compounds, were determined by high-performance liquid chromatography, and total antioxidant activity was determined by measuring the oxygen radical absorbance capacity. Rumen fermentation kinetics and in vitro digestibility of dry matter (IVDMD), organic matter (IVOMD), and neutral detergent fibre (IVNDFD) were determined per species and treatment by in vitro gas production. T. tubiformis had the highest CP and TP contents (P < 0.05), and C. bipinnatus had the highest fibre and CT contents (P < 0.05). Inclusion of T. lucida in the diet resulted in an 18% increase in TP content and a 30% increase in antioxidant activity in comparison to the control diet. No significant differences (P > 0.05) were found in rumen kinetics parameters, IVDMD, IVOMD, IVNDFD, or metabolizable energy, indicating that the tested weeds can be used as additives to increase antioxidant activity in sheep diets without negative effects.

Supplementation with green tea and oregano extracts on productive characteristics, blood metabolites, and antioxidant status of Jersey cows during the transition period

Plant extracts have been recognized as beneficial to human health and have been evaluated as feed additive for domestic and companion animals. This study evaluated oregano and green tea extracts fed to Jersey cows from approximately 21 d before calving to 21 d after calving on milk production, milk composition, and blood metabolites as well as investigated immunological and antioxidant attributes. Twenty-four Jersey cows with 441 ± 27 kg of BW, 3.5 ± 0.3 of body condition score (BCS), and 2.7 ± 1.8 lactations were selected at approximately 28 d before the expected parturition date and were randomly assigned to three treatments with eight cows each: without plant extracts in diet (control - CON), addition of 10 g per day of oregano extract (OR), and addition of 5 g per day of green tea extract (GT). Feed intake, BW, BCS, blood metabolites, hemogram as well as oxidative stress biomarkers were evaluated from approximately 3 weeks prepartum to 3 weeks postpartum (transition period) while milk production and composition were evaluated during the first 3 weeks of lactation. Plant extracts did not change BW, BCS, and DM intake (DMI) throughout the transition period, but OR increased in approximately 20% total digestive nutrients and metabolizable energy intake on days 15 and 16 postpartum compared with CON. In the prepartum, OR increased in 48% platelets count compared to the CON, while GT augmented in 142% eosinophils compared with CON. Oregano extract reduced the levels of reactive species in the erythrocytes in 40% during prepartum and postpartum compared with CON, while GT reduced its levels in 24 and 29% during prepartum and postpartum, respectively, when compared with CON. In the postpartum period, OR increased in 60% the carbonylated protein content compared with CON, while GT reduced in 45% the levels of reactive species in plasma compared with CON. During the postpartum, both extracts increased in 33% the concentration of reduced glutathione when compared with CON. Moreover, GT tended to decrease feed efficiency in 11% when compared with CON; OE reduced milk pH and somatic cell count when compared with CON. In conclusion, OE and GT did not expressively affect immunological attributes in blood but reduce some oxidative stress biomarkers without compromising productive traits of Jersey cows during the transition period.

Probiotic microorganisms and herbs in ruminant nutrition as natural modulators of health and production efficiency – a review

Probiotics, prebiotics, synbiotics, direct-fed microbials, and herbs may improve the production efficiency in ruminants. The beneficial effect of selected specific microbes on animal health is reflected in protection against pathogens, stimulation of immunological response, increased production capacity, and mitigation of stress effects. Phytobiotic plants used in the nutrition of ruminant animals increase feed palatability. This in turn has a positive effect on feed intake and, consequently, increases production performance. Pectins, terpenes, phenols, saponins, and antibioticlike substances contained in phytobiotics prevent irritation, diarrhea, and increase the activity of digestive enzymes. Thanks to the abundance of biologically active substances such as flavonoids, glycosides, coumarins, carotenoids, polyphenols, etc., phytobiotics exhibit immunostimulatory and antioxidant properties as well. Given such a wide range of effects on health status and production parameters in animals, an attempt was made in this review to compile the current knowledge on the possible application of these natural growth stimulants in ruminant nutrition and to demonstrate their potential benefits and/or risks for breeding these animals.

Haematology and Serum Biochemical Indices of Lambs Supplemented with Moringa oleifera, Jatropha curcas and Aloe vera Leaf Extract as Anti-Methanogenic Additives

Medicinal plants have been found to be effective in a wide range of applications in ruminant animals. However, some plant extracts may be toxic to animals, depending on their seconday metabolite composition and dose, and therefore, animal trials are needed to validate their safety when used as anti-methanogenic additives. This study investigated the effect of three plant extracts used as anti-methanogenic dietary additives, on the haematology and serum biochemical parameters in sheep. Methanolic extracts of Moringa oleifera (MO), Jatropha curcas (JC) and Aloe vera (AV) were orally dosed as experimental treatments for 75 days to sheep, and their effect on the haematology and serum biochemical parameters of SA Mutton Merino (SAMM) lambs were compared with sheep on a control treatment without any additive treatment. Extracts of MO, JC and AV were extracted in 100% methanol, freeze-dried, and reconstituted in distilled water. A total of 40 lambs were ranked according to their body weight into a group of four and one sheep at a time was randomly allocated into four dietary treatments which include a control treatment, and treatment with either MO, JC or AV extract. Lambs were drenched twice daily with doses equivalent to 50 mg/kg dry matter intake (DMI) based on previous week feed consumption. Blood samples were collected via jugular vein puncture and analysed for haematology and serum biochemistry parameters, using standard procedures. The results of the haematological analysis showed that most haematological parameters were not affected by plant extract used as anti-methanogenic additives (p > 0.05), except for higher white blood cell (WBC) and lymphocytes counts recorded in control lambs and lambs in the AV treatment. All serum biochemical properties (except alkaline phosphatase) were not different (p > 0.05) between the control and lambs treated with plant extracts. Alkaline phosphatase was influenced by the plant extract (p < 0.05), with lambs receiving MO, JC and AV having lower alkaline phosphatase concentrations compared to lambs on the control diet without any additive. The result of the study showed that extracts of MO, JC and AV were not toxic to sheep when used as antimethanogenic additives at the recommended dose of 50 mg/kg dry matter feed which had proved previously to be effective in reducing enteric methane emission. Therefore, these plant extracts could be used safely as alternative dietary additives to reduce enteric methane emission and boost the productivity of SA Mutton Merino sheep.

Immunostimulatory and antioxidant effects of supplemental feeding with macroalga Sargassum spp. on goat kids

Algae are a rich source of bioactive compounds and health properties that have been narrowly explored in goat production systems. The aim of this study was to determine the effect of feeding diets supplemented with Sargassum spp. on antioxidant status and immune parameters in goat kids. The diets were as follows: control (basal diet without alga), Sargassum spp. 2.5% (Ss2.5), and Sargassum spp. 5% (S5) fed over a 70-day period. A total of 11 body tissues, intestinal mucus, and blood serum were sampled at necropsy. Protein content, superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO), lysozyme, and anti-protease activities were determined, as well as immunoglobulin A (IgA) and immunoglobulin G (IgG). The results indicated that Sargassum spp. supplementation increased protein content in six tissues. Antioxidant activities (SOD and CAT) and immune-related (lysozyme, MPO, and anti-protease) activities were statistically higher (P < 0.05) in Sargassum spp. groups compared with control in several tissues, intestinal mucus, and serum. Imunoglobulin A levels in intestinal mucus were higher (P < 0.05) in Sargassum spp.-supplemented groups than the control group. In conclusion, diet supplementation of Sargassum spp. improves the antioxidant status and enhances the immune parameters in goats. Sargassum spp. dietary supplementation is proposed as strategy to strengthen antioxidant status and stimulate the immune system, which helps in the control of opportunistic pathogens in goats.

A Novel Combination of Vitamin C, Curcumin and Glycyrrhizic Acid Potentially Regulates Immune and Inflammatory Response Associated with Coronavirus Infections: A Perspective from System Biology Analysis

Novel coronaviruses (CoV) have emerged periodically around the world in recent years. The recurrent spreading of CoVs imposes an ongoing threat to global health and the economy. Since no specific therapy for these CoVs is available, any beneficial approach (including nutritional and dietary approach) is worth investigation. Based on recent advances in nutrients and phytonutrients research, a novel combination of vitamin C, curcumin and glycyrrhizic acid (VCG Plus) was developed that has potential against CoV infection. System biology tools were applied to explore the potential of VCG Plus in modulating targets and pathways relevant to immune and inflammation responses. Gene target acquisition, gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment were conducted consecutively along with network analysis. The results show that VCG Plus can act on 88 hub targets which are closely connected and associated with immune and inflammatory responses. Specifically, VCG Plus has the potential to regulate innate immune response by acting on NOD-like and Toll-like signaling pathways to promote interferons production, activate and balance T-cells, and regulate the inflammatory response by inhibiting PI3K/AKT, NF-κB and MAPK signaling pathways. All these biological processes and pathways have been well documented in CoV infections studies. Therefore, our findings suggest that VCG Plus may be helpful in regulating immune response to combat CoV infections and inhibit excessive inflammatory responses to prevent the onset of cytokine storm. However, further in vitro and in vivo experiments are warranted to validate the current findings with system biology tools. Our current approach provides a new strategy in predicting formulation rationale when developing new dietary supplements.

Oxidative Status of Goats with Different CSN1S1 Genotypes Fed ad Libitum with Fresh and Dry Forages

Forty late-lactation Girgentana goats were used to study the effect of diets fed ad libitum and αS1-casein (CSN1S1) genotype on redox balance. The goats genotyped at CSN1S1 locus (A/A, A/F) were subjected to four feeding treatments different for percentage inclusion of dry and fresh forage: DAF100 (98% of Dry Alfalfa Forage), DAF65 (65% of Dry Alfalfa Forage), FSF100 (100% of Fresh Sulla Forage) and FSF65 (65% of Fresh Sulla Forage). Blood samples were analyzed for superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, reactive oxygen metabolites (ROMs), biological antioxidant potential (BAP) and non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), albumin, glucose and cholesterol contents. The oxidative stress index (OSI) was calculated as percentage ratio of ROMs to BAP. Redox balance was improved by Sulla inclusion, as reflected in the lower OSI values found in FSF100 and FSF65 groups. DAF100 group displayed the highest GPX activity, while other groups exhibited the highest SOD activity. Fresh forage diets increased albumin concentration while no effect of tested factors was noted on glucose, NEFA, BHBA and cholesterol contents. The interaction diet × genotype was significant only for GPX activity. GPX and albumin were negatively correlated and were correlated positively and negatively with ROMs, respectively. Diet rather than genotype affects redox balance in dairy goats and a possible role of forage polyphenol compounds on oxidative status needs to be tested in future studies.

A multicomponent herbal feed additive improves somatic cell counts in dairy cows - a two stage, multicentre, placebo-controlled long-term on-farm trial

In contrast to natural and historical diets of wild and domesticated ruminants, the diversity of plant species is limited in diets of modern dairy cows. Are "production diseases" linked to this? We conducted a trial to test the effects of a multicomponent herbal feed additive (HFA) on health, performance and fertility traits. A dose-finding study (DF) with 62 cows on 11 commercial farms compared a low (50 g) and a high (100 g) dose of HFA (HFA-50, HFA-100) with a placebo (PL). In a subsequent field trial (FT) with 280 cows on 30 commercial farms, HFA-100 was compared to PL. Cows were randomly assigned to HFA and PL groups and received HFA or PL individually daily from 14 days pre- to 300 days post-calving. Data were analysed with mixed effects models. No differences between HFA and PL were found regarding performance, body condition score and overall culling rates. A tendency towards lower milk urea for HFA-100 compared to PL (p = .06) was found in DF. HFA significantly reduced elevated milk acetone observations (≥10 mg/L) in the first 10 lactation weeks (HFA-100: 4%; HFA-50: 4%; PL: 12%) in DF. HFA-50 significantly reduced lameness incidence (HFA-100: 11%; HFA-50: 2%; PL: 14%) in DF. Calving intervals were 15 days shorter in HFA compared to PL in both trials, which could be confirmed by tendency (p = .07) in FT. In both trials, the proportion of test days with elevated somatic cell score (≥3.0) was significantly lower in HFA compared to PL (DF: HFA-100: 40%, HFA-50: 45% and PL: 55%; FT: HFA-100: 38% and PL: 55%) which is also reflected by tendency (p = .08) in lower culling rates due to udder diseases in FT. HFA showed no negative impact on any of the measured parameters. The effects of HFA indicate a potential of phytochemically rich and diverse feed additives for dairy cows' nutrition and physiology.

Effect of supplementation of pelleted hazel (Corylus avellana) leaves on blood antioxidant activity, cellular immune response, and heart beat parameters in sheep1

Hazel leaves (Corylus avellana) fed to sheep resulted in decreased methane emissions without negatively affecting feed intake and were found to have antioxidant properties in vitro. The objective of this study was to evaluate effects of hazel leaves, rich in tannins, on blood antioxidant activity, cellular immune response, and heart beat parameters in sheep. Four experimental pellets were produced by mixing alfalfa and hazel leaves in different proportions, including alfalfa alone as a control, 30% and 60% of hazel leaves, the latter also with 3.8% polyethylene glycol (PEG). Six adult, nonpregnant, nonlactating female sheep (71 ± 5.7 kg of body weight) were allocated to 4 treatments in a 6 × 4 crossover design with four 18-d periods. The diet consisted of experimental pellets and ryegrass-dominated hay (ratio 80% to 20% in dry matter), resulting in hazel leaf proportions of approximately 0%, 25%, and 50% in the total diet. Blood samples were collected at the end of each period to determine plasma total phenol concentration and markers of oxidative status as well as peripheral blood mononuclear cells (PBMC) activation and proliferation response in vitro. Heart rate (HR) and HR variability parameters were measured for 2 consecutive days in each period, during different activities (i.e., eating pellets or hay, or lying). Treatments were compared with multiple comparisons and contrast analysis was used to test for linear and quadratic relations. Compared with control, feeding a high dosage of hazel leaves enhanced (P = 0.006) the plasma total antioxidant capacity, which linearly (P = 0.016) increased with increasing level of hazel leaves in the diet. The total phenol concentration and activities of the antioxidant enzymes superoxide dismutase, catalase, and glutathione reductase in the plasma were not different (P ≥ 0.23) among the treatments; however, the latter slightly increased linearly (P = 0.047) with increasing hazel leaves proportion. No differences were observed in the activation and proliferation of PBMC among treatments. The HR decreased linearly (P ≤ 0.009) during pellet eating and lying and the root mean square of successive differences of interbeat intervals (RMSSD) increased linearly (P = 0.037) when lying with increasing level of hazel leaves in the diet. In conclusion, our findings indicate that hazel leaves are a promising supplement to improve oxidative status with no effect on cellular immune response and cardiac stress level of sheep.

Effect of Flemingia macrophylla silage on in vitro fermentation characteristics and reduced methane production

Fodder shrub, Flemingia macrophylla silage (FMS), was nutritionally evaluated for rumen fermentation characteristics using an in vitro gas production technique. Dietary treatments were imposed in a 2 × 7 factorial arrangement in a completely randomised design. The first factor was two ratios of roughage:concentrate (R:C at 60:40 and 40:60), and the second factor was seven levels of FMS supplementation at 0, 20, 40, 60, 80, 100 and 120 g/kg of dietary substrate. The results revealed that a R:C ratio at 40:60 increased the kinetics of gas production (P &lt; 0.001). Moreover, supplementation of FMS increased in vitro degradability and the concentration of propionic acid (P &lt; 0.001), whereas acetic acid concentration, protozoal population and methane production were reduced (P &lt; 0.001). In conclusion, supplementation of FMS at 120 g/kg of dietary substrate improved rumen fermentation and subsequently reduced methane production. However, in vivo feeding trials using FMS should be conducted to gain more information for further implementations.

Altered rumen fermentation patterns in lactating dairy cows supplemented with phytochemicals improve milk production and efficiency

Tannins and other phytochemicals are known to improve RUP in the diet by binding protein and then limiting ruminal degradation, which may improve milk yield and milk protein synthesis. The objective of this study was to evaluate the effects of dietary phytochemicals (tannins and Capsicum species) as rumen modifiers on production parameters and milk efficiency in dairy cows. Twenty-four multiparous Holstein cows (96 ± 16 d in milk; mean ± standard deviation) were used in a replicated 3 × 3 Latin square design balanced to measure carryover effects. Cows were blocked according to days in milk, milk production, and body weight and randomly assigned to 1 of 3 groups (n = 8/group). Each group was assigned to a unique treatment sequence across the 3 periods in the Latin square. The experiment consisted of a 14-d covariate period and three 30-d treatment periods. Cows received a basal diet supplemented with soybean meal pellets (SB) as the control diet, phytochemicals (RUM; Rumiviv, CCPA, Janzé, France) pelleted with soybean meal, or expeller soybean meal (ESBM; SoyPlus, West Central Soy, Ralston, IA). Milk production and dry matter intake during the last 4 d of each period were used for statistical analysis. Blood and rumen fluid samples were collected on d 27 of each period. Rumen fluid was analyzed for ammonia N and volatile fatty acids as well as ruminal bacteria via quantitative PCR amplification of 16S ribosomal DNA genes. Greater milk yield (37.9 vs. 36 kg/d), energy-corrected milk (39.7 vs 37.1 kg/d), and protein yield (1.15 vs. 1.08 kg/d) were observed in RUM compared with SB, but these parameters were similar between RUM and ESBM. Concentrations of total volatile fatty acids (118.1 vs. 101.5 mM) were greater in RUM in comparison to SB and ESBM diets. Cows fed RUM had greater β-hydroxybutyrate (0.49 vs. 0.42 mmol/L) than SB and ESBM. Selenomonas ruminantium, Succinimonas amylolytica, and Streptococcus bovis in rumen fluid were lower in RUM fed cows in comparison to SB and ESBM. Increased total volatile fatty acids and lower ruminal abundance of bacteria associated with low feed efficiency in RUM cows can partially explain the improvements observed in milk yield and milk efficiency. Overall, these data suggest that feeding a combination of tannin mixture and Capsicum can significantly affect rumen fermentation characteristics via partial manipulation of rumen microbiota, and these effects were reflected in improved milk production and efficiency.