Nutrient utilization, growth performance, and antioxidative status of Barki lambs fed diets supplemented with black (Nigella sativa) and rocket (Eruca sativa) seeds.

The current study aimed to determine the polyphenol compounds in Nigella sativa (NS) and Eruca sativa (ES) seeds, and evaluate the impact of their addition either as a sole additive or in combination on the growth performance, digestibility, some rumen and blood parameters and antioxidative status of Barki lambs. Forty-eight male lambs (27.18 ± 0.22 kg, 5-6 months), were divided into 4 balanced groups. The experimental diets were randomly distributed to the control group (CON); fed alfalfa hay plus concentrate feed mixture at a ratio of 30:70% without additives, while, NSD, ESD, and NESD groups: fed CON diet plus 2% NS, 2% ES or 1% NS + 1% ES, respectively as a ratio from total mixed ration (TMR). Results indicated that rutin and catechin were the most phenolic compounds observed either in NS or ES seeds. The NS and ES-supplemented groups recorded the highest (P < 0.05) values for dry matter digestibility, nutritive values, average daily gain, and the best feed conversion ratio. However, growth performance, nutritive value, and all nutrient digestibility except for dry matter were not significantly altered with the NESD group. Concentrations of ruminal NH3-N and TVFA were significantly (P < 0.05) reduced with the NESD group, with no significant differences in pH values among different groups. Values of blood parameters showed significant increases in WBCs, PCV, and T-AOC, and decreases in cholesterol, triglycerides, and MDA with the addition of NS and ES seeds or both. Therefore, the addition of NS and ES seeds is recommended to improve lambs' health and antioxidant status.

Exploring the effects of Hippo signaling pathway on rumen epithelial proliferation.

BACKGROUND: The current understanding to the mechanism of rumen development is limited. We hypothesized that the Hippo signaling pathway controlled the proliferation of rumen epithelium (RE) during postnatal development. In the present study, we firstly tested the changes of the Hippo signaling pathway in the RE during an early growing period from d5 to d25, and then we expanded the time range to the whole preweaning period (d10-38) and one week post weaning (d45). An in vitro experiment was also carried out to verify the function of Hippo signaling pathway during RE cell proliferation. RESULTS: In the RE of lambs from d5 to d25, the expression of baculoviral IAP repeat containing (BIRC3/5) was increased, while the expressions of large tumor suppressor kinase 2 (LATS2), TEA domain transcription factor 3 (TEAD3), axin 1 (AXIN1), and MYC proto-oncogene (MYC) were decreased with rumen growth. From d10 to d38, the RE expressions of BIRC3/5 were increased, while the expressions of LATS2 and MYC were decreased, which were similar with the changes in RE from d5 to d25. From d38 to d45, different changes were observed, with the expressions of LATS1/2, MOB kinase activator 1B (MOB1B), and TEAD1 increased, while the expressions of MST1 and BIRC5 decreased. Correlation analysis showed that during the preweaning period, the RE expressions of BIRC3/5 were positively correlated with rumen development variables, while LAST2 was negatively correlated with rumen development variables. The in vitro experiment validated the changes of LATS2 and BIRC3/5 in the proliferating RE cells, which supported their roles in RE proliferation during preweaning period. CONCLUSIONS: Our results suggest that the LATS2-YAP1-BIRC3/5 axis participates in the RE cell proliferation and promotes rumen growth during the preweaning period.

Enhancing physicochemical, rheological properties, and in vitro rumen fermentation of starch with Melastoma candidum D. Don fruit extract.

The utilization of polyphenol-modified starch in ruminants has not undergone extensive exploration. This study aimed to investigate the impact of the complex formed between starch and Melastoma candidum D. Don fruit extract on physicochemical properties, phenol release kinetics in various buffers simulating the gastrointestinal tract, methane production, and post-rumen digestibility. The interaction between starch and M. candidum D. Don fruit extract significantly (p < 0.001) increased resistant starch and particle size diameter. The maximum phenolic release from complex between starch and M. candidum D. Don fruit extract, due to gastrointestinal tract-simulated buffers, ranged from 22.96 to 34.60 mg/100 mg tannic acid equivalent. However, rumen and abomasum-simulated buffers released more phenolic content, whereas the intestine-simulated buffer showed higher antioxidant activity (ferric ion-reducing antioxidant power). Furthermore, complex between starch and M. candidum D. Don fruit extract significantly decreased dry matter rumen digestibility (p < 0.001) and maximum methane gas production (p < 0.001).

Bioactive metabolites of Asparagopsis stabilized in canola oil completely suppress methane emissions in beef cattle fed a feedlot diet.

Asparagopsis taxiformis (Asparagopsis) has been shown to be highly efficacious at inhibiting the production of methane (CH4) in ruminants. To date, Asparagopsis has been primarily produced as a dietary supplement by freeze-drying to retain the volatile bioactive compound bromoform (CHBr3) in the product. Steeping of Asparagopsis bioactive compounds into a vegetable oil carrier (Asp-Oil) is an alternative method of stabilizing Asparagopsis as a ruminant feed additive. A dose-response experimental design used 3 Asp-Oil-canola oil blends, low, medium, and high Asp-Oil which provided 17, 34, and 51 mg Asparagopsis derived CHBr3/kg dry matter intake (DMI), respectively (in addition to a zero CHBr3 canola oil control), in a tempered-barley based feedlot finisher diet, fed for 59 d to 20 Angus heifers (five replicates per treatment). On four occasions, live weight was measured and CH4 emissions were quantified in respiration chambers, and blood, rumen fluid, and fecal samples were collected. At the end of the experiment, all animals were slaughtered, with carcasses graded, and samples of meat and edible offal collected for testing of consumer sensory qualities and residues of CHBr3, bromide, and iodide. All Asp-Oil treatments reduced CH4 yield (g CH4/kg DMI, P = 0.008) from control levels, with the low, medium, and high Asp-Oil achieving 64%, 98%, and 99% reduction, respectively. Dissolved hydrogen increased linearly with increasing Asp-Oil inclusion, by more than 17-fold in the high Asp-Oil group (P = 0.017). There was no effect of Asp-Oil treatment on rumen temperature, pH, reduction potential, volatile fatty acid and ammonia production, rumen pathology, and histopathology (P > 0.10). There were no differences in animal production and carcass parameters (P > 0.10). There was no detectable CHBr3 in feces or any carcass samples (P > 0.10), and iodide and bromide residues in kidneys were at levels unlikely to lead to consumers exceeding recommended maximum intakes. Overall, Asp-Oil was found to be safe for animals and consumers of meat, and effective at reducing CH4 emissions and yield by up to 99% within the range of inclusion levels tested.

Red seaweed, Asparagopsis taxiformis (Asparagopsis), has been shown to be highly effective at inhibiting the production of methane (CH4) in ruminants. An alternative to feeding whole, freeze-dried Asparagopsis is steeping the biomass in vegetable oil to stabilize the bioactive compounds (Asp-Oil) and feeding Asp-Oil to ruminants as a component of their dietary intake. This experiment measured the CH4 reduction potential and safety of Asp-Oil in a trial with 20 Angus heifers, fed iso-fat feedlot diets containing one of the three levels of Asp-Oil, or a control oil. Compared to the control, bromoform inclusion levels of 17, 34, and 51 mg/kg of dry matter (DM; low, medium, high) reduced CH4 yield (g CH4/kg DM intake) by 64%, 98%, and 99%, respectively. There were no effects on animal production or carcass characteristics. There were no impacts on animal health, welfare, or rumen function. Carcasses were safe for human consumption, and there was no bromoform detected in any carcass samples. Overall, Asp-Oil was found to effectively reduce CH4 emissions and is safe for animals and consumers of meat and edible offal.

Rumen fermentation parameters and papillae development in Simmental growing bulls with divergent residual feed intake.

Residual feed intake (RFI), a widespread index used to measure animal feed efficiency, is influenced by various individual biological factors related to inter-animal variation that need to be assessed. Herein, 30 Simmental bulls, raised under the same farm conditions, were divided on the basis of RFI values into a high efficient group (HE, RFI =  - 1.18 ± 0.33 kg DM/d, n = 15) and a low efficient group (LE, RFI = 0.92 ± 0.35 kg DM/d, n = 15). Subsequently, bulls were slaughtered at an average BW of 734 ± 39.4 kg. Their ruminal fermentation traits were analysed immediately after slaughtering and after 24 h of in vitro incubation. Furthermore, ruminal micro-biota composition and ruminal papillae morphology were examined. The LE group exhibited a higher propionate concentration as a percentage of total volatile fatty acids (17.3 vs 16.1%, P = 0.04) in the rumen fluid collected during slaughtering, which was also confirmed after in vitro fermentation (16.6 vs 15.4% respectively for LE and HE, P = 0.01). This phenomenon resulted in a significant alteration in the acetate-to-propionate ratio (A:P) with higher values for the HE group, both after slaughter (4.01 vs 3.66, P = 0.02) and after in vitro incubation (3.78 vs 3.66, P = 0.02). Methane production was similar in both groups either as absolute production (227 vs 218 mL for HE and LE, respectively) or expressed as a percentage of total gas (approximately 22%). Even if significant differences (P < 0.20) in the relative abundance of some bacterial genera were observed for the two RFI groups, no significant variations were observed in the alpha (Shannon index) and beta (Bray-Curtis index) diversity. Considering the papillae morphology, the LE subjects have shown higher length values (6.26 vs 4.90 mm, P < 0.01) while HE subjects have demonstrated higher papillae density (46.4 vs 40.5 n/cm2, P = 0.02). Histo-morphometric analysis did not reveal appreciable modifications in the total papilla thickness, boundaries or surface between the experimental groups. In conclusion, our results contribute to efforts to analyse the factors affecting feed efficiency at the ruminal level. Propionate production, papillae morphology and a few bacterial genera certainly play a role in this regard, although not a decisive one.

Utilization of some fruit rinds in small ruminant feeding: nutritional characteristics determination.

Every year, thousands of tons of fruit wastes are produced worldwide while most of them remain unused and are released into the environment. Incorporation of these wastes to feedstuffs reduces competition between food and feed, and reduces environmental risks or methane yield in ruminants. Nevertheless, no comprehensive research was available on the nutritional properties of rinds of different fruits in small ruminant feeding. Hence, this research investigates the nutritional potential of some fruit's rinds (Kiwi, Tangerine, Grapefruit, Sweet lemon, Sour lemon, Banana, Mango, Orange, Apple, Peach, and Persimmon) by in vitro ruminal-microbial and standard laboratory methods. Persimmon rind had the higher total phenolic contents (TPC, 22 mg gallic acid equivalents/g dry matter: DM) than the other treatments (P < 0.0001). The ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash contents of banana rind were greater (P < 0.0001), however its DM, relative feed value (RFV), and non-fiber carbohydrates (NFC) were lower than the other treatments (P < 0.0001). A different range of minerals was observed among fruit rinds along with a higher content of potassium (42.5 g/kg DM) and manganese (49 mg/kg DM) in banana rind (P < 0.0001). Persimmon (45.7 ml/200 mg DM) and sweet lemon (75.7 ml/200 mg DM) rinds recorded the lowest and highest potential gas production, respectively (P < 0.0001). Persimmon exhibited a lower percentage of methane (11.5%) rather than other rinds (P < 0.0001). The total volatile fatty acids (TVFA) and metabolizable energy (ME) in sweet lemon, and dry matter digestibility (DMD) and organic matter digestibility (OMD) in tangerine were greater compared with other rinds. The rind of the banana exhibited the highest amounts of titratable acidity (283 mEq×10- 3), acid-buffering capacity (200 mEq×10- 3), and acid-base buffering capacity (260 mEq×10- 3) (P < 0.0001). In conclusion, the present rinds differed in chemical-nutritional characteristics. These rinds may feed as a substitute for conventional forages in the diets of small ruminants on a large scale throughout the year; however, these in vitro findings need to be scientifically validated under in vivo experiments.

Metabolomics and proteomics insights into subacute ruminal acidosis etiology and inhibition of proliferation of yak rumen epithelial cells in vitro.

BACKGROUND: Untargeted metabolomics and proteomics were employed to investigate the intracellular response of yak rumen epithelial cells (YRECs) to conditions mimicking subacute rumen acidosis (SARA) etiology, including exposure to short-chain fatty acids (SCFA), low pH5.5 (Acid), and lipopolysaccharide (LPS) exposure for 24 h. RESULTS: These treatments significantly altered the cellular morphology of YRECs. Metabolomic analysis identified significant perturbations with SCFA, Acid and LPS treatment affecting 259, 245 and 196 metabolites (VIP > 1, P < 0.05, and fold change (FC) ≥ 1.5 or FC ≤ 0.667). Proteomic analysis revealed that treatment with SCFA, Acid, and LPS resulted in differential expression of 1251, 1396, and 242 proteins, respectively (FC ≥ 1.2 or ≤ 0.83, P < 0.05, FDR < 1%). Treatment with SCFA induced elevated levels of metabolites involved in purine metabolism, glutathione metabolism, and arginine biosynthesis, and dysregulated proteins associated with actin cytoskeleton organization and ribosome pathways. Furthermore, SCFA reduced the number, morphology, and functionality of mitochondria, leading to oxidative damage and inhibition of cell survival. Gene expression analysis revealed a decrease the genes expression of the cytoskeleton and cell cycle, while the genes expression associated with inflammation and autophagy increased (P < 0.05). Acid exposure altered metabolites related to purine metabolism, and affected proteins associated with complement and coagulation cascades and RNA degradation. Acid also leads to mitochondrial dysfunction, alterations in mitochondrial integrity, and reduced ATP generation. It also causes actin filaments to change from filamentous to punctate, affecting cellular cytoskeletal function, and increases inflammation-related molecules, indicating the promotion of inflammatory responses and cellular damage (P < 0.05). LPS treatment induced differential expression of proteins involved in the TNF signaling pathway and cytokine-cytokine receptor interaction, accompanied by alterations in metabolites associated with arachidonic acid metabolism and MAPK signaling (P < 0.05). The inflammatory response and activation of signaling pathways induced by LPS treatment were also confirmed through protein interaction network analysis. The integrated analysis reveals co-enrichment of proteins and metabolites in cellular signaling and metabolic pathways. CONCLUSIONS: In summary, this study contributes to a comprehensive understanding of the detrimental effects of SARA-associated factors on YRECs, elucidating their molecular mechanisms and providing potential therapeutic targets for mitigating SARA.

Effect of rice bran extract on in vitro rumen fermentation and methane production.

This study was done to investigate which components of rice bran (RB) are involved in the inhibition of methanogenesis by fractionating the rice bran and adding it to a rumen in vitro culture system. The RB extract obtained using ethanol and water was screened in an in vitro fermentation system. The experimental treatment conditions were as follows: a control group containing a substrate without supplements; substrates with 0.06 g of RB; 0.6 mL of ethanol; 0.6 mL of distilled water (DW); 0.6 mL of ethanol-soluble fraction (ESF); 0.06 g of ethanol-insoluble rice bran (EIRB); 0.6 mL of water-soluble fraction (WSF); and 0.06 g of water-insoluble rice bran (WIRB). Based on the result of the analysis, the addition of ESF significantly decreased CH4 and CH4 /g dry matter digested, methanogen population (p < 0.05), while gas and dry matter digestibility (DMD) were comparable with the control group. Total short-chain fatty acid (SCFA), and proportion of propionate were reduced, and the proportion of butyrate was increased by the addition of ethanol and ESF (p < 0.05). This result suggests that the supplementation of 10% ESF can substantially reduce methane production in vitro without a negative effect on substrate digestibility.

Effects of allicin on growth performance, antioxidant profile, and microbiota compared to monensin of growing goats.

Allicin is a sulfur-containing compound extracted from raw garlic (Allium sativum L.). We compared the effect of allicin addition on growth performance, serum biochemical parameters, and rumen microbiota of goats compared to monensin. Twenty-four Anhui white goats were assigned randomly to one of three dietary treatments: 1) a basal diet (CON); 2) the basal diet with allicin addition at 750 mg per head per day (AC); 3) the basal diet with monensin addition at 30 mg per kg of diet (MS). Animals were fed for 8 weeks. Results showed the average daily gain, and feed efficiency was increased with allicin and monensin addition. Serum levels of IgG, total superoxide dismutase, and glutathione peroxidase were higher in the AC group than those in the CON and MS groups. The microbiota analysis revealed that monensin addition mainly affected genera related to carbohydrate and protein metabolism, and allicin mainly affected genera related to energy metabolism and intestinal health. In conclusion, allicin could improve growth performance and have advantages over monensin in improving the antioxidant capacity and immune function of goats. Allicin may be a potential alternative to monensin.

Effect of nutmeg essential oil (Myristica fragrans Houtt.) on methane production, rumen fermentation, and nutrient digestibility in vitro.

The study evaluated the effect of adding of nutmeg (Myristica fragrans Houtt.) essential oil (NEO) as a feed additive on methane production, rumen fermentation parameters, rumen enzyme activity, and nutrient digestibility in vitro. This study was divided into three treatments based on the level of NEO addition, which included 0 µL/L (T0), 100 µL/L (T1), and 200 µL/L (T2). The feed substrate composition consisted of king grass as forage and concentrate in a 60:40 ratio. Feed fermentation was conducted using the Menke and Steingass gas production and two-step Tilley and Terry in-vitro digestibility technique. The data obtained from the study were analyzed using one-way ANOVA and if there were differences between means, they were further assessed using DMRT. The results showed that T2 treatment significantly decreased (P < 0.05) ammonia (NH3) levels, total VFA, acetate, propionate, butyrate, and microbial protein (P < 0.05). Methane production and the activity of rumen protease enzyme significantly decreased (P < 0.05) at T1 and T2 treatment. The T2 treatment significantly reduced (P < 0.05) protein digestibility (IVCPD) at 48 h, while IVCPD at 96 h significantly increased (P < 0.05). On the other hand, the addition of nutmeg essential oil did not effect the activity of the amylase, carboxymethyl cellulase, and ß-glucosidase enzymes, as well as the in-vitro digestibility of dry matter (IVDMD), crude fiber (IVCFD), and organic matter (IVOMD). The conclusion drawn from this study is that the optimum level for NEO is 200 µL/L, which can reduce methane production and increase crude protein digestibility at 96 h without any negative effect on rumen fermentation and nutrient digestibility.

Characterization of ruminal degradation, intestinal digestion and total true nutrient supply to dairy cows from feedstocks and coproducts from Canola bio-oil processing: Impact by source origin.

The objective of this study was to characterize ruminal degradation, intestinal digestion and total true nutrient supply to dairy cows from canola feedstock (canola seeds) and coproducts (meal and pellets) from bio-oil processing which were impacted by source origin. The feedstocks and coproducts (mash, pellet) were randomly collected from five different bio-oil processing plants with five different batches of samples in each bio-processing plant in Canada (CA) and China (CH). In situ rumen degradation kinetics were determined using four fistulated Holstein cows with incubation times at 0, 2, 4, 8, 12, 24 and 48 h. Intestinal digestions were determined using the three-step in vitro method with preincubation at 12 h. The DVE/OEB and National Research Council systems were applied to evaluate the truly absorbable nutrient supply to dairy cows and feed milk values (FMVs). The results showed that in situ undegradable fractions (U) (p = 0.025) were higher in CA meals, and potentially degradable fraction of D was higher (p = 0.016) in CH meals. CH meals had higher total digestible dry matter (TDDM, p = 0.018) and intestinal digestibility of protein (dIDP, p = 0.016). Canola meals from CA had lower MREE (microbial protein synthesized in the rumen based on available rumen degradable protein; p = 0.011) and DVME (rumen synthesized microbial protein digested in the small intestine; p = 0.011) and had higher ECP (endogenous protein in the small intestine, p = 0.001) and absorbed endogenous crude protein (truly absorbed ECP in the small intestine) than CH (p = 0.001). The FMV evaluated based on the metabolic protein and net energy showed no differences between CA and CH in both coproducts and feedstocks.

Comparative assessment of emulsifiers for in vitro ruminal gas production and fermentation measurements: Tween 80 is a suitable emulsifier.

Emulsifiers are essential for achieving a homogenous distribution of lipophilic supplements in in vitro rumen fluid incubations. Since emulsifiers can alter rumen fermentation, it is crucial to select one that minimally impacts fermentation parameters to reduce potential biases. This study aimed to evaluate seven emulsifiers' impact on in vitro ruminal fermentation using the Hohenheim Gas Test in order to identify the most inert emulsifier. Rumen fluids were collected from three non-lactating Original Brown-Swiss cannulated cows before morning feeding and incubated for 24 h with a basal diet in triplicates. The emulsifiers tested were ethanol, ethyl acetate, propylene glycol, glycerol, ethylene glycol, soy lecithin, and Tween® 80, each in two dosages (0.5% or 1% v/v). The untreated basal diet served as control. Compared to control, in vitro organic matter digestibility was enhanced by ethyl acetate (by 36.9 and 48.2%), ethylene glycol (by 20.6 and 20.1%), glycerol (by 46.9 and 56.8%) and soy lecithin (by 19.7 and 26.8%) at 0.5 and 1% dosage, respectively. Additionally, the 24-h methane production increased for ethanol (by 41.9 and 46.2%), ethylene glycol (by 50.5 and 51.5%), and glycerol (by 63.1 and 65.4%) for the 0.5 and 1% dosage, respectively, and 0.5% dosage for ethyl acetate (by 31.6%). The acetate molar proportion was 17.2%pt higher for ethyl acetate, and 25.5%pt lower for glycerol at 1% dosage, compared to the control. The propionate concentration was 22.1%pt higher 1% glycerol, and 15.2%pt and 15.1%pt higher for 0.5 and 1% propylene glycol, respectively, compared to the control. In summary, Tween® 80 did not significantly affect in vitro rumen fermentation parameters, making it the most suitable choice for in vitro incubations involving lipophilic substances in rumen fluid. Ethanol may be considered as an alternative emulsifier if methane production is not the variable of interest.

Starter protein content and supplemental soybean oil or hydrogenated palm fatty acids in Holstein dairy calves: growth performance, protozoa population, and nitrogen utilization efficiency.

The study hypothesized that a 24% protein starter diet supplemented with inert fat (palm fatty acids; PLFs) instead of triglyceride-rich soybean oil (SBO) would promote the growth of dairy calves. The effects of different protein contents (20 vs 24% CP) and fat sources (SBO vs PLF at 2.5% DM) on growth, digestibility, blood metabolites, rumen protozoa and urinary nitrogen in dairy calves were investigated. A total of 52 female dairy calves (mean age 3 days and BW 40.7 kg) were allocated to the following treatments in a completely randomized design: (1) 20% CP starter diet supplemented with SBO (20CP-SBO), (2) 20% CP starter diet supplemented with PLF (20CP-PLF), (3) 24% CP starter diet supplemented with SBO (24CP-SBO), and (4) 24% CP starter diet supplemented with PLF (24CP-PLF). Calves were weaned on day 53, and the study ended on day 73. The 24CP diets enhanced starter feed intake, average daily gain (ADG), withers height, hip width, organic matter (OM) digestibility, and preweaning blood glucose compared to the 20CP diets. In contrast, SBO supplementation reduced feed intake, ADG, withers height, OM and CP digestibility, and pre- and postweaning blood glucose and beta-hydroxybutyrate levels, while increasing preweaning aspartate aminotransferase, compared to PLF. SBO supplementation led to lower urinary excretion of purine derivatives and microbial protein synthesis postweaning, and a reduction in protozoa population both pre- and postweaning. Calves fed PLF had higher starter intake than those fed SBO, regardless of the diet being 20CP or 24CP. Calves fed the 24CP-PLF diet had the highest ADG, while calves fed the 20CP-SBO diet had the lowest ADG. Calves fed the 20CP-SBO diet had lower feed efficiency than calves fed the other diets during the preweaning period and throughout the experimental period. Calves fed the 24CP-PLF diet had higher hip heights at weaning and on day 73 than calves fed the other diets. Calves fed the 20CP-SBO diet had lower neutral detergent fiber digestibility than calves fed the other diets. Calves fed the 24CP-SBO diet had higher postweaning blood urea nitrogen concentration than calves fed the other diets. Feeding the 20CP-SBO diet to dairy calves decreased urinary allantoin excretion and rumen microbial protein synthesis but increased urinary nitrogen excretion during the preweaning period. Our results suggest that PLF is more suitable than SBO in calf diets, especially when calves fed 24% CP, possibly due to improved nutrient digestibility.

Effect of a blend of cinnamaldehyde, eugenol, and Capsicum oleoresin on methane emission and lactation performance of Holstein-Friesian dairy cows.

This study aimed to investigate the effect of administering a standardized blend of cinnamaldehyde, eugenol, and Capsicum oleoresin (CEC) to lactating dairy cattle for 84 d (i.e., 12 wk) on enteric CH4 emission, feed intake, milk yield and composition, and body weight. The experiment involved 56 Holstein-Friesian dairy cows (145 ± 31.1 d in milk at the start of the trial; mean ± standard deviation) in a randomized complete block design. Cows were blocked in pairs according to parity, lactation stage, and current milk yield, and randomly allocated to 1 of the 2 dietary treatments: a diet including 54.5 mg of CEC/kg of DM or a control diet without CEC. Diets were provided as partial mixed rations in feed bins, which automatically recorded individual feed intake. Additional concentrate was fed in the GreenFeed system that was used to measure emissions of CO2, CH4, and H2. Feeding CEC decreased CH4 yield (g/kg DMI) by on average 3.4% over the complete 12-wk period and by on average 3.9% from 6 wk after the start of supplementation onward. Feeding CEC simultaneously increased feed intake and body weight, and tended to increase milk protein content, whereas no negative responses were observed. These results must be further investigated and confirmed in longer-term in vivo experiments.

Effects of dietary rumen-protected choline supplementation to periparturient dairy cattle on inflammation and metabolism in mammary and liver tissue during an intramammary lipopolysaccharide challenge.

The objective of this experiment was to examine the effects of supplementation and dose of rumen-protected choline (RPC) on markers of inflammation and metabolism in liver and mammary tissue during an intramammary lipopolysaccharide (LPS) challenge. Parous Holstein cows were blocked by calving month and randomly assigned within block to receive 45 g/d of RPC (20.4 g/d of choline ions; CHOL45), 30 g/d of RPC (13.6 g/d of choline ions; CHOL30), or no RPC (CON) as a top-dress starting 24 d before expected calving until 21 d postpartum. Cows were alternately assigned within treatment group to either receive an intramammary LPS challenge (200 µg in each rear quarter; Escherichia coli O111:B4) or not at 17 DIM (CHOL45, n = 9; CHOL45-LPS, n = 9; CHOL30, n = 11; CHOL30-LPS, n = 10; CON, n = 10; CON-LPS, n = 9). Hepatic and mammary tissues were collected from all cows on d 17 postpartum. Hepatic and mammary tissues were collected at ∼7.5 and 8 h, respectively, after the LPS challenge. An additional mammary biopsy was conducted on LPS-challenged cows (CHOL45-LPS, CHOL30-LPS, and CON-LPS) at 48 h postchallenge. Hepatic and mammary RNA copy numbers were quantified for genes involved in apoptosis, methylation, inflammation, oxidative stress, and mitochondrial function using NanoString technology. Targeted metabolomics was conducted only on mammary tissue samples (both 8 and 48 h biopsies) to quantify 143 metabolites including choline metabolites, amino acids, biogenic amines and derivatives, organic acids, carnitines, and glucose. Hepatic IFNG was greater in CHOL45 as compared with CON in unchallenged cows, suggesting an improvement in type 1 immune responses. Hepatic CASP3 was greater in CHOL45-LPS as compared with CON-LPS, suggesting greater apoptosis. Mammary IL6 was reduced in CHOL30-LPS cows as compared with CHOL45-LPS and CON-LPS (8 and 48 h). Mammary GPX4 and COX5A were reduced in CHOL30-LPS as compared with CON-LPS (8 h), and SDHA was reduced in CHOL30-LPS as compared with CON-LPS (8 and 48 h). Both CHOL30-LPS and CHOL45-LPS cows had lesser mammary ATP5J than CON-LPS, suggesting that dietary RPC supplementation altered mitochondrial function following LPS challenge. Treatment did not affect mammary concentrations of any metabolite in unchallenged cows, and only 4 metabolites were affected by dietary RPC supplementation in LPS-challenged cows. Mammary concentrations of isobutyric acid and 2 acyl-carnitines (C4:1 and C10:2) were reduced in CHOL45-LPS as compared with CHOL30-LPS and CON-LPS. Taken together, reductions in medium- and short-chain carnitines along with an increase in long-chain carnitines in mammary tissue from CHOL45-LPS cows suggests less fatty acid entry into the ß oxidation pathway. Although the intramammary LPS challenge profoundly affected markers for inflammation and metabolism in liver and mammary tissue, dietary RPC supplementation had minimal effects on inflammatory markers and the mammary metabolome.

Gas exchange, rumen hydrogen sinks, and nutrient digestibility and metabolism in lactating dairy cows fed 3-nitrooxypropanol and cracked rapeseed.

Fat in the form of cracked rapeseed and 3-nitrooxypropanol (3-NOP, market as Bovaer) were fed alone or in combination to 4 Danish Holstein multicannulated dairy cows, with the objective to investigate effects on gas exchange, dry matter intake (DMI), nutrient digestion, and nutrient metabolism. The study design was a 4 × 4 Latin square with a 2 × 2 factorial treatment arrangement with 2 levels of fat supplementation; 33 g of crude fat per kg of dry matter (DM) or 64 g of crude fat per kg of DM for low and high fat diets, respectively, and 2 levels of 3-NOP; 0 mg/kg DM or 80 mg/kg DM. In total, 4 diets were formulated: low fat (LF), high fat (HF), 3-NOP and low fat (3LF), and 3-NOP and high fat (3HF). Cows were fed ad libitum and milked twice daily. The adaptation period lasted 11 d, followed by 5 d with 12 diurnal sampling times of digesta and ruminal fluid. Thereafter, gas exchange was measured for 5 d in respiration chambers. Chromic oxide and titanium dioxide were used as external flow markers to determine intestinal nutrient flow. No interactions between fat supplementation and 3-NOP were observed for methane yield (g/kg DM), total-tract digestibility of nutrients or total volatile fatty acid (VFA) concentration in the rumen. Methane yield (g/kg DMI) was decreased by 24% when cows were fed 3-NOP. In addition, 3-NOP increased carbon dioxide and hydrogen yield (g/kg DM) by 6% and 3,500%, respectively. However, carbon dioxide production was decreased when expressed on a daily basis. Fat supplementation did not affect methane yield but tended to reduce methane in percent of gross energy intake. A decrease (11%) in DMI was observed, when cows were fed 3-NOP. Likely, the lower DMI mediated a lower passage rate causing the tendency to higher rumen and total-tract neutral detergent fiber digestibility, when the cows were fed 3-NOP. Total VFA concentrations in the rumen were negatively affected both by 3-NOP and fat supplementation. Furthermore, 3-NOP caused a shift in the VFA fermentation profile, with decreased acetate proportion and increased butyrate proportion, whereas propionate proportion was unaffected. Increased concentrations of the alcohols methanol, ethanol, propanol, butanol, and 2-butanol were observed in the ruminal fluid when cows were fed 3-NOP. These changes in rumen metabolites indicate partial re-direction of hydrogen into other hydrogen sinks, when methanogenesis is inhibited by 3-NOP. In conclusion, fat supplementation did not reduce methane yield, whereas 3-NOP reduced methane yield, irrespective of fat level. However, the concentration of 3-NOP and diet composition and resulting desired mitigation effect must be considered before implementation. The observed reduction in DMI with 80 mg 3-NOP/kg DM was intriguing and may indicate that a lower dose should be applied in a Northern European context; however, the mechanism behind needs further investigation.

Feeding alfalfa-grass or red clover-grass mixture baleage: Effect on milk yield and composition, ruminal fermentation and microbiota taxa relative abundance, and nutrient utilization in dairy cows.

Our goal was to investigate the effect of diets containing baleages harvested from alfalfa-grass or red clover-grass mixture on production performance, ruminal fermentation and microbiota taxa relative abundance, milk fatty acid profile, and nutrient utilization in dairy cows. Twenty Jersey cows (18 multiparous and 2 primiparous) averaging (mean ± SD) 148 ± 45.2 days in milk and 483 ± 65.4 kg of body weight in the beginning of the study were used in a randomized complete block design with repeated measures over time. The experiment lasted 9 wk, with a 2 wk covariate period followed by 7 wk of data and sample collection (wk 4 and 7 used in the statistical analyses). Cows were fed diets containing (dry matter basis) 35% of a concentrate mash and the following forage sources: (1) 65% second- and third-cut (32.5% each) alfalfa-grass mixture baleages (ALF) or (2) 65% second- and third-cut (32.5% each) red clover-grass mixture baleages (RC). Diets did not affect dry matter intake, milk yield, and concentrations of milk fat and true protein. In contrast, milk fat yield tended to decrease and energy-corrected milk yield decreased with feeding RC versus ALF. The apparent total-tract digestibilities of dry matter, organic matter, and ash-free neutral detergent fiber, milk proportions of trans-10 18:1, cis-9,cis-12,cis-15 18:3, and total n-3 fatty acids, ruminal molar proportion of acetate, and plasma concentrations of Leu, Phe, and Val all increased in RC versus ALF. Diet × week interactions were found for several parameters, most notably ruminal molar proportions of propionate and butyrate, ruminal NH3-N, milk urea N, plasma urea N, and plasma His concentrations, urinary N excretion, enteric CH4 production, and all energy efficiency variables. Specifically, ruminal NH3-N and plasma urea N concentrations, urinary excretion of N, and CH4 production decreased in cows fed RC in wk 4 but not in wk 7. Milk urea N concentration decreased and that of plasma His increased with feeding RC during wk 4 and 7, although the magnitude of treatments difference varied between the sampling periods. Efficiency of energy utilization calculated as milk energy/metabolizable energy decreased and that of tissue energy/ME increased in RC versus ALF cows in wk 4, suggesting that ME was portioned toward tissue and not milk in the RC diet. Interactions were also observed for the relative abundance of the rumen bacterial phyla Verrucomicrobiota and Fibrobacterota, with cows offered RC showing greater values than those receiving ALF in wk 4 but no differences in wk 7. Several diet × week interactions were detected in the present study implying short-term treatment responses and warranting further investigations.

Ageratina adenophora damages the rumen epithelium via inducing the expression of inflammatory factors in goats.

The aim of this experiment was to investigate the effects of Ageratina adenophora on the expression of epithelium tight junction proteins and inflammatory factors in the rumen of goats. Twelve goats were randomly divided into three groups. The first group was the blank control group (n = 3, C) which was fed normal diet. The second group was fistulas control group (n = 3, RFC), which was fitted with rumen fistulas, and fed normal diet. The third group was the A. adenophora test group (n = 6, AA), which was fitted with rumen fistulas and fed a mixture of 60% of normal diet and 40% of A. adenophora grass powder. The feeding experiment lasted for 90 d, after which all goats were sacrificed and samples were collected from the rumen dorsal sac and ventral sac. The relative expression of mRNA of inflammatory factors in the rumen epithelium (tumor necrosis factor alpha [TNF-α], interferon gamma [IFN-γ], interleukin 1 beta [IL-1ß], IL-2, IL-4, IL-6, and IL-10) and tight junction protein genes (occludin, claudin-1, and ZO-1) was measured by quantitative real-time fluorescence PCR. Expression of tight junction proteins in the rumen epithelium was measured by Western blot. A correlation was established between the expression of inflammatory factors and tight junction protein genes using Graph Pad Prism. The results showed that A. adenophora caused a significant increase in the mRNA expression levels of TNF-α, IFN-γ, IL-1ß, IL-2, IL-6, and IL-10 in the rumen epithelial (P < 0.05 or P < 0.01). The expression of tight junction proteins at both gene and protein levels was significantly decreased (P < 0.05 or P < 0.01). Furthermore, the correlation analysis revealed that the changes in tight junction protein expression in the test group were closely related to the upregulation of the expression of inflammatory factors TNF-α and IFN-γ in rumen epithelial cells. In conclusion, the expression of inflammatory factors was increased and the expression of tight junction proteins was decreased in goats after feeding on A. adenophora, which caused some damage to the rumen epithelium.

The article aims to investigate the toxic effects of Ageratina adenophora, an invasive plant on the integrity of the rumen epithelium by measuring the changes in the expression of inflammatory factors and tight junction proteins after the consumption of A. adenophora in goats. The results showed that A. adenophora causes damage to the rumen epithelium by increasing the expression of pro-inflammatory markers like TNF-α and IFN-γ and reducing the expression of tight junction proteins such as occludin and claudin-1 in goats.

Effects of dietary palm oil supplementation on ruminal degradation and apparent digestibility of nutrients in sheep.

The aim of this study was to evaluate the effects of the inclusion of palm oil on the ruminal environment and nutrient digestibility of sheep diets. Twenty rumen-cannulated sheep were kept in individual stalls equipped with feeding and drinking troughs The animals were fed five diets based on Elephant grass (Pennisetum purpureum Schum. cv. Roxo) silage and supplemented with 0, 25, 50, 75, or 100 g kg-1 of palm oil (based on total DM). The Elephant grass was harvested at 90 days of regrowth and the concentrate was based on ground corn grain, soybean meal and mineral mix (20 g kg-1 DM), offered to the sheep at a ratio of 1.5 g kg-1d-1 of body weight (restricted intake) to maintain a forage-to-concentrate ratio of 1:1, based on DM. There were no differences (P = 0.324) in ruminal disappearance and degradability parameters with up to 75 g of oil per kg of DM. Organic matter showed a linear reduction in apparent digestibility, while ether extract increased linearly. Palm oil affected the digestibility and nutritional parameters in ruminant diets.

Integrated multi-omics analysis reveals the positive leverage of citrus flavonoids on hindgut microbiota and host homeostasis by modulating sphingolipid metabolism in mid-lactation dairy cows consuming a high-starch diet.

BACKGROUND: Modern dairy diets have shifted from being forage-based to grain and energy dense. However, feeding high-starch diets can lead to a metabolic disturbance that is linked to dysregulation of the gastrointestinal microbiome and systemic inflammatory response. Plant flavonoids have recently attracted extensive interest due to their anti-inflammatory effects in humans and ruminants. Here, multi-omics analysis was conducted to characterize the biological function and mechanisms of citrus flavonoids in modulating the hindgut microbiome of dairy cows fed a high-starch diet. RESULTS: Citrus flavonoid extract (CFE) significantly lowered serum concentrations of lipopolysaccharide (LPS) proinflammatory cytokines (TNF-α and IL-6), acute phase proteins (LPS-binding protein and haptoglobin) in dairy cows fed a high-starch diet. Dietary CFE supplementation increased fecal butyrate production and decreased fecal LPS. In addition, dietary CFE influenced the overall hindgut microbiota's structure and composition. Notably, potentially beneficial bacteria, including Bacteroides, Bifidobacterium, Alistipes, and Akkermansia, were enriched in CFE and were found to be positively correlated with fecal metabolites and host metabolites. Fecal and serum untargeted metabolomics indicated that CFE supplementation mainly emphasized the metabolic feature "sphingolipid metabolism." Metabolites associated with the sphingolipid metabolism pathway were positively associated with increased microorganisms in dairy cows fed CFE, particularly Bacteroides. Serum lipidomics analysis showed that the total contents of ceramide and sphingomyelin were decreased by CFE addition. Some differentially abundant sphingolipid species were markedly associated with serum IL-6, TNF-α, LPS, and fecal Bacteroides. Metaproteomics revealed that dietary supplementation with CFE strongly impacted the overall fecal bacterial protein profile and function. In CFE cows, enzymes involved in carbon metabolism, sphingolipid metabolism, and valine, leucine, and isoleucine biosynthesis were upregulated. CONCLUSIONS: Our research indicates the importance of bacterial sphingolipids in maintaining hindgut symbiosis and homeostasis. Dietary supplementation with CFE can decrease systemic inflammation by maintaining hindgut microbiota homeostasis and regulating sphingolipid metabolism in dairy cows fed a high-starch diet. Video Abstract.