Proportion Of Fatty Acids Research Articles

Effect of benzalkonium chloride adaptation on the tolerance of Cronobacter sakazakii exposed to subsequent lethal stresses

Benzalkonium Chloride (BC) is applied in food processing, clinical settings, and households to control the spread of pathogens. However, BC adaptation may promote bacterial resistance against biocides and physical stresses. In the study, the sensitivity of non-adapted and BC-adapted C. sakazakii to subsequent lethal stresses was assessed. Results indicated that BC adaptation provided C. sakazakii direct protection against high BC concentrations, but no cross-protection against heat, acid, osmotic, desiccative, and ethanol-related stress. BC adaptation reduced the proportion of saturated fatty acids (SFA) and the ratio of SFA to unsaturated fatty acids (SFA/USFA), whereas increasing the proportion of unsaturated fatty acids (USFA) in C. sakazakii. Six genes related to motility, metabolism, transport, and efflux were upregulated under BC adaptation. Some Surface-enhanced Raman spectroscopy (SERS) signal characteristics of the BC-adapted cell were significantly different from that of the non-adapted cell, which reflected the changes of intracellular proteins, nucleic acids, carbohydrates, and other cellular components. Consequently, the ability of BC-adapted C. sakazakii to withstand subsequent stresses should be taken into account when developing microbial control measures. A greater understanding of BC adaptation mechanisms in C. sakazakii will provide important insights for disease prevention.

Lighting intensity affects the fatty acid composition of total lipids of basil leaves and roots (Ocimum basilicum L.)

The vegetative organs of common basil (Ocimum basilicum L.) grown in water culture at different levels of illumination (50, 100, and 150 μmol PAR quanta/(m2 s)) for 21 days were studied. In the work, the Purple Velvet basil variety, which is popular in agriculture and has intensely colored leaves was used. The biomass, water content, and composition of fatty acids (FA) of total lipids in the leaves and roots of plants and the content of malondialdehyde and chlorophylls (a, b) in the aerial parts of plants were determined. The sensitivity of the FA composition and morphophysiological parameters (biomass and chlorophyll content in leaves) of O. basilicum plants to the intensity of illumination was shown. The greatest effect was caused by the illumination intensity mode of 150 μmol/(m2 s). Species composition of O. basilicum FA under all lighting conditions was wider in root lipids; however, more pronounced changes in the qualitative composition of Fas were observed in leaves. Photodependent regulation of FA component composition of O. basilicum manifested itself in an increase in the proportion of unsaturated FAs, especially polyene ones, which led to an increase in the unsaturation index (UI) of esterified lipid FAs. The highest UI values were obtained with illumination of 150 μmol/(m2 s). At the same time, with an increase in the illumination intensity, a significant increase in the activity of ω-3 and ω-9-desaturases occurred, which indicates in favor of their lightdependent activation. Thus, increasing the intensity of lighting to certain values directly proportionally affects the physiological parameters of O. basilicum. The maximum indicators of productive growth and the implementation of adaptive mechanisms of green and underground parts of basil plants correspond to illumination of 150 μmol/(m2 s).

Insight into the effect of microwave treatment on fat loss, fatty acid composition and microstructure of pork subcutaneous back fat

In this study, the effects of different microwave treatment times (10, 20, 30, 40, 50, and 60 s) on fat loss, fatty acid profile, lipid transfers, and microstructure of pork subcutaneous back fat (PSBF) were investigated. Results showed that the fat loss of PSBF after microwave treatment for 60 s was significantly increased (53.31%). Microwave treatment increased the proportion of saturated fatty acids but reduced the relative content of monounsaturated and polyunsaturated fatty acids. Cryo-scanning electron microscopy, ordinary optical microscope and confocal laser scanning microscope analysis demonstrated that microwave treatment facilitated a large outflow of fat from the adipocytes, and the increasing and then decreasing changes in the size of individual adipocytes. Magnetic resonance imaging enabled the visualization of fat migration of PSBF. Overall, PSBF can be used as a biological model to evaluate the effect of microwave treatment on the change and migration mechanism of fat.

Effects of dental age on proximate components, amino acid and fatty acid profiles of indigenous beef

The study was conducted to determine how the proximate composition, amino acid and fatty acid profiles of beef of indigenous cattle are affected by dental age. This experiment was conducted with five (5) treatments (T1, T2, T3, T4, and T5) where T1 = 0 Permanent incisors, T2 = 2 Permanent incisors, T3 = 4 Permanent incisors, T4 = 6 Permanent incisors, T5 = 8 Permanent incisors having ten (10) replications. This study has shown that the highest CP was 84.91% having the T5 while the lowest figure was 72.94% in T4. T1 had the lowest 3.34% EE content whereas T5 had the highest 4.15%. Essential amino acids (g/100g of meat) were highest at 41.51 in T5 and lowest at 37.79 in T1. The lowest total saturated fatty acid (SFA) in Longissimus dorsi was 46.25% in T5 and the highest was 51.89% in T1. The total monounsaturated fatty acid (MUFA) proportion of 66.87% in T2 was the highest and T5 had the lowest proportion of 52.07%. The lowest total polyunsaturated fatty acid (PUFA) was 1.52% in T1 and the highest was at 7.49% in T5. In conclusion, CP, EE, essential amino acid, and polyunsaturated (PUFA) fatty acid proportion increased with the advancement of dental age maturity and conversely, saturated fatty acid (SFA) proportion was decreased. Therefore, this research will play a vital role to characterize accurately in terms of its nutritional quality to be aware of the selection of indigenous beef in their daily diet according to dental age.

Effect of Long-Term Day/Night Temperature Oscillations on the Overall Performance of Gilthead Seabream (Sparus aurata) Juveniles

Water temperature variations affect fish growth and health, often leading to huge losses in fish production, especially during the cold season. To alleviate this constraint, fish farmers can use a water heating system driven by solar energy during daytime. This action will cause a water temperature drop during the night period, making it important to understand the physiological response of fish exposed to the resulting day/night temperature oscillations. To investigate this scenario, gilthead seabream juveniles (96.3 ± 1.0 g) were exposed to different thermal regimes for 67 days: Tconstant and Tdaily cycles. The latter group was exposed to daily water temperature oscillations between ~19 and 13 °C compared with a constant temperature of ~19 °C for the other experimental group. Temperature fluctuations compromised fish growth efficiency and reduced the proportion of fatty acids in several tissues, with implications for the whole proximate composition. Moreover, temperature oscillations influenced several blood parameters. These results favor the usage of a constant water temperature of ~19 °C for optimal gilthead seabream juvenile production instead of a day/night water temperature oscillating regime. Nevertheless, the type of energy used to warm the water will depend on the operational conditions and/or business strategy of fish farmers.

Striped catfish (Pangasianodon hypophthalmus) exploit food sources across anaerobic decomposition- and primary photosynthetic production-based food chains

Dietary information from aquatic organisms is instrumental in predicting biological interactions and understanding ecosystem functionality. In freshwater habitats, generalist fish species can access a diverse array of food sources from multiple food chains. These may include primary photosynthetic production and detritus derived from both oxic and anoxic decomposition. However, the exploitation of anoxic decomposition products by fish remains insufficiently explored. This study examines feeding habits of striped catfish (Pangasianodon hypophthalmus) at both adult and juvenile stages within a tropical reservoir, using stable carbon, nitrogen, and sulfur isotope ratios (δ13C, δ15N, and δ34S, respectively) and fatty acid (FA) analyses. The adult catfish exhibited higher δ15N values compared to primary consumers that feed on primary photosynthetic producers, which suggests ingestion of food sources originating from primary photosynthetic production-based food chains. On the other hand, juvenile catfish demonstrated lower δ15N values than primary consumers, correlating with low δ34S value and large proportions of bacterial FA but contained small proportions of polyunsaturated FA. This implies that juveniles utilize food sources from both anoxic decomposition and primary photosynthetic production-based food chains. Our results indicate that food chains based on anoxic decomposition can indeed contribute to the dietary sources of tropical fish species.

Bioproduction of n-3 polyunsaturated fatty acids by nematode fatty acid desaturases and elongase in Drosophila melanogaster.

n-3 polyunsaturated fatty acids (n-3 PUFAs), including α-linolenic acid and eicosapentaenoic acid (EPA), are essential nutrients for vertebrates including humans. Vertebrates are n-3 PUFA-auxotrophic; hence, dietary intake of n-3 PUFAs is required for their normal physiology and development. Although fish meal and oil have been utilized as primary sources of n-3 PUFAs by humans and aquaculture, these traditional n-3 PUFA sources are expected to be exhausted because of the increasing consumption requirements of humans. Hence, it is necessary to establish alternative n-3 PUFA sources to reduce the gap between the supply and demand of n-3 PUFAs. Here, we investigated whether insects, which are considered as a novel source of essential nutrients, could store n-3 PUFAs by the forced expression of n-3 PUFA biosynthetic enzymes. We utilized Drosophila as an insect model to generate transgenic strains expressing Caenorhabditis elegans PUFA biosynthetic enzymes and examined their effects on the proportion of fatty acids. The ubiquitous expression of methyl-end desaturase FAT-1 prominently enhanced the proportions of α-linolenic acid, indicating that FAT-1 is useful for metabolic engineering to fortify α-linolenic acid in insect. Furthermore, the ubiquitous expression of nematode front-end desaturases (FAT-3 and FAT-4), PUFA elongase (ELO-1), and FAT-1 led to EPA bioproduction. Hence, nematode PUFA biosynthetic genes may serve as powerful genetic tools for enhancing the proportion of EPA in insects. This study represents the first step toward the establishment of n-3 PUFA-producing insects.

Analysis of Nutritional Characteristics and Willingness to Pay of Consumers for Dry-Cured Sausages (Salchichón) Made with Textured Seed Oils.

The consumption of processed meat products beyond recommended limits has been associated with serious health conditions, including heart disease, diabetes, and cancer. In an effort to create healthier options, the meat industry is exploring alternatives to animal fat in processed meats. This study focuses on replacing animal fat in dry-cured sausages (Salchichón) with textured chia, poppy, melon, and pumpkin oils. The research aims to evaluate the physical and nutritional changes resulting from this substitution and assess consumer acceptance through sensory analysis. The use of seed oils led to slight color changes and comparable texture, except for cohesiveness. The incorporation of textured seed oils resulted in reduced fat content, increased proportions of ashes and protein, and decreased energy value. The fatty acid composition showed lower proportions of saturated fatty acids and increased polyunsaturated fatty acids. Sensory analysis revealed that the control sample with pork fat received the highest ratings for appearance, texture, and taste, while samples with higher seed oil percentages scored lower due to color, cohesiveness, and specific flavors from the seed oils. Despite these variations, consumers demonstrated a high level of acceptability for all samples. Choice analysis results indicated that higher prices had a negative impact on consumer willingness to purchase, while the use of the 100% Iberian pig breed and animal welfare labels positively influenced purchasing attitudes. Regarding the presence of a pumpkin seed oil label in the product, a negative willingness to pay was reported. However, significant individual variation was reported for this attribute, indicating the existence of consumer segments with more positive attitudes toward these innovative dry-cured sausages.

Climate change alters pasture productivity and quality: Impact on fatty acids and amino acids in Mediterranean silvopastoral ecosystems

Climate change is threatening ecosystem functioning and sustainability worldwide. In silvopastoral systems, ongoing warmer and drier conditions could impact productivity and quality of pastures (in terms of protein content and digestibility), with important economic consequences. However, the extent to which climate change could alter other nutritional traits with a potential role in livestock nutrition and production, such as essential fatty acids and amino acids, is a question that remains poorly known. We designed a field manipulative experiment of increased temperature (+2–3 °C) and rainfall exclusion (−30%) aimed to evaluate the influence of forecasted climate variations on the yield and nutritional composition of pastures (i.e. proteins, lipids, fibers, amino acids, fatty acids and digestibility) in a Mediterranean silvopastoral system. To test whether scattered trees typical of these ecosystems could buffer the effects of higher aridity, experimental plots were installed under trees and in open grasslands. First, we found that plant communities under tree canopies were less productive but exhibited higher quality than those located in open grasslands, likely due to the shade and higher soil fertility provided by trees. Both climatic stressors had a significant influence on pasture productivity and nutritional composition. Thus, pastures subjected to rainfall reduction produced less biomass with higher content in nitrogen, proteins, essential amino acids and lipids, likely as a mechanism of plant tolerance to water stress. In contrast, warming increased plant productivity and enhanced the proportion of unsaturated fatty acids, likely mediated by alterations in plant community composition. Finally, our results suggest that trees might slow the impact of climate change on productivity and specific amino acids in pasture. These results could be also applied for the design of management strategies to ensure the ecologic and economic value of silvopastoral ecosystems under future climate scenarios.

Mechanisms of Antioxidant Dipeptides Enhancing Ethanol-Oxidation Cross-Stress Tolerance in Lager Yeast: Roles of the Cell Wall and Membrane.

High concentrations of ethanol could cause intracellular oxidative stress in yeast, which can lead to ethanol-oxidation cross-stress. Antioxidant dipeptides are effective in maintaining cell viability and stress tolerance under ethanol-oxidation cross-stress. In this study, we sought to elucidate how antioxidant dipeptides affect the yeast cell wall and membrane defense systems to enhance stress tolerance. Results showed that antioxidant dipeptide supplementation reduced cell leakage of nucleic acids and proteins by changing cell wall components under ethanol-oxidation cross-stress. Antioxidant dipeptides positively modulated the cell wall integrity pathway and up-regulated the expression of key genes. Antioxidant dipeptides also improved the cell membrane integrity by increasing the proportion of unsaturated fatty acids and regulating the expression of key fatty acid synthesis genes. Moreover, the addition of antioxidant dipeptides significantly (p < 0.05) increased the content of ergosterol. Ala-His (AH) supplementation caused the highest content of ergosterol, with an increase of 23.68 ± 0.01% compared to the control, followed by Phe-Cys (FC) and Thr-Tyr (TY). These results revealed that the improvement of the cell wall and membrane functions of antioxidant dipeptides was responsible for enhancing the ethanol-oxidation cross-stress tolerance of yeast.

Análisis proximal y perfil de ácidos grasos de los tejidos musculares en diferentes partes del cuerpo del barbo de Crimea (Barbus tauricus Kessler, 1877)

This study aimed to determine proximate analysis and fatty acid profile of whole body muscle tissue (WM) and muscles in different parts of the body, including dorsal (D), ventral (V), and caudal (C) regions, of the crimean barbel (Barbus tauricus), which is an species caught from the Gelingüllü Dam. In whole body muscle the protein, lipid, moisture, and ash contents of the fish were 18.61, 1.54, 78.49, and 1.09% respectively. The lipid contents of crimean barbel varied between 1.78 and 2.68%, with the highest and lowest percentages in the C and V regions, respectively. There was a significant difference (P&lt;0.05) in the fatty acid content present in the different parts of the fish. The highest and lowest proportions of saturated fatty acids (SFA) were found in WM (23.03) and D (21.94%) region, respectively. The highest and lowest monounsaturated fatty acid (MUFA) contents were found in the D muscle (36) and V muscles (33.73%), respectively. The proportion of polyunsaturated fatty acids (PUFA) was highest and lowest in C (25.63) and D (22.62%) regions, respectively. The highest eicosapentaenoic acid (4.11) and docosahexaenoic acid (12.98%) contents were found in V and C regions, respectively. The results showed that lipid content and composition of fatty acids may vary in the different body parts of the fish.

Influences of Water Deficit Stress and Symbiosis with Growth-Promoting Bacteria on Seed Biochemistry of Camelina sativa

Camelina sativa, being a flowering plant in the family Brassicaceae, is traditionally cultivated as an oilseed crop due to its exceptionally high level (up to 45%) of omega-3 fatty acids, which is uncommon in vegetable sources. In the recent years camelina has been growing more than before because of its potentiality in the production of biodiesel and bioproduct. An aforementioned experiment was designed in three irrigation levels (100%, 75% and 50% of field capacity) and Micrococcus yunnanensis was used as plant growth-promoting bacteria during the reproductive phase.&#x0D; The bacteria were incubated in a nutrient broth medium at the temperature of 28°C for 24h on shaker ceaselessly. When sowing, seeds were treated with 1.0 ml bacteria suspension in the inoculated groups. Water stress was applied to each pot in the levels of 75 and 50 % FC from the budding stage to full maturity in generative phase. Camelina silique yield was harvested at the maturity stage for analysis of seed quality and biochemical responses. Total soluble carbohydrate was extracted thrice from 100 mg of mature seed using extraction soluble including glacial acetic acid, methanol, and water. Oil and protein content were measured using Near-Infrared Reflectance spectrometer. Seed fatty acid contents were determined using gas chromatography. The results showed a significant relation between the highest proportion of fatty acid and the polyunsaturated fatty acid (55.12 to 65.66%) in particular linolenic acid. The increase of polyunsaturated fatty acid and saturated fatty acid was coincided with the decrease of monounsaturated fatty acid under water deficit stress. The application of plant growth-promoting bacteria is proven to increase protein with 50% of field capacity. In general, water deficit stress and plant growth-promoting bacteria have significant effects on the remobilization of nutrients from the soil to developing seed and following metabolism synthesis.

Lipidomics characterized TAG biosynthesis of developing kernels in three walnut cultivars in Xinjiang region.

Walnut oil with very high proportion of polyunsaturated fatty acids exhibits many health beneficial effects. We hypothesized that the oil composition is led by a special pattern/mechanism for triacylglycerol (TAG) biosynthesis as well as accumulation in walnut kernel during embryo development. To test this hypothesis, shotgun lipidomics was performed for class-targeted lipid analysis (including TAG, phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid, phosphatidylglycerol, phosphatidylinositol, and lysophosphatidylcholine species) in walnut kernels from three cultivar collected at three critical stages of embryo development. The results indicated that TAG synthesis in the kernel happened before 84 days after flowering (DAF) and was significantly enhanced between 84 and 98 DAF. Moreover, TAG profile was changing along with DAFs due to the increased composition of 18:1 FA in TAG pool. Moreover, lipidomics also demonstrated that the enhanced acyl editing was responsible for the flux of FA through phosphatidylcholine for eventual TAG synthesis. Therefore, TAG biosynthesis in walnut kernel was characterized directly from lipid metabolism.

Exploring the use of fish as indicators of eicosapentaenoic and docosahexaenoic supply in lake ecosystems.

An adequate supply of food sources with high levels (i.e., weight proportion of total fatty acids) and contents (i.e., absolute amount per mass) of long chain polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are important for ecosystems. Therefore, the supply of EPA and DHA from basal food sources is a useful indicator of ecosystem health. To determine whether EPA and DHA levels and contents in fish can be used as indicators of EPA and DHA supply in lakes, five dominant species of fish and basal food sources (seston and sediment) were collected monthly from June to November from 2016 to 2021 from Lake Hachiro, Japan. Seston and Hypomesus nipponensis were collected from 12 lakes (one collection per lake) with varying seston contents in EPA and DHA. The trends of EPA and DHA in all fish species were similar to those of the basal food sources. Correlation analysis showed that the EPA levels were strongly correlated between fish and seston; moreover, the correlation coefficient increased when a 1- or 2-month moving average was applied to the basal food sources, suggesting that fish represent a time-integrated supply of EPA and DHA. EPA levels of H. nipponensis had the highest correlation coefficients with seston among all fish species. EPA levels of H. nipponensis were significantly correlated with those of seston among lakes. The results of this study suggest that H. nipponensis is a useful indicator of EPA and DHA supplies in lake ecosystems.

Effect of Storage Period on Acid Value and Sensory Attributes of Puffed Wheat Grains ‘Badyrak Vanilla’ and ‘Badyrak with Whey’

Abstract Puffed grains made from whole wheat, corn or rice grains are ready-to-eat breakfast cereals that do not require additional preparation. Two recipes for puffed grain coatings were developed in the previous studies. Sunflower oil was used in the coating, which may affect storage stability. Due to lipid hydrolysis, free fatty acids may be released, causing rancid off-flavour. The aim of this study was to determine the changes in the acid value of lipids and sensory attributes of sweet-coated puffed wheat grains ‘Badyrak vanilla’ (BV) and ‘Badyrak with whey’ (MC) depending on temperature during their eight-month storage. The products were packaged in metallised polypropylene pouches, 30 g each. The acid value was studied monthly at different storage temperatures (20 ± 2 °С and 4 ± 2 °С). In puffed wheat grain products, 65% of fatty acids are polyunsaturated, 25% monounsaturated, and 10% saturated. The high proportion of unsaturated fatty acids over saturated makes oil more susceptible to oxidation. Literature studies and sensory evaluation of puffed wheat grains allowed setting a limiting acid value at 4.0 mg KOH g−1 lipids. The increase in acid value was storage temperature dependent. Thus, the acid value exceeded the established limit in the fifth month for MC and the sixth month for BV when stored at 20 ± 2 °С. At the same time, noticeable changes in puffed wheat grain flavour were observed. The temperature coefficient (Q10) for MC was 2.0, whereas for BV it was 1.5, indicating that the acid value increase in MC was more affected by temperature than that in BV.

Thyroid Hormone Regulates the Lipid Content of Muscle Fibers, Thus Affecting Physical Exercise Performance.

Skeletal muscle (SkM) lipid composition plays an essential role in physiological muscle maintenance and exercise performance. Thyroid hormones (THs) regulate muscle formation and fuel energy utilization by modulating carbohydrates and lipid and protein metabolism. The best-known effects of THs in SkM include the promotion of mitochondrial biogenesis, the fiber-type switch from oxidative to glycolytic fibers, and enhanced angiogenesis. To assess the role of THs on the lipidic composition of SkM fibers, we performed lipidomic analyses of SkM cells and tissues, glucose tolerance experiments, and exercise performance tests. Our data demonstrated that TH treatment induces remodeling of the lipid profile and changes the proportion of fatty acids in SkM. In brief, THs significantly reduced the ratio of stearic/oleic acid in the muscle similar to what is induced by physical activity. The increased proportion of unsaturated fatty acids was linked to an improvement in insulin sensitivity and endurance exercise. These findings point to THs as critical endocrine factors affecting exercise performance and indicate that homeostatic maintenance of TH signals, by improving cell permeability and receptor stability at the cell membrane, is crucial for muscle physiology.

Fatty acids and organohalogen contaminants in seafood from the Pearl River Estuary, China: Risk-benefit analyses of seafood consumption

Seafood has long been considered a healthy food choice, but it is also an exposure source of contaminants that may bring potential health risks to humans. Here, 80 organohalogen contaminants (OHCs) and 36 fatty acids (FAs) were analyzed in 22 (n = 211) and 19 fishery species (n = 176) from the eastern- and western Pearl River Estuary (PRE), respectively, for risk–benefit analysis. The average concentrations of total FAs in seafood from the eastern- and western PRE were 26.0 ± 2.14 and 21.3 ± 1.66 mg g−1 wet weight, respectively. Seafood from the eastern PRE exhibited higher levels of OHCs than those from the western PRE, highlighting the spatial heterogeneity of OHC contamination within the PRE. Species occupying higher trophic levels (TLs) typically demonstrated higher levels of OHC accumulation, indicating the biomagnification potential of these contaminants in the PRE ecosystem. Significant negative correlations were observed between TLs and the proportions of monounsaturated fatty acids and polyunsaturated fatty acids, presumably attributed to the ability of fish to synthesize these FAs decreases with increasing TLs. Our benefit-risk quotient (BRQ) analyses revealed that, as far as OHCs are concerned, all seafood species had a BRQ∑OHCs value <1, except for one-spot snapper and daggertooth pike conger, which had BRQ values of 1.03 and 1.14, respectively. The findings indicate that most marine species here analyzed may not pose significant health risks to consumers as a result of OHC exposure. However, considering that many other pollutants and nutrients are not analyzed here, the results of our risk assessments should be treated as preliminary, not final. Future data collection is essential to enhance the comprehensiveness of this type of analysis.

Lactation performance, milk fat output, and nutrient digestibility responses to the addition of liquid molasses or yeast culture in dairy cows fed super-conditioned corn

Increased diet fermentability may decrease ruminal pH and fiber digestibility, and increase the flow of trans fatty acids (FA) to the lower tract ultimately leading to milk fat depression. We recently showed that feeding super-conditioned corn, a new method of corn processing (95°C for 6 min in super-conditioner) for ruminants has potential to the reduction in milk fat yield caused by changes in ruminal pH and increased trans FA in milk fat. Supplementing yeast culture (YC) and replacing starch with sugar sources in diet can counteract the negative effects of high fermentable diets by improving ruminal pH and milk fat output. This study aimed to evaluate the effect of feeding beet liquid molasses (LM) and YC on intake and total-tract digestibility of nutrients, milk yield and composition, ruminal fermentation, milk FA profile, and plasma concentrations of glucose, nonesterified FA, β-hydroxybutyric acid, and urea N in early-lactation dairy cows fed high-starch diets containing super-conditioned corn. Twelve primiparous and 18 multiparous Holstein cows (mean ± SD; 67 ± 12 d in milk and 42 ± 2.1 kg of milk at the beginning of the experiment) were blocked by parity, pre-experimental milk yield, and DIM. Cows were used in a randomized complete block design experiment with 14 d as covariate period and 37 d for the experimental period. The following dietary treatments were fed as total mixed rations: (1) control diet (CTRL = no YC or LM supplementation), (2) LM supplementation at 5% of the diet dry matter (MOL diet), and (3) CTRL supplemented with 10 g/d of YC (YST diet). Diets were formulated to be isonitrogenous and isoenergetic. Intake of nutrients and apparent total-tract digestibility of crude protein and starch did not change across treatments. In contrast, cows fed the YST diet had the greatest apparent total-tract digestibility of dry matter, organic matter and neutral detergent fiber. Compared with the CTRL diet, yield of 4% FCM increased by 2.4 and 1.8 kg in cows fed MOL or YST, respectively. The ruminal molar proportions of acetate and butyrate increased in cows fed the YST or MOL diets, respectively, but the proportion of ruminal propionate was not affected by treatments. Milk fat concentration increased by supplementing both LM and YC and the milk yield of total trans-18:1 dropped by 45% and 18% relative to CTRL with MOL or YST diets, respectively. While the MOL diet increased the milk proportion and yield of de novo FA, no treatment effects were observed for the proportion and yield of preformed FA in the milk fat. Apart from β-hydroxybutyric acid concentration in plasma, which was greatest in cows fed MOL, remaining blood metabolites were not affected by treatments. Overall, MOL and YST diets increased 4% FCM and milk fat concentration and reduced the proportion of total trans-18:1 FA in milk fat in cows fed a concentrate based on super-conditioned corn. These responses were associated with increased ruminal pH and the molar proportions of acetate and butyrate with feeding the MOL and YST diets.

Rumen bacterial cluster identification and its influence on rumen metabolites and growth performance of young goats

Enterotypes, which are defined as bacterial clusters in the gut microbiome, have been found to have a close relationship to host metabolism and health. However, this concept has never been used in the rumen, and little is known about the complex biological relationships between ruminants and their rumen bacterial clusters. In this study, we used young goats (n = 99) as a model, fed them the same diet, and analyzed their rumen microbiome and corresponding bacterial clusters. The relationships between the bacterial clusters and rumen fermentation and growth performance in the goats were further investigated. Two bacterial clusters were identified in all goats: the P-cluster (dominated by genus Prevotella, n = 38) and R-cluster (dominated by Ruminococcus, n = 61). Compared with P-cluster goats, R-cluster goats had greater growth rates, concentrations of propionate, butyrate, and 18 free amino acids¸ and proportion of unsaturated fatty acids, but lower acetate molar percentage, acetate to propionate ratio, and several odd and branched chain and saturated fatty acids in rumen fluid (P < 0.05). Several members of Firmicutes, including Ruminococcus, Oscillospiraceae NK4A214 group, and Christensenellaceae R-7 group were significantly higher in the R-cluster, whereas Prevotellaceae members, such as Prevotella and Prevotellaceae UCG-003, were significantly higher in P-cluster (P < 0.01). Co-occurrence networks showed that R-cluster enriched bacteria had significant negative correlations with P-cluster enriched bacteria (P < 0.05). Moreover, we found the concentrations of propionate, butyrate and free amino acids, and the proportions of unsaturated fatty acids were positively correlated with R-cluster enriched bacteria (P < 0.05). The concentrations of acetate, acetate to propionate ratio, and the proportion of odd and branched chain and saturated fatty acids were positively correlated with P-cluster enriched bacteria (P < 0.05). Overall, our results indicated that rumen bacterial clusters can influence rumen fermentation and growth performance of young goats, which may shed light on modulating the rumen microbiome in early life to improve the growth performance of ruminant animals.

The Effect of MSTN Mutation on Bile Acid Metabolism and Lipid Metabolism in Cattle.

Myostatin (MSTN) is a negative regulator of skeletal muscle genesis during development. MSTN mutation leads to increased lean meat production and reduced fat deposition in livestock. However, the mechanism by which MSTN promotes myogenesis by regulating metabolism is not clear. In this study, we compared the metabolomics of the livers of wild-type (WT) and MSTN mutation cattle (MT), and found changes in the content and proportion of fatty acids and bile acids in MT cattle. The differential metabolites were enriched in sterol synthesis and primary bile acid synthesis. We further analyzed the expression of genes involved in the regulation of lipid and bile acid metabolism, and found that the loss of MSTN may alter lipid synthesis and bile acid metabolism. This study provides new basic data for MSTN mutations in beef cattle breeding.