14C Content Research Articles

A RESPONSE TO COMMUNITY QUESTIONS ON THE MARINE20 RADIOCARBON AGE CALIBRATION CURVE: MARINE RESERVOIR AGES AND THE CALIBRATION OF 14C SAMPLES FROM THE OCEANS

ABSTRACTRadiocarbon (14C) concentrations in the oceans are different from those in the atmosphere. Understanding these ocean-atmospheric 14C differences is important both to estimate the calendar ages of samples which obtained their 14C in the marine environment, and to investigate the carbon cycle. The Marine20 radiocarbon age calibration curve is created to address these dual aims by providing a global-scale surface ocean record of radiocarbon from 55,000–0 cal yr BP that accounts for the smoothed response of the ocean to variations in atmospheric 14C production rates and factors out the effect of known changes in global-scale palaeoclimatic variables. The curve also serves as a baseline to study regional oceanic 14C variation. Marine20 offers substantial improvements over the previous Marine13 curve. In response to community questions, we provide a short intuitive guide, intended for the lay-reader, on the construction and use of the Marine20 calibration curve. We describe the choices behind the making of Marine20, as well as the similarities and differences compared with the earlier Marine calibration curves. We also describe how to use the Marine20 curve for calibration and how to estimate ΔR—the localized variation in the oceanic 14C levels due to regional factors which are not incorporated in the global-scale Marine20 curve. To aid understanding, illustrative worked examples are provided.

25 Centuries of lead white manufacturing processes identified by 13C and 14C carbon isotopes

Synthetic lead carbonates, cerussite and hydrocerussite, have been used for artistic and cosmetic purposes since Antiquity. Commonly known as lead white, the recipes for the manufacture of this pigment are recounted in many treatises on painting. Depending on the period considered, these two lead carbonates are derived either from a corrosion process or from industrial methods. In both cases, a carbon input, mainly CO2, is necessary to complete the synthesis of this pigment. Its origin depends on the historical period: initially, CO2 came only from microbial activity or the fermentation of organic matter, and from the 19th century on, it was derived mainly from fossil materials. Thus, lead white mainly acquires a 14C and 13C isotopic signature that reflects, to the nearest isotopic fractionation, the nature of the reactants used in its synthesis. In this article, we study the carbon isotopic signature of synthetic lead carbonates by Accelerator Mass Spectrometry (AMS) and Isotopic Ratio Mass Spectrometry (IRMS) through a large corpus of lead whites, composed of reference materials (known manufacturing processes) and of archaeological or museum collection pigments (unknown synthesis). Results show that the 14C content discriminates the manufacturing processes of lead white according to the organic or fossil origin of the CO2 source, and provides absolute dates when pigments are produced by the corrosion of metallic lead in a natural fermentation medium. In addition, δ13C values identify the CO2 source more precisely. This study based on the combination of 14C and 13C data from lead carbonates provides information about the ingredients involved in the synthesis of lead white pigment and demonstrates a good correspondence between the carbon isotopic signature of lead carbonates and the descriptions of lead white recipes in the historical literature.

Hydrocarbon regulation and lower temperature pyrolysis of balikun oil shale kerogen

Oil shale kerogen is a kind of composite nature of fossil energy polymer. Kerogen pyrolysis is a feasible and alternative strategy to produce fossil fuels from shales. However, the disadvantages including the high energy consumption, the high cost, and the low hydrocarbon conversion, significantly hinder the development and utilization of unconventional hydrocarbon resources. Herein, the hexagonal crystal structural layered double hydroxides (LDHs) with the Ni/Fe ratio of 5.64:2.36 is proposed as pyrolysis catalyst to improve the catalytic efficiency, the selectivity of target hydrocarbons, and lower the temperature for the process of kerogen pyrolysis. As a result, needle-like nanoscale NiFe-LDHs are prepared successfully to perform the fast thermal upgrading of Balikun oil shale kerogen. The catalytic pyrolysis performance has been observed that the temperature for maximum conversion (Tmax) is 401.18 °C, presenting a Tmax reduction of 37.84 °C, the yield of shale oil is increased by 7.83 wt%. And during 350°C– 400°C, a progressive increment of 147.67%, 230.86%, and 310.61% is obtained corresponding to the content of C1-C5, C6-C14, and C14 + hydrocarbons, respectively. This finding enriches the catalyst candidates for kerogen pyrolysis and provides new insights into industrial applications of in-situ pyrolysis technology for oil shale recovery processes.

Evaluation of climate variability on sustainability for transboundary water supply in Chihuahua, Mexico

Study regionThis is study of the Rio Conchos Watershed, Chihuahua, Mexico. Study focusThis study provides assessment of climate variability from analysis of instrumental climate and reservoir operations data, plus nearby tree-ring indices in Chihuahua, Mexico. Water demand include international treaty deliveries, growing agricultural land use, and intensified crop production. Analysis of climate cycles includes frequency analysis of local multidecadal instrumental hydrologic time series and multi-century tree-ring indices. In addition, tree-ring indices were compared with 14C content in tree rings to assess the presence of the millennial solar cycle. New hydrological insights for the regionMost of the climate variability within inter-annual to interdecadal periods are aligned with Pacific Decadal Oscillation (PDO)-like climate cycles. New multi-century climate cycles were discovered from tree-ring indices that have a profound impact on sustainability of food and water security. Historical droughts of 8-year average duration within PDO-like cycles that span longer (12–43 year) periods were newly identified which are longer than the 5-year delivery cycles used in the 1944 International Treaty of the Rivers. Mega-droughts were discovered to occur within multi-century climate cycles. Multi-century cycles identified in tree-ring indices were likely driven by solar luminosity changes from the millennial solar cycle and not just recent anthropogenic climate change. Climate variability and temperature increases will further amplify cycles of supply and demand and exacerbate sustainability, mitigation, and management strategies. Conjunctive use combined with reservoir operations will broaden sustainability portfolio of options, reducing demand effects as well as enhance supply options and replenishment effects.

PON2 mediates mitochondrial dysfunction in tracheal epithelial cells in response to a quorum sensing molecule N-(-3-oxododecanoyl)-l-homoserine lactone.

The opportunistic bacterium Pseudomonas aeruginosa secretes the quorum-sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (C12) to co-ordinate gene expression profiles favorable for infection. Recent studies have demonstrated that high concentrations of C12 impair many aspects of host cell physiology, including mitochondrial function and cell viability. The cytotoxic effects of C12 are mediated by the lactonase enzyme, Paraoxonase 2 (PON2), which hydrolyzes C12 to a reactive metabolite. However, the influence of C12 on host cell physiology at concentrations observed in patients infected with P. aeruginosa is largely unknown. Since the primary site of P. aeruginosa infections is the mammalian airway, we sought to investigate how PON2 modulates the effects of C12 at subtoxic concentrations using immortalized murine tracheal epithelial cells (TECs) isolated from wild-type (WT) or PON2-knockout (PON2-KO) mice. Our data reveal that C12 at subtoxic concentrations disrupts mitochondrial bioenergetics to hinder cellular proliferation in TECs expressing PON2. Subtoxic concentrations of C12 disrupt normal mitochondrial network morphology in a PON2-dependent manner without affecting mitochondrial membrane potential. In contrast, higher concentrations of C12 depolarize mitochondrial membrane potential and subsequently trigger caspase signaling and apoptotic cell death. These findings demonstrate that different concentrations of C12 impact distinct aspects of host airway epithelial cell physiology through PON2 activity in mitochondria.

The importance of bone sample selection when using radiocarbon analysis in cases of unidentified human remains

The radiocarbon (14C) analysis of skeletonised human remains can provide vital information regarding the time since death. This study analysed the 14C content in both cortical and trabecular bone from the femur and rib of 18 human remains donated to the Australian Facility for Taphonomic Experimental Research. To determine the most appropriate bone to sample for 14C analysis when estimating the time since death, differences in turnover time between the bone types, and the difference between environmental 14C during the year of death (YOD) and the level of 14C found within the bone (i.e., the lag time) were examined. Overall, the average lag time for all donors was 25 years, with the cortical bone from femur samples providing the largest lag time (39 years) and the trabecular bone from rib samples containing the lowest level of 14C (most modern), with an average lag time of 13 years. The results of this study suggest that in cases of unidentified human remains, the analysis of trabecular bone from a rib may be preferred sample, as this bone contains the most recent 14C, and can provide an estimate of both the time since death, and a broad approximation of YOD.

14C in tree rings in the vicinity of the nuclear facility deployment areas

14C is naturally and artificially occurred radionuclide presented in atmosphere. 14C is produced during the operation of a nuclear reactor of any type, enters the atmosphere and became a part of carbon cycle. The article presents the results of measuring the concentration of 14C in the tree rings of 10 pines in the area of the Beloyarsk NPP (BelNPP) and the Institute of Nuclear Materials (INM), Zarechny. The sampling site, located 1200 m east of the INM, was selected based on long-term observations of meteorological parameters. The measurements were carried out using the accelerator mass spectrometer of the Budker Institute of Nuclear Physics, Novosibirsk. The influence of the operation of nuclear installations on the concentration of 14C in the atmospheric air is demonstrated. The range of values for the concentration of carbon-14 in the sample ranged from 116.0 ± 4.4 to 192.0 ± 8.5 pMC.

Correlations between Fatty Acid Profile and Body Fat Distribution in Postmenopausal Women-A Cross Sectional Study.

The aim of the study was to assess the fatty acid profile of the whole blood of postmenopausal women, taking into account anthropometric parameters. The study involved 156 healthy women with an average age of 60 (SD = 6.3 years) years who were living in the West Pomerania Province (Poland). An original questionnaire was presented to all patients, conducting anthropometric measurements of them: weight, height, waist and hip circumference, body mass index (BMI), waist–hip ratio (WHR) and body adipose index (BAI), as well as an assessment of the fatty acid profile by employing gas chromatography. It has been observed that in menopausal women, the concentration of C16:1 increases with respect to their BMI (r = 0.205 p = 0.01). Similar correlations were noted with regard to body weight (C16:1 r = 0.177 p = 0.029). It was also shown that the concentration of C18trans11 (r = −0.166 p = 0.039), 18:2n6 (r = −0.165 p = 0.04) and n6/n9 (r = −0.194 p = 0.015) were negatively correlated with respect to their WHR, while the levels C16:1 (r = 0.22 p = 0.006), C18:1n9 (r = 0.22 p = 0.007), C24:1 (r = 0.251 p = 0.002), MUFA (r = 0.227 p = 0.046) and n9 (r = 0.224 p = 0.005) were correlated positively with respect to their BAI. The fatty acid profile of the whole blood of postmenopausal women is modulated to a poor extent by anthropometric variables. Therefore, more prospective research is warranted.

Development of a carbon accumulation model for estimating the concentration of 14C in Japanese radish

ABSTRACT Atmospheric 14C released from nuclear fuel reprocessing plants can accumulate in crop plants. Japanese radish (daikon) is a major crop plant in the area surrounding the Japan’s first commercial nuclear fuel reprocessing plant in Rokkasho. We previously developed a dynamic two-compartment model for 14C accumulation in the leaves and roots of Japanese radish. This model was constructed using measured data obtained under controlled experimental conditions in a growth chamber; however, it was not capable of simulating plant carbon accumulation in actual fields resulting from photosynthesis and respiration under fluctuating environments. In order to apply our previous model to actual fields, the present study aims to modify the model by incorporating the environmental responses of photosynthesis and respiration. The modified model was validated with observed temporal changes in the carbon inventories of the leaves and roots of Japanese radish in the field. The model estimates were found to be in relatively good agreement with the observed data. In addition, our modified model provides reasonable simulation results for 14C accumulation in Japanese radish exposed to 14CO2 at different growth stages. The results of this study indicate that our modified model could contribute to the estimation of 14C accumulation in Japanese radish under field conditions.

RESEARCH ON THE ENVIRONMENTAL EFFECTS OF RADIONUCLIDES AT IES - AN OVERVIEW.

This paper summarises the research works of the Institute for Environmental Sciences on the environmental behaviour of radionuclides related to the first commercial-spent nuclear fuel reprocessing plant at Rokkasho Village, Aomori Prefecture, Japan. The distribution and fluctuation in natural radiation in Aomori Prefecture were estimated as basic data. Radionuclides possibly released from the plant operation have been continuously measured using a variety of samples from different locations in Aomori Prefecture. During the test of cutting and chemical treatment of the spent fuel rods from 2006 to 2008, the concentration of 85Kr, 14C, 3H and 129I in the air increased, whereas that of 3H and 129I increased in several environmental samples. A numerical simulation model consisting of several sub-models was constructed for predicting the behaviour of released radionuclides in the environment and for evaluating the realistic radiation dose of residents around the facility.

METABOLISMS OF 13C IN CATTLE SEMITENDINOSUS MUSCLE AFTER ADMINISTRATION OF 13C LABELED ORCHARD GRASS.

14C released from nuclear facilities is transferred to cattle through their consumption of 14C contaminated grasses. To estimate the concentrations of 14C in their meat, we conducted two sets of experiments. In the first experiment, 230mg of 13C per day was administered to cattle aged 10months for 28days in the form of 13C-labeled grass. The 13C concentration in the semitendinosus muscle decreased exponentially after reaching its peak value. The mean half-life was 76±13days. In the second experiment, 550mg of 13C per day was administered to 24-month-old cattle. The change in the semitendinosus muscle was smaller than that recorded in the first experiment, even though the amount of 13C administered per body weight was slightly higher than that in the first experiment. Consequently, the half-life was not determined. Therefore, further studies are required to clarify the metabolism of carbon in 2-year-old cattle.

Assessment of the influence of benzalkonium chloride addition on radiocarbon analysis of dissolved inorganic carbon

AbstractThis study aimed to assess whether benzalkonium chloride (BAC) addition to water samples could be used as a disinfectant in the radiocarbon (14C) analysis of dissolved inorganic carbon (DIC). We investigated the effectiveness of BAC addition in inhibiting 14C changes in DIC due to microbial activity during water preservation. The DIC and 14C concentration of natural waters (groundwater, seawater, river water, and lake water) without BAC increased by 1.4–3.3 mg L−1 and 1.8–4.2 percent modern carbon (pMC) for 2 weeks, and 2.2–7.9 mg L−1 and 3.0–11.9 pMC for 4 weeks, respectively, while none of the BAC‐treated water samples, excluding seawater, exhibited changes in DIC or 14C concentration. Although slight increases in DIC and 14C concentrations in seawater with BAC treatment were observed, 0.4 mg L−1 and 0.4 pMC for 2 weeks, and 1.6 mg L−1 and 1.5 pMC for 4 weeks, respectively, these changes were 20–40% lower than that in seawater without BAC treatment. Furthermore, carbon contamination into the sample water due to BAC decomposition and BAC‐induced microorganism decomposition was negligible in 14C analysis, albeit using BAC solution without atmospheric CO2 contamination could be a significant issue. Our results demonstrate that BAC is an effective inhibitor of biological DIC changes for 14C analysis of freshwater samples, although slightly less effective in seawater

Influence of different types of sugar on overfeeding performance–part of meat quality

Previous research in our lab showed that 10% glucose, 10% fructose, and 10% sucrose can induce lipid deposition in goose fatty liver formation process more efficiently. However, whether the overfeeding diet supplement with sugar can affect the meat quality is unclear. The aim of this research was to estimate the meat quality of geese overfed with overfeeding diet adding with different types of sugar. The results indicated there were no significant differences in the diameter of muscle fiber, the muscle fiber density, pH0, pH24, the meat color, the cooking loss, the drip loss, the shear force and the dry matter in breast muscle and thigh muscle between corn flour groups and three sugars groups (P > 0.05). The crude fat content of breast muscle in fructose group was significantly higher than that in sucrose group (P < 0.05); the inosinic acid content of leg muscle in fructose group was significantly higher than that in the sucrose group (P < 0.05); the ratios of essential amino acids to total amino acids (EAA/TAA) in the breast muscle of maize flour group, fructose group, sucrose group and glucose group were 42%, 35%, 32% or 34%;57%, 64%, 64%, and 62%, respectively; the ratios of essential amino acids to total amino acids in leg muscle of maize flour group, fructose group, sucrose group and glucose group were 31%, 33%, 35%, and 34%, respectively. The contents of C16:1 and C18:1 n-9c in breast muscle in fructose group were significantly higher than that in sucrose group (P < 0.05). Compared with maize flour group, the contents of C18:0 and C20:0 were lower in leg muscle of sugar group (P < 0.05). Compared with the maize flour group, the activities of hydrogen peroxide (H2O2) and glutathione peroxidase (GSH-PX) in breast muscle were higher than those of sucrose group (P < 0.05), the total antioxidant capacity (T-AOC) levels in breast muscle was higher than that of fructose group and sucrose group (P < 0.05). Cluster analysis and principal component analysis (PCA) showed that there was no difference in meat quality between maize flour and sugar group. In conclusion, the overfeeding with maize flour supplement with 10% sugar had no evident influence on the meat quality.

REFINING RADIOCARBON DATING OF IVORY.

Elephants are on the verge of extinction due to extensive poaching to obtain ivory and illegal income. According to international law, the trade in ivory of African elephants is outlawed, with a few exceptions, as for example in European Union for antique ivory obtained before 1947. There is basically only one physical method for determining the age of ivory and that is radiocarbon dating. The method uses artificially temporarily enhanced 14C content in the atmosphere to date relevant samples with high resolution. Since this advantage is slowly fading, the question arises of how to fill in the loss of the resolution. One possibility is exploiting the chronology of ivory. This work studies a whole elephant tusk and uses radiocarbon dating of samples obtained longitudinally and transversely from along the tusk to analyse the growth rate.

Tissue composition and meat quality of lambs fed diets containing whole-plant sesame silage as a replacement for whole-plant corn silage

The purpose of this study was to evaluate the effects of the replacement of whole-plant corn silage (WPCS) by whole-plant sesame silage (WPSS) in diets of lambs on leg tissue composition, physicochemical properties, and fatty acids profile of the meat. Forty castrated Santa Inês crossbred lambs presenting an average initial body weight (iBW) of 21.8 ± 1.97 kg were distributed in a randomized block design with four treatments [four replacement levels: (control (no sesame), 333, 670, and 1000 g/kg of DM)] in ten replications. No effect (P > 0.05) of replacing WPCS with WPSS was observed on DM intake, final weight at slaughter, weight gain, leg weight, the proportion of muscle (M), bone (B), fat (F), and other tissues, muscularity, M:B ratio, M:F ratio, protein content, ash, pH, water holding capacity, cooking losses, shear force, color parameters (L*, a*, b*, C* and H*), ƩPUFA, ƩMUFA:ƩSFA ratio, Ʃn-6:Ʃn-3 ratio, h:H, atherogenicity index (AI) and on the activity of enzymes Δ9-desaturase C18 and elongase. WPSS promoted quadratic increase (P < 0.05) in the moisture content and quadratic increase trend in C4:0 (P = 0.08). The inclusion of WPSS caused linear increases (P < 0.05) in the concentrations of C18:1 n-11trans, C18:2 c9trans-11 (CLA), ƩMUFAtrans, and ƩPUFA:ƩSFA ratio, and linear increase trend in C18:2 trans10c12 (P = 0.06) and C18:3 n-3 (P = 0.08). It was observed a linear decrease (P < 0.05) in the contents of C16:0, total FA, ƩSFA, ƩMUFA, ƩMUFAcis, and desirable FA, and a linearly decreasing trend in the thrombogenicity index (TI; P = 0.07). Ʃn-6 presented quadratic reduction (P = 0.03), while Ʃn-3 (P = 0.07) and Δ9-desaturase C16 enzyme activity (P = 0.06) tended toward quadratic reduction. WPSS can fully replace WPCS as it does not compromise performance, tissue composition, and meat physicochemical parameters, and improves the quality of meat fat as it reduces ƩSFA and TI and increases CLA content and PUFA:SFA ratio.

Using the triple proxy δ13C–radiocarbon–major and trace elements to understand stalagmite stable carbon composition in Madagascar

Stalagmite δ13Cc is one of the most complicated and difficult proxies to interpret in paleoclimate and paleoenvironmental studies because of its sensitivity to various local, regional, and global factors. The significance of the large δ13Cc shift (~12‰, vs. VPDB) in several stalagmites from Anjohibe Cave, in northwestern Madagascar, in the late Holocene remains a subject of scientific debate. Although it was assumed to reflect C3 to C4 vegetation cover change caused by anthropogenic activities, recent investigations inside the cave, at different locations, revealed a wide δ13Cc range of ~10‰ (vs. VPDB), a value that is comparable in its significance to the 12 ‰ temporal variability mentioned above.In this paper we combine δ13C, radiocarbon (14C), and major and trace elements (MTE) as a proxy to provide additional insights about the non-vegetation drivers of δ13Cc in Madagascar. Our study uses two models, the CaveCalc model and the Fohlmeister model, to help our interpretation of the drip water evolution while it percolates down to the cave and precipitates CaCO3. The radiocarbon results, with values >100 pMC, demonstrate that the bomb peak, i.e., the pronounced increase in atmospheric 14C signals, are clearly recorded in these modern stalagmites. This suggests that the samples are younger than 1950 CE, and the soil carbon cycling has been fast without significant formation of aged soil organic matter. These radiocarbon results further suggests that stalagmites from Anjohibe Cave might be of use for future efforts to reconstruct past atmospheric 14C concentrations. Drip water geochemistry, δ13Cc and MTE, combined with two model simulations (CaveCalc and Fohlmeister model) suggests that the great δ13Cc range is best explained by the combined effects of the DIC residence time in the epikarst that affect the water-rock interaction and the rate of prior carbonate precipitation. This study therefore demonstrated how combined modelling and multi-proxy approaches can advance our understanding of the control mechanisms of δ13Cc for paleoclimate research.

THE MIYAKE EVENT IN 993 CE RECORDED IN OAK SUB-ANNUAL TREE RINGS FROM KUJAWY (POLAND)

ABSTRACTThis article presents measurements of the radiocarbon (14C) concentration in sub-annual tree rings. Samples of earlywood (EW) and latewood (LW) from dendrochronologically dated tree rings (English oak, Quercus robur) from Kujawy, near Kraków (Poland), spanning the years of 990–997 CE, are extracted and their 14C content is measured at the Center for Applied Isotope Studies at the University of Georgia, USA. The EW and LW data show a gradual increase in the Δ14C values between 991–995 CE, which are similar to those observed by Rakowski et al. (2018). An increase of 10.3 ± 2.6‰ in Δ14C for the EW data, and 8.6 ± 2.6‰ for the LW data has been recorded for this period. Using this data, it is possible to estimate the time period for when a major historical event occurred, which seems to have been in the late summer (September –2/+1 month) of 993 CE.

Circulating amino acids and acylcarnitines correlated with different CAC score ranges in diabetic postmenopausal women using LC–MS/MS based metabolomics approach

BackgroundDiabetes mellitus (DM) and its cardiovascular disease (CVD) complication are among the most frequent causes of death worldwide. However, the metabolites linking up diabetes and CVD are less understood. In this study, we aimed to evaluate serum acylcarnitines and amino acids in postmenopausal women suffering from diabetes with different severity of CVD and compared them with healthy controls.MethodsThrough a cross-sectional study, samples were collected from postmenopausal women without diabetes and CVD as controls (n = 20), patients with diabetes and without CVD (n = 16), diabetes with low risk of CVD (n = 11), and diabetes with a high risk of CVD (n = 21) referred for CT angiography for any reason. Metabolites were detected by a targeted approach using LC–MS/MS and metabolic -alterations were assessed by applying multivariate statistical analysis. The diagnostic ability of discovered metabolites based on multivariate statistical analysis was evaluated by ROC curve analysis.ResultsThe study included women aged from 50–80 years with 5–30 years of menopause. The relative concentration of C14:1, C14:2, C16:1, C18:1, and C18:2OH acylcarnitines decreased and C18 acylcarnitine and serine increased in diabetic patients compared to control. Besides, C16:1 and C18:2OH acylcarnitines increased in high-risk CVD diabetic patients compared to no CVD risk diabetic patients.ConclusionDysregulation of serum acylcarnitines and amino acids profile correlated with different CAC score ranges in diabetic postmenopausal women. (Ethic approval No: IR.TUMS.EMRI.REC.1399.062).

The relationships between early lactation energy status indicators and endocrine fertility traits in dairy cows

The relationships between dairy cow milk-based energy status (ES) indicators and fertility traits were studied during periods 8 to 21, 22 to 35, 36 to 49, and 50 to 63 d in milk. Commencement of luteal activity (C-LA) and interval from calving to the first heat (CFH), based on frequent measurements of progesterone by the management tool Herd Navigator (DeLaval), were used as fertility traits. Energy status indicator traits were milk β-hydroxybutyrate (BHB) concentration provided by Herd Navigator and milk fat:protein ratio, concentration of C18:1 cis-9, the ratio of fatty acids (FA) C18:1 cis-9 and C10:0 in test-day milk samples, and predicted plasma concentration of nonesterified fatty acids (NEFA) on test days. Plasma NEFA predictions were based either directly on milk mid-infrared spectra (MIR) or on milk fatty acids based on MIR spectra (NEFAmir and NEFAfa, respectively). The average (standard deviation) C-LA was 39.3 (±16.6) days, and the average CFH was 50.7 (±17.2) days. The correlations between fertility traits and ES indicators tended to be higher for multiparous (r < 0.28) than for primiparous (r < 0.16) cows. All correlations were lower in the last period than in the other periods. In period 1, correlations of C-LA with NEFAfa and BHB, respectively, were 0.15 and 0.14 for primiparous and 0.26 and 0.22 for multiparous cows. The associations between fertility traits and ES indicators indicated that negative ES during the first weeks postpartum may delay the onset of luteal activity. Milk FPR was not as good an indicator for cow ES as other indicators. According to these findings, predictions of plasma NEFA and milk FA based on milk MIR spectra of routine test-day samples and the frequent measurement of milk BHB by Herd Navigator gave equally good predictions of cow ES during the first weeks of lactation. Our results indicate that routinely measured milk traits can be used for ES evaluation in early lactation.

Effect of Hydrogen-Consuming Compounds on In Vitro Ruminal Fermentation, Fatty Acids Profile, and Microbial Community in Water Buffalo.

The present study aimed to investigate the effect of hydrogen-consuming compounds on ruminal methane (CH4) production, in vitro fermentation parameters, fatty acids profile, and microbial community in water buffalo. Different sodium nitrate to disodium fumarate ratios [2:1 (F), 1:1 (S), 1:2 (T)]were studied in vitro by batch culture technique in the presence of linoleic acid. Results revealed that the dominant bacterial communities were not affected with sodium nitrate and disodium fumarate, whereas CH4 production and Verrucomicrobia, Succiniclasticum, norank_f__Muribaculaceae, and Prevotellaceae_UCG-003 were reduced (P < 0.05). However, ruminal pH, unsaturated fatty acids/saturated fatty acids (UFA/SFA) and Campilobacterota, Selenomonas, Succinivibrio, Oribacterium, Christensenellaceae_R-7_group, Campylobacter, Shuttleworthia, Schwartzia, and Prevotellaceae_YAB2003_group were increased (P < 0.05). Total volatile fatty acids (TVFA) and Spirochaetae, Fibrobacterota, Verrucomicrobia, Fibrobacter, Treponema, and Prevotellaceae were decreased in F (P < 0.05), but cis-9, trans-11CLA, acetate/propionate and Proteobacteria, Campilobacterota, Selenomonas, Succinivibrio, and Campylobacter were increased in F (P < 0.05). The highly selected bacterial genera in F were Campylobacter and Succinivibrio. The disodium fumarate, enhanced (P < 0.05) the TVFA, propionate, total bacteria, Butyrivibrio proteoclasticus, and Atypical butyrivibrio. The concentrations of C18:3n3, C20:3n6, C21:0, C22:2n6, and C22:1n9, as well as the populations of total fungi, protozoa, methanogens, Butyrivibrio hungatei in T were higher (P < 0.05). The highly selected bacterial genera in T were Fibrobacter and Treponema. Conclusively, the addition of sodium nitrate and disodium fumarate can reduce the CH4 production and optimize ruminal fatty acid composition. Furthermore, disodium fumarate can alleviate the adverse effect of sodium nitrate on the rumen fermentation.