Increasing Accumulation of Perfluorocarboxylate Contaminants Revealed in an Antarctic Firn Core (1958-2017).

Perfluoroalkyl acids (PFAAs) are synthetic chemicals with a variety of industrial and consumer applications that are now widely distributed in the global environment. Here, we report the measurement of six perfluorocarboxylates (PFCA, C4-C9) in a firn (granular compressed snow) core collected from a non-coastal, high-altitude site in Dronning Maud Land in Eastern Antarctica. Snow accumulation of the extracted core dated from 1958 to 2017, a period coinciding with the advent, use, and geographical shift in the global industrial production of poly/perfluoroalkylated substances, including PFAA. We observed increasing PFCA accumulation in snow over this time period, with chemical fluxes peaking in 2009-2013 for perfluorooctanoate (PFOA, C8) and nonanoate (PFNA, C9) with little evidence of a decline in these chemicals despite supposed recent global curtailments in their production. In contrast, the levels of perfluorobutanoate (PFBA, C4) increased markedly since 2000, with the highest fluxes in the uppermost snow layers. These findings are consistent with those previously made in the Arctic and can be attributed to chlorofluorocarbon replacements (e.g., hydrofluoroethers) as an inadvertent consequence of global regulation.

High Concentrations of Perfluoroalkyl Acids in Arctic Seawater Driven by Early Thawing Sea Ice.

Poly- and perfluoroalkyl substances are synthetic chemicals that are widely present in the global environment including the Arctic. However, little is known about how these chemicals (particularly perfluoroalkyl acids, PFAA) enter the Arctic marine system and cycle between seawater and sea ice compartments. To evaluate this, we analyzed sea ice, snow, melt ponds, and near-surface seawater at two ice-covered stations located north of the Barents Sea (81 °N) with the aim of investigating PFAA dynamics in the late-season ice pack. Sea ice showed high concentrations of PFAA particularly at the surface with snow-ice (the uppermost sea ice layer strongly influenced by snow) comprising 26-62% of the total PFAA burden. Low salinities (<2.5 ppt) and low δ18OH20 values (<1‰ in snow and upper ice layers) in sea ice revealed the strong influence of meteoric water on sea ice, thus indicating a significant atmospheric source of PFAA with subsequent transfer down the sea ice column in meltwater. Importantly, the under-ice seawater (0.5 m depth) displayed some of the highest concentrations notably for the long-chain PFAA (e.g., PFOA 928 ± 617 pg L-1), which were ≈3-fold higher than those of deeper water (5 m depth) and ≈2-fold higher than those recently measured in surface waters of the North Sea infuenced by industrial inputs of PFAAs. The evidence provided here suggests that meltwater arising early in the melt season from snow and other surface ice floe components drives the higher PFAA concentrations observed in under-ice seawater, which could in turn influence the timing and extent of PFAA exposure for organisms at the base of the marine food web.

Investigating the Uptake and Fate of Poly- and Perfluoroalkylated Substances (PFAS) in Sea Ice Using an Experimental Sea Ice Chamber.

Poly- and perfluoroalkyl substances (PFAS) are contaminants of emerging Arctic concern and are present in the marine environments of the polar regions. Their input to and fate within the marine cryosphere are poorly understood. We conducted a series of laboratory experiments to investigate the uptake, distribution, and release of 10 PFAS of varying carbon chain length (C4-C12) in young sea ice grown from artificial seawater (NaClsolution). We show that PFAS are incorporated into bulk sea ice during ice formation and regression analyses for individual PFAS concentrations in bulk sea ice were linearly related to salinity (r2 = 0.30 to 0.88, n = 18, p < 0.05). This shows that their distribution is strongly governed by the presence and dynamics of brine (high salinity water) within the sea ice. Furthermore, long-chain PFAS (C8-C12), were enriched in bulk ice up to 3-fold more than short-chain PFAS (C4-C7) and NaCl. This suggests that chemical partitioning of PFAS between the different phases of sea ice also plays a role in their uptake during its formation. During sea ice melt, initial meltwater fractions were highly saline and predominantly contained short-chain PFAS, whereas the later, fresher meltwater fractions predominantly contained long-chain PFAS. Our results demonstrate that in highly saline parts of sea ice (near the upper and lower interfaces and in brine channels) significant chemical enrichment (ε) of PFAS can occur with concentrations in brine channels greatly exceeding those in seawater from which it forms (e.g., for PFOA, εbrine = 10 ± 4). This observation has implications for biological exposure to PFAS present in brine channels, a common feature of first-year sea ice which is the dominant ice type in a warming Arctic.

Mechanistic Insight into the Uptake and Fate of Persistent Organic Pollutants in Sea Ice.

The fate of persistent organic pollutants in sea ice is a poorly researched area and yet ice serves as an important habitat for organisms at the base of the marine foodweb. This study presents laboratory-controlled experiments to investigate the mechanisms governing the fate of organic contaminants in sea ice grown from artificial seawater. Sea ice formation was shown to result in the entrainment of chemicals from seawater, and concentration profiles in bulk ice generally showed the highest levels in both the upper (ice-atmosphere interface) and lower (ice-ocean interface) ice layers, suggesting their incorporation and distribution is influenced by brine advection. Results from a 1-D sea ice brine dynamics model supported this, but also indicated that other processes may be needed to accurately model low-polarity compounds in sea ice. This was reinforced by results from a melt experiment, which not only showed chemicals were more enriched in saltier brine, but also revealed that chemicals are released from sea ice at variable rates. We use our results to demonstrate the importance of processes related to the occurrence and movement of brine for controlling chemical fate in sea ice which provides a pathway for exposure to ice-associated biota at the base of the pelagic food web.

Spatial variability and temporal trends in water-use efficiency of European forests.

The increasing carbon dioxide (CO2 ) concentration in the atmosphere in combination with climatic changes throughout the last century are likely to have had a profound effect on the physiology of trees: altering the carbon and water fluxes passing through the stomatal pores. However, the magnitude and spatial patterns of such changes in natural forests remain highly uncertain. Here, stable carbon isotope ratios from a network of 35 tree-ring sites located across Europe are investigated to determine the intrinsic water-use efficiency (iWUE), the ratio of photosynthesis to stomatal conductance from 1901 to 2000. The results were compared with simulations of a dynamic vegetation model (LPX-Bern 1.0) that integrates numerous ecosystem and land-atmosphere exchange processes in a theoretical framework. The spatial pattern of tree-ring derived iWUE of the investigated coniferous and deciduous species and the model results agreed significantly with a clear south-to-north gradient, as well as a general increase in iWUE over the 20th century. The magnitude of the iWUE increase was not spatially uniform, with the strongest increase observed and modelled for temperate forests in Central Europe, a region where summer soil-water availability decreased over the last century. We were able to demonstrate that the combined effects of increasing CO2 and climate change leading to soil drying have resulted in an accelerated increase in iWUE. These findings will help to reduce uncertainties in the land surface schemes of global climate models, where vegetation-climate feedbacks are currently still poorly constrained by observational data.

A framework for the extraction and interpretation of organic molecules in speleothem carbonate.

RATIONALE: The organic content of speleothem calcite is a well-recognized component of their chemical composition. To date, the techniques for interpretation of this material include UV fluorescence, FTIR spectroscopy and biomarker analysis using gas chromatography/mass spectroscopy (GC/MS). However, investigation of the minute concentrations of molecules in speleothems demands careful sampling and laboratory controls. METHODS: To be certain extracted molecules were encapsulated at the time of speleothem growth and do not represent contamination, we submitted three pieces of speleothem calcite to a rigorous extraction procedure. Based on sequential digestion and analysis by GC/MS, we measured concentration profiles of individual compounds with increasing distance from sample surfaces. RESULTS: Declining concentrations toward interior extracts identified cholesterol, phthalates, and n-alkanes as surface contaminants. In contrast, iodo organic compounds had homogeneous concentration profiles and were also significantly above laboratory background levels, consistent with an indigenous origin. However, further laboratory testing demonstrated that iodo organics were produced by the reaction of iodine derived from the speleothem with solvent additives and other impurities of the extraction procedure. Sitosterol and some fatty acids demonstrated distributions which were probably indigenous to the speleothem archive, thus recording environmental conditions commensurate with time of growth. CONCLUSIONS: We do not aim to provide an environmental interpretation of extracted molecules, but highlight the caution necessary before doing so. We ultimately establish a framework for differentiating between organic constituents that are introduced to the speleothems during storage, handling and as artifacts of extraction, and those encapsulated in situ at the time of growth.

The influence of protein fractions from bovine colostrum digested in vivo and in vitro on human intestinal epithelial cell proliferation.

Colostrum consists of a number of biologically active proteins and peptides that influence physiological function and development of a neonate. The present study investigated the biological activity of peptides released from first day bovine colostrum through in vitro and in vivo enzymatic digestion. This was assessed for proliferative activity using a human intestinal epithelial cell line, T84. Digestion of the protein fraction of bovine colostrum in vitro was conducted with the enzymes pepsin, chymosin and trypsin. Pepsin and chymosin digests yielded protein fractions with proliferative activity similar to that observed with undigested colostrum and the positive control foetal calf serum (FCS). In contrast trypsin digestion significantly (P<0·05) decreased colostral proliferative activity when co-cultured with cells when compared with undigested colostrum. The proliferative activity of undigested colostrum protein and abomasal whey protein digesta significantly increased (P<0·05) epithelial cell proliferation in comparison to a synthetic peptide mix. Bovine colostrum protein digested in vivo was collected from different regions of the gastrointestinal tract (GIT) in newborn calves fed either once (n=3 calves) or three times at 12-h intervals (n=3 calves). Digesta collected from the distal duodenum, jejunum and colon of calves fed once, significantly (P<0·05) stimulated cell proliferation in comparison with comparable samples collected from calves fed multiple times. These peptide enriched fractions are likely to yield candidate peptides with potential application for gastrointestinal repair in mammalian species.

Significance of honeybee pollination in increasing seed yield of Trifolium alexandrinum (Fabales: Fabaceae) and its impact on economic sustainability of smallholder farmers.

A major limitation to producing high seed yields in berseem clover (Trifolium alexandrinum L.) is failure to set seed, predominantly due to lack of pollination. Despite the importance of berseem clover as a leading forage legume, the contribution of pollinators to seed set is scarce. In Pakistan, the honeybee population is declining mainly because of the extensive use of neonicotinoid pesticides and habitat fragmentation. This, combined with the region's harsh environment and the use of inferior, locally bred genotypes, has resulted in low seed yields. Insufficient seed availability leads to limited forage supply, resulting in poor livestock nutrition, which subsequently impacts livestock health and productivity, and reduces farmers' income. The present study estimated the seed production of 3 berseem clover genotypes resulting from honeybees [Apis mellifera L. (Hymenoptera: Apidae)] pollination in 2 growing seasons (2012-2014) in the central Punjab region of Pakistan. Experiments had 2 pollination treatments (open pollination and honeybee inclusion) and 3 seed genotypes, viz. farmer own-saved, market, and the improved variety cultivars. For both growing seasons, honeybee pollination resulted in significant increases in seed yields ranging from 35% to 67%, regardless of seed genotype. With the exception of the number of seed heads/m2, all seed yield parameters also increased significantly in response to honeybee inclusion. The combination of improved variety and honeybee inclusion resulted in the production of a maximum number of seeds per head (45.3), 1,000-seed weight (3.7 g), and estimated seed yield (375.5 kg/ha). In addition, the increase in estimated net income of seed ranged from PKR 82,485 Rs/ha (US$844/ha) to PKR 168,975 Rs/ha (US$1728/ha) with the use of honeybees as an insect pollinator across all the seed genotypes. Honeybee pollination has broader implications for mixed farming systems by playing a key role in preserving biodiversity and promoting sustainable agriculture. It also enhances the quality and quantity of berseem crops by increasing the production of high-quality seeds and forage leading to improved livestock productivity and family food security which strengthens the economic resilience of rural communities.

Evidence that Notch and Delta expressions have a role in dermal condensate aggregation during wool follicle initiation.

Notch pathway genes have been implicated in the commitment of mesenchymal cells to a wool follicle cell fate. Notch1 and Delta1 transcripts were quantified in fetal skin of fine-woolled (Merino) and strong-woolled (Tukidale) sheep at two time points: either preceding (d56) or during (d70) the first wave of follicle initiation. DIG-labelled probes for both transcripts were localised in the epithelium, some mesenchymal cells, and in the dermal condensates of primordia. The possibility that condensates selectively incorporated Delta1-labelled mesenchymal cells is considered. The involvement of Notch1 in condensate formation was also explored in cultured fetal skin explants and whisker papilla cells using DAPT to block Notch signalling. In its presence, follicle initiation in skin explants was reduced, and the propensity for cultured papilla cells to aggregate was abolished. Results suggest that Notch1 activation is a prerequisite for mesenchymal aggregation. It is speculated that Delta interactions contribute to condensate formation, in vivo.

Red Meat Derived Glycan, N-acetylneuraminic Acid (Neu5Ac) Is a Major Sialic Acid in Different Skeletal Muscles and Organs of Nine Animal Species-A Guideline for Human Consumers.

Sialic acids (Sias) are acidic monosaccharides and red meat is a notable dietary source of Sia for humans. Among the Sias, N-acetylneuraminic acid (Neu5Ac) and 2-keto-3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN) play multiple roles in immunity and brain cognition. On the other hand, N-glycolylneuraminic acid (Neu5Gc) is a non-human Sia capable of potentiating cancer and inflammation in the human body. However, their expression within the animal kingdom remains unknown. We determined Neu5Ac and KDN in skeletal muscle and organs across a range (n = 9) of species using UHPLC and found that (1) caprine skeletal muscle expressed the highest Neu5Ac (661.82 ± 187.96 µg/g protein) following by sheep, pig, dog, deer, cat, horse, kangaroo and cattle; (2) Among organs, kidney contained the most Neu5Ac (1992−3050 µg/g protein) across species; (3) ~75−98% of total Neu5Ac was conjugated, except for in dog and cat muscle (54−58%); (4) <1% of total Sia was KDN, in which ~60−100% was unconjugated, with the exception of sheep liver and goat muscle (~12−25%); (5) Neu5Ac was the major Sia in almost all tested organs. This study guides consumers to the safest red meat relating to Neu5Ac and Neu5Gc content, though the dog and cat meat are not conventional red meat globally.

Effect of diet on preweaning performance of Sahiwal calves.

The objective was to study the growth potential of Sahiwal calves given milk or milk replacer with or without concentrates. For this purpose, forty-eight Sahiwal calves were divided into four groups of 12 animals each with equal sex ratio. In each group, the calves were offered either milk or a milk replacer (MR) at a rate of 10% of their body weight adjusted weekly. In addition to this, calves were fed either a starter ration plus Egyptian clover hay (SR + H) or hay only (H) until the end of trial. The milk or MR was withdrawn gradually from day 56 until animals were weaned completely by day 84. Calves offered milk grew faster than those offered MR (357 ± 9 vs. 162 ± 9 g/day; p < 0.05) and displayed higher weaning weights (51.6 ± 0.8 vs. 35.2 ± 0.8 kg; p < 0.05). The calves offered SR + H grew faster (311 ± 9 vs. 208 ± 9 g/day; p < 0.05) and displayed higher weaning weights (48.7 ± 0.8 vs. 38.1 ± 0.8 kg; p < 0.05) than those fed H alone. Calves offered milk plus SR + H showed the highest growth rate and weaning weights (401 ± 13 g/day and 56.3 ± 1 kg, respectively). The lowest growth rate and weaning weights were observed in calves offered MR and H only (115 ± 13 g/day and 30.3 ± 1 kg, respectively). Calves offered the MR had higher number of scour days than those offered milk (13.5 vs. 3.3). The feeding of whole milk in combination with the starter ration and hay resulted in superior growth rates, higher weaning weights, and healthier calves than the other feeding regimens.

High temperature methane emissions from Large Igneous Provinces as contributors to late Permian mass extinctions.

Methane (CH4) emissions induced by Large Igneous Provinces have the potential to contribute to global environmental changes that triggered mass extinctions in Earth's history. Here, we explore the source of methane in gas samples from central Sichuan Basin, which is within the Emeishan Large Igneous Province (ELIP). We report evidence of high methane formation temperatures (between 249-17/+19 and 256-20/+22 °C) from clumped methane measurements and mantle-derived signatures of noble gases, which verify that oil-cracked CH4 and pyrobitumen are by-products within the reservoirs, associated with hydrothermal activity and enhanced heating by the ELIP. We estimate the volume of oil-cracked CH4 induced by the ELIP and argue that CH4 emissions would have been sufficient to initiate global warming prior to the end of the Permian. We also suggest that similar emissions from oil-cracked CH4 associated with the Siberian Traps Large Igneous Province may also have contributed to the end-Permian mass extinction significantly.

Chitosan Oligosaccharide Supplementation Affects Immunity Markers in Ewes and Lambs during Gestation and Lactation.

Chitosan oligosaccharide (COS) is derived through deacetylation of chitin from crustacean shells. Previous studies reported the benefits of COS to gut microbiota, immunity and health of host species. In this study, 120 pregnant composite ewes were subdivided into treatment and control groups in duplicate. COS was supplemented via a loose lick to provide an estimated intake of COS @100−600 mg/d/ewe for five weeks pre-lambing until lamb marking. Body weight was recorded pre-treatment for ewes, and at lamb marking and weaning for both ewes and lambs. Serum immunity markers immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), secretory immunoglobulin A (sIgA), interleukin (IL)-2, IL10 and faecal sIgA were determined for ewes and lambs at lamb marking and weaning by enzyme-linked immunosorbent assay (ELISA). We found that COS can be incorporated in sheep feed without compromising palatability. Maternal COS supplementation did not influence the body weight of ewes or lambs. It did, however, significantly increase the concentrations of serum IL2 in ewes at marking and weaning (p < 0.001). In lambs, COS also significantly increased the IL2 concentration at making (p = 0.018) and weaning (p = 0.029) and serum IgM at marking (p < 0.001). No significant effect was observed in the concentration of any other immune marker or cytokine in either ewes or lambs. In conclusion, maternal COS supplementation significantly modulated some immunity markers in both ewes and lambs. The short duration of maternal COS supplementation and optimal seasonal conditions during the trial may explain the lack of significant body weight in ewes and lambs from the COS supplementation.

Developing a methodology for carbon isotope analysis of lacustrine diatoms.

Stable isotope analysis of sedimentary carbon in lakes can help reveal changes in terrestrial and aquatic carbon cycles. A method based on a single, photosynthetic organism, where host effects are minimised, should offer more precision than carbon isotope studies of bulk lake sediments. Here we report the development of a systematic method for use on fossil lacustrine diatom frustules, adapted from previous studies in marine environments. A step-wise cleaning experiment on diatomaceous lake sediments from Lake Challa, near Mount Kilimanjaro, was made to demonstrate the necessary treatment stages to remove external sedimentary carbon. Changes in soluble carbon compounds during these cleaning experiments were measured using gas chromatography/mass spectrometry (GC/MS). The mass spectrometry methods were refined to measure the small percentage of carbon in these samples and details of these methods are presented. Samples of cleaned diatoms containing <1% carbon yielded robust results. Carbon isotope analyses of diatom samples containing different species mixtures were performed and suggested that differences existed, although the effects lay within current experimental error and require further work. Unlike what was found in work on oxygen and silicon isotopes from diatom frustules, mineral contamination had no discernible impact on the diatom carbon isotope ratios from these sediments. The range of values found in the lakes investigated thus far can be interpreted with reference to the supply and nature of carbon from the catchment as well as to the demand generated from lake primary productivity.

The Potential for Sialic Acid and Sialylated Glycoconjugates as Feed Additives to Enhance Pig Health and Production.

Swine are one of the most important agricultural species for human food production. Given the significant disease challenges confronting commercial pig farming systems, introduction of a new feed additive that can enhance animal performance by improving growth and immune status represents a major opportunity. One such candidate is sialic acid (Sia), a diverse family of nine-carbon acidic sugar, present in various organs and body fluid, as well as an essential structural and functional constituent of brain ganglioside of humans and animals. Sias are key monosaccharide and biomarker of sialylated milk oligosaccharide (Sia-MOS's), sialylated glycoproteins and glycolipids in milk and all vertebrate cells. Sias accomplish many critical endogenous functions by virtue of their physiochemical properties and via recognition by intrinsic receptors. Human milk sialylated glycoconjugates (Sia-GC's) are bioactive compounds known to act as prebiotics that promote gut microbiota development, gut maturation, pathogen resistance, immunomodulation, anti-inflammation and neurodevelopment. However, the importance of Sia in pig health, especially in the growth, development, immunity of developing piglet and in pig production remains unknown. This review aims to critically discuss the current status of knowledge of the biology and nutritional role of Sia and Sia-GC's on health of both female sow and newborn piglets.

The non-human glycan, N-glycolylneuraminic acid (Neu5Gc), is not expressed in all organs and skeletal muscles of nine animal species.

Red meat-derived sialic acid (Sia), N-glycolylneuraminic acid (Neu5Gc), promotes the risk of carcinoma and inflammation. Expression in skeletal muscle and organs across animal species remains unknown. We measured Neu5Gc in skeletal muscle and organ tissues from nine species using UHPLC and found that: (1) neu5Gc concentration in skeletal muscle was highest in goats (166 ± 48.7 µg/g protein), followed by cattle, pig, sheep, horse, cat and deer: >75% was conjugated. No Neu5Gc was detected in kangaroo and dog muscles; (2) total Neu5Gc in organ meats was generally about 2-54% higher than in muscle. Surprisingly Neu5Gc was absent in seven organs of female deer; (3) nine commercial ovine meat cuts contained similar Neu5Gc levels. Thus, red meat Neu5Gc concentration is tissue and species-specific and absent in muscle and organ tissue of some species. Our study provides guidelines for animal meat preferences for consumers and sheds light on the functionality of Neu5Gc.

Precision and cost-effectiveness of bioindicators to estimate nutrient regimes on coral reefs.

Bioindicators are useful for determining nutrient regimes in marine environments, but their ability to evaluate corals reefs in different ecological states is poorly understood. The precision, availability and congruency of eight potential bioindicators (brown macroalgae, green macroalgae, turf algae, cyanobacteria, soft corals, zoanthids, sponges, and sediment) and their stable isotopic and elemental signatures (δ15N, δ13C, %N, %C, and C:N Ratio) were assessed across 21 reefs in the Inner Seychelles. The coefficient of variation (CoV) for δ15N showed that green and brown macroalgae were highly precise (2.47 ± 0.95, n = 11; 4.68 ± 1.33, n = 16, respectively), though were less common on coral-mortality reefs relative to macroalgal-dominated ones. Zoanthids were also highly precise for δ15N (2.98 ± 1.20), but were more readily available regardless of reef state (n = 18). Congruency was low among these indicators, suggesting that different physiological mechanisms for nutrient processing have a stronger influence on a bioindicator's effectiveness than reef state.

Sensory and Physical Characteristics of M. biceps femoris from Older Cows Using Ginger Powder (Zingibain) and Sous Vide Cooking.

This study aimed to evaluate the sensory and physical characteristics of zingibain-injected meat combined with sous vide cooking. M. biceps femoris (BF; n = 12) acquired from 6-7 year old Angus cows were cooked using the sous vide method at 65 °C, for 8 h or 12 h, either with ginger powder (GP) injected in a 2 g/L solution in water (treatment) or un-injected (control). The sensory attributes included flavour, juiciness, tenderness, and physicochemical characteristics were Warner-Bratzler shear (WBSF), hardness, total water content (TWC), cooking loss (CL) and collagen content. A significant improvement in tenderness with injection treatment and cooking time was observed, as evaluated through trained sensory panellists, and reduced WBSF and hardness (p < 0.05 for all). The flavour of the meat was not affected by injection treatment or cooking time (p > 0.05), but juiciness and TWC were reduced with longer cooking times (p < 0.01 for both). Soluble collagen increased with injection treatment and cooking time (both p < 0.05). Moderate to high correlations were found between sensory and physical measurements for tenderness and juiciness. The longer cooking time (12 h) with GP injection treatment caused over tenderization of the meat. The soft texture associated with over-tenderization may be suitable for some specialised consumer markets, for instance, the elderly population with chewing difficulties. Improving the eating quality of low-quality meat from old animals through sous vide cooking and the use of ginger proteases may increase the acceptability of lower value beef, potentially enhancing the commercial value of carcasses typically produced in the beef industry.

Maternal chitosan oligosaccharide intervention optimizes the production performance and health status of gilts and their offspring.

Chitosan oligosaccharides (COS) are the hydrolyzed product of chitosan and have multifunctional health benefits. The objective of this study was to elucidate the effect of COS as a dietary supplement to gilts on their productivity and health and that of their litters. Gilts were randomly assigned to either a treatment (n = 30) or control group (n = 30). The treatment gilts were fed a standard dry sow ration supplemented with COS at 0.12 and 0.24 g/gilt per d during gestation and lactation, respectively, and the control group was fed the standard dry sow ration only. The body weight, reproductive performance, milk production and litter size for each gilt and body weight of corresponding litters were recorded. The serum immunoglobulins (IgA, IgG, IgM) and secretory immunoglobulin A (sIgA) concentrations of gilts and piglets and fecal sIgA concertation of gilts were measured by Enzyme-linked immunosorbent assay (ELISA). Our study showed that maternal COS supplementation 1) significantly increased gilt body weight in late pregnancy (P < 0.05), 2) significantly increased milk production of gilts at different stages (d 1, 3, 7 and 19) of lactation (P < 0.05), 3) significantly increased body weight gain of piglets at weaning (P < 0.05), 4) significantly increased the serum concentrations of IgM and sIgA in piglets, and sIgA in fecal sample of gilts (P < 0.05), and 5) tended to increase the pregnancy success rate (P > 0.05) in the treatment group compared to the control group. These results suggest that maternal COS intervention in gilts can improve gilt milk production, piglet pre-weaning growth and immunity parameters in both gilts and piglets.

Possible links between extreme oxygen perturbations and the Cambrian radiation of animals.

The role of oxygen as a driver for early animal evolution is widely debated. During the Cambrian explosion, episodic radiations of major animal phyla occurred coincident with repeated carbon isotope fluctuations. However, the driver of these isotope fluctuations and potential links to environmental oxygenation are unclear. Here, we report high-resolution carbon and sulphur isotope data for marine carbonates from the southeastern Siberian Platform that document the canonical explosive phase of the Cambrian radiation from ~524 to ~514 Myr ago. These analyses demonstrate a strong positive covariation between carbonate δ13C and carbonate-associated sulphate δ34S through five isotope cycles. Biogeochemical modelling suggests that this isotopic coupling reflects periodic oscillations in atmospheric O2 and the extent of shallow ocean oxygenation. Episodic maxima in the biodiversity of animal phyla directly coincided with these extreme oxygen perturbations. Conversely, the subsequent Botoman-Toyonian animal extinction events (~514 to ~512 Myr ago) coincided with decoupled isotope records that suggest a shrinking marine sulphate reservoir and expanded shallow marine anoxia. We suggest that fluctuations in oxygen availability in the shallow marine realm exerted a primary control on the timing and tempo of biodiversity radiations at a crucial phase in the early history of animal life.