Low-yield Group Research Articles

Hepatic Transcriptome Reveals Potential Key Genes Contributing to Differential Milk Production.

Despite the widespread adoption of TMR or PMR and the formulas designed to sufficiently cover the cows' requirements, individual dairy cows' milk production varies significantly. The liver is one of the most important organs in cow lactation metabolism and plays an essential role in the initiation of lactation. This study aimed to investigate the potential key genes in the liver contributing to the different milk production. We enrolled 64 cows and assigned them to high or low milk yield (MY) groups according to their first 3 weeks of milk production. We performed RNAseq for 35 liver samples with 18 from prepartum and 17 from postpartum cows. The continuous milk yield observation showed a persistently higher milk yield in high MY cows than low MY cows in the first 3 weeks. High MY cows showed better feed conversion efficiency. We identified 795 differentially expressed genes (DGEs) in the liver of high MY cows compared with low MY cows, with up-regulated genes linked to morphogenesis and development pathways. Weighted gene co-expression network analysis (WGCNA) revealed four gene modules positively correlating with milk yield, and protein and lactose yield (p < 0.05). Using the intersected genes between the four gene modules and DEGs, we constructed the linear mixed-effects models and identified six hub genes positively associated and two hub genes negatively associated with milk yield (Coefficients > 0.25, p < 0.05). Random forest machine learning model training based on these eight hub genes could efficiently predict the milk yield (p < 0.001, R2 = 0.946). Interestingly, the expression patterns of these eight hub genes remained remarkably similar before and after parturition. The present study indicated the critical role of liver in milk production. Activated processes involved in morphogenesis and development in liver may contribute to the higher milk production. Eight hub genes identified in this study may provide genetic research materials for dairy cow breeding.

Water Stress Assessment of Cotton Cultivars Using Unmanned Aerial System Images

Efficiently monitoring and quantifying the response of genotypes to water stress is critical in developing resilient crop cultivars in water-limited environments. The objective of this study was to assess water stress in cotton (Gossypium hirsutum L.) using high-resolution unmanned aerial system (UAS) images and identify water-stress-resistant cultivars in plant breeding. Various vegetation indices (VIs) and the crop water stress index (CWSI) derived from UAS images were applied to assess water stress in eight cotton cultivars under four irrigation treatments (90%, 60%, 30%, and 0% ET). The enhanced vegetation index (EVI), green normalized difference vegetation index (GNDVI), normalized difference red-edge index (NDRE), normalized difference vegetation index (NDVI), and crop water stress index (CWSI) were effective in detecting the effects of the irrigation treatments during the growing season. These VIs effectively differentiated cultivars in the middle and late seasons, while the CWSI detected cultivar differences in the mid–late growing season. The NDVI, GNDVI, NDRE, and EVI had a strong positive relationship with cotton yield starting from the mid-growing season in two years (R2 ranged from 0.90 to 0.95). Cultivars under each irrigation treatment were clustered into high-, medium-, and low-yielding groups based on the VIs at the mid–late growing seasons using hierarchical cluster analysis (HCA). The EVI derived from UAS images with high temporal and spatial resolutions can effectively screen drought-resistant cotton varieties under 30% and 60% irrigation treatments. The successful classification of cultivars based on UAS images provides critical information for selecting suitable varieties in plant breeding to optimize irrigation management based on water availability scenarios. This technology enables the targeted selection of water-stress-resistant cotton cultivars and facilitates site-specific crop management and yield prediction, ultimately contributing to precision irrigation and sustainable agriculture in water-limited environments.

Composition of the rumen microbiome and its association with methane yield in dairy cattle raised in tropical conditions

BackgroundMethane (CH4) emissions from rumen fermentation are a significant contributor to global warming. Cattle with high CH4 emissions tend to exhibit lower efficiency in milk and meat production, as CH4 production represents a loss of the gross energy ingested by the animal. The objective of this study was to investigate the taxonomic and functional composition of the rumen microbiome associated with methane yield phenotype in dairy cattle raised in tropical areas.Methods and resultsTwenty-two Girolando (F1 Holstein x Gyr) heifers were classified based on their methane yield (g CH4 / kg dry matter intake (DMI)) as High CH4 yield and Low CH4 yield. Rumen contents were collected and analyzed using amplicon sequencing targeting the 16 and 18S rRNA genes. The diversity indexes showed no differences for the rumen microbiota associated with the high and low methane yield groups. However, the sparse partial least squares discriminant analysis (sPLS-DA) revealed different taxonomic profiles of prokaryotes related to High and Low CH4, but no difference was found for protozoa. The predicted functional profile of both prokaryotes and protozoa differed between High- and Low CH4 groups.ConclusionsOur results suggest differences in rumen microbial composition between CH4 yield groups, with specific microorganisms being strongly associated with the Low (e.g. Veillonellaceae_UCG − 001) and High (e.g., Entodinium) CH4 groups. Additionally, specific microbial functions were found to be differentially more abundant in the Low CH4 group, such as K19341, as opposed to the High CH4 group, where K05352 was more prevalent. This study reinforces that identifying the key functional niches within the rumen is vital to understanding the ecological interplay that drives methane production.

Whole-Transcriptome Sequencing of Ovary Reveals the ceRNA Regulation Network in Egg Production of Gaoyou Duck.

To investigate the regulatory mechanism of the competing endogenous RNAs (ceRNAs) on the egg performance of Gaoyou ducks, full transcriptome sequencing was performed to analyze the ovarian tissues in Gaoyou ducks. The ducks were categorized into high- and low-yield groups based on the individual in-cage egg production records and the hematoxylin-eosin (HE) staining results. The differentially expressed genes (DEGs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) were further processed by GO (gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses. In total, 72 DEmRNAs; 23 DElncRNAs; 4 DEcircRNAs; and 5 signaling pathways, including the ovarian steroidogenesis, PI3K-Akt, hedgehog, tryptophan metabolism, and oocyte meiosis signaling pathways, were significantly enriched. These results suggest that they could be associated with the Gaoyou duck's ovarian function and affect the total egg production or double-yolked egg production. Furthermore, a coregulation network based on the related candidate ceRNAs across the high- and low-yield egg production groups was constructed. Our findings provide new insights into the mechanisms underlying the molecular regulation of related circRNA/lncRNA-miRNA-mRNA in the egg production and double-yolked egg traits of Gaoyou ducks.

DNA methylation of GDF-9 and GHR genes as epigenetic regulator of milk production in Egyptian Zaraibi goat

BackgroundDNA methylation is an epigenetic mechanism that takes place at gene promoters and a potent epigenetic marker to regulate gene expression.ObjectiveThe study aimed to improve the milk production of Zaraibi goats by addressing the methylation pattern of two milk production-related genes: the growth hormone receptor (GHR) and the growth differentiation factor-9 (GDF-9).Methods54 and 46 samples of low and high milk yield groups, respectively, were collected. Detection of methylation was assessed in two CpG islands in the GDF-9 promoter via methylation-specific primer assay (MSP) and in one CpG island across the GHR promoter using combined bisulfite restriction analysis (COBRA).ResultsA positive correlation between the methylation pattern of GDF-9 and GHR and their expression levels was reported. Breeding season was significantly effective on both peak milk yield (PMY) and total milk yield (TMY), where March reported a higher significant difference in PMY than November. Whereas single birth was highly significant on TMY than multiple births. The 3rd and 4th parities reported the highest significant difference in PMY, while the 4th parity was the most effective one on TMY.ConclusionThese results may help improve the farm animals' milk productive efficiency and develop prospective epigenetic markers to improve milk yield by epigenetic marker-assisted selection (eMAS) in goat breeding programs.

Characterization and mitigation option of greenhouse gas emissions from lactating Holstein dairy cows in East China

BackgroundThis study investigated greenhouse gas (GHG) emission characteristics of lactating Holstein dairy cows in East China and provided a basis for formulating GHG emission reduction measures. GreenFeed system was used to measure the amount of methane (CH4) and carbon dioxide (CO2) emitted by the cows through respiration. Data from a commercial cow farm were used to observe the effects of parity, body weight, milk yield, and milk component yield on CH4 and CO2 emissions.ResultsMean herd responses throughout the study were as follows: 111 cows completed all experimental processes, while 42 cows were rejected because they were sick or had not visited the GreenFeed system 20 times. On average, lactating days of cows was 138 ± 19.04 d, metabolic weight was 136.5 ± 9.5 kg, parity was 2.8 ± 1.0, dry matter intake (DMI) was 23.1 ± 2.6 kg/d, and milk yield was 38.1 ± 6.9 kg/d. The GreenFeed system revealed that CH4 production (expressed in CO2 equivalent, CO2-eq) was found to be 8304 g/d, {mathrm{CH}}_{4left({mathrm{CO}}_2-mathrm{eq}right)} /DMI was 359 g/kg, {mathrm{CH}}_{4left({mathrm{CO}}_2-mathrm{eq}right)} /energy-corrected milk (ECM) was 229.5 g/kg, total CO2 production (CH4 production plus CO2 production) was 19,201 g/d, total CO2/DMI was 831 g/kg, and total CO2/ECM was 531 g/kg. The parity and metabolic weight of cows had no significant effect on total CO2 emissions (P > 0.05). Cows with high milk yield, milk fat yield, milk protein yield, and total milk solids yield produced more total CO2 (P < 0.05), but their total CO2 production per kg of ECM was low (P < 0.05). The total CO2/ECM of the medium and high milk yield groups was 17% and 27% lower than that of the low milk yield group, respectively.ConclusionsThe parity and body condition had no effect on total CO2 emissions, while the total CO2/ECM was negatively correlated with milk yield, milk fat yield, milk protein yield, and total milk solids yield in lactating Holstein dairy cows. Measurement of total CO2 emissions of dairy cows in the Chinese production system will help establish regional or national GHG inventories and develop mitigation approaches to dairy production regimes.

Promoter Methylation Changes in KRT17: A Novel Epigenetic Marker for Wool Production in Angora Rabbit.

Wool production is an important economic trait of Angora rabbits. Exploring molecular markers related to wool production is one of the essentials of Angora rabbits’ breeding. KRT17 (Keratin 17) is an important gene of hair follicle development, which must be explored for genetic/epigenetic variation to assess its effect on wool production. Based on the effective wool production data of 217 Angora rabbits, the high and low yield groups were screened with 1.5 standard deviations of the population mean. The full-length sequence of KRT17 was obtained by rapid amplification of cDNA ends technology, and the polymorphism was analyzed in the promoter, exon, and intron regions by direct sequencing. KRT17, SP1 over-expression plasmids, and siRNA were constructed and transfected into dermal papilla cells. The mRNA expressions of relevant genes were analyzed by RT-qPCR. The methylation level of the KRT17 promoter was determined by Bisulfite Sequencing PCR. Dual-luciferase system, site-directed mutagenesis, and electrophoretic mobility shift assays were used to analyze the binding relationship between SP1 and the promoter of KRT17. The structure map of KRT17 was drawn, and no SNPs were found in the promoter, exon, and intron, indicating a relatively conserved structure of KRT17. Expression of KRT17 was significantly higher in cutaneous tissues than in other tissues and was significantly upregulated in the high-yield group compared to the low-yield group (p < 0.05). Furthermore, the overall high methylation levels of KRT17 CpG I and CpG III showed significant association with low wool yield; the methylation levels of 5 CpG locus (CpG I site 4 and CpG III site 2–5) were significantly different between the high and low yield groups (p < 0.05). The methylation levels of 3 CpG locus (CpG I site 4 and CpG III site 4, 14) showed a significant correlation with KRT17 expression (p < 0.05). Overall, CpG III site 4 significantly affects wool production and KRT17 expressions (p < 0.05). This site promotes SP1 binding to the KRT17 promoter region (CGCTACGCCC) to positively regulate the KRT17 expression. KRT17 CpG III site 4 can be used as candidate epigenetic markers for the breeding of high wool-producing Angora rabbits.

Metagenomic and Metabolomic Insights Into the Mechanism Underlying the Disparity in Milk Yield of Holstein Cows.

This study was conducted to investigate the metabolic mechanism underlying the disparity in the milk yield of Holstein cows. Eighteen lactating Holstein cows in their second parity and 56 (±14.81 SD) days in milking (DIM) were selected from 94 cows. Based on the milk yield of the cows, they were divided into two groups of nine cows each, the high milk yield group (HP) (44.57 ± 2.11 kg/day) and the low milk yield group (LP) (26.71 ± 0.70 kg/day). The experimental cows were fed the same diet and kept under the same management system for more than 60 days. Rumen metagenomics revealed that two Archaea genera, one Bacteria genus, eight Eukaryota genera, and two Virus genera differ between the HP and LP groups. The analysis of metabolites in the rumen fluid, milk, and serum showed that several metabolites differed between the HP and LP groups. Correlation analysis between the predominant microbiota and milk yield-associated metabolites (MP-metabolites) revealed that four Bacteria and two Eukaryota genera have a positive relationship with MP-metabolites. Pathway enrichment analysis of the differential metabolites revealed that five pathways were enriched in all the samples (two pathways in the milk, two pathways in the serum, and one pathway in the rumen fluid). Further investigation revealed that the low milk yield observed in the LP group might be due to an upregulation in dopamine levels in the rumen fluid and milk, which could inhibit the release of prolactin or suppress the action of oxytocin in the udder resulting in reduced milk yield. On the other hand, the high milk yield in the HP group is attributed to an upregulation in citrulline, and N-acetylornithine, which could be used as substrates for energy metabolism in the citric acid cycle and ultimately gluconeogenesis.

Chlorophyll Fluorescence and Drought Tolerance in a Mapping Population of Durum Wheat

Summary This study was conducted to compare and estimate the genetic variability among durum wheat lines in response to drought according to their grain yields and physiological traits. The use of fluorescence parameters as drought selection criteria for durum wheat was investigated in a population of 249 recombinant inbred lines (RILs) derived from a cross between two cultivars of durum wheat: ‘Svevo’ and ‘Kofa’. The durum wheat RILs considered were analyzed to determine the relationship between their grain yields and chlorophyll fluorescence parameters at the grain filling stage under drought stress (rainfed) and supplemental irrigation (irrigated) conditions during the 2004 and 2005 seasons at the ICARDA center. The results obtained show that the durum wheat line performance was influenced by drought stress, indicating significant differences between the grain yields and fluorescence parameters recorded under drought rainfed (RF) and irrigation (IR) conditions. Significant differences between the experimental groups of durum wheat RILs (P&lt;0.05) were only recorded under drought conditions, with the exception of leaf water potential (Lwp). Under such conditions, nearly all the parameters examined were significantly increased in the high-yielding group (with the exception of the Que parameter), thus revealing the genetic variability of the durum wheat lines considered in response to drought stress. The potential quantum efficiency of photosystem II (Fv/Fm) was found to be positively associated with the grain yield parameter. The mean values of Fv/Fm in both the high- and low-yielding groups significantly dropped under drought stress (0.71 and 0.68, respectively) compared to the Fv/Fm values recorded under irrigated conditions (0.80 and 0.81). Under drought conditions, slopes were highly significant (P&lt;0.001) nearly for all the fluorescence parameters examined (with the exception of CHLSPAD) compared to those recorded under irrigation conditions. It was concluded that chlorophyll content (SPAD), F0, Fm, Fv, Fv/Fm, Lwp, and Que could be used as additional indicators in screening wheat germplasm for drought tolerance.

Transcriptome study underling difference of milk yield during peak lactation of Kazakh horse

This study was designed to provide a basis for further understanding of the mechanism of lactation based on mRNA expression differences in milk fat between different milk yields in Kazakh horses. Total RNA was extracted from the milk fat during the peak of lactation period. A total of 310 differentially expressed genes (DEGs) were identified by comparative transcriptome analysis of the high-yield and low-yield group. These DEGs regulate lactation by participated in AMPK signaling pathway, FoxO signaling pathway, ErbB signaling pathway, VEGF signaling pathway. In addition, we performed quantitative PCR to validated 5 selected DEGs and the results were in agreement with RNA-seq analysis. A new profile has been established for revealing the mechanism of equid's mammalian lactation.

Comparison of Growth and Yield Characteristics of Mid-Season Hybrid Rice under Different Yield Levels

Analysis of growth and yield characteristics of rice with different yield levels is very important for the breeding of high-yield rice cultivators. To investigate the yield components’ variation, morphological characteristics of the panicles, leaves, and stems of rice varieties under different yield levels, a two-year field experiment was conducted in Chongqing China. The 20 mid-season Indica hybrid rice varieties were classified into three groups based on yield, comprising high-yield group (HG), mid-yield group (MG), and low-yield group (LG). The main reason for the superior yield of HG is that the varieties of this group had a significantly higher number of effective panicles per unit area than the MG and LG. In plant type factors, the leaf type factors were the most important reason causing yield difference of HG, MG, and LG. The average leaf roll index, average leaf length to width ratio, average leaf base angle, average leaf droop angle, and average leaf pillow distance of the upper three leaves were significantly or significantly negatively correlated with the yield, while the average leaf width, average leaf area, and the average distance of leaf edge were significantly or significantly positively correlated with yield, and the leaf droop angle was the most important plant type factor affecting the yield. Based on these results, we further quantified the plant type factors of HG and constructed an ideal plant type model for high-yield hybrid mid-season rice. Theoretical and practical basis could be provided for breeding mid-season Indica hybrid rice with super-high yield in the future to ensure food security.

Soil chemical properties affecting soybean yield on a nationwide scale in Japan

ABSTRACT Wide-area surveys have been conducted on a prefectural or regional scale in Japan for revealing soil chemical properties affecting soybean yield. However, they vary by region and thus, the common chemical factors through Japan remain unclear. This study aims to identify the soil chemical properties involved in soybean yield based on field data in various prefectures throughout Japan. We collected datasets of the topsoil chemical properties and soybean yields at 228 sampling points from 16 prefectures in Japan over the period of 2015–2017. The data sampling was conducted on two fields with different yield levels, namely high- and low-yield groups, which were managed by the same cooperating farmers in each point. We regarded the two fields at each point as a pair for a pairwise comparison. The average yield of the high- and low-yield groups was 3.1 t ha−1 and 2.5 t ha−1, respectively. The p-values of the pairwise comparison results were calculated via the Wilcoxon signed rank test. The differences of the exchangeable Mg (p= 0.040), and the Mg/K (p= 0.027) and Ca/Mg (p= 0.007) ratio between the high-yield and low-yield groups were statistically significant, whereas the other variables were not significant. The exchangeable Mg and Mg/K ratio were negatively related to yield, while the Ca/Mg ratio was positively related. The results suggested that excessive Mg for K or Ca adversely affects the soybean yield. As far as we know, there have been few reports focusing on the relation between the exchangeable cation, especially for the cation balance, and soybean yield. Our results may help researchers and producers deepen their understanding of the relationship between soil chemical properties and soybean yield.

Ovarian transcriptomic analysis and follicular development of Leizhou black duck

This study investigated the factors that caused the differences in egg production during the development of ovarian follicles in Leizhou black ducks. Leizhou black ducks population was divided into 2 groups as high-yield group (HG) and low-yield group (LG). The number of eggs (NE), age at first egg (AFE), weight at first egg, and egg weight (EW) of both groups were recorded, and differences were analyzed using the t test. The logistic model was used to simulate the egg production curves to analyze the production rules. The ovarian follicles of both duck groups were collected to count the number of different grades sized follicles, weigh the ovaries, and observe follicular sections to analyze the developmental differences. Ovarian transcriptomic sequencing was performed to investigate differentially expressed genes and signal pathways in both duck groups. The results revealed a significant difference (P < 0.01) in the NE laid, AFE, and EW between both groups. Comparatively, HG had significantly more (P < 0.01) large yellow follicles (LYF) than LG. The density of medullary layer cells of the follicle section was greater in HG than LG ducks. Transcriptome sequencing revealed a total of 1,027 differentially expressed genes between the HG and LG ducks of which 495 genes were upregulated, and 532 genes were downregulated. Fifty genes were related to reproduction and reproductive processes. Kyoto Encyclopedia of Genes and Genomes–enriched signaling pathways revealed 274 signal pathways enriched in these differentially expressed genes of which the steroid biosynthesis pathway was significantly enriched. Analysis (Q < 0.05) showed that HSD3β → gonadotropin-releasing hormone (GnRH) and estrogen receptor (ESR) → LHβ/ERK1/2 were enriched in the steroid biosynthesis signal pathway. Follicle-stimulating hormone signal pathway mediated by HSD3β → GnRH and ESR → LHβ/ERK1/2 may be involved in ovarian follicle development to regulate LYF reserve process and affect its ovulation cycle, which in turn influence the egg production of Leizhou black ducks.

Metabolomics reveals potential biomarkers in the rumen fluid of dairy cows with different levels of milk production.

ObjectiveIn the present study, an liquid chromatography/mass spectrometry (LC/MS) metabolomics approach was performed to investigate potential biomarkers of milk production in high- and low-milk-yield dairy cows and to establish correlations among rumen fluid metabolites.MethodsSixteen lactating dairy cows with similar parity and days in milk were divided into high-yield (HY) and low-yield (LY) groups based on milk yield. On day 21, rumen fluid metabolites were quantified applying LC/MS.ResultsThe principal component analysis and orthogonal correction partial least squares discriminant analysis showed significantly separated clusters of the ruminal metabolite profiles of HY and LY groups. Compared with HY group, a total of 24 ruminal metabolites were significantly greater in LY group, such as 3-hydroxyanthranilic acid, carboxylic acids, carboxylic acid derivatives (L-isoleucine, L-valine, L-tyrosine, etc.), diazines (uracil, thymine, cytosine), and palmitic acid, while the concentrations of 30 metabolites were dramatically decreased in LY group compared to HY group, included gentisic acid, caprylic acid, and myristic acid. The metabolite enrichment analysis indicated that protein digestion and absorption, ABC transporters and unsaturated fatty acid biosynthesis were significantly different between the two groups. Correlation analysis between the ruminal microbiome and metabolites revealed that certain typical metabolites were exceedingly associated with definite ruminal bacteria; Firmicutes, Actinobacteria, and Synergistetes phyla were highly correlated with most metabolites.ConclusionThese findings revealed that the ruminal metabolite profiles were significantly different between HY and LY groups, and these results may provide novel insights to evaluate biomarkers for a better feed digestion and may reveal the potential mechanism underlying the difference in milk yield in dairy cows.

Metagenomic profiles of the rumen microbiota during the transition period in low‐yield and high‐yield dairy cows

We investigated potential relationships between rumen microbiota and milk production in dairy cows during the transition period. Twelve dairy cows were divided into a low-yield (LY) or high-yield (HY) group based on their milk yield. Rumen samples were taken from dairy cows at 3weeks before parturition, and at 4, 8, and 12weeks after parturition. 16S rDNA-based metagenomic analysis showed that diversities of rumen microbiota in both groups were similar and the number of operational taxonomic units (OTUs) was lower in the postpartum than prepartum period in both groups. The abundance of Bacteroidetes and ratio of Bacteroidetes:Firmicutes was higher in the HY than the LY group. OTUs assigned to Prevotella bryantii, Fibrobacter succinogenes, Ruminococcus albus, Butyrivibrio fibrisolvens, and Succinivibrio sp. were abundant in the HY group. These OTUs were significantly related to the propionate molar proportion of rumen fluids in the HY group. OTUs assigned to Lachnospiraceae, Bifidobacterium sp. and Saccharofermentans were dominant in the LY group. Predictive functional profiling revealed that abundance of gene families involved in amino acid and vitamin metabolism was higher in the HY than the LY group. These results suggest that the community structure and fermentation products of rumen microbiota could be associated with milk production of dairy cows.

Differences in methane production, yield and intensity and its effects on metabolism of dairy heifers

The effects of divergent phenotypic classification in crossbreed Holstein × Gyr dairy heifers for methane emissions in relation to performance, digestibility, energy and nitrogen partition, blood metabolites and temperature of body surface were evaluated. Thirty-five heifers were classified as high and low emission for CH4 production (g/day), yield (g/kg dry matter intake) and intensity (g/kg average daily gain). Digestibility was evaluated by total collection of feces and urine. Gas exchanges were obtained in open-circuit respiratory chambers. A completely randomized design was used and divergent groups were compared by Fisher's test. No differences were found in intake traits between groups of CH4 production and intensity. The low yield group had higher intake. For digestibility and temperature at different body sites were no differences between variables. High production group had higher energy losses as methane and heat production. Low intensity group had higher digestible energy, energy balance and ratio between metabolizable and digestible energy. Urinary nitrogen was 14.3% lower for low production group. There was a difference between methane yield divergent groups for nitrogen intake, digestible and retained. Energy and nitrogen partitioning traits are correlated to the animals divergent for methane production and yield. The low production group presented lower blood insulin concentration. It was not possible to identify divergent animals for CH4 emission using the infrared thermography technique.

115 Is MBS restriction on EEGs truly beneficial? Retrospective observational analysis of EEG referral patterns

IntroductionThe November 2018 Medicare Benefits Schedule (MBS) Taskforce draft report recommends standardised national referral form for routine electroencephalogram (EEG) requests to prevent low value clinician referrals. MBS defines twelve clinical presentations where routine EEG is of relatively low diagnostic value. We aim to identify proportion of MBS defined low diagnostic value EEGs and likely referral patterns.MethodsRetrospective single centre observational study was conducted from January to December 2018. All EEG referrals to a tertiary hospital neurodiagnostic unit were categorised as low or high yield based on MBS recommendation. Sub-group analysis of the low yield group was carried out.ResultsTotal of 1210 EEG referrals were analysed and 5 were excluded from analysis due to insufficient clinical data. Of these referrals 1114 (92.4%) were for high yield indications, 77 (6.4%) for low yield and 14 (1.2%) were indeterminate as to low or high value. Of low yield referrals, 70% were referred for syncope or presyncope and 18.2% for psychogenic nonepileptic seizures. Low yield EEGs were referred by hospital doctors, neurologists and general partitioners by proportions of 37.7%, 33.7% and 28.6% respectively. Four (5.2%) low diagnostic value EEGs were abnormal.ConclusionCurrent clinical practice for EEG referrals is in line with MBS draft review recommendations. We believe addition of a standardised referral form and restricting referrals will have minimal impact on referral quality.

Growth, yield formation, and inulin performance of a non-food energy crop, Jerusalem artichoke (Helianthus tuberosus L.), in a semi-arid area of China

Jerusalem artichoke is an important crop that is used as a foodstuff, animal feed, and an energy crop. However, there has been little fundamental research on its breeding, and a lack of elite cultivars has seriously limited its industrial use. This study was conducted to characterize Jerusalem artichoke’s yield formation mechanism based on its growth and photosynthetic characteristics, to identify reliable criteria for high yield cultivar screening, and to guide the breeding of new high yield cultivars. High yield group (MH) cultivars exhibited vigorous aboveground and root growth, higher photosynthetic capacities (especially in terms of their ability to utilize weak light and minimize dark respiration) and lower rates of sexual reproduction than low yield group (ML) cultivars. Traits associated strongly with high yields included a high leaf area index (LAI), plant height, and stem diameter; a low dark respiration rate (Rd), light compensation point (LCP), and light saturation point (LSP); and late maturation with a long vegetative period. In addition, high yields were due more to increases in tuber number than tuber size, and growth under elevated CO2 conditions was identified as a potentially effective way of increasing yields. The tubers of high yield cultivars exhibited elevated inulin contents, and the inulin content depended more on the total sugar content than the reducing sugar content. Because high yield cultivars have low rates of sexual reproduction, it may be necessary to complement hybrid breeding efforts with mutation breeding, molecular breeding, and other breeding strategies to improve Jerusalem artichoke yields.

Illumina sequencing analysis of the ruminal microbiota in high-yield and low-yield lactating dairy cows.

In this study, differences in the ruminal bacterial community between high-yield and low-yield lactating dairy cows under the same dietary conditions were investigated. Sixteen lactating dairy cows with similar parity and days in milk were divided into high-yield (HY) and low-yield (LY) groups based on their milk yield. On day 21, rumen content samples were collected, and their microbiota compositions were determined using high-throughput sequencing of the 16S rRNA gene by the Illumina MiSeq platform. During the study period, dry matter intake (DMI) and milk yield were measured daily, and milk composition was assessed 3 times per week. The results showed that the milk of the LY group tended to have higher fat (P = 0.08), protein (P = 0.01) and total solid contents (P = 0.04) than that of the HY group, while the HY group had higher ruminal propionate (P = 0.08) proportion and volatile fatty acid (VFA) (P = 0.02) concentrations. Principal coordinate analysis indicated significant differences in ruminal bacterial community compositions and structures between the HY group and LY group. The abundances of Ruminococcus 2, Lachnospiraceae and Eubacterium coprostanoligenes were significantly higher in the HY group than in the LY group. In addition, Bacteroides, Ruminococcus 2 and Candidatus-Saccharimonas were positively correlated with ruminal propionate proportion (r>0.4, P<0.05). These findings enhance the understanding of bacterial synthesis within the rumen and reveal an important mechanism underlying differences in milk production in dairy cows.

Genes Encoding Transcription Factors TaDREB5 and TaNFYC-A7 Are Differentially Expressed in Leaves of Bread Wheat in Response to Drought, Dehydration and ABA.

Two groups of six spring bread wheat varieties with either high or low grain yield under the dry conditions of Central and Northern Kazakhstan were selected for analysis. Experiments were set up with the selected wheat varieties in controlled environments as follows: (1) slowly progressing drought imposed on plants in soil, (2) rapid dehydration of whole plants grown in hydroponics, (3) dehydration of detached leaves, and (4) ABA treatment of whole plants grown in hydroponics. Representatives of two different families of transcription factors (TFs), TaDREB5 and TaNFYC-A7, were found to be linked to yield-under-drought using polymorphic Amplifluor-like SNP marker assays. qRT-PCR revealed differing patterns of expression of these genes in the leaves of plants subjected to the above treatments. Under drought, TaDREB5 was significantly up-regulated in leaves of all high-yielding varieties tested and down-regulated in all low-yielding varieties, and the level of expression was independent of treatment type. In contrast, TaNFYC-A7 expression levels showed different responses in the high- and low-yield groups of wheat varieties. TaNFYC-A7 expression under dehydration (treatments 2 and 3) was higher than under drought (treatment 1) in all high-yielding varieties tested, while in all low-yielding varieties the opposite pattern was observed: the expression levels of this gene under drought were higher than under dehydration. Rapid dehydration of detached leaves and intact wheat plants grown in hydroponics produced similar changes in gene expression. ABA treatment of whole plants caused rapid stomatal closure and a rise in the transcript level of both genes during the first 30 min, which decreased 6 h after treatment. At this time-point, expression of TaNFYC-A7 was again significantly up-regulated compared to untreated controls, while TaDREB5 returned to its initial level of expression. These findings reveal significant differences in the transcriptional regulation of two drought-responsive and ABA-dependent TFs under slowly developing drought and rapid dehydration of wheat plants. The results obtained suggest that correlation between grain yield in dry conditions and TaNFYC-A7 expression levels in the examined wheat varieties is dependent on the length of drought development and/or strength of drought; while in the case of TaDREB5, no such dependence is observed.