Relationship between rumen bacterial community and milk fat in dairy cows.

Introduction: Milk fat is the most variable nutrient in milk, and recent studies have shown that rumen bacteria are closely related to milk fat. However, there is limited research on the relationship between rumen bacteria and milk fatty. Fatty acids (FAs) are an important component of milk fat and are associated with various potential benefits and risks to human health. Methods: In this experiment, forty-five healthy Holstein dairy cows with alike physiological and productive conditions were selected from medium-sized dairy farms and raised under the same feeding and management conditions. The experimental period was two weeks. During the experiment, raw milk and rumen fluid were collected, and milk components were determined. In this study, 8 high milk fat percentage (HF) dairy cows and 8 low milk fat percentage (LF) dairy cows were selected for analysis. Results: Results showed that the milk fat percentage in HF group was significantly greater than that of the dairy cows in the LF group. 16S rRNA gene sequencing showed that the rumen bacterial abundance of HF dairy cows was significantly higher than that in LF dairy cows; at the genus level, the bacterial abundances of Prevotellaceae_UCG-001, Candidatus_Saccharimonas, Prevotellaceae_UCG-003, Ruminococcus_1, Lachnospiraceae_XPB1014_group, Lachnospiraceae_AC2044_group, probable_genus_10 and U29-B03 in HF group were significantly higher than those in the LF group. Spearman rank correlation analysis indicated that milk fat percentage was positively related to Prevotellaceae_UCG-001, Candidatus_Saccharimonas, Prevotellaceae_UCG-003, Ruminococcus_1, Lachnospiraceae_XPB1014_group, Lachnospiraceae_AC2044_group, probable_genus_10 and U29-B03. Furthermore, Prevotellaceae_UCG-001 was positively related to C14:0 iso, C15:0 iso, C18:0, Ruminococcus_1 with C18:1 t9, Lachnospiraceae_AC2044_group with C18:1 t9 and C18:1 t11, U29-B03 with C15:0 iso. Discussion: To sum up, rumen bacteria in dairy cows are related to the variation of milk fat, and some rumen bacteria have potential effects on the deposition of certain fatty acids in raw milk.

Effects of α-lipoic acid on growth performance, antioxidant capacity, and immune function in sheep.

α-Lipoic acid (α-LA) was usually applied to improve the ability of removing the reactive oxygen species of host. The affection of α-LA on ruminants was mainly focused on the variation of serum antioxidant and immune indexes, but the research on tissues or organs remained limited. The aim of this study was to explore the effects of dietary supplementation with different levels of α-LA on growth performance, antioxidant status, and immune indexes of serum and tissues in sheep. One hundred Duhu F1 hybrid (Dupo♀ × Hu sheep♂) sheep aged 2 to 3 mo with similar body weight (27.49 ± 2.10 kg) were randomly allocated into five groups. Five diets supplemented with 0 (CTL), 300 (LA300), 450 (LA450), 600 (LA600), and 750 (LA750) mg/kg α-LA were fed to sheep for 60 d. The results showed that α-LA supplementation significantly increased the average daily feed intake (P < 0.05); however, no significant variation was found in the average daily gain, feed conversion rate, carcass weight, and slaughter rate among groups (P > 0.05). Compared with CTL group, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities in serum of LA600 and LA750 groups were increased (P < 0.05). At LA450-LA750 groups, SOD, CAT activities in liver and ileum tissues and GSH-Px activities in ileum tissues were increased than CTL group (P < 0.05), while malondialdehyde (MDA) contents in serum and muscle tissue were decreased than CTL group (P < 0.05). The total antioxidant capacity contents in liver, muscle, and ileum tissues of LA600 group were increased compared with CTL group (P < 0.05). Additionally, the interleukin-10 (IL-10) contents of serum in LA450-LA750 groups were increased than CTL group (P < 0.05); the contents of interleukin-1ß (IL-1ß) in serum, interleukin-2 (IL-2) in liver, and interleukin-6, IL-1ß in muscle were decreased than CTL group (P < 0.05). The content of immunoglobulin A in serum of LA600 group, ileum, and muscle of LA750 group was increased than CTL group (P < 0.05). Based on the quadratic regression analysis of GSH-Px, MDA, IL-2, IL-10, and IL-1ß, the optimal dietary α-LA levels were estimated to be 495.75, 571.43, 679.03, 749.75, and 678.25 mg/kg, respectively. This research will provide certain contribution for the effective utilization of α-LA in sheep production.

This article studied the effects of α-lipoic acid (α-LA) on growth performance, antioxidant capacity, and immune function of serum and tissues in sheep. α-LA was usually applied to improve the ability of removing the reactive oxygen species of host. The affection of α-LA on ruminants was mainly focused on the variation of serum antioxidant and immune indexes, but the research on tissues or organs remained limited. One hundred sheep aged 2 to 3 mo were randomly allocated into five groups; five diets supplemented with 0, 300, 450, 600, and 750 mg/kg α-LA were fed to sheep for 60 d. Results showed that adding appropriate α-LA in diet has the potential ability to improve the production performance, increase the activity of antioxidant enzymes, and regulate the secretion of inflammatory factors in sheep serum, rumen epithelium, liver, ileum, and muscle tissues. Therefore, these results indicated that α-LA has the potential to become a safe, high-quality, and environmentally friendly feed additive that could protect the health of sheep and improve the economic benefits of pasture.

Epsilon-near-zero substrate-enabled strong coupling between molecular vibrations and mid-infrared plasmons.

As the strong light-matter interaction between molecular vibrations and mid-infrared optical resonant modes, vibrational strong coupling (VSC) has the potential to modify the intrinsic chemistry of molecules, leading to the control of ground-state chemical reactions. Here, by using quartz as an epsilon-near-zero (ENZ) substrate, we have realized VSC between organic molecular vibrations and mid-infrared plasmons on metallic antennas. The ENZ substrate enables sharp mid-infrared plasmonic resonances (Q factor ∼50) which efficiently couple to the molecular vibrations of polymethyl methacrylate (PMMA) molecules with prominent mode splitting. The coupling strength is proportional to the square root of the thickness of the PMMA layer and reaches the VSC regime with a thickness of ∼300 nm. The coupling strength also depends on the polarization of the incident light, illustrating an additional way to control the molecule-plasmon coupling. Our findings provide a new, to the best of our knowledge, possibility to realize VSC with metallic antennas and pave the way to increase the sensitivity of molecular vibrational spectroscopy.

Effect of Flaxseed Supplementation on Milk and Plasma Fatty Acid Composition and Plasma Parameters of Holstein Dairy Cows.

The objective of this study was to determine the effect of whole flaxseed and ground flaxseed supplementation on the composition of fatty acids in plasma and milk, particularly the content of omega-3 polyunsaturated fatty acids (n-3 PUFAs). Thirty Holstein dairy cows were randomly assigned to three treatment groups. Cows were fed a total mixed ration without flaxseed (CK), 1500 g of whole flaxseed (WF), and 1500 g of ground flaxseed (GF) supplementation. There were no differences observed in dry matter intake, milk yield, energy-corrected milk, and 4% fat-corrected milk (p > 0.05). Compared with the CK group, the contents of α-linolenic acid (ALA), eicosatrienoic acid, and eicosapentaenoic acid increased in the plasma and milk WF and GF groups, and the content of docosahexaenoic acid and total n-3 PUFA was higher in GF than the other groups (p < 0.001). The ALA yield increased to 232% and 360% in WF and GF, respectively, compared to the CK group. Compared with the WF group, GF supplementation resulted in an increased milk ALA/ALA intake ratio (p < 0.001). Flaxseed supplementation increased the activity of GSH-Px and decreased the concentration of MDA in milk (p < 0.001). Plasma parameters did not differ among the treatments (p > 0.05). This result indicated that compared with the WF group, GF supplementation in the diet showed higher efficiency in increasing the total n-3 PUFA levels and the milk ALA/ALA intake ratio, and decreased the ratio of n-6 PUFAs to n-3 PUFAs in milk.

Elevating Surface-Enhanced Infrared Absorption with Quantum Mechanical Effects of Plasmonic Nanocavities.

Plasmonic nanocavities, with the ability to localize and concentrate light into nanometer-scale dimensions, have been widely used for ultrasensitive spectroscopy, biosensing, and photodetection. However, as the nanocavity gap approaches the subnanometer length scale, plasmonic enhancement, together with plasmonic enhanced optical processes, turns to quenching because of quantum mechanical effects. Here, instead of quenching, we show that quantum mechanical effects of plasmonic nanocavities can elevate surface-enhanced infrared absorption (SEIRA) of molecular moieties. The plasmonic nanocavities, nanojunctions of gold and cadmium oxide nanoparticles, support prominent mid-infrared plasmonic resonances and enable SEIRA of an alkanethiol monolayer (CH3(CH2)n-1SH, n = 3-16). With a subnanometer cavity gap (n < 6), plasmonic resonances turn to blue shift and the SEIRA signal starts a pronounced increase, benefiting from the quantum tunneling effect across the plasmonic nanocavities. Our findings demonstrate the new possibility of optimizing the field enhancement and SEIRA sensitivity of mid-infrared plasmonic nanocavities.

Differentiating Clinical Characteristics Between Necrotizing Enterocolitis and Food Protein-induced Enterocolitis When Both have Pneumatosis Intestinalis: A Single-centre Study.

OBJECTIVE: To compare the clinical characteristics of necrotizing enterocolitis (NEC) and food protein-induced enterocolitis (FPIES) when both have pneumatosis intestinalis (PI) and to identify them. STUDY DESIGN:  Analytical study. PLACE AND DURATION OF STUDY:  Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, China, from January to December 2019. METHODOLOGY: Medical data of neonates, who were diagnosed with NEC (Bell's Stage ≥2a) or FPIES, were retrospectively evaluated. All included infants had abdominal radiographic PI positive. According to the infants' diagnoses, they were classified into groups NEC and FPIES. The clinical characteristics of NEC and FPIES were compared to find the differences. RESULTS: A total of 293 infants were included, of which 205 were diagnosed with NEC and other 88 were FPIES. NEC was characterised by low birth weight (BW), gestational age (GA) and onset time; NEC had higher rates of mother's antenatal steroid therapy, formula feeding, sepsis, and anemia. NEC and FPIES both had a set of similar signs and symptoms which varied depending on the severity of the disease, except for abdominal tenderness and absent bowel sounds only observed in NEC. The rates of continuous elevated C-reactive protein (CRP) and thrombocytopenia were also higher in NEC than in FPIES (p<0.05). CONCLUSION: When PI-positive, although infants diagnosed with NEC or FPIES lack specific signs and symptoms, there are still clinical characteristics that need to be focused on: risk factors (BW, GA, onset time, mother's antenatal steroid therapy, formula feeding, sepsis, and anemia), abdominal signs (abdominal tenderness and absent bowel sounds), the results of CRP and platelet, which may help clinicians to identify them. KEY WORDS:  Necrotizing enterocolitis, Food protein-induced enterocolitis syndrome, Pneumatosis intestinalis, Neonate.

Ruminal bacterial community is associated with the variations of total milk solid content in Holstein lactating cows.

Total milk solid (TMS) content directly reflects the quality of milk. Rumen bacteria ferment dietary components, the process of which generates the precursors for the synthesis of milk solid, therefore, the variation in rumen bacterial community could be associated with milk solid in dairy cows. In this study, 45 healthy mid-lactation Holstein dairy cows with the similar body weight, lactation stage, and milk yield were initially used for the selection of 10 cows with high TMS (HS) and 10 cows with low TMS (LS). All those animals were under the same feeding management, and the individual milk yield was recorded for 14 consecutive days before milk and rumen fluid were sampled. Rumen fluid was used to determine bacterial community by 16S rRNA gene sequencing technique. The HS cows had significantly greater feed intake and milk TMS, fat, protein content than LS cows (P < 0.05). Among the volatile fatty acids (VFA), propionic acid and valeric acid concentrations were significantly greater in HS cows than those in LS cows (P < 0.05). There was no significant difference in the concentrations of acetate, butyrate, isobutyrate, valerate, and the total VFA (P > 0.05), nor was the acetate-to-propionate ratio, pH value, ammonia nitrogen and microbial crude protein concentrations (P > 0.05). Significant differences in the relative abundances of some bacterial genera were found between HS and LS cows. Spearman's rank correlation analysis revealed that TMS content was correlated positively with the abundances of Ruminococcaceae UCG-014, Ruminococcaceae NK4A214 group, Prevotellaceae UCG-001, Butyrivibrio 2, Prevotellaceae UCG-003, Candidatus Saccharimonas, Ruminococcus 2, Lachnospiraceae XPB1014 group, probable genus 10, Eubacterium ventriosum group, but negatively correlated with Pyramidobacte. In addition, Ruminococcaceae UCG-014, Ruminococcus 2, Ruminococcaceae UCG001, probable genus 10 and Eubacterium ventriosum group might boost the total VFA production in the rumen. In conclusion, the dry matter intake of dairy cows and some special bacteria in rumen were significantly associated with TMS content, which suggests the potential function of rumen bacteria contributing to TMS content in dairy cows.

Effect of Flaxseed Supplementation in Diet of Dairy Cow on the Volatile Organic Compounds of Raw Milk by HS-GC-IMS.

Flaxseed supplementation in diet of dairy cow can effectively enhance the production of ω-3 polyunsaturated fatty acids (n-3 PUFA) in raw milk, which further give rise to the changes of volatile organic compounds (VOCs). In this study, we used headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) to investigate the VOCs in milk from cows fed three different diets (CK: supplemented with 0 g/d flaxseed; WF: 1,500 g/d whole flaxseed and GF: 1,500 g/d ground flaxseed). A total of 40 VOCs including three acids, six esters, 11 aldehydes, seven alcohols, 13 ketones were identified in all the raw milk samples. Compared with GF supplementation, suppling with WF could influence more compounds in raw milk (GF: five compounds; WF: 22 compounds). Supplementation with WF could increase the concentration of nonanal, heptanal, hexanal, which could cause the occurrence of off-flavors, and reduce the concentration of hexanoic acid (monomer; M), 2-hexanol, ethanol (M), 2-heptanone (dimer; D), 2-pentanone (M), 2-pentanone (D), acetoin (M) in raw milk. GF supplementation in diet could reduce the 2-pentanone (M), 2-pentanone (D). In addition, principal component analysis (PCA) based on the signal intensity of identified VOCs indicated that it is possible to distinguish between the CK and WF milk. However, GF milk could not be distinguished from CK milk. The results demonstrate that compared with GF milk, WF supplementation in diet of dairy cows could increase fishy (heptanal) cardboard-like (pentanal) flavor in milk and decrease sweet (hexanoic acid, 2-heptanone), fruity (ethyl butanoate, ethyl hexanoate, 2-heptanone) flavor which may lead the milk less acceptable. In conclusion, compared with WF, GF supplementation in diet of dairy cow showed higher increase in n-3 PUFA in raw milk, and less influence in VOCs of raw milk and this study might provide theoretical supports for the production of milk rich in n-3 PUFA.

Vibrational Strong Coupling between Surface Phonon Polaritons and Organic Molecules via Single Quartz Micropillars.

Vibrational strong coupling (VSC), the strong coupling between optical resonances and the dipolar absorption of molecular vibrations at mid-infrared frequencies, holds the great potential for the development of ultrasensitive infrared spectroscopy, the modification of chemical properties of molecules, and the control of chemical reactions. In the realm of ultracompact VSC, there is a need to scale down the size of mid-infrared optical resonators and to elevate their optical field strength. Herein, by using single quartz micropillars as mid-infrared optical resonators, the strong coupling is demonstrated between surface phonon polariton (SPhP) resonances and molecular vibrations from far-field observation. The single quartz micropillars support sharp SPhP resonances with an ultrasmall mode volume, which strongly couples with the molecular vibrations of 4-nitrobenzyl alcohol (C7 H7 NO3 ) molecules featuring pronounced mode splitting and anticrossing dispersion. The coupling strength depends on the molecular concentration and reaches the strong coupling regime with only 7300 molecules. The findings pave the way for promoting the VSC sensitivity, miniaturing the VSC devices, and will boost the development of ultracompact mid-infrared spectroscopy and chemical reaction control devices.

Effect of Whole or Ground Flaxseed Supplementation on Fatty Acid Profile, Fermentation, and Bacterial Composition in Rumen of Dairy Cows.

Flaxseed is rich in α-linolenic acid (ALA) and can increase omega-3 polyunsaturated fatty acid in the milk of dairy cows. However, the response of rumen fermentation to different forms of flaxseed supplementation is unknown. This study aimed to investigate the effect of different forms of flaxseed on the fatty acid profile, fermentation, and composition of bacteria in the rumen of dairy cows. In total, 30 Holstein dairy cows were selected and randomly assigned into three groups (10/group). Cows were fed a basal diet (control check; CK) or basal diets supplemented with either 1,500 g per day whole flaxseed (WF) or 1,500 g per day ground flaxseed (GF). The WF group had the highest ALA content in rumen fluid, whereas no difference was found between the CK and GF groups. However, the molar proportion of acetate increased in the WF and GF groups and was the highest in the GF group, and a similar trend was shown by propionate, isobutyrate, butyrate, isovalerate, and valerate (CK < WF < GF). The abundance of Ruminococcaceae_NK4A214_group, Christensenellaceae_R-7_group, and Eubacterium_coprostanoligenes_group also showed the same trend (CK < WF < GF). Different forms of flaxseed release ALA by different mechanisms in the rumen, and the molar proportions of volatile fatty acids and the bacterial composition were potentially influenced mainly by the amount of ALA released into the rumen.

Ruminal microbiota-host interaction and its effect on nutrient metabolism.

Rumen microbiota has a close and intensive interaction with the ruminants. Microbiota residing in the rumen digests and ferments plant organic matters into nutrients that are subsequently utilized by the host, making ruminants a unique group of animals that can convert plant materials indigestible by humans into high-quality animal protein as meat and milk. Many studies using meta-omics technologies have demonstrated the relationships between rumen microbiome and animal phenotypes associated with nutrient metabolism. Recently, the causality and physiological mechanisms underpinning the host-microbiota interactions have attracted tremendous research interest among researchers. This review discusses the host-microbiota interactions and the factors affecting these interactions in ruminants and provides a summary of the advances in research on animal husbandry. Understanding the microbiota composition, the functions of key bacteria, and the host-microbiota interaction is crucial for the development of knowledge-based strategies to enhance animal productivity and host health.

HFOV vs CMV for neonates with moderate-to-severe perinatal onset acute respiratory distress syndrome (NARDS): a propensity score analysis.

This study aimed to evaluate whether high-frequency oscillatory ventilation (HFOV) could reduce mortality and the incidence of bronchopulmonary dysplasia (BPD) of perinatal-onset neonatal acute respiratory distress syndrome (NARDS) compared with conventional mechanical ventilation (CMV). Medical records were collected and retrospectively analyzed. Among the 700 neonates with NARDS who needed invasive ventilation, 501 (71.6%) received CMV, while 199 (28.4%) received HFOV. One-to-one propensity score matching (127:127) was used to match the baseline characteristics of patients who received CMV and HFOV. The results showed that birth weight and oxygenation index (OI) were independently associated with mortality in the multivariate logistic regression. No significant differences were observed in mortality or the incidence of BPD between the two groups. The incidence of intraventricular hemorrhage (IVH) and ventilation-free days were significantly lower in the HFOV group than in the CMV group (3.9 vs 11.80%, p=0.02; 15.226 vs 20.967 days, p=0.01). There were no significant differences between the two groups regarding other secondary outcomes.Conclusion: HFOV was associated with a decreased incidence of IVH in infants with NARDS compared with CMV. However, there were significantly more VFDs in the CMV group than in the HFOV group, and HFOV did not appear to be superior to CMV in decreasing the mortality and incidence of BPD in infants with NARDS. What is Known: • The diagnostic criteria of neonatal acute respiratory distress syndrome (Montreux criteria) were established in 2017. • To date, studies comparing high-frequency oscillatory ventilation and conventional mechanical ventilation in the treatment of neonatal acute respiratory distress syndrome are insufficient. What is New: • High-frequency oscillatory ventilation did not appear to be superior to conventional mechanical ventilation in decreasing the mortality and incidence of bronchopulmonary dysplasia in infants with moderate-to-severe perinatal-onset neonatal acute respiratory distress syndrome. • High-frequency oscillatory ventilation was associated with a decreased incidence of intraventricular hemorrhage in infants with moderate-to-severe perinatal-onset acute respiratory distress syndrome compared with conventional mechanical ventilation.

Effects of Sugar Cane Molasses Addition on the Fermentation Quality, Microbial Community, and Tastes of Alfalfa Silage.

The objective was to study the effects of sugar cane molasses addition on the fermentation quality and tastes of alfalfa silage. Fresh alfalfa was ensiled with no additive (Control), 1% molasses (M1), 2% molasses (M2), and 3% molasses (M3) for 206 days. The chemical composition and fermentation characteristics of the alfalfa silages were determined, the microbial communities were described by 16S rRNA sequencing, and the tastes were evaluated using an electronic tongue sensing system. With the amount of added molasses (M), most nutrition (dry matter and crude protein) was preserved and water-soluble carbohydrates (WSC) were sufficiently used to promote the fermentation, resulting in a pH reduction from 5.16 to 4.48. The lactic acid (LA) content and LA/acetic acid (AA) significantly increased, indicating that the fermentation had turned to homofermentation. After ensiling, Enterococcus and Lactobacillus were the dominant genus in all treatments and the undesirable microbes were inhibited, resulting in lower propionic acid (PA), butyric acid (BA), and NH3-N production. In addition, bitterness, astringency, and sourness reflected tastes of alfalfa silage, while umami and sourness changed with the amount of added molasses. Therefore, molasses additive had improved the fermentation quality and tastes of alfalfa silage, and the M3 group obtained the ideal pH value (below 4.5) and the best condition for long-term preservation.

The effect of different sowing dates on dry matter and nitrogen dynamics for winter wheat: an experimental simulation study.

BACKGROUND: Timely sowing is an important agronomic measure to ensure the normal germination, stable seedling establishment, and yield formation for winter wheat (Triticum aestivum L.). Delayed sowing frequently occurs in the current multi-cropping system and mechanized production of this crop. However, the ways in which different sowing dates affect yield and its potential mechanism is still unknown in the middle-lower Yangtze River Basin. We sought to provide a theoretical basis for these mechanisms to improve regional wheat production. METHODS: We investigated the wheat's yield differences in a two-year field study under different sowing dates and took into account related growth characteristics including meteorological conditions, growth period, tillers, dry matter accumulation (DMA), and nitrogen accumulation (NA). We used the logistic curve model to simulate DMA and NA dynamics of single stem wheat under different sowing dates. We then analyzed and compared wheat accumulation for different sowing dates. RESULTS: Our results showed that grain yield declined by 0.97 ± 0.22% with each one-day change (either early or delayed) in sowing beyond the normal sowing date. The yield loss could be explained by the inhibition of crop growth, yield components, biomass and nitrogen (N) production. The negative effects of delayed sowing were caused by environmental limitations including adverse weather factors such as low temperature during vegetative growth, shortened duration of various phases of crop development, and increased temperature during the grain-filling period. The grain yield gap decreased between the late and normal sowing periods owing to a compensatory effect between the highest average rates (Vt ) and the rapid accumulation period (T) of DMA and NA for single stem wheat. The grain yield was maintained at 6,000 kg ha-1 or more when the ratio of DMA at the mature-to-jointing stage (MD/JD) and the ratio of NA at the mature-to-jointing stage (MN/JN) was 4.06 (P < 0.01) and 2.49 (P < 0.05), respectively. The compensatory effect did not prevent the impact caused by delayed sowing, which caused biomass and N production to decrease. Physiological development reached a maximal accumulation rate (Tm ) of NA earlier than DMA.

DHA content in milk and biohydrogenation pathway in rumen: a review.

Docosahexaenoic acid (DHA) is an essential human nutrient that may promote neural health and development. DHA occurs naturally in milk in concentrations that are influenced by many factors, including the dietary intake of the cow and the rumen microbiome. We reviewed the literature of milk DHA content and the biohydrogenation pathway in rumen of dairy cows aim to enhance the DHA content. DHA in milk is mainly derived from two sources: α-linolenic acid (ALA) occurring in the liver and consumed as part of the diet, and overall dietary intake. Rumen biohydrogenation, the lymphatic system, and blood circulation influence the movement of dietary intake of DHA into the milk supply. Rumen biohydrogenation reduces DHA in ruminal environmental and limits DHA incorporation into milk. The fat-1 gene may increase DHA uptake into the body but this lacks experimental confirmation. Additional studies are needed to define the mechanisms by which different dietary sources of DHA are associated with variations of DHA in milk, the pathway of DHA biohydrogenation in the rumen, and the function of the fat-1 gene on DHA supply in dairy cows.

Clinical significance of positive fecal occult blood test in neonates.

The fecal occult blood test (FOBT) is a screening tool for hematochezia. This study aims to summarize the clinical features associated with a positive FOBT in neonates and to explore some clues for the underlying causes. Combination with other clinical information, identifying the possible etiology is more likely and could be useful for choosing an effective therapeutic strategy. The medical records of 282 neonates with positive FOBTs from January 1 to July 31, 2016, were collected and retrospectively analyzed. The total incidence rate of FOBT positivity in neonates was 6.2%. Among these patients, 71 (25.2%) neonates had false-positive FOBTs, whereas 211 (74.8%) neonates had intraintestinal sources of hematochezia. Necrotizing enterocolitis (NEC, 20.9%), structural abnormalities of gastrointestinal tract (SAGT, 12.4%), and suspected food allergy (sFA, 10.6%) were the most common causes of neonatal hematochezia. It indicated that FOBT-positive neonates with NEC were more likely to suffer due to a younger gestational age, lower birth weight, and lower weight on admission than the neonates with other conditions. The proportions of neonates with bloody stool (90.0%) and diarrhea (63.3%) in the sFA group were markedly higher than those in the other groups. However, in the SAGT group, emesis (94.3%) and abdominal distension (80.0%) were evidently higher, usually accompanied by a relatively poor response (60.0%) and weakened bowel sounds (48.6%). Furthermore, the higher incidences of poor response (72.1%), abdominal distension (71.2%), bloody stools (64.4%), and weakened bowel sounds (62.7%) were observed in the NEC group. Due to the complicated etiology associated with a positive FOBT, the analyzed indexes were combined with other clinical features to identify the likely causes of neonatal hematochezia. Because NEC, sFA and SAGT show similar clinical manifestations and can occasionally transform into each other, close and frequent observation is crucial for timely intervention to achieve a better prognosis. Although it failed to provide an early warning of severe disease through FOBT, and the early intervention for FOBT might not decrease NEC, sFA, structural bowel injuries, or any other complications, newborn FOBT positive reminds medical staff to be alert to the related diseases including NEC, SAGT and sFA, by closer observation and follow-up.

Bacterial Community Diversity Associated With Different Utilization Efficiencies of Nitrogen in the Gastrointestinal Tract of Goats.

The objective of this study was to examine the association between bacterial community structure and the utilization efficiency of nitrogen (UEN) phenotypes by determining the bacterial community in the gastrointestinal tract (GIT) of goats that differ in UEN using high-throughput 16S rRNA gene sequencing. Thirty Nubian goats were selected as experimental animals, and their UEN was determined in a metabolic experiment. Subsequently, eight individuals were grouped into the high nitrogen utilization (HNU) phenotype, and seven were grouped into the low nitrogen utilization (LNU) phenotype. The bacterial 16S rRNA gene amplicons from the rumen, abomasum, jejunum, cecum and colon contents of these animals were sequenced using next-generation high-throughput sequencing technology. Two hundred thirty-nine genera belonging to 23 phyla in the rumen, 319 genera belonging to 30 phyla in the abomasum, 248 genera belonging to 36 phyla in the jejunum, 248 genera belonging to 25 phyla in the colon and 246 genera belonging to 23 phyla in the cecum were detected, with Bacteroidetes and Firmicutes predominating. In addition, a significant correlation was observed between the UEN and the genera Succiniclasticum, Bacteroides, Ruminobacter, Methanimicrococcus, Mogibacterium, Eubacterium_hallii_group and Ruminococcus_1 in the rumen; Bacteroidales_S24-7_group, Bacteroidales_RF16_group, Bacteroidales_UCG-001 and Anaerovibrio in the abomasum; Ruminococcus_2, Candidatus_Saccharimonas, Candidatus_Arthromitus and Coprococcus_1 in the jejunum; Erysipelotrichaceae_UCG-004, Akkermansia, Senegalimassilia, Candidatus_Soleaferrea and Methanocorpusculum in the colon; and Ruminococcaceae_UCG-002, Anaerovibrio and Ruminococcaceae_UCG-007 in the cecum. Furthermore, the real-time PCR results showed that the ruminal copies of Fibrobacter_succinogenes, Butyrivibrio_fibrisolvens, Ruminococcus_sp._HUN007, Prevotella ruminicola and Streptococcus bovis in the HNU animals were significantly higher than those in the LNU animals. This study suggests an association of GIT microbial communities as a factor that influences UEN in goats.

Relationship between the structure and composition of rumen microorganisms and the digestibility of neutral detergent fibre in goats.

OBJECTIVE: This experiment was conducted to compare the structure and composition of ruminal microorganisms in goats with high and low neutral detergent fibre (NDF) digestibility. METHODS: Nineteen crossbred goats were used as experimental animals and fed the same total mixed rations during the 30-day pre-treatment and 6-day digestion trialperiods. All faeces were collected during the digestion period for measuring the NDF digestibility. Then, high and the low NDF digestibility individuals were chosen for the high NDF digestibility group (HFD) and low NDF digestibility group (LFD), respectively. Rumen contents were collected for total microbial DNA extraction. The V4 region of the bacterial 16S rRNA gene was amplified using universal primers of bacteria and sequenced using high-throughput sequencer. The sequences were mainly analysed by QIIME 1.8.0. RESULTS: A total of 18,694 operational taxonomic units were obtained, within 81.98% belonged to bacteria, 6.64% belonged to archaea and 11.38% was unassigned microorganisms. Bacteroidetes, Firmicutes, and Proteobacteria were the predominant microbial phyla in both groups. At the genus level, the relative abundance of fifteen microorganisms were significantly higher (p<0.05) and six microorganisms were extremely significantly higher (p<0.01) in LFD than HFD. Overall, 176 core shared genera were identified in the two groups. The relative abundance of 2 phyla, 5 classes, 10 orders, 13 families and 15 genera had a negative correlation with NDF digestibility, but only the relative abundance of Pyramidobacter had a positive correlation with NDF digestibility. CONCLUSION: There were substantial differences in NDF digestibility among the individual goats, and the NDF digestibility had significant correlation with the relative abundance of some ruminal microorganisms.

The impact of diet on the composition and relative abundance of rumen microbes in goat.

OBJECTIVE: This experiment was conducted to explore the impact of diet on the ruminal microbial community in goats. METHODS: Twelve goats were divided into two groups and fed complete feed (CF) or all forage (AF) diet. The total microbial DNAs in the rumen liquid were extracted. The V4 region of microbial 16S rRNA genes was amplified and sequenced using high-throughput. Information of sequences was mainly analyzed by QIIME 1.8.0. RESULTS: The results showed that Bacteroidetes and Firmicutes were the most predominant microbial phyla in the rumen of all goats. At genus level, the abundance of fiber-digesting bacteria such as Ruminococcus and Lachnospiracea incertae sedis was significantly higher in AF than that in CF, while the levels of fat-degrading bacterium Anaerovibrio and protein-degrading bacterium Pseudomonas were opposite. The core shared genera, Prevotella and Butyrivibrio were widespread in the rumen of goats and no significant difference was observed in relative abundance between groups. CONCLUSION: We concluded that the richness of fiber-, protein-, and fat-digesting bacteria was affected by diet and tended to increase with the rise of their corresponding substrate contents in the ration; some bacteria shared by all goats maintained stable despite the difference in the ration, and they might be essential in maintaining the normal function of rumen.