Cow Feces Research Articles

Temporal Changes in Faecal Microbiota Composition and Diversity in Dairy Cows Supplemented with a Lactobacillus-Based Direct-Fed Microbial

The rumen microbiota of dairy cows plays a crucial role in fermenting fibrous material, essential for nutrient extraction and overall productivity, detoxification of anti-nutritional toxic compounds, synthesis of vital nutrients, and is essential for optimal animal health. This study investigated the impact of Lentilactobacillus-, Lactocaseibacillus-, and Lacticaseibacillus-based direct-fed microbial (DFM) supplementation on dairy cows’ faecal microbial composition and diversity. The study was carried out on a commercial dairy farm using 50 Holstein-Friesian cows randomly assigned into control (CON) and treatment (TRT) groups. Faecal samples were collected directly from the rectum every two months from September 2021 to January 2023. The bacterial 16S rRNA gene and fungal ITS-1 regions were amplified, sequenced, and analysed. Microbial diversity was assessed through alpha- and beta-diversity metrics. Linear discriminant analysis effect size (LEfSe) was performed to identify which taxa were driving the changes seen in the microbiota over time and treatment. Bacteroidaceae were the most prevalent bacterial family, followed by Lachnospiraceae and Muribaculaceae in both CON and TRT cows. Ascomycota, Basidiomycota, and Mucoromycota were the dominant three fungal phyla in the faeces of both CON and TRT cows. Bacterial genera Fructilactobacillus was abundant in the CON and Absicoccus in the TRT groups. Fungal taxa Chaetothryriales_incertae_sedis and Pseudomentella were absent in the faeces of TRT cows. Significant temporal and specific taxonomic differences were observed between the CON and TRT groups. The study’s findings underscore the dynamic nature of microbial communities and the importance of targeted dietary interventions. Further research is necessary to elucidate these microbial shifts, long-term impacts, and functional implications, aiming to optimise ruminant nutrition and enhance dairy cow performance.

Assessing the Risk of Spreading Clostridioides difficile and Its Toxins Within the Dairy Farm.

Clostridioides difficile currently constitutes a major pathogen of the gastrointestinal tract, which poses a significant growing burden on medicine and veterinary medicine in many regions. A farm was assessed (feed table, silage pit, and feces (healthy animals, emaciated animals, and animals with mastitis)) for the presence of C. difficile toxins using the PCR method and for the microbiome in cow feed and feces using NGS technology, one month apart. C. difficile toxin A and binary toxin were detected in feed samples. C. difficile toxin genes were found in the feces of sick animals two to three times more often than in healthy animals. Analysis of the microbial community of cow feces revealed that, during the month, the animals experienced major changes in the community structure associated with the accumulation of pathogenic bacteria, in particular Paeniclostridium sp., as well as with the development of methanogenic archaea of the Methanobacteriaceae and associated microorganisms (Lachnospiraceae and Anaerovoracaceae), which may speak of a decrease in feed efficiency and, subsequently, animal productivity. Thus, it seems likely that C. difficile enters the gastrointestinal tract of animals through feed, while animals weakened by diseases are more sensitive to the reproduction of pathogens in the GIT due to a weakened organism.

Maternal gastrointestinal microbiome shapes gut microbial function and resistome of newborns in a cow-to-calf model

BackgroundThe maternal gut microbiome is the direct and important source of early colonization and development of the neonatal gut microbiome. However, differences in unique and shared features between mothers with different physiological phenotypes and their newborns still lack exhaustive investigation. Here, using a cow-to-calf model, a comprehensive investigation was conducted to elucidate the pattern and characterization of microbial transfer from the maternal source to the offspring.ResultsThe microbiota in the rumen and feces of dairy cows were divided into two clusters via enterotype analysis. The cows from the enterotype distinguished by Prevotella in the rumen had better production performance, whereas no difference was observed in the cows classified by feces enterotype. Furthermore, through a pairwise combination of fecal and ruminal enterotypes, we screened a group of dairy cows with excellent phenotypes. The gastrointestinal microbiomes of cows with different phenotypes and their offspring differed significantly. The rumen was a more important microbial source for meconium than feces. Transmission of beneficial bacteria from mother to offspring was observed. Additionally, the meconium inherits advantageous metabolic functions of the rumen. The resistome features of the rumen, feces, and meconium were consistent, and resistome abundance from cows to calves showed an expanding trend. The interaction between antibiotic-resistance genes and mobile genetic elements from the rumen to meconium was the most remarkable. The diversity of core metabolites from cows to calves was stable and not affected by differences in phenotypes. However, the abundance of specific metabolites varied greatly.ConclusionsOur study demonstrates the microbial taxa, metabolic function, and resistome characteristics of maternal and neonatal microbiomes, and reveals the potential vertical transmission of the microbiome from a cow-to-calf model. These findings provide new insights into the transgenerational transmission pattern of the microbiome.2cueHjjtpyRzwmAWUdZ5oAVideo

Utilisation of Cow Faeces as a Base Material to Making Bokashi Fertiliser to Increase Farmers Income in Balai Hamlet, Taram Village, Harau District

The application of technology in agriculture aims to increase food production through the substitution of traditional farming systems with modern farming systems by utilising more advanced technology. This has an impact on the use of chemical fertilisers and pesticides, which can cause environmental damage and ultimately reduce agricultural productivity. Processing cow dung into organic fertiliser for crops is an applied technology in the framework of implementing zero waste farming technology. One of the benefits that can be obtained is increased income by reducing the cost of artificial fertiliser needs. Cow faeces as cattle farming waste has not been optimally utilised. Cow faeces are usually piled up by farmers behind or near the cowshed, causing a strong smell (air pollution). The results of the activity of making cow feces bokashi organic fertiliser are very beneficial for farmers as a substitute for inorganic fertiliser; The creation of clean cowshed conditions, and environmentally friendly rice fields.

Fermented total mixed ration enhances nutrient digestibility and modulates the milk components and fecal microbial community in lactating Holstein dairy cows.

Fermented total mixed ration (FTMR) is an effective method of preserving high-moisture byproducts with higher aerobic stability after fermentation. FTMR has the potential to fulfill the daily nutritional requirements of cattle and enhance their production performance. The objective of this research was to examine the influence of FTMR on lactation performance, total tract apparent digestibility, fecal microbiota communities, and fermentation profiles in lactating dairy cows. A total of 12 cows were randomly assigned into two groups: the TMR group and the FTMR group. The TMR group was fed a total mixed ration (TMR) diet, and the FTMR group was fed an FTMR diet. The FTMR did not impact milk yield in dairy cows despite a decrease in dry matter intake, which increased the efficiency of the feed. In contrast to that in the TMR group, the milk fat content in the FTMR group was greater. The FTMR group showed greater digestibility of neutral detergent fiber (NDF), organic matter (OM), dry matter (DM), crude protein (CP), and acid detergent fiber (ADF) in the total digestive tract than did the TMR group. The FTMR increased the concentration of butyrate in the fecal matter and reduced the pH of the feces. The Chao1, ACE, and Shannon indices of the archaeal community in dairy cow feces were significantly higher in cow fed the FTMR compared to those fed the TMR. LefSe analysis revealed higher levels of Oscillospira, Lactobacillus, Prevotella, and Dehalobacterium in the feces of dairy cows fed the FTMR than in those fed the TMR. However, the abundances of Roseburia, rc4-4, Bulleidia and Sharpea exhibited the opposite trend. The abundances of Halobacteria, Halobacteriales, and Halobacteriaceae, which are biomarkers for distinguishing fecal archaea in the TMR from the FTMR, were substantially greater in the feces of dairy cows that consumed the TMR than in those that consumed the FTMR. Therefore, FTMR can improve the milk fat content, total tract apparent feed digestibility efficiency, and diversity of archaea in the feces. Additionally, this work provides a theoretical basis for the feasibility of FTMR feeding for dairy cows.

First Report on the Occurrence and Antibiotic Resistance Profile of Colistin-Resistant Escherichia coli in Raw Beef and Cow Feces in Vietnam.

Colistin-resistant Escherichia coli (COE) has been recently recognized as a serious threat to animal and human health. This study aimed to determine the prevalence and antibiotic resistance profile of COE isolated from raw beef and cow feces in Vietnam. Our results showed that 16% (16/100) and 32% (32/100) of raw beef and cow feces samples were positive for COE, respectively. A total of 48 COE strains were isolated, with 16 originating from raw beef and 32 from cow feces samples. The antibiotic susceptibility test revealed that the COE isolates were highly resistant to ampicillin, tetracycline, florfenicol, trimethoprim/sulfamethoxazole, streptomycin, and nalidixic acid, with resistance rates ranging from 66.67% to 87.5%. In addition, 87.5% of the isolates were identified to be multidrug-resistant strains. Further molecular characterization indicated that all COE isolates carried the mcr-1 gene, with 16 of them also harboring blaCTX-M-55 genes. Taken together, the findings in this study demonstrate that raw beef and cow feces are important sources of COE, which can be potentially transmitted to humans through the food chain.

Gas Concentration Measuring-System (CH4, NH3, CO2) Upon Cow Feces in an Encased-Space Based on Arduino Uno

The goal of this exploration is to fabricate an estimating instrument for perceiving Methane, Smelling salts, and Carbon Dioxide gas concentrations in cow feces within a confined space. The feasibility of gas concentration detection devices using MQ-2 sensors, MQ-4 sensors, and Arduino Uno-based MQ-135 sensors will also be tested. This research relates to physics, particularly instrument physics. The research will employ hardware design, software design, and testing methodologies. The gas used for testing was produced from 500 grams of cow feces through three treatments: no treatment, addition of 50 grams of activated charcoal, and addition of 50 milliliters of EM4. The tool validation test was conducted by three experts, and the typical worth acquired was 95.8%, classified as entirely achievable. The experiment yielded the highest concentrations of CH4, NH3, and CO2 gases at 11:30 AM (plus EM4), 03:00 AM (plus EM4), and 24:00 AM (without treatment), respectively, with readings of 9.49 ppm, 26.89 ppm, and 4.57 ppm.

TOTAL BAKTERI DAN KOLIFORM PADA MEDIA PERTUMBUHAN MAGGOT Black Soldier Fly KOMBINASI FESES SAPI PERAH, ENDAPAN SUSU DAN SAMPAH ORGANIK DAPUR

Livestock industry waste and kitchen waste contain high levels of organic matter and are dangerous if not managed properly. To overcome this problem, bioconversion can be carried out using BSF maggot. This research aims to determine whether the growth media after being degraded by BSF maggots still contains bacteria and coliform that meet the requirements for solid organic fertilizer Kepmentan No. 261 Tahun 2019. The research was carried out experimentally with 4 treatments and 5 repetitions. Treatment consists of P0 = 100% organic kitchen waste, P1 = 50% dairy cow feces and 50% organic kitchen waste, P2 = 50% milk sludge and 50% organic kitchen waste, P3 = 33,33% dairy cow feces, milk sludge 33,33% and kitchen organic waste 33,33%. The data was analyzed using a paired t-test. The results for total bacteria and coliform before and after degradation of BSF maggot experienced a significant decrease (P<0,05) and fulfilled the requirements for Escherichia coli in the coliform group with a total of <102 MPN/g in the BSF maggot growth media.

Application of an electronic nose for the diagnosis of ketosis in dairy cows

Ketosis in dairy cows is a nutritional and metabolic disease that severely affects the milk industry and dairy cow health. An electronic nose can identify volatile organic compounds (VOCs). This study applied the electronic nose to detect VOCs in dairy cow milk, feces, and blood. Blood ketone bodies (BHBA) were measured, and 10 ketosis cows, 71 subclinical ketosis cows, and 75 healthy cows were considered the research subjects. Cow milk, feces, and blood samples were collected for electronic nose testing. The measured VOC data were processed through multivariate analysis and machine learning algorithms. The electronic nose analysis results were validated through the GC-MS analysis of the milk samples. The results unveiled spatial differences in the electronic nose VOC values of milk, feces, and blood, and the cumulative contribution rates of both principal component variables (PC) 1 and PC2 reached more than 95%. The machine learning algorithm results revealed that the accuracy of the milk probabilistic neural network (PNN) was 87.5%, the stool support vector machine was 100%, and the blood PNN was 66.7%. This result revealed that electronic nose detection can effectively differentiate healthy, subclinical ketosis, and clinical ketosis cows. According to the milk GC-MS results, significant differences were noted in the VOC content of milk samples between the different groups.The aforementioned studies revealed that electronic nose can aid in the effective prediction and diagnosis of ketosis in dairy cows. This lays the foundation for establishing a new method for diagnosing ketosis in dairy cows.

Multidrug-resistance and extended-spectrum beta-lactamase-producing lactose-fermenting enterobacteriaceae in the human-dairy interface in northwest Ethiopia.

Antimicrobial resistance (AMR) is among the top public health concerns in the globe. Estimating the prevalence of multidrug resistance (MDR), MDR index (MDR-I) and extended-spectrum beta-lactamase (ESBL)-producing lactose fermenting Enterobacteriaceae (LFE) is important in designing strategies to combat AMR. Thus, this study was designed to determine the status of MDR, MDR-I and ESBL-producing LFE isolated from the human-dairy interface in the northwestern part of Ethiopia, where such information is lacking. A cross-sectional study was conducted from June 2022 to August 2023 by analyzing 362 samples consisting of raw pooled milk (58), milk container swabs (58), milker's hand swabs (58), farm sewage (57), milker's stool (47), and cow's feces (84). The samples were analyzed using standard bacteriological methods. The antimicrobial susceptibility patterns and ESBL production ability of the LFE isolates were screened using the Kirby-Bauer disk diffusion method, and candidate isolates passing the screening criteria were phenotypically confirmed by using cefotaxime (30 μg) and cefotaxime /clavulanic acid (30 μg/10 μg) combined-disk diffusion test. The isolates were further characterized genotypically using multiplex polymerase chain reaction targeting the three ESBL-encoding- genes namely blaTEM, blaSHV, and blaCTX-M. A total of 375 bacterial isolates were identified and the proportion of MDR and ESBL-producing bacterial isolates were 70.7 and 21.3%, respectively. The MDR-I varied from 0.0 to 0.81 with an average of 0.30. The ESBL production was detected in all sample types. Genotypically, the majority of the isolates (97.5%), which were positive on the phenotypic test, were carrying one or more of the three genes. A high proportion of the bacterial isolates were MDR; had high MDR-I and were positive for ESBL production. The findings provide evidence that the human-dairy interface is one of the important reservoirs of AMR traits. Therefore, the implementation of AMR mitigation strategies is highly needed in the area.

Potential of Methane (CH4), Nitrogen (N2), and Carbon Dioxide (CO2) from Eco-Enzyme with the Addition of Cow Feces Starter

Eco-enzyme solutions are generally used in the manufacture of disinfectants, floor cleaners, liquid fertilizers, preservatives and others. In this study, eco-enzyme was used as the main ingredient in the manufacture of biogas fermentation with the addition of cow feces as an additional starter in the fermentation. The aim of this study was to determine the content of CH4, CO2, N2, pH, temperature, and pressure in eco-enzyme fermentation with the addition of cow feces starter. his research is a quantitative research with the type of experimental research as well as direct observation data collection techniques and data analysis techniques using descriptive statistical analysis. The results showed that the treatment that produced the highest methane (CH4) gas was the P5 treatment with a concentration of 2.889%. 6,1. The highest volume pressure value was produced in the P5 treatment which was 70 ml. Nitrogen gas (N2) and carbon dioxide gas (CO2), the concentration of nitrogen gas (N2) from reactor P0 - P4 is in the range of 95.875-99.669 % and the concentration of carbon dioxide (CO2) from reactor P0 - P4 is in the range of 0.237 - 4.125 %.

Optimization of Biohydrogen Production from Vinasse and Cow Manure Using the Response Surface Method (RSM)

The problem of greenhouse gas emissions and the energy crisis experienced by countries in the world, including Indonesia, makes it necessary to develop alternative energy. Biohydrogen from biomass waste can be the best alternative to overcome this problem because it is a clean energy and is capable of producing high energy. This research was carried out with the aim of analyzing the increase in biohydrogen production using the anaerobic fermentation method with a nanomaterial catalyst. The test material in this study was a volatile solid which was analyzed using the gravimetric method. The experimental design used to determine optimum conditions is the Response Surface Method (RSM). The variable used in this research is the ratio between the cow manure and vinasse raw material with variations of 1:1, 1:2, and 1:3. The other variables used are pH with variations of 6.7 and 8. Based on the test results, it is known that the optimum conditions for the variable ratio of cow feces to banana peel waste and pH are 1:3 (the variable ratio of cow feces to banana peel waste) and variations pH 6 (variable pH) with a total volatile solid of 100 mg/L. The addition of nickel-based nanomaterial also has a significant effect on the volatile solid content, where the volatile solid content without the addition of nanomaterial is 42.62 g/L, while with the addition of the volatile solid nanomaterial produced is 100.92 g/L.

Aplikasi Tepung Biji Pepaya sebagai Alternatif Obat Herbal dalam Pengendalian Penyakit Cacingan pada Sapi Potong

This research aims to analyze the potential of Papaya Seed Flour as an Alternative to Herbal Deworming Medicine in Controlling Worm Disease in Beef Cattle. The research was carried out in Paseh District, Sumedang Regency in January 2024. This research was carried out experimentally. The sampling technique was carried out using purposive random sampling. This research used bulls, aged around 1-1.5 years. This research uses a Pre-test Post-test Control Group Design. The research sample consisted of 10 penned bulls. Before the cow is given treatment in the form of giving the herbal medicine papaya seed flour (Pre-treatment), the cow's feces are taken to be identified and the number of worm eggs infecting the digestive tract is counted. The treatment given is in the form of administering herbal medicine from papaya seed flour (TBP) at a dose of 5g/head, for 3 consecutive days within a period of one week, then testing feces samples (post-treatment) to test the effectiveness of the herbal medicine in reducing levels of and the number of infecting worms. The test parameters in this study were the number of EPGs before and after administration of TBP and FECR until seven days after treatment ended. The research results showed that Papaya Seed Flour has the potential to be an alternative herbal worm medicine in suppressing the growth of digestive tract worms in cattle significantly (p<0.05) with an FECR value reaching 76.9%.

Dietary phytosterols improves the metabolic status of perinatal cows as evidenced by plasma metabolomics and faecal microbial metabolism.

Previous research reported that dietary addition with phytosterols improved the energy utilisation of the rumen microbiome, suggesting its potential to alleviate the negative energy balance of perinatal cows. This experiment aimed to explore the effects of feeding phytosterols on the metabolic status of perinatal cows through plasma metabolomics and faecal bacteria metabolism. Ten perinatal Holstein cows (multiparous, 2 parities) with a similar calving date were selected four weeks before calving. After 7 days for adaptation, cows were allocated to two groups (n = 5), which respectively received the basal rations supplementing commercial phytosterols at 0 and 200 mg/d during a 42-day experiment. The milk yield of each cow was recorded daily after calving. On days 1 and 42, blood and faeces samples were all collected from perinatal cows before morning feeding for analysing plasma biochemicals and metabolome, and faecal bacteria metabolism. Dietary addition with phytosterols at 200 mg/d had no effects on plasma cholesterol and numerically increased milk yield by 1.82 kg/d (p>0.10) but attenuated their negative energy balance in perinatal cows as observed from the significantly decreased plasma level of β-hydroxybutyric acid (p = 0.002). Dietary addition with phytosterols significantly altered 12 and 15 metabolites (p<0.05) within the plasma and faeces of perinatal cows, respectively. Of these metabolites, 5 upregulated plasma fatty acids indicated an improved energy status (i.e., C18:1T, C14:0, C17:0, C18:0, and C16:0). Milk yield negatively correlated with plasma concentrations of ketone bodies (p = 0.035) and 5-methoxytryptamine (p = 0.039). Furthermore, dietary addition with phytosterols at 200 mg/d had no effects on fermentation characteristics and bacterial diversity of cow faeces (p>0.10) but improved potentially beneficial bacteria such as Christensenellaceae family (p<0.05) that positively correlated with feed efficiency. Dietary addition with phytosterols at 200 mg/d could effectively improve the energy status in perinatal cows by attenuating their negative energy balance.

DETECTION OF CRYPTOSPORIDIUM SPECIES IN CATTLE AND HANDLERS BY MOLECULAR TECHNIQUE IN WASIT PROVINCE

I collected 300 cow feces samples (130 males - 170 females) and used molecular analysis to detect the parasite. The results showed significant differences (p ≤ 0.05) between the infection rate using particle technology of 38% (38/100) and 41% (41/100) in cows and breeders, respectively, while traditional microscopic methods showed 21% (21/100) and 17% (17/100) in cows and breeders, respectively. DNA sequence analyzes of 10 isolates from infected cows identified four species of the Cryptosporidium parasite genus which included: C. parvum (6/10), C. andersoni (2/10), C. bovis (1/10) and C. ryanae (1/10. The species C. andersoni, C. parvum, C. bovis and C. ryanae have been genetically confirmed through DNA sequence analysis, and it is considered the first recording of these species in local cattle in Iraq. In breeders, three types of the Cryptosporidium parasite were recorded through DNA sequence analysis in 10 isolates from infected individuals, which included: C. parvum (2/10), C. andersoni (5/10) and C. hominis (3/10). It is considered the first recording of this species among breeders in Iraq.

Comparison of the gastrointestinal bacterial microbiota between dairy cows with and without mastitis.

Mastitis causes significant losses in the global dairy industry, and the health of animals has been linked to their intestinal microbiota. To better understand the relationship between gastrointestinal microbiota and mastitis in dairy cows, we collected blood, rumen fluid, and fecal samples from 23 dairy cows, including 13 cows with mastitis and 10 healthy cows. Using ELISA kit and high-throughput sequencing, we found that cows with mastitis had higher concentrations of TNF-α, IL-1, and LPS than healthy cows (p < 0.05), but no significant differences in microbiota abundance or diversity (p > 0.05). Principal coordinate analysis (PCOA) revealed significant differences in rumen microbial structure between the two groups (p < 0.05), with Moryella as the signature for rumen in cows with mastitis. In contrast, fecal microbial structure showed no significant differences (p > 0.05), with Aeriscardovia, Lactococcus, and Bacillus as the signature for feces in healthy cows. Furthermore, the results showed distinct microbial interaction patterns in the rumen and feces of cows with mastitis compared to healthy cows. Additionally, we observed correlations between the microbiota in both the rumen and feces of cows and blood inflammatory indicators. Our study sheds new light on the prevention of mastitis in dairy cows by highlighting the relationship between gastrointestinal microbiota and mastitis.

Biodiversity and antibiotic resistance profile provide new evidence for a different origin of enterococci in bovine raw milk and feces.

Enterococci are widely distributed in dairy sector. They are commensals of the gastrointestinal tract of animals, thus, via fecal contamination, could reach raw milk and dairy products. The aims of this study were: 1) to investigate the enterococcal diversity in cow feces and milk samples and 2) to evaluate the antibiotic resistance (AR) of dairy-related enterococci and their ability to transfer resistance genes.E. faecalis (59.9%), E. faecium (18.6%) and E. lactis (12.4%) were prevalent in milk, while E. faecium (84.2%) and E. hirae (15.0%) were dominant in bovine feces. RAPD-PCR highlighted a high number of Enterococcus biotypes (45 from milk and 37 from feces) and none of the milk strains exhibited genetic profiles similar to those of feces biotypes.A high percentage of enterococci isolated from milk (71%) were identified as multidrug resistant and resistance against streptomycin and tetracycline were widespread among milk strains while enterococci from feces were commonly resistant to linezolid and quinupristin/dalfopristin. Only E. faecalis strains were able to transfer horizontally the tetM gene to Lb. delbrueckii subsp. lactis. Our results indicated that Enterococcus biotypes from milk and bovine feces belong to different community and the ability of these microorganisms to transfer AR genes is strain-dependent.

Utilization of dried dairy cow feces as biogas substrate and biogas sludge as organic soil conditioner

Utilization of farm waste as an alternative energy source is a form of farm waste management, but field applications are not optimal. The purpose of this study is to find out to what extent the dried dairy cow feces can function as a biogas substrate for an overview of the number of anaerobic bacteria, the volume of bio-gas, and the use of organic carbon-containing biodiesel mud so that it can be used as an organic soil fertilizer. This study uses an experimental research method and looks at the results of an independent T test with two treatments: sundry and dry oven. The tests were done on days 0 (after 4 hours), 7, 14, 21, and 28. The water level, number of bacteria, volume of gas, and pH and organic C content of the biogas sludge were all recorded. The study's findings showed that the number of anaerobic bacteria on days 0 (after 4 hours), 7, 14, 21, and 28 and the amount of biogas on days 14 and 21 did not change whether the samples were dried in the sun or in a furnace. However, on days 7 and 28, the amounts of biogas changed depending on whether the samples were dried in the sun or in a furnace.

Comparison of LC-MS-based methods for the determination of carboxylic acids in animal matrices

Carboxylic acids (CAs) are key players in human and animal metabolism. As they are hardly retained under reversed-phase liquid chromatography (RP-LC) conditions in their native form, derivatization is an option to make them accessible to RP-LC and simultaneously increase their response for mass spectrometric detection. In this work, two RP-LC tandem mass spectrometry-based methods using aniline or 3-nitrophenylhydrazine (3-NPH) as derivatization agents were compared with respect to several factors including completeness of derivatization, apparent recoveries (RAs) in both cow feces and ruminal fluid, and concentrations obtained in feces and ruminal fluid of cows. Anion exchange chromatography coupled to high-resolution mass spectrometry (AIC-HR-MS) served as reference method. Derivatization efficiencies were close to 100% for 3-NPH derivatization but variable (20–100%) and different in solvent solutions and matrix extracts for aniline derivatization. Likewise, average RAs of 13C-labeled short-chain fatty acids as internal standards were around 100% for 3-NPH derivatization but only 45% for aniline derivatization. Quantification of CAs in feces and ruminal fluid of cows initially fed a forage-only diet and then transitioned to a 65% high-grain diet which yielded similar concentrations for 3-NPH derivatization and AIC-HR-MS, but concentrations determined by aniline derivatization were on average five times lower. For these reasons, derivatization with aniline is not recommended for the quantitative analysis of CAs in animal samples.Graphical abstract

In vitro susceptibility testing of phytochemicals from essential oils against Prototheca species.

Phytochemicals isolated from essential oils are effective alternatives for inhibiting microbial pathogens. Bovine protothecal mastitis is the cause of a reduction in milk production and the secretion of thin, watery milk with white flakes. In the present study, we performed in vitro susceptibility testing of the phytochemicals carvacrol, citral, and thymol in Prototheca strains isolated from cases of protothecosis in small animals and cow feces. The susceptibility of the algae to carvacrol, citral, and thymol was assessed using the modified CLSI M27-A3 broth microdilution method. The ranges of the minimum inhibitory concentrations (MIC%) of the phytochemicals in all isolates were 0.03% to 0.125% for carvacrol, 0.03% to 0.25% for citral, and 0.06% to 0.25% for thymol. Based on these results, carvacrol, citral, and thymol appear effective against Prototheca species at the tested concentrations, and may thus be useful for environmental disinfection in barns.