Urea Nitrogen Concentrations Research Articles

RENAL FUNCTION PARAMETERS OF HEALTHY CAPTIVE AND SEMICAPTIVE AMAZONIAN MANATEES (TRICHECHUS INUNGUIS).

Evaluating renal function is essential for managing captive wild animals, particularly threatened species like the Amazonian manatee (Trichechus inunguis) in rehabilitation and prerelease programs. A series of urine diagnostic tests, such as gross appearance, semiquantitative chemical analyses, microscopic review of sediments, and quantitative analyses of urea and creatinine, were performed in 57 free-catch urine samples. On the same occasion, 52 serum samples from the same individuals were analyzed for creatine kinase activity, creatinine, blood urea nitrogen, albumin, sodium, potassium, and chloride concentrations; serum symmetric dimethylarginine (SDMA) was measured for the first time in the species. Females had higher urine creatinine concentration (21.7 ± 11.8 mg/dl) and specific gravity (1.003 ± 0.003 mg/dl) than males (11.9 ± 8.5 mg/dl and 1.001 ± 0.002 mg/dl) (P < 0.01 for both). Males presented higher urine creatinine:urea ratio than females (24.8 ± 29.2 and 20.5 ± 29.2, respectively) (P < 0.05). Urine pH was lower in manatees from the semicaptive area (7.8 ± 0.6) than in manatees under human care (8.5 ± 0.6) (P = 0.02) using the benchtop pH meter but showed no difference between areas in the dipstick reaction (P = 0.71), given its lower sensitivity and narrower range detection. Furthermore, 18 and 75% of urine samples were positive for the presence of blood and/or nitrite, respectively, in the dipstick reaction, possibly because of sample contamination. Significant correlation was observed between serum blood urea nitrogen and urine urea concentrations (P = 0.02), and between serum and urine creatinine concentrations (P = 0.01). Serum SDMA did not differ between sex or between captive and semicaptive individuals. However, it positively correlated with urine (P = 0.02) and serum creatinine (P = 0.01) demonstrating its potential as a bioindicator of kidney function. The renal function of Amazonian manatees can be effectively assessed by urinalysis, especially when combined with serum biochemistry.

Serum symmetric dimethylarginine concentrations in enalapril- or telmisartan-treated dogs with proteinuric chronic kidney disease

IntroductionRenin-angiotensin-aldosterone system inhibition (RAASi) reduces intraglomerular pressure and is a standard therapy for dogs with proteinuric chronic kidney disease (CKD). RAASi can acutely decrease glomerular filtration rate (GFR); however, its effects on the marker of GFR serum symmetric dimethylarginine (SDMA) concentration in dogs have not been specifically evaluated. The objective of this study was to evaluate changes, relative to pretreatment values, in serum SDMA concentrations in dogs with proteinuric CKD receiving RAASi therapy.MethodsThis retrospective study used banked samples from 29 dogs with proteinuric CKD treated with enalapril (0.5 mg/kg PO q12h; n = 16) or telmisartan (1 mg/kg PO q24h; n = 13) alone (n = 22) or in combination with amlodipine if severely hypertensive (n = 7). Serum SDMA, creatinine, and urea nitrogen (SUN) concentrations were measured before and 7 and 30 days after starting RAASi. Percentage and absolute changes in these biomarkers were calculated for each dog and time point. A linear mixed model was used to test whether changes significantly differed from zero (α &amp;lt; 0.05).ResultsOverall, mean ± SEM Day 7 and 30 percentage change in SDMA were − 4.8 ± 3.6% and − 3.2 ± 3.4%, respectively; in creatinine were 7.4 ± 3.3% and 3.0 ± 3.1%, respectively; and in SUN were 22.1 ± 6.8% and 16.7 ± 6.2%, respectively. Mean changes varied according to whether all dogs, those on RAASi alone, or those co-treated with amlodipine were evaluated. In dogs receiving RAASi alone, at day 7, there were significant mean percentual increases in creatinine (9%; p = 0.023) and SUN (23%; p = 0.005), but SDMA was unchanged. In dogs co-treated with amlodipine, a significant absolute decrease in mean SDMA (−2.29 μg/dL; p = 0.026) occurred at days 7 and 30, while mean creatinine was unchanged and mean SUN increased.DiscussionProteinuric dogs receiving RAASi had low-magnitude changes in serum SDMA and creatinine, and moderate-magnitude changes in SUN concentrations. The direction of change in SDMA did not consistently match that of creatinine and SUN.

Protracted maternal malnutrition induces aberrant changes in maternal uterine artery hemodynamics and the metabolic profiles of the dam and neonate

Malnutritional stress during gestation is a well-established driver of metabolic disfunction in offspring. Extended exposure to malnutrition requires metabolic plasticity as the animal shifts toward a catabolic state. In this paper we demonstrate the influence of malnutrition throughout gestation on uterine artery hemodynamics and the metabolism of the dam and neonate. We hypothesized that gestational malnutrition reduces blood flow of the maternal uterine artery and regulates the metabolic profile of the dam and offspring. Further, the combination of these factors consequently influences the concentration of metabolites in the cerebrospinal fluid of the neonate at birth. To test our hypotheses, pregnant cows caring a single female fetus were assigned to treatments by age and body condition score to one of three individually-fed dietary treatments: Underfed, Control, or Overfed throughout gestation. Uterine blood flow was measured via transrectal Doppler ultrasonography in late gestation. Blood samples were collected from dams throughout gestation, and blood and cerebrospinal fluid were collected from neonates at birth to analyze concentration of metabolites. In the current report, we reveal that maternal malnutrition regulates uterine artery hemodynamics and the maternal metabolic profile throughout gestation. This is the first report to demonstrate that maternal undernutrition leads to an increase in the concentration of urea nitrogen in neonates. Finally, a concentration gradient of metabolites from the dam to neonatal cerebrospinal fluid was observed, which may have potential implications for central nervous system development. These findings not only illustrate the complexity of the maternal-to-fetal interaction required to support the growth of the fetus and homeostasis of the dam but also reveals a novel avenue for investigating the influence of protracted maternal malnutrition on metabolic pathway preferences in offspring. Moreover, these findings are of paramount importance in the development of intervention strategies for morbid neonates.

Comparing clinical and biochemical characteristics of febrile seizures in children with and without COVID-19: a retrospective study

BackgroundTransmission of COVID-19 is now normalized. There is an association between it and increased incidence of febrile seizures in children. Exploring whether COVID-19 has a specific effect on the clinical and biochemical features of febrile seizures is critical for the development of clinical treatment and prevention strategies. This study is to compare the differences in clinical features, hematological features, and cerebrospinal fluid characteristics between COVID-19 and non-COVID-19 children with febrile seizures and to provide a new perspective for further exploring the impact of COVID-19 on the nervous system of children.MethodsThis was a retrospective case–control study. The cases included children with COVID-19 and non-COVID-19 febrile seizures admitted to Xiamen Children’s Hospital from December 2022 to December 2023. The age, gender, length of hospital stay, peak body temperature, presence or absence of other viral infections, hematological characteristics, and cerebrospinal fluid characteristics were compared between children with COVID-19 febrile seizures and non-COVID-19 febrile seizures.ResultsA total of 50 COVID-19 children with febrile seizures and 192 non-COVID-19 children with febrile seizures were enrolled in this study. Multivariate analysis showed that age (OR = 0.715, P = 0.031), blood urea nitrogen (OR = 0.454, P = 0.029), platelet count (OR = 0.987, P = 0.009) and magnesium ion concentration (OR = 0.109, P < 0.001) were negatively correlated with COVID-19 febrile seizures. Albumin (OR = 1.840, P < 0.001) was positively correlated. The concentration of potassium ion in cerebrospinal fluid (OR = 0.334, P = 0.012) was negatively correlated with COVID-19 febrile seizures, and the concentration of sodium ion (OR = 4.383, P = 0.022) was positively correlated with COVID-19 febrile seizures.ConclusionThere were differences in age, blood urea nitrogen, platelet count, magnesium ion concentration, albumin, potassium ion concentration in cerebrospinal fluid, and sodium ion concentration in the cerebrospinal fluid between children with COVID-19 febrile seizures and non-COVID-19 febrile seizures. This study may provide valuable insights into the potential mechanisms of COVID-19 damage to the nervous system in children, and the long-term neurological prognosis of these children requires long-term follow-up.

Dietary sanguinarine supplementation improves the growth performance and intestinal immunity of broilers

Dietary sanguinarine (SAN) can enhance the growth performance of poultry and livestock, but the regulatory mechanism of the SAN monomer on intestinal homeostasis and how it promotes growth performance has not yet been clarified. In this study, 200 chickens were divided into four groups and fed different doses of SAN (0, 0.225, 0.75, 2.25mg/kg) for transcriptome and microbiota analysis. The data showed that different doses of SAN supplementation increased the feed conversion rate (FCR) of 22 to 42 d old and 1 to 42 d old broilers (P < 0.01), and 0.225 mg/kg SAN reduced the contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA) and blood urea nitrogen (BUN) in serum (P < 0.01). Dietary SAN increased the villus height and the villus height/crypt depth (V/C) ratio in the ileum (P < 0.01). The levels of tight junction proteins (zonula occludens-1, occludin and claudin-1) were up-regulated in the ileum and cecum (P < 0.01) and the levels of immunoglobulin (Ig) A, IgM, IgG, interleukin (IL)-4, IL-10 and interferon (IFN)-γ were up-regulated in the serum and ileum (P < 0.01). RNA-seq analysis revealed 385 differentially expressed genes (DEGs) (|log2 fold change| ≥ 1, FDR < 0.05) between the SAN group and CON group. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed 15 pathways mostly associated with the immune system. Additionally, the reverse transcription-PCR results showed that the relative mRNA expression of β-defensin and mucin 2 were up-regulated (P < 0.01) and Toll-like receptor (TLR) 2 and TLR 4 mRNA were down-regulated by SAN (P < 0.01), which was consistent with the transcriptomic analysis. Western blot analysis also showed that SAN reduced the expression of inflammatory proteins such as TLR4, nuclear factor-kappa B and IL-1β in the ileum (P < 0.01). In addition, at the genus level, SAN significantly increased the relative abundance of bacteria (Bacteroides, unclassified_f__Lachnospiraceae, Lactobacillus and Romboutsia) involved in acetate and butyrate production in the cecum, which are associated with enhanced intestinal immune function and maintaining intestinal health. In conclusion, SAN ameliorates the growth performance of broilers, enhances intestinal immune function, regulates the structure of microbiota and maintains intestinal health.

Agreement between lacrimal fluid and serum for detecting urea nitrogen and creatinine in dogs.

To determine whether urea nitrogen and creatinine levels differ in lacrimal fluid (LF) and serum (SER) in nonazotemic (control) and azotemic dogs and whether there is an agreement between LF and SER. A prospective observational study was performed at the Auburn University Small Animal Teaching Hospital between May 2023 and March 2024. Forty control and 38 azotemic dogs were enrolled. Twenty microliters of LF per eye was collected with microcapillary tubes, and 3 mL of blood was drawn. Bland-Altman plot and intraclass correlation coefficient (ICC) were used to evaluate the agreement between LF and SER. There was good agreement between LF and SER levels of urea nitrogen in the control group (Bland-Altman plot mean bias of -0.8108 ± 2.407 mg/dL; ICC of 0.874 [95% CI, 0.773 to 0.934]) and the azotemic group (Bland-Altman plot mean bias of -9.681 ± 23.89 mg/dL; ICC of 0.82 [95% CI, 0.658 to 0.906]). There was poor agreement between LF and SER concentrations for creatinine in the control and azotemic groups, with only 26 dogs with creatinine detectable in LF. Lacrimal fluid and SER concentrations of urea nitrogen showed good agreement in both the control and azotemic groups, whereas poor agreement was found for creatinine in both groups. Measurement of urea nitrogen in LF may provide an alternative to blood for diagnosing uremia. However, additional research is necessary before substituting LF for SER.

A diet containing mango peel silage impacts upon feed intake, energy supply and growth performances of male dairy calves

The major challenges for disposal of waste from fruit processing factories are high transportation costs, limited landfill availability and environmental pollution. Therefore, developing efficient waste management techniques to reduce transportation costs and environment pollution is important. In 2021, global mango production was estimated to be at 57 million tons and mango peel (MP) represents 7–24% of the whole fruit weight. MP has been considered for use as ruminant feed in the form of fresh, dried, or silage. Fresh MP was abundant during the mango season and high in fermentable carbohydrate, which can easily breakdown and pollute the environment if a proper waste management method is not implemented. Thus, in this study, fresh MP was ensiled after sun-drying for one day and then fed to male dairy calves as a roughage source to evaluate its effect on feed intake, digestibility, energy balance, BW gain, feed efficiency and blood metabolites. Eight growing crossbred weaned male dairy calves (Holstein Friesians × Zebu) were allocated into two groups [Control (n = 4) and mango peel silage (MPS, n = 4)]. This experiment lasted for 12 weeks and calves were housed in 3.0 × 1.5 meters individual pen with concrete floor. Before feeding times, the weights of feed ingredients were weighed and mixed for 15 min. Calves were then given their respective diets ad libitum twice a day, at 0800 and 1600 h. Daily feed offered and refusals were recorded to determine the daily feed intake. A digestion trial was performed over the last five days of the experiment. BW and measurements were recorded every two weeks to determine the weight gain and body physical changes. Blood was collected at the end of experiment to analyze serum biochemical parameters. Ensiling improved the energy and protein content and decreased fiber content of MP, thereby improving the forage quality. Feeding a diet containing MPS at 30% of DM weight, compared to an isonitrogenous Control diet increased (P < 0.05) feed intake, energy supply and energy balance, changes in body measurements, weight gain, feed efficiency, and glucose concentration, as well as lowered (P < 0.05) the blood urea nitrogen concentration of male dairy calves. Ensiling fresh MP after sun-drying for one day led to stable, high-DM silage. Therefore, ensiling fresh MP could improve the feed supply for ruminant production and be an effective waste management strategy for fruit processing businesses.

Validating urea-nitrogen CARS spectra with collaborative filtering

As someone passionate about improving end stage renal disease (ESRD) treatment, I covered a program that I developed which enhances the success of dialysis. ESRD is a condition where the kidneys lose function, requiring dialysis to remove urea nitrogen from the blood via dialysate fluid. Accurate analysis of dialysate samples is important, as it reveals excretory success, and Coherent Anti-Stokes Raman Spectroscopy (CARS) is ideal for this purpose. CARS measures the molecular composition of a sample by using light interactions to produce a molecule vibrational signal, revealing urea nitrogen concentrations. To ensure the validity of CARS results, as measurements can be inaccurate, I’ve integrated collaborative filtering techniques into a program. These techniques find patterns from user input to identify valid samples. My program has two algorithms: Byzantine Generals and Iyengar, the latter providing more in-depth analysis. Both algorithms compare user input parameters—such as wavelengths, intensities, and concentrations—to a database of lab values from Atonarp's pilot study. The tool interface allows users to input their spectral data, select an algorithm for validation, and get results with comparison graphs. If no data is available, sample data can be copied and pasted. Tested with real-life data from Atonarp, this tool can be used to make the dialysis process safer and more accurate.

Association between serum urea nitrogen levels and prostate-specific antigens (NHANES 2003–2010)

BackgroundIncreasing evidence suggests that serum urea nitrogen may be a risk factor for prostate cancer (PCa) and influence serum prostate-specific antigen (PSA) concentrations, but direct evidence of a relationship between PSA and serum urea nitrogen levels in the general population is still lacking. The aim of this study was to demonstrate the relationship between serum urea nitrogen levels and prostate-specific antigen (PSA) and prostate cancer.MethodsWe conducted a cross-sectional study using the National Health and Nutrition Examination Survey (NHANES, 2003–2010) database. We performed a multifactorial regression analysis of the association between serum urea nitrogen levels and PSA and PCa, followed by subgroup analyses.ResultsA total of 5256 subjects were included in this study, and after adjusting for demographic, biological, and immunologic variables, we found that there was a threshold for blood urea nitrogen concentration below which every 1 ng/mL increase in serum urea nitrogen was associated with a 0.0325 ng/mL increase in PSA concentration (log2 transformed) (95% CI: 0.0064, 0.0586), and the P trend was was less than 0.05 and the difference was statistically significant. Sensitivity analyses using the generalized additive model (GAM) showed a linear relationship between serum urea nitrogen and serum PSA concentrations when blood urea nitrogen concentrations ranged from 0 ng/ml to 6.78 ng/ml.ConclusionSerum urea nitrogen was independently and positively correlated with serum PSA concentration when the concentration of serum urea nitrogen ranged from 0 ng/ml to 6.78 ng/ml.

Influence of different concentrations of milk urea nitrogen on the reproductive performance of Holstein cows.

The purpose of this study was to assess how various MUN levels affected the reproductive performance traits of Iranian Holsteins. The dataset used in this study included reproduction performance records for 16,000 Holstein cows and was gathered by the Animal Breeding Center and Promotion of Animal Products of Iran on 30 large dairy herds during 2018-2021. The MUN concentrations were grouped into four classes: [Formula: see text] mg/dL (MUN1), [Formula: see text] mg/dL (MUN2), [Formula: see text] mg/dL (MUN3), and [Formula: see text] mg/dL (MUN4). The study took into account various reproductive and fertility traits, such as the number of inseminations per conception (NINS), the percentage of pregnant cows till 120 days in milk (PP120), the calving interval (CI), the days open (DO), the days from calving to the first service (DCFS), the first service conception rate (FSCR), and the abortion rate (ABR). The impact of MUN levels on the incidence of abortion and non-pregnancy in dairy cows was investigated using logistic regression models. Also, to evaluate the effect of MUN concentrations on reproduction traits, a generalized linear model was used. The MUN2 group had the greatest odds of non-pregnancy (P < 0.05; OR = 2.81; MUN2 vs. MUN1). Also, the MUN4 group had the greatest odds of abortion (P < 0.01, OR = 3.36; MUN4 vs. MUN1). The MUN2 and MUN4 groups had the greatest (51.91%) and the lowest (34.32%) FSCR, respectively. MUN classes had a significant influence on DO (P < 0.05), and MUN4 had the largest value (145.44 days). The results indicated the negative association between MUN with reproduction and fertility in Iranian Holsteins.

Development of a risk score for predicting one-year mortality in patients with atrial fibrillation using XGBoost-assisted feature selection.

There are no tools specifically designed to assess mortality risk in patients with atrial fibrillation (AF). This study aimed to utilize machine learning methods to identify pertinent variables and develop an easily applicable prognostic score to predict 1-year mortality in AF patients. This study, based on the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database, focused on patients aged 18 years and older with AF. A critical care database from China was the external validation set. The importance of variables from XGBoost guided the development of a logistic model, forming the basis for an AF scoring model. Records of of 26 365 AF patients were obtained from the MIMIC-IV database. The external validation dataset included 231 AF patients. The CRAMB score (Charlson comorbidity index, readmission, age, metastatic solid tumor, and maximum blood urea nitrogen concentration) outperformed the CCI and CHA2DS2-VASc scores, demonstrating superior predictive value for 1-year mortality. In the test set, the area under the receiver operating characteristic (AUC) for the CRAMB score was 0.765 (95% confidence interval [CI], 0.753-0.776), while in the external validation set, it was 0.582 (95% CI, 0.502-0.657). The simplicity of the CRAMB score makes it user-friendly, allowing for coverage of a broader and more heterogeneous AF population.

Effects of Dietary Energy Profiles on Energy Metabolic Partition and Excreta in Songliao Black Pigs Under Different Ambient Temperature.

In order to further reveal the special characteristics of energy metabolism and the characteristics of energy requirements of fattening pigs grown in low-temperature environments, this study used a 2 × 2 × 2 factorial array of treatments, which harnessed two temperatures (low-temperature, LT group: 10 °C; normal-temperature, NT group: 20 °C), two feed energy levels (normal-energy, NE group: 14.02 MJ/kg metabolic energy; high-energy, HE group: 15.14 MJ/kg metabolic energy), and two feed energy sources (LF group: low fat, HF group: high fat). Thirty-two Songliao black fattening pigs with an initial body weight of 85.48 ± 2.31 kg were completely randomized into eight treatment groups, with four replicates in each treatment group and one pig in each replicate. The pigs were placed in a respiratory metabolic chamber for a 6-day trial. There was one pig per respiratory metabolic chamber in a single cage. The results showed that the average daily weight gain in the normal-temperature, high-energy, and high-fat groups was higher than that of the low-temperature, normal-energy, and low-fat groups (p < 0.05). The fat deposition rate, protein oxidation, and fat oxidation of the high-fat group were higher than those of the low-fat group (p < 0.05). The energy digestibility, protein digestibility, and fat digestibility in the high-fat group were higher than those in the normal-energy group (p < 0.05). The fat digestibility and energy deposition rate in the high-fat group were higher than those in the low-fat group (p < 0.05). The respiratory quotient in the high-energy group was lower than that in the normal-energy group (p < 0.05), and the respiratory quotient in the high-fat group was lower than that in the low-fat group (p < 0.05). There was an interaction between temperature and energy sources in terms of the respiratory quotient, fat oxidation, blood urea nitrogen content, and glucose content (p < 0.05). Appropriately increasing the energy level of the diet and improving the energy structure of the feed (increasing the level of fats and oils) will benefit Songliao black fattening pigs by increasing their energy use efficiency and at the same time reducing greenhouse gas CO2 emissions, and these changes are more pronounced in cold environments.

High-intensity interval training attenuates renal injury induced by myocardial ischemia-reperfusion in rats

Background: High-Intensity Interval Training (HIIT) has been recognized as an effective form of short-duration exercise. The purpose of this study was to assess whether HIIT could reduce renal injury induced by myocardial ischemia-reperfusion in rats. Methods: Male Sprague-Dawley rats were randomly assigned to the Sham Group (SHAM), Coronary Artery Occlusion (CAO) group, HIIT group, and Ischemic Precondition (IPC) group. Rats underwent 40 minutes of left anterior descending coronary artery occlusion under anesthesia, followed by 3 hours of reperfusion, to induce myocardial ischemia-reperfusion (MIR). Post-surgery, rats were sacrificed, and their blood, heart, and kidney tissues were examined. The HIIT group underwent 4 weeks of HIIT training before surgery. Results: HIIT intervention significantly reduced renal injury after MIR and the concentrations of Blood Urea Nitrogen (BUN) and Creatinine (CRE) in the serum. Moreover, pro-inflammatory cytokines, including Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-1β), and IL-6, were significantly decreased, while the anti-inflammatory cytokine IL-10 was significantly increased in the serum. Additionally, HIIT intervention suppressed the expression of FoxO1, BAX/Bcl-2 ratio, TNF-α, and Cleaved-caspase-3/caspase-3 ratio in kidney tissues, ultimately reducing renal cell apoptosis. Conclusion: This study is the first to demonstrate that HIIT has effects similar to IPC, significantly reducing renal injury after MIR. HIIT regulates the production of pro-inflammatory and anti-inflammatory cytokines, inhibits renal cell apoptosis, thereby reducing the occurrence of cardio-renal syndrome.

Investigating the chemical composition, digestion and fermentation of Alternanthera sessilis red plant and its effect on the performance of fattening lambs.

The present experiment was conducted to evaluate the nutritional value of red Alternanthera sessilis for fattening lambs when they were replaced with alfalfa forage. Forty growing lambs with an average weight of 21.12kg and an age of 5 months were randomly assigned to four experimental treatments. Growth performance, nutrient digestibility, rumen fermentation parameters, protozoa population, blood parameters, and composition of carcass components were evaluated. The results of this experiment showed that the use of Alternanthera sessilis in the diet significantly reduced feed intake, increased the average daily weight gain, and improved the feed conversion ratio compared to the control treatment (P < 0.05). The digestibility of dry matter and protein was significantly increased (P < 0.05), while the digestibility of neutral detergent fiber, acid detergent fiber, and organic matter showed a numerical increase. Diets containing different levels of the Alternanthera sessilis plant did not affect pH, but the increase in the amount of this plant in the diet led to an increase ammonia nitrogen concentration and rumen protozoa population (P < 0.05). The addition of Alternanthera sessilis to the diet significantly reduced the concentration of blood glucose and cholesterol and increased the concentration of blood urea nitrogen (P < 0.05). Except for the weight of the thigh and neck, the effect of experimental treatments on other carcass components was not significant. Overall, the results of this experiment showed that using the Alternanthera sessilis plant in the rations of fattened lambs as a substitute for alfalfa forage not only had no negative effect on the studied parameters but also improved them in some cases. Therefore, Alternanthera sessilis can be used in rations of fattened lambs as a substitute for part of alfalfa forage.

375 The effects of protease supplementation on weaned piglet performance and intestinal function fed greater amounts of lower digestible protein sources

Abstract The present study investigated the impact of dietary protease supplementation on the growth performance and intestinal function of weaned piglets when fed a diet comprising high levels of low digestible protein sources, in comparison with a standard commercially representative piglet diet. A total of 180 weaned piglets, 21 d old, of Duroc × Large White × Landrace crossbreeds, with an initial body weight (BW) of 6.27 ± 0.45 kg, were randomly assigned to three dietary treatments: 1) a standard commercial positive control (PC) diet comprising 22.2% soy protein, 5% whey protein, and 3% fish meal, 2) a negative control (NC) diet comprising 30.1% soy protein without whey protein and fish meal, and 3) a NC diet supplemented with 0.02% protease (NC + PROT). The diets were formulated to be iso-nitrogenous and iso-caloric and were pelleted at conditions of 0.4 MPa and 75°C. The experimental design employed a completely randomized design with 6 replicate pens per treatment, each pen containing 10 piglets. Statistical analysis was conducted using one-way ANOVA, with differences between means assessed using Duncan’s Multiple Range Test (P &amp;lt; 0.05). In terms of piglet performance, feeding the NC diet, containing high levels of low digestible protein sources, resulted in a significant decrease (P &amp;lt; 0.05) in final BW, average daily gain (ADG), and average daily feed intake (ADFI) by 3.1%, 8.2%, and 5.2%, respectively, compared with piglets fed the PC diet. Conversely, the NC diet significantly increased (P &amp;lt; 0.05) the feed-to-gain ratio and incidence of diarrhea by 3.4% and 88.3%, respectively, relative to PC. However, the supplementation of protease in the NC + PROT diet restored final BW, feed-to-gain ratio, and incidence of diarrhea to the same level as PC, while ADG and ADFI were increased (P &amp;lt; 0.05) by 4.6% and 4.3%, respectively. Regarding intestinal function, relative to PC, piglets fed the NC diet exhibited significantly less (P &amp;lt; 0.05) duodenal villus height, crude protein digestibility, and gene expressions of duodenal peptide transporter PepT1 and jejunal amino acid transporter b0,+AT, while blood urea nitrogen and diamine oxidase concentrations were greater (P &amp;lt; 0.05). However, the addition of protease in the NC diet reinstated measures of intestinal function, as NC + PROT-fed piglets showed similar duodenal villus height, crude protein digestibility, gene expressions of duodenal peptide transporter PepT1 and jejunal amino acid transporter b0,+AT, as well as blood urea nitrogen and diamine oxidase concentrations to PC. In conclusion, dietary supplementation of protease in weaned piglets fed higher levels of lower digestible protein sources mitigated losses in growth performance and intestinal functionality by enhancing intestinal development, protein digestibility, nutrient transport efficiency, and overall health status of piglets.

336 Effects of feeding an immunomodulatory feed additive (NutraGen) on metabolite concentrations and cortisol production in calves following exposure to a combination bovine respiratory disease challenge

Abstract Two 89-d experiments (Exp 1 and Exp 2) evaluated the effects of feeding an immunomodulatory feed additive (NutraGen; NG) in calves following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (MH) infection on d 0. For each experiment, steers [body weight (BW) = 251 ± 38.2 kg)] were randomly allocated to 1 of 3 treatments. Treatments included a placebo (CON; Exp 1 n = 5; Exp 2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; Exp 1 n = 5; Exp 2 n = 6), and NG fed from d -18 to d 28 (PREC; Exp 1 n = 6; Exp 2 n = 5). Data were analyzed using the GLIMMIX procedure of SAS Version 9.4 (SAS Institute, Cary, N.C.). Animal served as the experimental unit and time served as a repeated measure. Treatment, time, and the treatment × time interaction served as fixed effects. Block was included as a random effect. Multiple treatment × time interactions and time effects occurred for serum glucose, lactate, blood urea nitrogen, and non-esterified fatty acid concentrations (P ≤ 0.003) in both experiments. There was a general trend for serum glucose to decrease over time post-challenge, suggesting increased cellular utilization of glucose in response to the challenge. In Exp 1, treatment effects occurred for serum glucose (P ≤ 0.001) and serum lactate (P ≤ 0.01), where calves assigned to the CHLG treatment displayed the greatest concentrations of the metabolites. Blood urea nitrogen concentrations peaked at h 48 in Exp 1 and h 6 in Exp 2. There were no treatment effects or treatment × time interactions for serum cortisol, hair cortisol, or fecal corticosterone concentrations in either experiment (P ≥ 0.17). There were, however, multiple time effects for serum cortisol, hair cortisol, and fecal corticosterone concentrations in both experiments (P ≤ 0.02), indicating that the challenge directly impacted cortisol and corticosterone production. Serum cortisol steadily increased from h 96 to h 168 in both experiments. Trends in cortisol and corticosterone production were similar in both experiments; however, peak concentration times for these variables occurred later in Exp 2. These data suggest that feeding NG to calves may alter glucose availability and nutrient utilization in response to infection resulting from a bovine respiratory disease challenge.

A field study to optimize protein and lipid levels in diet for cage-cultured subadult rockfish Sebastes schlegelii

A feeding trial was conducted to evaluate growth, body composition, serum biochemistry, digestion and metabolism, and oxidation resistence of S. schlegelii fed 9 diets in a 3×3 factorial design (protein levels: 44 %, 48 %, 52 %; lipid levels: 6 %, 10 %, 14 %), to optimize protein and lipid levels for practical feed formula. Rockfish (114.25 g) were stocked into 27 cages in an offshore system and fed test diets to satiation twice daily for 8 weeks. Growth increased but feed conversion rate decreased with dietary protein increasing. Increasing dietary protein to >48 % led to reduced feeding intake but increased protein efficiency ratio. Lipid efficiency ratio increased with dietary protein increasing but decreased with dietary lipid increasing. Hepatosomatic index decreased coupling with the increases in condition factor and liver lipid content as dietary lipid increased to 14 %. Intraperitoneal fat ratio increased with dietary lipid increasing. Increasing dietary protein to > 48 % significantly elevated serum total protein and glucose concentrations, hepatic glycogen synthase activity. High-protein (52 %) diets elevated serum albumin and urea nitrogen concentrations, hepatic pyruvate kinase and alanine aminotransferase (ALT) activities but downregulated hepatic growth-hormone (GH) receptor. Activities of trypsin, lipase, serum superoxide dismutase and total antioxidant capacity decreased with the dietary lipid increasing. Increasing dietary lipid to > 10 % reduced serum GH concentration, and high-lipid (14 %) diets significantly enhanced serum triglyceride concentration and hepatic transaminases activities, and resulted in a visual increase of adipocytes in liver. Serum cholesterol and low-density lipoprotein decreased as dietary protein increased to 48–52 % or dietary lipid >10 %. Hepatic succinate dehydrogenase activity and serum IGF-1 significantly increased while hepatic fatty acid synthetase decreased as dietary protein increased to >48 % or dietary lipid >10 %. High-protein (52 %) diet or high-lipid (14 %) diet elevated serum malonaldehyde concentration. These findings suggested 48 % protein and 10 % lipid were the optimal in diet for subadult S. schlegelii.

Handheld microfluidic multiple detection device for concurrent blood urea nitrogen and creatinine ratio determination using colorimetric approach

A novel microfluidic multiple detection (MMD) platform consisting of a microfluidic chip and a self-built detection system is proposed for determining the creatinine (CRE) and blood urea nitrogen (BUN) concentrations in whole blood samples. In the proposed approach, a drop of whole blood is injected into the inlet of the microfluidic chip and filtered through strips of hemofiltration paper. The plasma enters the BUN and CRE detection chambers and is absorbed by pre-placed test strips embedded with analyte-specific reagents. Secondary reagents are then introduced into the detection chambers using a finger pump, and the chip is heated to induce Berthelot and Jaffe reactions. An image of the reaction compounds is captured by a CMOS camera and transmitted to a smartphone, where the BUN and CRE concentrations are derived from predetermined calibration curves using RGB analysis software. The proposed MMD platform is demonstrated by comparing the results obtained for 43 whole blood samples collected from patients with chronic kidney disease (CKD) and health volunteers with the measurements obtained using a traditional benchtop system. The results confirm that the proposed MMD platform offers a cost-effective, convenient, and rapid technique for BUN/CRE ratio (BCR) determination in point-of-care (POC) contexts.

Effects of Short-Term Differences in Concentrate Feeding on the Recovery of In Vivo Embryos in Hanwoo Donor Cows through Superovulation Treatment.

Superovulation is a technique used to increase the number of oocytes released for fertilization. This study investigated the effects of short-term differences in concentrate feed intake on in vivo embryo production through superovulation in indigenous Korean (Hanwoo) cows. The cows were given fresh water and hay ad libitum and randomly divided into three groups (control (CON, n = 9): 2.0 kg/day (unchanged diet); low concentrate (LC, n = 10): 0 kg/day; and high concentrate (HC, n = 8): 4.0 kg/day) according to the amount of formula they were fed. This feeding treatment began seven days before the start of the hormonal treatment for superovulation. From the results, the LC group had the greatest weight change and the lowest body condition score at harvest, followed by the CON and HC groups (p < 0.05). The LC group had the highest number of harvesting embryos, followed by the HC and CON groups (p < 0.05). Estradiol, progesterone, glucose, total cholesterol, high-density lipoprotein, low-density lipoprotein, total protein, and blood urea nitrogen concentrations did not differ between the groups, except for a temporary increase in the HC group on day 0. These findings suggest that more embryos may be harvested when short-term changes in concentrate intake are made during superovulatory responses in Hanwoo cows.

Relationship between Plasma and Saliva Urea Nitrogen Concentrations in New Zealand Red Deer Calves (Cervus elaphus).

Red deer (Cervus elaphus), like other ruminants, excrete approximately 70% of the nitrogen they ingest. Developing ways in which to reduce the rate of loss, such as manipulating the diet or selecting for efficiency of growth, requires close monitoring of the plasma urea N (PUN) concentration which, in turn, requires a simple, safe, and reliable method for collecting samples. Saliva is easier to collect than blood, but the relationship between the salivary urea N (SUN) and the PUN is not known for red deer. This was therefore evaluated in two strains of mixed-sex red deer calves (Cervus elaphus): a phenotype with a high seasonality of growth (H, n = 10) and a phenotype with a low seasonality of growth (L, n = 13). Both phenotypes were divided into two groups, which were each offered one of two forage-based diets ad libitum: a medium-quality diverse treatment and a low-quality perennial ryegrass-white clover treatment. Blood and saliva samples for the determination of the PUN and SUN were collected at dawn every four weeks for five months (April to September 2022). There was a strong linear relationship between the PUN and SUN in the pooled sample (R2 = 0.65, p < 0.001). The estimations of the PUN were significantly improved by adding diet and the date of sampling into the model (p < 0.001), but not phenotype (p > 0.75). SUN represents a reliable index of the PUN, and collecting saliva therefore represents a simple and inexpensive alternative to collecting blood samples in studies of nitrogen metabolism in red deer.