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Current agricultural production systems face challenges of poor economic returns, soil fatigue and negative environmental outcomes from excess use of nitrogenous fertilizers, especially in wheat production under middle gangetic plains. To overcome these challenges, the current study was conducted to optimize nitrogen management in different wheat genotypes with precision nitrogen management tools and approaches. The field experiment was laid out in split-plot design, with three genotypes assigned to the main plot and six nitrogen management practices to the sub-plot. The soil of the experimental field was sandy loam in texture, with low levels of organic carbon and available nitrogen, and medium levels of available phosphorus and potassium. Results revealed that the HD-2967 genotype outperformed others in terms of growth, grain yield (4.7 and 4.81 t ha−1), gross return (1417.41 and 1505.48 US$ ha−1), net return (953.43 and 1019.76 US$ ha−1), and B-C ratio (2.04 and 2.08) in 2015-16 and 2016-17, respectively. Among the nitrogen management practices, application of 150 kg N ha−1 in three equal splits demonstrated improved crop growth, grain yield (4.7 and 4.81 t ha−1), and economic returns (gross return, 1500.40 and 1607.65 US$ ha−1, net return, 1025.40 and 1110.38 US$ ha−1 and B: C ratio, 2.17 and 2.23) in 2015-16 and 2016-17, respectively. However, it resulted in higher nitrogen losses. Green seeker guided N application significantly reduced apparent nitrogen losses compared to all other nitrogen applied treatments. These findings provide valuable insights for optimizing wheat production by selecting appropriate genotypes and implementing precision nitrogen management techniques to enhance yield, profitability, and environmental sustainability. [ABSTRACT FROM AUTHOR]

Background: The pervasively imprudent practices of irrigation and nitrogen (N) application within Oasis Cool Irrigation zones have led to significant soil nitrogen loss and a marked decrease in water and nitrogen use efficiency. Methods: To address this concern, a comprehensive field experiment was conducted from April to September in 2023 to investigate the impact of varying degrees of water and fertilization regulation strategies on pivotal parameters including potato yield, quality, nitrogen balance, and water-nitrogen use efficiency. The experimental design incorporated two water deficit degrees at potato seedling (W1, 55%-65% of Field Capacity (FC); W2, 45%-55% of FC), and four distinct nitrogen application gradients (N0, 0 kg ha-1 of N; N1, 130 kg ha-1 of N; N2, 185 kg ha-1 of N; N3, 240 kg ha-1 of N). A control was also included, comprising N0 nitrogen application and full irrigation (W0, 65%-75% of FC), totally eight treatments and one check. Results: The results indicated that the tuber yield, plant dry matter accumulation, plant height, plant stem, and leaf area index increased with higher nitrogen fertilizer application and irrigation volume. However, tuber starch content, vitamin C, and protein content initially increased and then decreased, while reducing sugar content consistently decreased. Except for W1N2 treatment, the irrigation water use efficiency increased as the N application rate rose, while the nitrogen partial factor productivity, crop nitrogen use efficiency and soil nitrogen use efficiency decreased with an increase in N fertilizer application. The W1N2 treatment resulted in a higher yield (43.16 t ha-1), highest crop nitrogen use efficiency (0.95) and systematic nitrogen use efficiency (0.72),while maintaining moderate levels of soil nitrate and ammonium nitrogen. Conclusion: Therefore, through the construction of an integrated evaluation index (IEI), the W1N2 treatment of mild water deficit (55%-65% of FC) at potato seedling combined with the medium nitrogen application (185 kg ha-1 of N) has the highest IEI (0.978), it was recommended as the optimal water-nitrogen regulation and management strategies to facilitate high-yield, high-efficiency, and environmentally sustainable potato production in the cold and arid oasis areas of northwest China. [ABSTRACT FROM AUTHOR]

The incorporation of aquaculture feed within a rice–crayfish coculture system significantly enhances nitrogen cycling, thereby diminishing the reliance on chemical fertilizers. However, this benefit is often overlooked in practice, and farmers continue to use large quantities of chemical fertilizers to maximize production, resulting in excessive soil fertility and water nitrogen pollution. Thus, avoiding nitrogen pollution in rice–crayfish coculture systems has become a pressing issue. In this study, we conducted a two-year experiment with two rice cultivars, and a 33.3% reduction in nitrogen fertilizer in a rice–crayfish coculture system (RC), to systematically analyze the overall nitrogen balance, rice nitrogen nutrition, and soil fertility, as compared with a rice monoculture system (RM). Our findings revealed the following: (1) Under the 33.3% reduction in nitrogen fertilizer, the nitrogen surplus in the rice–crayfish coculture system was comparable to that in the rice monoculture, and was controlled at an environmental safety level. (2) Nitrogen utilization efficiency and the accumulation of nitrogen in the rice–crayfish coculture were comparable to those in the rice monoculture. The nitrogen cycle in this system was able to provide the nitrogen required for rice growth after nitrogen fertilizer reduction. (3) The rice–crayfish coculture significantly improved the overall soil fertility and the effectiveness of soil nitrogen nutrition. Furthermore, cutting off the application of nitrogen fertilizer after the mid-tillering stage effectively controlled the total nitrogen content in soil after rice maturity. In conclusion, reducing nitrogen fertilizer in a rice–crayfish coculture system is feasible and beneficial. It ensures rice production, reduces the risk of excessive nitrogen surplus and surface pollution, and promotes a greener, more environmentally friendly paddy field ecosystem. [ABSTRACT FROM AUTHOR]

Inclusion of legumes in cereal based cropping system restores soil fertility and improves carbon storage and soil quality. In this background a field experiment was conducted in a strip-split plot design using three legume species viz., green gram, groundnut and cluster bean as vertical strip, two residue management practices i.e. residue removal (-R) and residue retention (+R) as horizontal strip, and three nitrogen levels i.e. 100%, 75% and 50% recommended rate of nitrogen (N) application in intersectional sub plots with four replications during summer 2017 and 2018. The grain and stover yield of maize, N uptake and soil properties were monitored after each crop harvest; soil nitrogen balance and soil organic carbon were estimated. Under 100% N fertilization, cluster bean – maize cropping system with residue (+R) recorded 12.78 and 9.78% higher maize grain and stover yield, respectively than without residue (–R) treatment. Highest available N (189.9 kg ha−1) and available P (54.5 kg ha−1) were registered under cluster bean- maize cropping system. Legume residue incorporation resulted 9.65, 8.46, 7.09 and 8.86% higher (p = 0.05) WBC content, WBC stock, available N and P contents over residue removal scenario. Annually, 1.71% added carbon converted into soil organic carbon. Legume residue retention and 100% recommended rate of nitrogen application enhanced nitrogen balance. Soil N balance was highest under groundnut – maize system (165 kg ha−1). Overall, for better soil health and optimum crop production, cluster bean – maize cropping system with legume residue retention and 100% N fertilization may be promoted in semi-arid Western India. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of lemongrass essential oil (LEO) addition during the ensiling and subsequent sheep feed intake, particle selection, in vitro rumen fermentation, total-tract apparent digestibility and nitrogen balance. Eight Dorper lambs 19.4±2.40 (mean±SD) kg of body weight were used in a trial using a 4 × 4 Latin Square design to evaluate: I. LEO addition during the whole-plant sorghum ensiling: 0 (EN−) and 4 (EN+) mL per kg of sorghum dry matter (DM); and II. LEO supply during the animals feeding: 0 (F−) and 1.6 (F+) mL per kg of diet DM. Treatments showed no effect on feed intake and particle size selection. Ensiling with LEO increased ammonia-N when LEO was not added during incubation. LEO addition during incubation decreased neutral detergent fibre (NDF) degradation when LEO was not added during the ensiling. In addition, LEO addition increased fermentation gas production and decreased digestibility. LEO addition in sheep feeding tended to decrease crude protein digestibility. Treatments did not affect nitrogen balance and the average daily gain. Thus, LEO supply during ensiling and sheep feeding does not affect feed intake, particle selection and nitrogen balance. [ABSTRACT FROM AUTHOR]

Field zones at risk of low nitrogen use efficiency (NUE) can be identified by analyzing in-field spatial variability. This hypothesis was validated by analyzing soil mineral nitrogen (Nmin) and several plant and soil N management indices. The research was conducted in Karmin (central Poland) during two growing seasons, with winter oilseed rape (2018/2019) and winter wheat (2019/2020). The study showed that the crop yield was positively related to Nmin. However, this N trait did not explain all the observed differences in the spatial variation of crop yield and plant N accumulation. In addition, the soil N management indices were more spatially variable during the growing season than the plant N management indices. Particularly high variability was found for the indices characterizing the N surplus in the soil-plant system. The calculated N surplus (Nb = N fertilizer input − N seed output) ranged from −62.8 to 80.0 kg N ha−1 (coefficient of variation, CV = 181.2%) in the rape field and from −123.5 to 8.2 kg N ha−1 (CV = 60.2%) in the wheat field. The spatial distribution maps also confirm the high variability of the parameters characterizing the post-harvest N surplus, as well as the total N input (soil + fertilizer) to the field with rape. The results obtained indicate that a field N balance carried out in different field zones allows a more accurate identification of potential N losses from the soil-plant system. [ABSTRACT FROM AUTHOR]

Protection of high-yielding winter wheat (WW) with fungicides increases the productivity of nitrogen (N) present in the soil–crop system during the growing season. As a consequence of the action of fungicides, the nitrogen gap (NG) reduces. This hypothesis was verified on the basis of data from a field experiment conducted with WW during three growing seasons (2013/2014; 2014/2015, 2015/2016) in Poland. The field experiment included two crop protection systems (CP): (i) CP-0—without fungicides and CP-F—with fungicides and (ii) six N doses increased gradually by 40 kg N ha−1 from 0 to 240 kg N ha−1. The grain yield (GY) of WW treated with fungicides was significantly higher than that of the unprotected. The difference in yields between both CP systems was 17.3% on a plot fertilized with 200 kg N ha−1 (9.13 vs. 11.2 t ha−1). The fungicide yield gap increased progressively with Nf doses from 0.76 t ha−1 in the Nf control plot to 2.17 t ha−1 in the fertilized with 200 kg ha−1. The use of fungicides increased the amount of N in grain (Ngr) from 15 kg N ha−1 in the control N plot to 51 kg N ha−1 in the plot with 200 kg N ha−1. The main source of additional N in grain (Ngr) was inorganic N released from the soil (Ng89) during the WW growing season. The maximum Ng89 values were 64.4 and 83.0 kg N ha−1. These values corresponded to Nf doses of 94.4 and 80.8 kg N ha−1. The Ng89 of 70.1 kg N ha−1 conditioned 100-percentage Nf recovery. As a consequence, the prediction reliability of GY and Ngr was highest when Ng89 was used as a predictor. The net increase in the absolute NG size in response to increasing N input was significantly slower and therefore smaller in fungicide-protected than in unprotected WW. It can be concluded that the use of fungicides due to the increase in inorganic N productivity in the soil–crop system reduces the potential threat of N dispersion into the environment. In the light of the results obtained, it should be concluded that the fungicidal protection of crop plants should be treated as a factor significantly reducing the nitrogen gap and, thus, the yield gap. [ABSTRACT FROM AUTHOR]

Introduction: Crude protein is a key element in regulating the diet of ruminants and is considered one of the most expensive nutrients needed by livestock. Feeding management plays an important role in the elimination of nitrogen in the production environment and the emission of greenhouse gases in animal husbandry systems (Avathar et al 2021). When there is excessive discharge of nitrogen in the environment, it causes the ecological balance in surface waters to be disrupted and the groundwater to be polluted (Dijkstra et al 2011). Excretion of these compounds in the environment will increase with fermentation, digestion and inefficient metabolism, and the increase in inefficiency in the rumen is caused by the complex and competitive metabolic pathways in the rumen microbial population. Therefore, increasing efficiency in the use of nutrients, especially nitrogen, to minimize their excretion from the animal's body should be considered. Various methods can be implemented in an animal husbandry unit to improve the use of nitrogen in ruminants. One of these solutions is to reduce the crude protein in the diet, but it has been reported that this method can have a negative effect on animal production (Chibisa and Motswangwa 2013). Another solution is nutrient synchronization or synchronizing the fermentation rate of dietary protein and energy sources, which has led to limited success (Yelchi et al. 2020). Another solution is to create oscillating in the concentration of crude protein in the diet and feed it intermittently at intervals of one to three days, and previous reports show that this method has improved nitrogen retention and its utilization in the body compared to eating constant amounts of crude protein daily in sheep and cattle (Rach et al., 2021). This study was conducted in order to investigate the effect of constant and intermittent feeding of dietary crude protein on ruminal parameters and microbial protein synthesis in sheep. Material and methods: Three diets were adjusted with 12, 14 and 16% crude protein but with the same metabolizable energy and protein. 8 male sheep were used in metabolic cages in a 4x4 Latin square design (four treatments with 2 squares and 8 replications). The first treatment received a diet with a crude protein level of 14% constantly. The second, third and fourth treatments received diets with 12 and 16% crude protein at intervals of 24, 48 and 72 hours, respectively. Nitrogen balance and retention, rumen and blood parameters, volatile fatty acids and microbial protein synthesis were measured. Results and discussion: The lowest total excreted nitrogen (via urine and feces) was observed in the treatment with 48-hour raw protein consumption interval (P<0.05). The retained nitrogen showed a significant increase in this treatment as compared to the constant crude protein feeding treatment (P<0.05). It has been reported that the increase in nitrogen retention in ruminants that received diets with oscillating crude protein levels is due to increased urea recycling in the rumen (Cole 1999). It seems that the transfer of urea from the blood to the rumen during the consumption of diets with low crude protein level (times 24, 48 and 72 hours) in oscillating diets increased and it compensates for the shortage of nitrogen in the rumen. In this condition, nitrogen excretion through urine also decreases and the efficiency of nitrogen use increases. The highest rumen liquid ammonia nitrogen was observed in the treatment with 48-hour crude protein consumption interval, but the pH and concentration of volatile fatty acids did not show any significant difference among the experimental treatments. Comparing the treatment of constant crude protein feeding (14%) with the treatments with intermittent consumption of crude protein (12 and 16%) in terms of the concentration of volatile fatty acids in the rumen fluid of the experimental sheep, including acetate, propionate and butyrate, as well as total volatile fatty acids, there is not a significant difference. The same ratio of concentrate to fodder and the similarity of the feed ingredients in the diets can be a reason for the lack of significance between the experimental treatments, which is in line with the results of previous researches (Khattab and Abdulwahid 2018). A significant difference was observed between the experimental treatments in terms of allantoin, total purine bases excreted, as well as nitrogen and microbial protein production, and the treatment with oscillating consumption of raw protein at a time interval of 48 hours had the highest amount. Albumin and total blood protein measured between the experimental treatments showed no significant difference, but blood urea nitrogen was the highest in the treatment with 48- hour crude protein consumption interval (P<0.01). Microbial protein synthesis in the rumen is affected by many animal and dietary factors, including nitrogen amounts, nitrogen sources, carbohydrate and nitrogen degradation rates, type and amount of carbohydrates in the diet, dry matter consumption, stability of fermentation in the rumen, and synchronization between nitrogen and energy (Hall 2013). It seems that in diets that cause fluctuation in the entry of protein sources into the rumen, the recycling of nitrogen to the rumen is done more effectively through the blood vessels and the liver, which in addition to reducing the excretion of nitrogen from the body also increases the production of microbial protein, in other words, the efficiency of using feed nitrogen increases, which is evident in the results of this research. Conclusion: The results showed that using the strategy of oscillating dietary crude protein concentration in sheep's diet improved nitrogen retention, rumen fermentation activities and microbial protein synthesis. [ABSTRACT FROM AUTHOR]

Objective: Exploring protein requirements for critically ill patients has become prominent. On the other hand, considering the significant impact of coma therapy and targeted temperature management (TTM) on the brain as well as systemic metabolisms, protein requirements may plausibly be changed by treatment application. However, there is currently no research on protein requirements following the application of these treatments. Therefore, the aim of this study is to elucidate changes in patients' protein requirements during the application of TTM and coma therapy. Methods: This study is a retrospective analysis of prospectively collected data from March 2019 to May 2022. Among the patients admitted to the intensive care unit, those receiving coma therapy and TTM were included. The patient's treatment period was divided into two phases (phase 1, application and maintenance of coma therapy and TTM; phase 2, tapering and cessation of treatment). In assessing protein requirements, the urine urea nitrogen (UUN) method was employed to estimate the nitrogen balance, offering insight into protein utilization within the body. The patient's protein requirement for each phase was defined as the amount of protein required to achieve a nitrogen balance within ±5, based on the 24-hour collection of UUN. Changes in protein requirements between phases were analyzed. Results: Out of 195 patients, 107 patients with a total of 214 UUN values were included. The mean protein requirement for the entire treatment period was 1.84±0.62 g/kg/day, which is higher than the generally recommended protein supply of 1.2 g/kg/day. As the treatment was tapered, there was a statistically significant increase in the protein requirement from 1.49±0.42 to 2.18±0.60 in phase 2 (p<0.001). Conclusion: Our study revealed a total average protein requirement of 1.84±0.62 g during the treatment period, which falls within the upper range of the preexisting guidelines. Nevertheless, a notable deviation emerged when analyzing the treatment application period separately. Hence, it is recommended to incorporate considerations for the type and timing of treatment, extending beyond the current guideline, which solely accounts for the severity by disease. [ABSTRACT FROM AUTHOR]

Purpose: Obesity, defined as abnormal or excessive fat accumulation that presents a risk to health, rose from 8.6 to 10.5% in Singapore's residents. Bariatric surgery, the primary treatment for severe obesity, induces fat and muscle loss. Adequate protein intake is vital for preventing muscle loss. This study examines nitrogen balance in individuals with obesity pre- and post-surgery. Materials and Methods: Sixteen participants with severe obesity (BMI ≥ 32.5 kg/m2) undergoing bariatric surgery (14 sleeve gastrectomy, 2 Roux-en-Y gastric bypass) and 20 normal-weight controls (BMI < 25 kg/m2) were recruited. Nitrogen balance, calculated from dietary protein intake and urine nitrogen excretion, was assessed. Participants with obesity were re-evaluated 6 months post-surgery. Data were analyzed using parametric methods. Results: At baseline, controls had a BMI of 20.8 ± 2.1 kg/m2; those with obesity had 40.9 ± 7.3. Daily calorie and protein intake for participants with obesity were not statistically significantly different from controls (calorie intake at 1467 ± 430 vs. 1462 ± 391 kcal, p = 0.9701, protein intake 74.2 ± 28.7 vs. 64.6 ± 18.3 g, p = 0.2289). Post-surgery, BMI, fat-free mass, fat mass, total energy intake, carbohydrate, and protein intake decreased significantly (p < 0.01). Protein oxidation and urine nitrogen excretion did not change after bariatric surgery. However, nitrogen balance significantly reduced from 2.62 ± 5.07 to − 1.69 ± 5.07 g/day (p = 0.025). Conclusion: Dietary protein intake is inadequate in individuals with obesity at 6 months post-bariatric surgery and contributes to a state of negative nitrogen balance. [ABSTRACT FROM AUTHOR]

Nitrogen balance (NB), the principal methodology used to derive recommendations for human protein and amino acid requirements, has been widely criticised, and calls for increased protein and amino acid requirement recommendations have been made, often on the basis of post-prandial amino acid tracer kinetic studies of muscle protein synthesis, or of amino acid oxidation. This narrative review considers our knowledge of the homeostatic regulation of the FFM throughout the diurnal cycle of feeding and fasting and what can and has been learnt from post-prandial amino acid tracer studies, about amino acid and protein requirements. Within the FFM, muscle mass in well fed weight-stable adults with healthy lifestyles appears fixed at a phenotypic level within a wide range of habitual protein intakes. However homoeostatic regulation occurs in response to variation in habitual protein intake, with adaptive changes in amino acid oxidation which influence the magnitude of diurnal losses and gains of body protein. Post-prandial indicator amino acid oxidation (IAAO) studies have been introduced as an alternative to NB and to the logistically complex 24 h [13C-1] amino acid balance studies, for assessment of protein and amino acid requirements. However, a detailed examination of IAAO studies shows both a lack of concern for homeostatic regulation of amino acid oxidation and  major flaws in their design and analytical interpretation, which seriously constrain their ability to provide reliable values. New ideas and a much more critical approach to existing work is needed if real progress is to be made in the area. [ABSTRACT FROM AUTHOR]

The growing concern for health and the environment among individuals is anticipated to boost the demand for organic foods. However, there is a research gap in expanding field experiment results for the impact of organic farming to the real world. This study examines the causal relationship between nitrogen balance, organic farming area, agricultural land, and Gross Domestic Product per capita in 18 Organisation for Economic Co‐operation and Development countries from 2000 to 2019. By employing panel Autoregressive Distributed Lag, we found that a 1% increase in organic farming areas is associated with a 0.054% decrease in nitrogen balance in the long run. However, we found that the nitrogen balance increased by 0.392% and 0.487% with 1% expansion of agricultural farmland and economic development in the long run, respectively. Our findings will help policymakers develop or implement soil health management practices to reduce and maintain the amount of nitrogen in the environment. In addition, environmentally friendly raising livestock practices might be another consideration to improve nitrogen balance in livestock‐intensive countries. Finally, expanding agricultural land may not be an appropriate way to solve the problems of soil and underground water contamination. [ABSTRACT FROM AUTHOR]

Reducing dietary CP is a well-established means to improve N use efficiency. Yet, few studies have considered if transient restrictions in dietary CP could reduce the environmental footprint of late-lactation cows. We hypothesized that the effects of CP feeding pattern on digestibility and environmental outputs would be amplified at lower dietary CP. We tested CP levels below and near predicted requirements (low protein [LP], 13.8%; high protein [HP], 15.5%) offered in 2 feeding patterns: where diets alternated ±1.8 percentage units CP every 2 d (oscillating [OF]) or remained static. Our study used a 2 × 2 factorial design with 16 mid- to late-lactation Holsteins (mean = 128, SD = 12 DIM), divided into rumen-cannulated (n = 8) and noncannulated subsets (n = 8). For each 28-d experimental period, we recorded feed intake and milk production and took samples of orts (1×/d) and milk (2×/d) for 4 d. For the cannulated subset, we measured and sampled from the total mass of feces and urine production and collected plasma 2×/d across 4 d. For the noncannulated subset, we sampled carbon dioxide and methane emissions 3×/d for 4 d. For each subset, we fit linear mixed models with fixed effects for CP level, CP feeding pattern, the interaction of CP level and CP feeding pattern, period, and a random effect for cow. For plasma and urinary urea-N, we conducted time series analysis. Contrary to our hypothesis, we found no evidence that dietary CP level and CP feeding pattern interacted to influence N balance, nutrient digestibility, or gas emissions. Results showed HP resulted in similar milk N but increased manure N, reducing N use efficiency (milk true protein N/intake N) relative to LP. For OF, urea-N in urine and plasma peaked 46 to 52 h after the first higher-CP phase feeding. Nutrient digestibility and gas emissions were similar across treatments, except CO 2 production was greater for OF-HP. In summary, measured variables were minimally affected by dietary CP alternating ±1.8 percentage units every 48 h, even when average dietary CP was fed below predicted requirements (LP). Although our findings suggest that mid- to late-lactation cows are resilient to oscillation in dietary CP, oscillating CP neither reduced the environmental footprint by improving nutrient use efficiencies nor reduced the potential for direct and indirect greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Serum prealbumin is considered to be a sensitive predictor of clinical outcomes and a quality marker for nutrition support. However, its susceptibility to inflammation restricts its usage in critically ill patients according to current guidelines. We assessed the performance of the initial value of prealbumin and dynamic changes for predicting the ICU mortality and the effectiveness of nutrition support in critically ill patients. This monocentric study included patients admitted to the ICU between 2009 and 2016, having at least one initial prealbumin value available. Prospectively recorded data were extracted from the electronic ICU charts. We used both univariable and multivariable logistic regressions to estimate the performance of prealbumin for the prediction of ICU mortality. Additionally, the association between prealbumin dynamic changes and nutrition support was assessed via a multivariable linear mixed-effects model and multivariable linear regression. Performing subgroup analysis assisted in identifying patients for whom prealbumin dynamic assessment holds specific relevance. We included 3136 patients with a total of 4942 prealbumin levels available. Both prealbumin measured at ICU admission (adjusted odds-ratio (aOR) 0.04, confidence interval (CI) 95% 0.01–0.23) and its change over the first week (aOR 0.02, CI 95 0.00–0.19) were negatively associated with ICU mortality. Throughout the entire ICU stay, prealbumin dynamic changes were associated with both cumulative energy (estimate: 33.2, standard error (SE) 0.001, p < 0.01) and protein intakes (1.39, SE 0.001, p < 0.01). During the first week of stay, prealbumin change was independently associated with mean energy (6.03e-04, SE 2.32e-04, p < 0.01) and protein intakes (1.97e-02, SE 5.91e-03, p < 0.01). Notably, the association between prealbumin and energy intake was strongest among older or malnourished patients, those suffering from increased inflammation and those with high disease severity. Finally, prealbumin changes were associated with a positive mean nitrogen balance at day 7 only in patients with SOFA <4 (p = 0.047). Prealbumin measured at ICU admission and its change during the first-week serve as an accurate predictor of ICU mortality. Prealbumin dynamic assessment may be a reliable tool to estimate the effectiveness of nutrition support in the ICU, especially among high-risk patients. [ABSTRACT FROM AUTHOR]

Current and proposed policies aim to leverage the Federal Crop Insurance Program (FCIP) to promote conservation practices. This study uses corn farm‐level survey data to inform the effectiveness of targeting FCIP participants. We implement an unsupervised machine learning algorithm to assess what conservation practices are most common among participants. We find that farms that use crop insurance have higher adoption rates for practices that are generally profit‐maximizing. We also calculate nitrogen balance, a yield‐scaled measure of nitrogen fertilizer's potential environmental impact. We find a positive relationship between crop insurance and nitrogen balance closer to the optimum. [ABSTRACT FROM AUTHOR]

Agricultural producers are increasingly using plant-based feed additives in the diets of livestock and poultry as a way to increase animal productivity and stabilize the protective functions of the body. The purpose of the research was to study the effectiveness of using Astragalus cicer feed supplement in the diets of laying hens of the Lohmann Brown-Light cross at the age of 25-51 weeks. The composition of the compound feed included a phytoadditive made from Astragalus cicer in the volume: I experimental group – 3.60 %, II experimental – 7.20 % by the weight of the compound feed. The duration of the scientific and production experiment was 183 days. The analysis of the content of biologically active substances in the Astragalus cicer phytoadditive has revealed a high content of dihydroquercetin – 336.25 mg/100g of absolutely dry substance.image As the result of the research, it was found that laying hens of the II experimental group, which received 7.20 % of Astragalus cicer phytoadditive in the compound feed, had more intensive metabolic processes in the body, which contributed to obtaining a greater effect from them. Laying hens of the II experimental group compared with the control and I experimental groups had 2.19 and 2.18 % higher values of nitrogen utilization out of taken feed, egg production was higher by 2.81 and 1.10 %, the cost of compound feed decreased by 10 pcs. eggs, that was by 4.76 and 2.38 %, respectively. The profitability level of egg production in the II experimental group was higher compared with the control and I experimental groups by 3.83 and 5.16%, respectively.

ABSTRACT: Improved nitrogen utilization of dairy production systems should improve not only the economic output of the systems but also the environmental metrics. One strategy to improve efficiency is through breeding programs. Improving a trait through breeding is conditional on the presence of exploitable genetic variability. Using a database of 1,291 deeply phenotyped grazing dairy cows, the genetic variability for 2 definitions of nitrogen utilization was studied: nitrogen use efficiency (i.e., nitrogen output in milk and meat divided by nitrogen available) and nitrogen balance (i.e., nitrogen available less nitrogen output in milk and meat). Variance components for both variables were estimated using animal repeatability linear mixed models. Genetic variability was detected for both nitrogen utilization metrics, even though their heritability estimates were low (

Nitrogen (N) is abundant in the atmosphere as N2, which is converted into reactive forms (Nr) for plant assimilation. In pre-industrial times, atmospheric N2 conversion to Nr balanced Nr reconversion to N2, but 20th-century human activity intensified this conversion via synthetic fertilizers, biological N2 fixation, and fossil fuel burning. The surplus of Nr detrimentally impacts ecosystems and human well-being. This study aimed to assess the N use efficiency in the soil–plant system of the soybean-corn succession (SPSS,C) in Mato Grosso and Mato Grosso do Sul, Brazil’s midwest. We estimated N macrofluxes in SPSS,C and identified key agro-environmental indicators. Between 2008 and 2020, the yearly sowed area for the SPSS,C increased by 3.3-fold (currently 7.3 million ha). The average annual input of net anthropogenic Nr, average annual N balance, and N loss in SPSS,C was estimated to be ~204 kg [N] ha−1, 57 kg [N] ha−1, and 30 kg [N] ha−1, respectively, indicating persistent N accumulation and loss. The average results of the agronomic efficiency and N retention indicator in the SPSS,C was 0.71 and 0.90, respectively. Modest N use efficiency results reflect N loss effects. Despite these limitations, there are opportunities in SPSS,C for management strategies to reduce N loss and enhance efficiency.

Diets reliant on grazed, temperate herbage are prone to greater nitrogen (N) losses via urine than balanced stall-fed diets which poses a greater risk for N emissions. Measures for improving the N utilisation in grazing-based dairy cattle systems are predominantly investigated on homogenous clover-ryegrass pastures with high herbage yields and nutritional quality. In contrast, grazing-based systems reliant on less external inputs (e.g., synthetic fertilisers or concentrates) using semi-natural grassland as main feed source, such as in large parts of Central Europe, received less attention. The N utilisation and excretion of grazing cows in low-input dairy farms were, thus, investigated on nine commercial organic dairy farms in South Germany across one to four periods per farm. The dataset captured a diverse set of dairy production systems comprising 323 individual animal observations. A mean (± one SD) milk production, DM intake (DMI), and pasture DMI of 23.9 kg (± 5.35), 21.0 kg (± 3.21), and 11.3 kg/d (± 4.83), respectively, was determined. Feed intake was estimated using titanium dioxide and faecal CP concentration as markers of faecal excretion and diet digestibility, respectively. Milk N use efficiency (MNE; i.e., milk N secretion as share of N intake) averaged 24.7 g/100 g N intake (± 5.91), which is greater than observations in temperate, high-input grazing systems but lower than in cows receiving balanced diets in the barn. The MNE and another seven indicators of N utilisation and excretion displayed a wide range of values. The grazing management factors explaining this variation were, thus, identified via backward elimination. The supplementation strategy had the greatest potential for manipulating N utilisation and excretion of dairy cows. Increasing shares of fresh forages (i.e., meadow grass or clover-grass leys) as well as of hay in supplement DMI increased N utilisation (e.g., MNE) and decreased urinary N excretion (e.g., urinary N to creatinine ratio), while increasing shares of concentrates in supplement DMI are related to lower N losses via urine. At the same time, increases in total supplement DMI reduced N utilisation and increased urinary N excretion. Hence, full-time grazing combined with supplementation of fresh forage and hay in the barn is a viable option for low-input, grazing-based dairy operations with moderate levels of N losses.

To clarify the migration and accumulation of nitrogen (N), magnesium (Mg), calcium (Ca), and potassium (K) in soil profiles of plastic-greenhouse vegetable fields with cultivation years, soil samples from the 0–7 m soil profiles were collected from 10 pepper greenhouses with 10 and 20 years planting history, and parallel soil samples were taken from adjacent wheat-maize fields as controls. The results showed that: (1) Compared with wheat-maize fields, the total N amount in the 0–7 m soil layers from the greenhouses increased by 6.19 ± 1.16 and 9.11 ± 3.43 t ha−1 at 10 and 20 years, respectively, accounting for about 30.4% and 17.5% of the N input. (2) The N amount that entered the environment outside the 0–7 m soil layers were 6.95 t ± 2.76 and 29.10 ± 10.14 t ha−1 after 10 and 20 years of continuous planting, accounting for approximately 34.2% and 55.9% of the N input, respectively. (3) The concentration of water-soluble Ca and Mg in the 0–7 m soil layers increased significantly with cultivation years, and correlated positively with mineral N concentration. (4) Moreover, K mainly accumulates in the form of non-exchangeable K in the surface layers (0–50 cm). Our results demonstrated that huge amounts of N migrate to the deep soil with the extension of cultivation years in plastic-greenhouse pepper production systems, accompanied by significant leaching of Ca and Mg, while K mainly accumulates in the surface layers. [ABSTRACT FROM AUTHOR]

Ensured ammonia reduction by novel technologies and guaranteed low ammonia emission from livestock houses is essential for the granting and monitoring of legal permits. This study focuses on methods to underpin the long-term effectiveness of an air scrubber and was done in a commercial poultry house. The measured ammonia removal by an air scrubber with ammonia sensors (method 1) was compared to the acid use for ammonia binding (method 2) and the nitrogen balance over the process water (method 3). Also, the effect of the length of the time period used for the comparison was evaluated, as was the effect of the spatial variation of the ammonia concentration in the house. The overall weekly data showed a clear linear relation between method 1 on the one hand and methods 2 and 3 on the other hand, with regression coefficients close to 1 and a variation of +/- 20% on a 4-weekly basis. The 4-weekly data showed a clearly reduced variation compared to weekly data, due to leveling out of the impact of irregular time events like acid dosage and water discharge. The barn emission assessed by method 1 was significantly (12%) influenced by the spatial aerial concentration differences of ammonia in the house. Taking this into account, method 2 overestimated the emission reduction of method 1 with 16.8% and method 3 was in good agreement with method 1. For method 2, a revised value for acid use per kg of ammonia binding needs to be substantiated in further research. Possible measurement errors influenced calculated ammonia removal with a maximum of +/-2%, but the relative effect on remaining emissions was larger with +/- 15% for method 3. This study shows that monitoring acid use and/or the nitrogen balance can validate the ammonia reduction of air scrubbers and the remaining ammonia emission and support local authorities in granting environmental permits and their enforcement. [ABSTRACT FROM AUTHOR]

Improved nitrogen utilization of dairy production systems should improve not only the economic output of the systems but also the environmental metrics. One strategy to improve efficiency is through breeding programs. Improving a trait through breeding is conditional on the presence of exploitable genetic variability. Using a database of 1,291 deeply phenotyped grazing dairy cows, the genetic variability for 2 definitions of nitrogen utilization was studied: nitrogen use efficiency (i.e., nitrogen output in milk and meat divided by nitrogen available) and nitrogen balance (i.e., nitrogen available less nitrogen output in milk and meat). Variance components for both variables were estimated using animal repeatability linear mixed models. Genetic variability was detected for both nitrogen utilization metrics, even though their heritability estimates were low (<0.10). Validation of genetic evaluations revealed that animals divergent for nitrogen use efficiency or nitrogen balance indeed differed phenotypically, further demonstrating that breeding for improved nitrogen efficiency should result in a shift in the population mean toward better efficiency. Nitrogen use efficiency and nitrogen balance were not genetically correlated with each other (<|0.28|), and neither metric was correlated with milk urea nitrogen (<|0.12|). Nitrogen balance was unfavorably correlated with milk yield, showing the importance of including the nitrogen utilization metrics in a breeding index to improve nitrogen utilization without negatively impacting milk yield. In conclusion, improvement of nitrogen utilization through breeding is possible, even if more nitrogen utilization phenotypic data need to be collected to improve the selection accuracy considering the low heritability estimates. [ABSTRACT FROM AUTHOR]

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Nitrous oxide (N2O) emissions are closely linked to agricultural fertilisation. European and national policy incentives have been set to reduce greenhouse gas (GHG) emissions; however, only a few evaluations have been conducted. Avoiding such emissions is an important climate change mitigation measure, but it is still uncertain which management measures over a long‐term, best out‐balance crop yield and GHG balances in agricultural systems. We here used the process‐based LandscapeDNDC model to simulate N2O emissions and trade‐offs in yield and soil nitrogen budget for four alternative arable cropping systems in three Austrian agricultural production zones belonging to different climatic regions. We evaluated statistical data on crop rotations and management practices, predominant soil types, and 10‐year daily weather conditions for four cropping systems: (1) conventional farming receiving the maximum allowed nitrogen fertilisation rate (Nmax), (2) conventional farming receiving 15% less fertiliser, (3) conventional farming receiving 25% less fertiliser, and (4) organic farming. Our results showed that soil N2O emissions could be best reduced in wet, high‐yield regions. Reducing nitrogen fertilisation by 15% and 25% mitigated N2O emissions by, on average, 22% and 39%, respectively, while the yield was reduced by 5% and 9%, respectively. In comparison, the same crops grown in the organic cropping system released 60% less N2O, but yield declined on average by 23%. Corn, winter barley, and vegetables showed the highest N2O reduction potential under reduced fertiliser input in conventional farming. In addition to N2O emissions, reduced fertilisation substantially decreased other nitrogen losses into the water and atmosphere. Generally, the soils under all cropping systems maintained a positive mean nitrogen budget. Our results suggest a significant emission reduction potential in certain production zones which, however, were accompanied by yield reductions. Knowledge of the emission patterns from cropping systems under different environmental conditions is essential to set the appropriate measures. In addition, region‐specific measures to reduce soil N2O emissions have to be in line with farmers' interests in order to facilitate the successful implementation of targeted nitrogen management. [ABSTRACT FROM AUTHOR]

This study investigated the growth performance, nitrogen balance, and economics of production of Red Sokoto bucks (RSBs) fed Saccharomyces cerevisiaetreated, biodegradable groundnut haulms (SCGH) and dried cassava peels (DCP). Four dietary treatments were formulated including a control diet (T1; 0% SCGH:DCP) and DCP in combination with SCGH at the different proportions of 275:695 (T2), 375:595 (T3), and 475:495 (T4) g/kg of dry matter (DM). A combination of 5 g and 50 g of yeast as a probiotic and molasses, respectively, were added to 1 kg of GH after been dissolved in 1 L of water. Twelve healthy RSBs weighing 9.5 ± 0.40 kg of body weight (BW) and aged 7 to 8 months were exposed to four treatments. This was replicated three times in a completely randomized design (CRD). The experiment lasted for 90 days. The average final weight, average daily weight gain (gram/day), nitrogen intake, and nitrogen balance were significantly influenced by the inclusion of DCP and SCGH in the diets. There was no significant difference (p > 0.05) between the ADG of T1 (58.20 g/d) and the T4 (58.89 g/d) groups. Feed conversion ratio and feed-cost saving ($630.80) increased with the inclusion of DCP and SCGH in the goats' diets. In conclusion, T4 (SCGH: 475g, DCP: 495g) had a better chemical composition, ADG, nitrogen balance, and feed-cost saving; therefore, SCGH are recommended and are readily available agricultural wastes that can be fed to RSBs to improve performance and nitrogen utilization in a cost-effective way, especially during dry season. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is abundant in the atmosphere as N2, which is converted into reactive forms (Nr) for plant assimilation. In pre-industrial times, atmospheric N2 conversion to Nr balanced Nr reconversion to N2, but 20th-century human activity intensified this conversion via synthetic fertilizers, biological N2 fixation, and fossil fuel burning. The surplus of Nr detrimentally impacts ecosystems and human well-being. This study aimed to assess the N use efficiency in the soil–plant system of the soybean-corn succession ( S P S S , C ) in Mato Grosso and Mato Grosso do Sul, Brazil's midwest. We estimated N macrofluxes in S P S S , C and identified key agro-environmental indicators. Between 2008 and 2020, the yearly sowed area for the S P S S , C increased by 3.3-fold (currently 7.3 million ha). The average annual input of net anthropogenic Nr, average annual N balance, and N loss in S P S S , C was estimated to be ~204 kg [N] ha−1, 57 kg [N] ha−1, and 30 kg [N] ha−1, respectively, indicating persistent N accumulation and loss. The average results of the agronomic efficiency and N retention indicator in the S P S S , C was 0.71 and 0.90, respectively. Modest N use efficiency results reflect N loss effects. Despite these limitations, there are opportunities in S P S S , C for management strategies to reduce N loss and enhance efficiency. [ABSTRACT FROM AUTHOR]

Scientific literature for mineral soil nitrogen content (ammonium and nitrate) measurements usually differs regarding the chosen soil sample conservation method (fresh, frozen or air-dry) before soil extraction and analysis. In addition, most of the commonly used methodologies focus on the definition of the analysis processes, regardless of the previous sample conservation methodology. With the aim to fill this gap, we performed an analysis of the conservation method effect on the nitrate, and ammonium content in frozen or air-dried samples, comparing the results with direct fresh extraction. Moreover, the effects of additional soil parameters, such as soil texture, organic matter content or mineral nitrogen content range were also studied. The results showed that both, frozen and air drying soil samples, were capable of reliably preserving the N content of soil samples in most cases. However, some ammonium losses may occur in frozen samples when a high N content (>30 mg kg−1) is present. It was also observed that air-dried soil samples can reduce the soil nitrate and increase ammonium content in samples with a high N content. It was also observed that significant amounts of organic matter in soil can alter the mineral N measured depending on the conservation method chosen. On the other hand, the soil texture presented small effects on the mineral N measurements. In any case, a broader range of soils conditions (including i.e. pH or different natural organic matter content) should be further tested to confirm our findings.

Proteins are needed for providing essential amino acids, nitrogen, and fuel for the body’s needs in all age groups. Proteins are especially required during active growth in pregnancy, lactation, childhood, and tissue growth in general. An adequate protein intake is needed in old adults to avoid premature muscle loss. According to the current dietary surveys, protein intake in the Nordic and Baltic countries varies from 15 to 19% of the total energy intake in adults. Comprehensive data regarding children and older adults are lacking. No good measure for protein status exists, and the estimation of physiological requirements is based on N-balance studies having some weaknesses. Protein quality is assessed by considering the protein digestibility of individual indispensable amino acids and their utilization (bioavailability), which is affected by food antinutrients and processing. The evidence regarding the association of protein intake per se with health outcomes is limited or suggestive. It is difficult to separate from the effect of other nutrients or ingredients in protein-rich foods. Proteins are widespread in foods, deriving from both animal and plant sources. Animal-sourced protein production puts more strain on the environment than plant-sourced proteins and contributes significantly to greenhouse gas emissions, thereby enhancing climate change. In Nordic and Baltic countries, consumption of animal-sourced proteins is relatively high. A shift toward more plant-based protein diets would be advisable for promoting a healthy and sustainable diet.

ABSTRACT: Reducing nitrogen pollution while maintaining milk production is a major challenge of dairy production. One of the keys to delivering on this challenge is to improve the efficiency of how dairy cows use nitrogen. Thus, estimating the nitrogen utilization of lactating grazing dairy cows and exploring the association between animal factors and productivity with nitrogen utilization are the first steps to understanding the nitrogen utilization complex in dairy cows. Nitrogen utilization metrics were derived from milk and body weight records from 1,291 grazing dairy cows of multiple breeds and crossbreeds; all cows had sporadic information on nitrogen intake concurrent with information on nitrogen sinks (and other nitrogen sources, such as body tissue mobilization). Several nitrogen utilization metrics were investigated, including nitrogen use efficiency (nitrogen output as products such as milk and meat divided by nitrogen intake) and nitrogen excreted (nitrogen intake less the nitrogen output as products such as milk and meat). In the present study, a primiparous Holstein-Friesian used, on average, 20.6% of the nitrogen it ate, excreting the surplus as feces and urine, representing 402 g of nitrogen per day. Intercow variability existed, with a between-cow standard deviation of 0.0094 for nitrogen use efficiency and 24 g of nitrogen per day for nitrogen excretion. As lactation progressed, nitrogen use efficiency declined and nitrogen excretion increased. Nevertheless, nitrogen use efficiency improved (i.e., decreased) from first to second parity, even though it did not improve from second to third parity or greater. Furthermore, nitrogen excretion continued to increase from first to third parity or greater. Nitrogen use efficiency and nitrogen excretion were negatively correlated (−0.56 to −0.40), signifying that dairy cows who partition more of the ingested nitrogen into products such as milk and meat, on average, also excrete less nitrogen. Milk urea nitrogen was, at best, weakly correlated with nitrogen use efficiency and nitrogen excretion; the correlations were between −0.01 and 0.06. In conclusion, several cow-level factors such as parity, stage of lactation, and breed were associated with the range of different nitrogen efficiency metrics investigated; moreover, even after accounting for such effects, 4.8% to 6.3% of the remaining variation in the nitrogen use efficiency and nitrogen balance metrics were attributable to intercow differences.

ABSTRACT: Inclusion of urea in dairy cattle diets is often limited by negative effects of high levels of feed urea on dry matter intake (DMI) and efficiency of rumen N utilization. We hypothesized that supplying urea postruminally would mitigate these limitations and allow greater inclusion of urea in dairy cattle diets. Four rumen-fistulated Holstein-Friesian dairy cows (7 ± 2.1 lactations, 110 ± 30.8 d in milk; mean ± standard deviation) were randomly assigned to a 4 × 4 Latin square design to examine DMI, milk production and composition, digestibility, rumen fermentation, N balance, and plasma constituents in response to 4 levels of urea continuously infused into the abomasum (0, 163, 325, and 488 g/d). Urea doses were targeted to linearly increase the crude protein (CP) content of total DMI (diet plus infusion) by 0%, 2%, 4%, and 6% and equated to 0%, 0.7%, 1.4%, and 2.1% of expected DMI, respectively. Each 28-d infusion period consisted of a 7-d dose step-up period, 14 d of adaptation, and a 7-d measurement period. The diet was fed ad libitum as a total mixed ration [10.9% CP, 42.5% corn silage, 3.5% grass hay, 3.5% wheat straw, and 50.5% concentrate (dry matter basis)] and was formulated to meet 100%, 82%, and 53% of net energy, metabolizable protein, and rumen-degradable protein requirements, respectively. Linear, quadratic, and cubic effects of urea dose were assessed using polynomial regression assuming the fixed effect of treatment and random effects of period and cow. Dry matter intake and energy-corrected milk yield responded quadratically to urea dose, and milk urea content increased linearly with increasing urea dose. Apparent total-tract digestibility of CP increased linearly with increasing urea dose and ruminal NH3-N concentration responded quadratically to urea dose. Mean total VFA concentration was not affected by urea dose. The proportion of N intake excreted in feces decreased linearly and that excreted in urine increased linearly in response to increasing urea dose. The proportion of N intake excreted in milk increased linearly with increasing urea dose. Urinary urea excretion increased linearly with increasing urea dose. Microbial N flow responded cubically to urea dose, but the efficiency of microbial protein synthesis was not affected. Plasma urea concentration increased linearly with increasing urea dose. Regression analysis estimated that when supplemented on top of a low-CP diet, 179 g/d of postruminal urea would maximize DMI at 23.4 kg/d, corresponding to a dietary urea inclusion level of 0.8% of DMI, which is in line with the current recommendations for urea inclusion in dairy cattle diets. Overall, these results indicate that postruminal delivery of urea does not mitigate DMI depression as urea dose increases.

The incorporation of aquaculture feed within a rice–crayfish coculture system significantly enhances nitrogen cycling, thereby diminishing the reliance on chemical fertilizers. However, this benefit is often overlooked in practice, and farmers continue to use large quantities of chemical fertilizers to maximize production, resulting in excessive soil fertility and water nitrogen pollution. Thus, avoiding nitrogen pollution in rice–crayfish coculture systems has become a pressing issue. In this study, we conducted a two-year experiment with two rice cultivars, and a 33.3% reduction in nitrogen fertilizer in a rice–crayfish coculture system (RC), to systematically analyze the overall nitrogen balance, rice nitrogen nutrition, and soil fertility, as compared with a rice monoculture system (RM). Our findings revealed the following: (1) Under the 33.3% reduction in nitrogen fertilizer, the nitrogen surplus in the rice–crayfish coculture system was comparable to that in the rice monoculture, and was controlled at an environmental safety level. (2) Nitrogen utilization efficiency and the accumulation of nitrogen in the rice–crayfish coculture were comparable to those in the rice monoculture. The nitrogen cycle in this system was able to provide the nitrogen required for rice growth after nitrogen fertilizer reduction. (3) The rice–crayfish coculture significantly improved the overall soil fertility and the effectiveness of soil nitrogen nutrition. Furthermore, cutting off the application of nitrogen fertilizer after the mid-tillering stage effectively controlled the total nitrogen content in soil after rice maturity. In conclusion, reducing nitrogen fertilizer in a rice–crayfish coculture system is feasible and beneficial. It ensures rice production, reduces the risk of excessive nitrogen surplus and surface pollution, and promotes a greener, more environmentally friendly paddy field ecosystem.

Key points We measured the impact of blood flow restriction on muscle protein synthesis rates, muscle mass and strength during 2 weeks of strict bed rest. Twelve healthy, male adults (age: 24 ± 3 years, body mass index: 23.7 ± 3.1 kg/m2) were subjected to 14 days of strict bed rest with unilateral blood flow restriction performed three times daily in three 5 min cycles (200 mmHg). Participants consumed deuterium oxide and we collected blood and saliva samples throughout 2 weeks of bed rest. Before and immediately after bed rest, lean body mass (dual‐energy X‐ray absorptiometry scan) and thigh muscle volume (magnetic resonance imaging scan) were assessed in both the blood flow restricted (BFR) and control (CON) leg. Muscle biopsies were collected and unilateral muscle strength (one‐repetition maximum; 1RM) was assessed for both legs before and after the bed rest period. Bed rest resulted in 1.8 ± 1.0 kg lean body mass loss (P < 0.001). Thigh muscle volume declined from 7.1 ± 1.1 to 6.7 ± 1.0 L in CON and from 7.0 ± 1.1 to 6.7 ± 1.0 L in BFR (P < 0.001), with no differences between treatments (P = 0.497). In addition, 1RM leg extension strength decreased from 60.2 ± 10.6 to 54.8 ± 10.9 kg in CON and from 59.2 ± 12.1 to 52.9 ± 12.0 kg in BFR (P = 0.014), with no differences between treatments (P = 0.594). Muscle protein synthesis rates during bed rest did not differ between the BFR and CON leg (1.11 ± 0.12 vs. 1.08 ± 0.13%/day, respectively; P = 0.302). Two weeks of bed rest substantially reduces skeletal muscle mass and strength. Blood flow restriction during bed rest does not modulate daily muscle protein synthesis rates and does not preserve muscle mass or strength. Bed rest, often necessary for recovery from illness or injury, leads to the loss of muscle mass and strength. It has been postulated that blood flow restriction may attenuate the loss of muscle mass and strength during bed rest. We investigated the effect of blood flow restriction on muscle protein synthesis rates, muscle mass and strength during 2 weeks of strict bed rest. Blood flow restriction applied during bed rest does not modulate daily muscle protein synthesis rates and does not preserve muscle mass or strength. Blood flow restriction is not effective in preventing muscle atrophy during a prolonged period of bed rest. [ABSTRACT FROM AUTHOR]

This study was performed to investigate the nitrogen (N) and carbohydrate digestive traits of grazing heifers. The experiment was carried out at the Federal University of Lavras. The treatments were a Marandu palisadegrass (Urochloa brizantha [Syn, Brachiaria brizantha] Stapf. A. Rich. cv. Marandu) monoculture fertilised with 150 kg N/[ha ∙ year] (FP) or Marandu palisadegrass mixed pasture with forage peanut (MP). The pastures were grazed by six rumen-cannulated zebu heifers. A double cross-over design was used in four periods. Nutritive value, intake and apparent digestibility of forage, ruminal traits and kinetics and N balance were evaluated. Apparent total-tract digestibility of dry matter (DM) and neutral detergent fibre (NDF) were greater for FP than for MP. There was no effect in apparent total-tract digestibility of N. The estimated intestinal digestibility of nutrients was greater on MP than FP. Even though N intake and faecal N output were greater on MP than FP, there was no effect in urine N output. The N balance tended to be greater on MP than FP. The forage peanut, which contains condensed tannins, decreased ruminal fibre degradation, apparent digestibility and ruminal protein degradation, increased N flow from the rumen. Inclusion of forage peanut in the mixed pasture decreased the ruminal fibre degradability but increased N retention by the animals. [ABSTRACT FROM AUTHOR]

Hydrolysed proteins have been shown to be potential ingredients in cat diets due to their high digestibility, presence of bioactive peptides, and relatively low antigenicity. The effects of the substitution of conventional low ash poultry byproduct meal (PBM) with hydrolysed poultry byproduct meal (HPM) as a protein source were evaluated in extruded cat diets. Five diets with similar nutrient contents were formulated: a control (CO) diet based on PBM and 4 diets with different inclusions of HPM (5%, 10%, 20%, and 30%, on an as-fed basis) replacing PBM as the protein source. The total tract apparent digestibility (CTTAD) of nutrients, faecal characteristics and microbial fermentation products, urine production and pH, nitrogen balance and urea renal excretion were evaluated using 30 healthy cats (15 males and 15 females; 4.18 ± 0.86 kg; 4.17 ± 1.38 years old), with 6 cats per diet in a complete randomised block design. When significant differences were found with the F test, the effects were evaluated by polynomial contrasts according to HPM inclusion (p < 0.05). The CTTADs of DM (89 ± 0.41%), CP (90 ± 0.36%), fat (93 ± 0.41%) and gross energy (90 ± 0.33%) were similar among treatments (p > 0.05). The faecal production, score, short-chain fatty acids and ammonia concentration were similar among treatments (p > 0.05). Isobutyric, isovaleric, valeric, and total branched-chain fatty acid contents increased quadratically (p < 0.05), with the highest level in the faeces of cats fed the diet with 20% HPM. Lactate concentration in faeces increased linearly with the inclusion of HPM (p < 0.05). Urine characteristics and urea renal excretion did not differ among treatments (p > 0.05). At 10% inclusion, HPM tended to increase the nitrogen retention of cats (p = 0.083), which may reflect the higher tryptophan, methionine, lysine, and available lysine contents of HPM in comparison to PBM. The inclusion of up to 30% HPM can be considered in cat formulations without affecting nutrient digestibility or faecal and urine characteristics. HPM tended to increase nitrogen retention and increased branched-chain fatty acids in faeces, aspects which deserves further studies. [ABSTRACT FROM AUTHOR]

Onions (Allium cepa L.) contain various flavonols, including quercetin, kaempferol, anthocyanin, luteolin, and myricetin. Quercetin in onions is considered the primary bioactive component. To assess the impact of quercetin on hyperuricemia in healthy Wistar albino rats, this study used high‐performance liquid chromatography with ultraviolet (HPLC‐UV) to identify and measure quercetin in onion powder. Twenty‐four 160 ± 10 g, six wistar albino male rats in each group were kept: NC (control sample, no onion powder), OT1, OT2, and OT3, which contained 11.13, 14.84, and 18.61 g/100 g onion powder, respectively. The treatment lasted 28 days, during which the last 7 days were for urine, feces, and blood collection. The results showed a trend of decreasing levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, total bilirubin, total cholesterol, and low‐density lipoprotein in rats fed OT1, OT2, and OT3 diets. Improvements were observed in feed, water, and nutrient intake, feed conversion ratio, feed efficiency ratio, nutrient digestibility, nitrogen balance, body weight, blood urea nitrogen, creatinine, and uric acid levels (p ≤.05). In contrast, high‐density lipoprotein, triglycerides, serum total protein, neutrophils, and lymphocytes did not change (p ≥.05). White blood cells, red blood cell count, platelet count, hemoglobin, and monocytes showed an upward trend. Based on our calculations, we determined the optimal human dosage from the most effective amount of onion powder. By taking into account the ratio of human‐to‐rat surface area, we estimate that the equivalent human dose of onion is 181.04 grams with 204 mg of quercetin. Additionally, when factoring in the dry matter content, the recommended dose of onion is 29.19 grams with 220 mg of quercetin. [ABSTRACT FROM AUTHOR]

Background: This retrospective cohort study sought to describe the ability of high protein regimens to achieve nitrogen equilibrium in patients receiving venovenous extracorporeal membrane oxygenation (VV ECMO). Methods: Patients aged ≥18 years with a documented nitrogen balance study (NB) on VV ECMO between February 2018 and December 2021 were included. Studies with incomplete 24‐h urine collections or changes in blood urea nitrogen ≥10 mg/dl were excluded. Data were summarized, correlation between first NB and potentially contributing variables was assessed with Kendall tau. Subanalysis described findings after stratifying for weight class (obese vs nonobese) and duration of VV ECMO at the time of NB. Results: A total of 68 NBs in 30 patients were included; 47% of the cohort had obesity. The number of NBs per patient was 2.2 ± 1.1, which were completed on a median of 31.5 (interquartile range: 16, 53.8) days receiving ECMO. Nitrogen equilibrium or positive balance was achieved in 72% of studies despite elevated nitrogen excretion. Patients received 87.9 ± 16.8% of prescribed protein on NB days for average intakes of 2.4 ± 0.4 g/kg of actual weight per day and 2.4 ± 0.5 g/kg of ideal weight per day in patients without and with obesity. Median NB in patients without obesity was −1.46 (−8.96, 2.98) g/day and −0.21 (−10.58, 4.04) g/day in patients with obesity. A difference in median NB after stratification for timing was observed (P = 0.029). Conclusion: Nitrogen equilibrium can be achieved with high protein intake in adults receiving VV ECMO. NB monitoring is one tool to individualize protein prescriptions throughout the course of VV ECMO. [ABSTRACT FROM AUTHOR]

On dairy farms, fertilization of grass-clover swards ensures stable grass yields but may increase the potential for nitrate leaching on light-textured soils. The aim of this study was to quantify the N use efficiency and nitrate leaching under fertilized grass-clover leys. The study was conducted over 2 years at two sites, with increasing applications of mineral fertilizer (0–480 kg available N ha−1) alone or in combination with a basic application of cattle slurry. For plots fertilized with mineral N, the N soil surface balance was independent of the application rate and in the same range as for unfertilized plots (− 11 to 51 kg N ha−1). However, when plots were fertilized with slurry N (+ mineral N), the surplus was substantially increased owing to the fraction of organic N applied in slurry (95–100 kg N ha−1) and higher biological N2 fixation inputs (55–228 kg N ha−1). The type of fertilizer had no effect on nitrate leaching across the full range of application rates. Nitrate leaching increased quadratically as a function of application rate, with a range of 3–117 kg N ha−1 (0.33–17 mg l−1 in soil solution sampled with suction cups) in the first year and less in the second year, when clover proportion was lower due to the self-regulatory nature of grass-clover mixtures. Importantly, the rate of marginal leaching increased with fertilization level: below 150 kg N ha−1 there was no additional leaching from fertilization and at 200 kg N ha−1 around 5% of additional fertilizer-N was leached. This is less than generally found for arable crops and thus even in intensive dairy systems, grass-clover leys are an environmentally favorable crop. [ABSTRACT FROM AUTHOR]

The main goal of this article is to elucidate the SDZ and TN removal characteristics and mechanisms of a saline-resistant strain of Acinetobacter sp. RT-6. The SDZ and TN removal characteristics indicated that SDZ and TN removal were significantly affected by SDZ concentration and salinity. The removal curves and kinetics of different typical amounts of nitrogen showed the shortcut nitrification and denitrification present in the ammonia-N removal process; the nitrogen-containing compound was mainly transformed into N2, and approximately 19.05 ± 0.83 mM of the electrons was transferred to the nitrate respiratory chain. The intermediates of SDZ degradation were identified, and it was speculated that the main reaction sites for SDZ transformation were the N–C bond, N–S bond, pyrimidine ring, and benzene ring. [ABSTRACT FROM AUTHOR]

Simple Summary: Ammonia gases are produced from urea in the urine and slurry due to the action of urease. Odorous compounds are produced by microbial fermentation that utilizes an undigested nutrient in pig slurry. Various additives have been researched to mitigate ammonia emissions or odorous compound production. These studies involve inducing acidic conditions in urine or slurry, enhancing nitrogen utilization, inhibiting urease, or absorbing odorous compounds in pig slurry. However, information about the comparison of these additives is lacking. In this study, we evaluate and compare the effects of each additive on nitrogen utilization, urinary pH, slurry pH, and odorous compound concentrations. The five experimental diets were (1) a control diet, (2) the control diet with 1% benzoic acid, (3) the control diet with 1% adipic acid, (4) the control diet with 1% bromelain, and (5) the control diet with 1% humic substances. Fecal dry matter and nitrogen output were greatest in pigs fed the humic substances diet. Daily retained nitrogen and the nitrogen retention rate tended to be lowest in pigs fed an adipic acid diet. Urinary pH was lowest in pigs fed the adipic acid diet. In addition, slurry pH did not affect odorous compound concentrations, and some odorous compounds tended to be lowest in pigs fed the humic substances diet. The objective was to evaluate the effects of benzoic acid, bromelain, adipic acid, and humic substance supplementation on nitrogen balance, urinary pH, slurry pH, and manure odorous compounds in pigs. Fifteen castrated male pigs with an initial body weight of 37.9 kg (standard deviation = 4.1) were individually housed in metabolism crates. The animals were allocated to a triplicated 5 × 2 incomplete Latin square design with 15 animals, 5 experimental diets, and 2 periods. The basal diet mainly consisted of corn, soybean meal, and rapeseed meal. Four experimental diets were prepared by supplementing each additive at a concentration of 10 g/kg at the expense of corn starch to the basal diet. Each period consisted of a 4-day adaptation period, a 24 h collection period for slurry sampling, and a 4-day collection period for feces and urine. The feces and urine collected for 24 h on day 5 were mixed at a ratio of fecal weight and urine weight to obtain slurry samples. The apparent total tract digestibility N in pigs fed the humic substance diet was the least (p < 0.05) compared to the other groups. The daily retained N and N retention as % ingested tended (p < 0.10) to be the lowest in the adipic acid group among the treatments. The urinary pH in pigs fed the adipic acid diet was less (p < 0.05) than that in other groups except the benzoic acid group. The slurry pH tended to differ among the treatment groups (p = 0.074) with the lowest value in the pigs fed the adipic acid diet. The concentrations of indole in slurry (p = 0.084) and isovalerate in feces (p = 0.062) tended to differ among the groups with the lowest values in the pigs fed the humic substance diet. In conclusion, adipic acid supplementation in pig diets can decrease urinary pH and slurry pH. Although benzoic acid and adipic acid have limited effects in reducing odorous compounds, humic substances have the potential to reduce some odorous compounds. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of sex on growth performance, carcass characteristics, meat quality, and blood metabolite parameters of Awassi lambs. Twenty-seven Awassi lambs were allocated into two sex groups: males (n=13) and females (n=14). Lambs were individually penned and fed according to the nutritional needs of small ruminants. The experimental period of the study continued for 63 days, preceded by seven days for dietary and pen adaptation. On day 56 of the experimental period, five lambs of each sex group were randomly chosen and distributed in metabolism chambers to examine the digestibility and nitrogen balance. After 70 days of the trial, all lambs were butchered to determine their carcasses and meat quality. The average dry matter (DM) and crude protein (CP) intakes were significantly affected by sex (p < 0.05). Both sexes had similar DM and CP digestibility. Male lambs had greater nitrogen intake and retention (p < 0.05). Growth performance, weights of fasting animals, weights of hot and cold carcasses, non-carcass parts and carcass cuts were influenced (p < 0.05) by the lambs, sex. [ABSTRACT FROM AUTHOR]

Introduction: Onions (Allium cepa L.) are excellent sources of bioactive compounds and phytochemicals such as allicin, quercetin, fisetin, and other sulfurous compounds. Therefore, our study aimed to investigate the effects of dried onion powder on growth performance, nitrogen balance, and biochemical parameters in Wistar albino rats with induced hyperuricemia. Methods: A total of 24 rats were randomly divided into four groups, with six in each group: HU (positive control) and HOT1, HOT2, and HOT3 groups, which received a diet containing onion powder at concentrations of 11.13,14.84, and 18.61 g/100 g, respectively. Hyperuricemia was induced in rats by administering a new formulation intraperitoneally (250 mg/kg potassium oxonate) and orally (40 mg/kg potassium bromate) daily for 14 days. After confirmation of hyperuricemia induction, rats were fed with onion-treated diets with various concentrations of quercetin for 21 days. Results: Significant decreases (p ≤ 0.05) in serum uric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, total cholesterol, and low-density lipoprotein were observed. An increasing trend (p ≤ 0.05) in the levels of hemoglobin (Hb), white blood cell (WBC), red blood cell (RBC), and platelet count was observed. An improvement in the levels of serum high-density lipoprotein, triglycerides, blood urea nitrogen, serum creatinine, serum total protein and neutrophils, lymphocytes, and monocytes was observed. A positive progress (p ≤ 0.05) was observed in growth performance and nutrient digestibility. Conclusion: In conclusion, a significantly lower uric acid level was observed in rats fed with HOT2 diet. Based on the ratio of the surface area (human/rat), the best recommended dose of onion for the incidence and prevention of hyperuricemia is 189.95 g, corresponding to the dose of 204 mg/day of quercetin in humans. [ABSTRACT FROM AUTHOR]

In a simple randomized design trial, 420 growing male V-Line rabbits were randomly distributed into four groups to investigate the impact of exogenous dietary lysozyme on some physiological and nutritional parameters of male growing rabbits supplemented with exogenous dietary lysozyme. The witness group received a basal diet without exogenous dietary lysozyme (LYZ0), while the exogenous dietary lysozyme groups received 50, 100 and 150 mg/kg of basal diet (Groups; LYZ50, LYZ100 and LYZ150), respectively. The results showed significantly increased in blood cell count, hemoglobin concentration, total white blood cell, lipase, protease, amylase, total protein, triiodothyronine and thyroxine levels, while thyroid stimulating hormone levels significantly lessened in rabbits received LYZ. The LYZ- rabbit diets improved total digestible nutrient, digestible crude protein, and digestible energy values, with the LYZ100 group outperforming the others. LYZ-treated rabbits had significantly higher nitrogen intake, digestible nitrogen, and nitrogen balance than the witness group. The lysozyme in a rabbit's diet is taking on a new role as a digestive enzyme, enhancement thyroid hormones, as well as improvement hematology, daily protein efficiency ratio, daily performance index, hot carcass, total edible parts, nutritional value, and nitrogen balance, with decreasing the daily caloric conversion ratio and total non-edible parts. [ABSTRACT FROM AUTHOR]

2023. Introduction: Exercise with low carbohydrate availability increases protein degradation, whichmay reduce subsequent performance considerably. The present study aimed to investigate the effect of carbohydrate ingestion during standardized exercise with and without exhaustion on protein degradation and next-day performance. Methods: Seven trained male cyclists ( VO2max 66.8 ± 1.9 mL·kg-1·min-1; mean ± SEM) cycled to exhaustion (-2.5 h) at a power output eliciting 68% of VO2max (W68%). This was followed by repeating 1-min work/1-min recovery intervals at 90% of VO2max (W90%) until exhaustion. During W68%, cyclists consumed a placebo water drink (PLA) the first time and a carbohydrate drink (CHO), 1 g carbohydrate·kg-1·h-1, the second time. The participants performed the same amount of work under the two conditions, separated by at least 1 wk. A standardized diet was provided to the participants so that the two conditions were isoenergetic. To test the impact of carbohydrates on recovery, participants completed a time trial (TT) the next day. Results: Carbohydrate ingestion maintained carbohydrate availability duringW68% andW90%: total carbohydrate oxidation was significantly higher in CHO (P = 0.022), and plasma glucose concentration was maintained compared with PLA (P = 0.025). Next-day performance during TT was better after CHO ingestion (CHO, 41:49 ± 1:38 min; PLA, 42:50 ± 1:46 min; P = 0.020; effect size d = 0.23, small), as was gross efficiency (CHO, 18.6% ± 0.3%; PLA, 17.9% ± 0.3%; P = 0.019). Urinary nitrogen excretion (P = 0.897) and urinary 3-methylhistidine excretion (P = 0.673) did not significantly differ during the study period. Finally, tyrosine and phenylalanine plasma concentrations increased in PLA but not in CHO (P = 0.018). Conclusions: Carbohydrate ingestion during exhaustive exercise reduced deterioration in next-day performance through reduced metabolic stress and development of fatigue. In addition, some parameters point toward less protein degradation, which would preserve muscle function. [ABSTRACT FROM AUTHOR]

Decreased dietary protein intake (DPI) may lead to protein-energy malnutrition and may be associated with increased mortality risk. We hypothesized that longitudinal changes in dietary protein intake have independent associations with survival in peritoneal dialysis (PD) patients. 668 stable PD patients were selected in the study from January 2006 to January 2018 and were followed up until December 2019. Their three-day dietary records were collected at the baseline (the sixth month after PD) and thereafter every 3 months for two and a half years. The latent class mixed models (LCMM) were used to identify subgroups of PD patients with similar longitudinal trajectories of DPI. The relation between DPI (baseline and longitudinal data) and survival was examined using Cox model to estimate death hazard ratios. Meanwhile, different formulae were used to assess nitrogen balance. The results showed that baseline DPI ≤ 0.60g/kg/day was associated with the worst outcome in PD patients. Patients with DPI 0.80–0.99g/kg/day and DPI ≥ 1.0g/kg/day both presented positive nitrogen balance; patients with DPI 0.61–0.79g/kg/day presented obviously negative nitrogen balance. Longitudinal association between time-dependent DPI and survival was found in PD patients. The consistently low DPI' (0.61–0.79g/kg/d) group was correlated with increased death risk as compared with the 'consistently median DPI' group (0.80–0.99g/kg/d, HR = 1.59, p = 0.008), whereas there was no difference in survival between 'consistently median DPI' group and 'high-level DPI' group (≥1.0 g/kg/d, p > 0.05). Our study revealed that DPI ≥ 0.8 g/kg/day was beneficial to the long-term outcome for the PD population. [ABSTRACT FROM AUTHOR]

Inclusion of urea in dairy cattle diets is often limited by negative effects of high levels of feed urea on dry matter intake (DMI) and efficiency of rumen N utilization. We hypothesized that supplying urea postruminally would mitigate these limitations and allow greater inclusion of urea in dairy cattle diets. Four rumen-fistulated Holstein-Friesian dairy cows (7 ± 2.1 lactations, 110 ± 30.8 d in milk; mean ± standard deviation) were randomly assigned to a 4 × 4 Latin square design to examine DMI, milk production and composition, digestibility, rumen fermentation, N balance, and plasma constituents in response to 4 levels of urea continuously infused into the abomasum (0, 163, 325, and 488 g/d). Urea doses were targeted to linearly increase the crude protein (CP) content of total DMI (diet plus infusion) by 0%, 2%, 4%, and 6% and equated to 0%, 0.7%, 1.4%, and 2.1% of expected DMI, respectively. Each 28-d infusion period consisted of a 7-d dose step-up period, 14 d of adaptation, and a 7-d measurement period. The diet was fed ad libitum as a total mixed ration [10.9% CP, 42.5% corn silage, 3.5% grass hay, 3.5% wheat straw, and 50.5% concentrate (dry matter basis)] and was formulated to meet 100%, 82%, and 53% of net energy, metabolizable protein, and rumen-degradable protein requirements, respectively. Linear, quadratic, and cubic effects of urea dose were assessed using polynomial regression assuming the fixed effect of treatment and random effects of period and cow. Dry matter intake and energy-corrected milk yield responded quadratically to urea dose, and milk urea content increased linearly with increasing urea dose. Apparent total-tract digestibility of CP increased linearly with increasing urea dose and ruminal NH 3 -N concentration responded quadratically to urea dose. Mean total VFA concentration was not affected by urea dose. The proportion of N intake excreted in feces decreased linearly and that excreted in urine increased linearly in response to increasing urea dose. The proportion of N intake excreted in milk increased linearly with increasing urea dose. Urinary urea excretion increased linearly with increasing urea dose. Microbial N flow responded cubically to urea dose, but the efficiency of microbial protein synthesis was not affected. Plasma urea concentration increased linearly with increasing urea dose. Regression analysis estimated that when supplemented on top of a low-CP diet, 179 g/d of postruminal urea would maximize DMI at 23.4 kg/d, corresponding to a dietary urea inclusion level of 0.8% of DMI, which is in line with the current recommendations for urea inclusion in dairy cattle diets. Overall, these results indicate that postruminal delivery of urea does not mitigate DMI depression as urea dose increases. [ABSTRACT FROM AUTHOR]

Reducing nitrogen pollution while maintaining milk production is a major challenge of dairy production. One of the keys to delivering on this challenge is to improve the efficiency of how dairy cows use nitrogen. Thus, estimating the nitrogen utilization of lactating grazing dairy cows and exploring the association between animal factors and productivity with nitrogen utilization are the first steps to understanding the nitrogen utilization complex in dairy cows. Nitrogen utilization metrics were derived from milk and body weight records from 1,291 grazing dairy cows of multiple breeds and crossbreeds; all cows had sporadic information on nitrogen intake concurrent with information on nitrogen sinks (and other nitrogen sources, such as body tissue mobilization). Several nitrogen utilization metrics were investigated, including nitrogen use efficiency (nitrogen output as products such as milk and meat divided by nitrogen intake) and nitrogen excreted (nitrogen intake less the nitrogen output as products such as milk and meat). In the present study, a primiparous Holstein-Friesian used, on average, 20.6% of the nitrogen it ate, excreting the surplus as feces and urine, representing 402 g of nitrogen per day. Intercow variability existed, with a between-cow standard deviation of 0.0094 for nitrogen use efficiency and 24 g of nitrogen per day for nitrogen excretion. As lactation progressed, nitrogen use efficiency declined and nitrogen excretion increased. Nevertheless, nitrogen use efficiency improved (i.e., decreased) from first to second parity, even though it did not improve from second to third parity or greater. Furthermore, nitrogen excretion continued to increase from first to third parity or greater. Nitrogen use efficiency and nitrogen excretion were negatively correlated (−0.56 to −0.40), signifying that dairy cows who partition more of the ingested nitrogen into products such as milk and meat, on average, also excrete less nitrogen. Milk urea nitrogen was, at best, weakly correlated with nitrogen use efficiency and nitrogen excretion; the correlations were between −0.01 and 0.06. In conclusion, several cow-level factors such as parity, stage of lactation, and breed were associated with the range of different nitrogen efficiency metrics investigated; moreover, even after accounting for such effects, 4.8% to 6.3% of the remaining variation in the nitrogen use efficiency and nitrogen balance metrics were attributable to intercow differences. [ABSTRACT FROM AUTHOR]

A experiment was conducted at the Jiangxi Province Center Station of Irrigation Experiment from 2019 to 2021 to study the water and nitrogen balance under water and fertilizer regulation modes. The study aimed to propose a recommended mode for paddy fields that could save water, control pollution, reduce gas emission, and improve fertilizer use efficiency. This study examined the impact of different irrigation methods and nitrogen application levels on water saving and emission reduction in paddy fields. The experiment included six treatments, which involved two irrigation methods (intermittent irrigation and flooding irrigation, referred to as W1 and W0, respectively) and three application rates of nitrogen fertilizer (0 kg/ha, 135 kg/ha, 180 kg/ha, referred to as N0, N1 and N2, respectively). The study found that irrigation methods had a significant effect on the amount of irrigation, drainage, leakage, nitrogen load from drainage, soil nitrification potential, and ammonia volatilization. The results showed that compared to flooding irrigation, intermittent irrigation reduced the amount of irrigation, drainage, leakage and nitrogen load from drainage by an average of 25.98%, 16.03%, 8.43% and 10.86%, respectively. However, the study also found that the nitrification potential and ammonia volatilization increased by an average of 6.45% and 4.32%, respectively. Fertilization levels had a significant effect on drainage nitrogen load, early soil nitrification potential and ammonia volatilization. Compared with the treatment of N2 (180 kg N/ha), the drainage nitrogen load under the treatment of N1 (135 kg N/ha) decreased by 10.86% on average, while nitrification potential and ammonia volatilization increased by 38.74% and 3.33%, respectively. In terms of nitrogen output, the amount of nitrogen absorbed by crops was the largest, followed by the nitrogen load from field drainage, then ammonia volatilization, and then denitrification. Considering the goals of water saving, emission reduction, and the efficient utilization of water and fertilizer in paddy fields, the optimal water and fertilizer regulation mode was the W1N1 mode (intermittent irrigation combined with reduced nitrogen fertilizer application rate, 135 kg N/ha). [ABSTRACT FROM AUTHOR]

Background: Serum prealbumin has long been used as a marker of nutritional status. However, prealbumin is a negative acute phase reactant influenced by several non-nutritional-related factors including surgery, infection, and cancer. An increasing prealbumin has been correlated with a positive nitrogen balance in general surgery patients receiving parenteral nutrition (PN) with 88% specificity and 70% sensitivity. To date, no trial has evaluated the effect of concurrent cancer and surgery on the value of prealbumin in predicting nitrogen balance. Methods: This study is a concurrent retrospective design of post-operative patients (≥ 19 years of age) identified by the nutrition support service who received PN for ≥ 5 days, had a baseline and follow-up serum prealbumin and C-reactive Protein (CRP) measured, as well as a 24-h urinary urea nitrogen (UUN) performed between days 5–10 of PN. Exclusion criteria include anuric renal failure, Child–Pugh Class C liver failure, pregnancy, and corticosteroid use. Prealbumin was correlated to nitrogen balance, measuring sensitivity, specificity, and negative and positive predictive values. Information was collected regarding patient demographics and presence or absence of metastatic cancer. Results: Thirty patients were identified and evaluated for this study from December 1st, 2010 to July 15th, 2011. Patients included in the study had a mean age of 57 years old (range 20–82), 53% male, with a mean weight of 84 kg (range 42–140) and body mass index (BMI) of 29 kg/m2 (range 14.9–56.8). The mean daily caloric dose of PN per actual body weight was 21 kcal/kg (range 10–34) and the mean daily protein dose was 1.4 g/kg (range 1–2). Forty seven percent of patients were obese (BMI > 30 kg/m2) and were prescribed high-protein hypocaloric PN. The most common indication for PN was post-operative ileus (23/30 patients). 24-h urine collection for UUN was performed on average of day 8 after PN initiation (range 5–10 days). Nitrogen balance as calculated from 24-h UUN was positive in 17/30 patients. A positive prealbumin change of greater than 2.8 mg/dL was found to have a statistically significant association with positive nitrogen balance (p = 0.02). At the cut off level of positive 2.8 mg/dL, the likelihood of a positive nitrogen balance had a sensitivity of 82% (95% confidence interval (CI) 64–100%); specificity of 62% (95% CI 35–88%); positive predictive value of 74% (95% CI 54–93%); negative predictive value of 73% (95% CI 46–99%). No absolute value for prealbumin level (e.g., > 20 mg/dL) was found to be a significant predictor of positive nitrogen balance. CRP levels at initiation of PN were significantly elevated with a mean level of 147 mg/dL. Conclusion: These results indicate a positive change in serum prealbumin (> 2.8 mg/dL) has sufficient sensitivity (82%) to predict positive changes in nitrogen balance in the surgical oncology population. However, the low specificity (62%) makes it less useful in predicting a negative nitrogen balance. Absolute prealbumin levels were greatly affected by inflammation, as evidenced by CRP levels, and single values were not useful in predicting positive nitrogen balance. Clinical relevancy: Positive changes in serum prealbumin levels have previously been associated with a positive nitrogen balance (NB) in surgical patients receiving parenteral nutrition (PN); however, it is unclear if this is true in oncologic surgery patients. This study highlights how changing levels of serum prealbumin and C-reactive protein correlates to NB for cancer patients in the post-operative period requiring PN. Changes in prealbumin levels from baseline showed sufficient sensitivity, but not specificity to utilize routinely for predicting NB in this population. [ABSTRACT FROM AUTHOR]