Nitrogen Balance Research Articles

Influence of crop rotation, the treatment of crop residues, and the application of nitrogen fertilizers on soil properties and maize yield

AbstractThis inquiry is aimed at discerning the impact of various agricultural practices, such as crop rotation, the incorporation of plant residues, and the application of mineral fertilizers, on soil health and crop productivity, notably focusing on maize production. Cultivation included maize (Zea mays), velvet beans (Mucuna pruriens), soybeans (Glycine max), and vetch (Vicia sativa). After harvest, maize seeds were sown across all 48 plots to evaluate the influence of preceding crop rotation on soil properties and maize yield. Hypotheses posited in the study suggested that crop rotation, nitrogen fertilizer application, and the incorporation of crop residues positively impact soil fertility. The study further argues that the utilization of cover crops in crop rotation aids in nitrogen retention within the soil and enhances yield. The results were processed utilizing a two‐way analysis of variance (ANOVA) with interaction and post hoc comparisons. The findings confirm that crop rotation, nitrogen fertilizer application, and incorporation of crop residues influence soil fertility. The study found that crop rotation and nitrogen fertilizers have a significant impact on soil properties. Crop rotations such as “velvet beans‐maize” and “soybeans‐maize” increased soil fertility by 10%–15% compared to crop rotations of “vetch‐maize” and maize monocultures. Nitrogen fertilizers increased the total nitrogen content in the soil by 5%–10% in both years. Crop residues also positively affected soil properties, increasing pH and total nitrogen by 1%–5%. The study demonstrates that crop rotation, nitrogen fertilizers, and crop residues can be effective management methods for improving soil fertility and reducing the risk of nitrate leaching.

Nitrogen reduction enhances crop productivity, decreases soil nitrogen loss and optimize its balance in wheat-maize cropping area of the Loess Plateau, China

In winter wheat-summer maize double cropping, fertilization changes the nitrogen (N) balance in the soil N pool, grain N uptake, N loss, and nitrogen use efficiency (NUE), ultimately impacting crop productivity and environmental health. For agricultural systems to maintain yields at lower environmental costs, N budgets must be balanced. Still, there is a deficiency in the reporting of N budgets of farming systems that incorporate all N flows. We evaluated the effects of various N fertilizer application rates on soil N balance and crop productivity in the 2017–2021 winter wheat-summer maize growing seasons. These rates included non-N fertilization (N0), 75 kg·N·ha−1 (N75), 150 kg·N·ha−1 (N150), 225 kg·N·ha−1 (N225), and conventional N fertilizer application rate, 300 kg·N·ha−1 (N300). Our analysis was based on a long-term field fertilization experiment and in-situ observation (established in 2010). The results show that fertilization significantly increased crop yields (wheat: 29.2 %–97.6 %; maize:25.4 %–98.1 %; annal: 27.0 %–96.7 %), among which N225 showed the highest increase value, compared with N0. Moreover, the N225 maximized grain N uptake by 201.0 %, reducing N losses and increasing N sequestration compared to the conventional N application rate of N300. N balance changes from negative to positive as the N application rate increases (wheat: −63.78–85.24 kg·ha−1; maize: −55.77–82.25 kg·ha−1; annal: −119.58–167.46 kg·ha−1·yr−1). Combining years of N inputs and outputs, the N225 is more balanced. Therefore, our study shows that an appropriate reduction of N fertilizer (N225) can help maintain agricultural productivity and promote N sequestration in farmland by reducing environmental N loss. Maintaining the virtuous cycle of N in the farmland ecosystem is beneficial and essential for the efficient utilization, high yield, and sustainable development of farmland resources.

PSXII-18 Nitrogen balance and ruminal bacterial diversity indexes of Nellore cattle fed with amylolytic and fibrolytic enzymes in feedlot

Abstract This study was carried out to evaluate the use of dietary exogenous enzyme (ENZ) products with amylolytic and fibrolytic activity on nitrogen balance and ruminal alpha and beta diversity of Nellore cattle in feedlot. Rumen cannulated Nellore steers [n = 10; body weigh (BW) = 543 kg ± 28.6 kg] were distributed in a replicate 5 × 5 Latin-square design using individual pens. The treatments consisted of a negative control (CON; without ENZ); Amylase [AML, Amaize, Alltech; 0.5 g/kg of diet dry matter (DM); Xylanase (FBL, Fibrozyme, Alltech; 0.9 g/kg of diet DM]; Half dose (HD; AML 0.25 g/kg of diet DM and FBL 0.45 g/kg of diet DM); and Full dose (FD; AML 0.5 g/kg of diet DM and FBL 0.90 g/kg of diet DM; Table 1). The experimental period lasted 19 d (14 d of adaptation and 5 d of collection). Between d 15 and 18, total urine collection was performed to calculate the nitrogen balance. On d 19 a mixed ruminal sample (6 mL of solid and liquid content) was taken 4 h after feeding and stored at -80 ºC until DNA extraction. Total genomic DNA was extracted using the ZymoBIOMICS DNA Miniprep Kit. The library was prepared using primers for the region V3V4 of the16S rRNA gene; 341F (5’-CCTAYGGGRBGCASCAG-3’) x 806R (5’- GGACTACNNGGGTATCTAAT-3’). The amplicons (~ 470 bp) were sequenced with the Illumina NovaSeq 6000 PE 250 platform. The sequences were analyzed using qiime2 with the SILVA database for the taxonomic assignment. Alpha and beta diversities were calculated in Rstudio using phyloseq. All data were analyzed as orthogonal contrasts assuming treatment as a fixed effect: 1) CON vs. ENZ, 2) AML vs. FBL, 3) HD vs. FD, and 4) AML + FBL vs. HD + FD. Animals that received ENZ had reduced fecal nitrogen excretion (FNE, P = 0.014) and greater efficiency of nitrogen utilization (ENU, P = 0.031) than animals in the CON group. The FBL treatment resulted in greater CP/DOM ratio (P = 0.049), nitrogen balance (P = 0.089), and ENU (P = 0.015) compared with AML treatment. No differences were observed between HD and FD for any nitrogen balance variable (P > 0.10). Animals supplemented with both enzymes (HD + FD) had greater values of N intake (P = 0.018), greater CP/DOM ratio (P = 0.006), and greater FNE (P = 0.002) than animals fed either enzyme alone (AML + FBL). The ENZ supplementation did not impact alpha diversity index or beta diversity (P > 0.10). In conclusion, the addition of exogenous enzymes affected nitrogen balance but not ruminal alpha and beta diversity of Nellore cattle in feedlot.

PSIX-19 Effect of protein and starch level on N balance and ruminal fermentation parameters in steers consuming low-quality forage: Bos taurus taurus

Abstract Globally cattle convert low-quality forage to beef and milk; therefore, understanding protein utilization in Bos taurus taurus is critical to enhancing sustainability as over and under-supplementation of protein are economically and environmentally costly. Low-quality forage lacks the N necessary for proper utilization and metabolic function. Supplemental protein improves low-quality forage utilization and is expected to increase N absorption and retention. Supplement starch can increase volatile fatty acid (VFA) production and energy supplied to the animal; however, too much starch decreases ruminally available N and pH potentially decreasing fibrolytic activity. Accordingly, our objective was to determine the effect starch supplementation on N balance and ruminal fermentation parameters in Bos taurus steers. Ruminally cannulated Angus steers [n = 5; body weight (BW) = 375 ± 45 kg] were used in a 4 × 4 Latin square to evaluate the effect of decreasing supplemental starch when consuming King Ranch Bluestem hay (3.5% CP, 73% NDF). Steers received four isonitrogenous (130 mg N/kg BW) supplements providing increasing levels of starch (2% starch = 100% soybean meal; 20% starch = 26.3% corn, 73% soybean meal, 0.7% urea; 38% starch = 51.6% corn, 47% soybean meal, 1.4% urea; 56% starch = 78.6% corn, 19% soybean meal, 2.4% urea). Five 14-d periods were conducted, consisting of 9 d adaptation and 4 d to measure intake and digestion, and 1 d for ruminal fermentation. Supplemental N intake decreased linearly (P < 0.01) with increasing starch as the crude protein content of the soybean was underestimated. Forage and total N intake were not affected by starch level (P ≥ 0.17). Fecal and total urinary N excretion were not different between starch levels (P ≥ 0.43). Urinary ammonia-N and urea-N averaged 6.6 and 16.8% of total urinary N excretion, respectively, but no differences between starch levels were observed (P ≥ 0.39). Level of starch supplementation had no effect on N retention and absorption (P ≥ 0.50). There was a treatment × time interaction observed for ruminal ammonia concentration (P < 0.01). All treatments, except 2% starch, peaked at 4 h post feeding, 20 and 38% treatments gradually decreased following four, but the concentration of ruminal ammonia decreased by 80% between 4 h and 8 h after feeding in the 56% starch treatment. Starch level had no effect total VFA concentration, VFA molar proportions, or ruminal pH (P ≥ 0.10). In conclusion, providing supplemental starch did not affect N balance or VFA production when fed to steers consuming low-quality forage. Nitrogen balance and VFA production likely were not affected because all supplements provided sufficient ruminally available N and, therefore, exerted minimal effects on forage utilization.

High rate methanogenesis and nitrogenous component transformation in the high-solids anaerobic digestion of chicken manure enhanced by biogas recirculation ammonia stripping

High-solids anaerobic digestion is a promising technology for treating animal manure. However, the high nitrogen content in chicken manure leads to severe ammonia inhibition, thereby hindering the application of this technology for chicken manure. This study operated a high-solid anaerobic system feeding the reactor with 20 % total solids (TS) chicken manure for 650 days to investigate whether the anaerobic metabolic performance could be enhanced by adopting biogas recirculation ammonia stripping. The results show that, with ammonia stripping, the total ammonia nitrogen (TAN) was reduced from 8.2 to 3.0 g/L. The methanogenic activity was enhanced 1.3 – 2.9 fold. This led to a low level of volatile fatty acids (VFA, 0.6 g/L) and a high methane yield of 0.3 L/g-volatile solids (VS). Protein decomposition was facilitated under stripping conditions and correlated with a higher abundance of protein decomposition bacteria and enhanced methane production. The dynamics of ammonium formation and removal were illustrated for different stripping conditions. The ability to maintain low ammonium and the carbon and nitrogen balance was also verified. The proven effectiveness observed in this long continuous experiment may provide a foundation for further demonstrating the high-solids anaerobic digestion of chicken manure.

PSV-11 Significance of specialty protein ingredients in feeding programs for broiler chickens on nitrogen utilization and excretion- A meta-analysis

Abstract The utility of specialty protein ingredients (SPI) in feeding programs for broiler chickens is premised on poor utilization of conventional vegetable proteins (CVP). The SPI includes ingredients of animal origin such as processed animal proteins (PAP), insect proteins (IP) and further processed conventional vegetable proteins (PCVP) characterized with greater concentration of crude protein/amino acids, and low anti-nutritional factors. The objective of this study was to apply meta-analysis approach of published studies that incorporated SPI to provide insights into their effectiveness on nitrogen utilization and excretion in broiler chickens. The data were retrieved from Web of Science, PubMed, ScienceDirect, hand searching and cross-referencing, and resulted in 44 publications meeting inclusion criteria such as being a broiler study and treatments diets being isocaloric and isonitrogenous Model development was performed in PROC GLIMMIX of SAS and treated the study as a random effect. The SPI protein source (PAP, IP, and PCVP), bird age (starter 0 to 14 d, grower 14 to 24 d and finisher 25 to 42 d), nitrogen intake and level were the main X variables of interest, while outcome (Y) variables explored included nitrogen excretion, nitrogen retention, nitrogen efficiency, average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR). To address heterogeneity in sample size and errors between treatment means from different studies, the WEIGHT statement in PROC GLIMIXX was employed to weight variables using the inverse of their squared variance. The inclusion or rejection of models developed was based on the evaluation of root mean square prediction error and concordance correlation coefficient. Comparatively, the slopes of PAP, IP and PCVP (soybean meal) linearly reduced and quadratically (P < 0.05) increased ADG during the starter phase against their respective controls. The extent ADG was greatest with intake of PCVP followed by PAP. During the grower phase, ADG was highest for PAP, followed by IP with PCVP being the least (P < 0.05). However, PCVP had the greatest ADG during the finisher phase (P < 0.05). On nitrogen excretion, provision of PAP during the stater phase increased the nitrogen excretion while it reduced the excretion during the grower and finisher phase (P < 0.05) relative to control. The intake of IP up to 10% inclusion reduced nitrogen excretion only during the starter and grower phase (P < 0.05) when compared with respective controls. The intake of PCVP reduced nitrogen excretion in all growth stages compared with respective controls (P < 0.05). In conclusion specialty proteins (PAP and PCVP) and insect protein at an inclusion level of < 10%, were effective ways of reducing nitrogen excretion while improving growth performance. Combining these strategies may have a synergistic effect.

PSLBII-4 The effect of standardized ileal digestible sulfur amino acid intake during late gestation on gilt whole-body nitrogen retention and subsequent litter performance

Abstract Gestating gilts [n = 27; body weight (BW) = 158 ± 5.5 kg] were used to determine the effect of standardized ileal digestible (SID) sulfur amino acid (SAA) intake during late gestation on whole-body nitrogen (N) retention and subsequent litter performance. Gilts were assigned to one of two experimental diets that provided SAA at 60 or 200 % of estimated requirements during late gestation (0.29 and 0.92 % SID SAA, respectively; n = 15 and 12, respectively; Table 1 and 2). Each gilt received 2.53 kg of the assigned diet between gestation d 90 and farrowing; standard lactation and nursery diets were provided to gilts after farrowing and offspring after weaning, respectively. Gilt whole-body N balance was determined between d 107 and 109 of gestation using total urine collection and fecal grab-sampling. After farrowing, litters were standardized to 13 piglets and were not offered creep feed. Whole-body N retention was greater in gilts fed the diet containing 0.92 vs. 0.29 % SID SAA in late gestation (27.2 vs. 19.3 ± 1.8 g/d; P < 0.05; Table 3), but the number of piglets born alive, litter birth weight, subsequent piglet growth rates, and litter size at weaning were not different between treatment groups. The post-weaning growth performance of offspring was also not influenced by maternal dietary treatment in late gestation (Table 4). At farrowing, the post-absorptive plasma concentration of Cys tended to be less (P = 0.072) and taurine was greater (P < 0.01) for gilts fed 0.92 vs. 0.29 % SID SAA in late gestation; however, there were no differences in plasma SAA metabolites concentrations for gilts at weaning or offspring at birth (Table 5. At weaning, offspring from gilts fed 0.92 % SID SAA had greater plasma homocysteine (P < 0.05) and plasma Cys concentrations (tendency; P = 0.072) vs. offspring from gilts fed 0.29 % SID SAA in late gestation. Three weeks after weaning, plasma taurine concentration was less (P < 0.05) for offspring from gilts fed 0.92 vs. 0.29 % SID SAA in late gestation (Table 6). Six weeks after weaning, plasma glutathione concentration tended to be less (P = 0.057) for offspring from gilts fed 0.92 vs 0.29 % SID SAA in late gestation. When SAA were fed below estimated requirements during late gestation, whole-body N retention was reduced, but fetal growth appeared to be maintained, likely at the expense of maternal N retention. Such divergences in dietary SAA supply in late gestation had no effect on subsequent offspring growth performance, but it appeared that offspring SAA metabolism was impacted until at least 6 wk after weaning. The influence of differences in sulfur AA metabolites on offspring performance beyond the nursery phase remains unknown. Therefore, carry-over effects of maternal SAA supply in late gestation should be considered when developing feeding recommendations for gestating gilts.

54 Development of an equine metabolism model to describe post-absorptive nutrient dynamics

Abstract Nutrition modelling is instrumental to modern feed formulation and diet optimization across livestock sectors. Mechanistic models of nutrient digestion, absorption, and metabolism are implemented in industry as ‘decision support systems’, and in academia to summarize and examine our cumulative biological knowledge, identify knowledge gaps and test/evaluate hypotheses. However, comparatively less progress in this field has been made in the equine sector. This limits the ability of the equine sector to address complex challenges such as interactions between equine nutrition, management, health, and welfare. To address this gap, a first iteration of a dynamic, deterministic, mechanistic model describing postabsorptive nutrient dynamics for equines has been developed. Model coding and development was performed using Python with specific libraries for mathematical equations and integration. This model was developed primarily based on extant published mechanistic models of protein and energy metabolism in other species. The present model simulates the partitioning of ingested nutrients into digested nutrients, through intermediary metabolism and ultimately to growth and deposition of protein, fat, water, and ash into the body compartments. As shown in Figure 1, the model takes digested nutrients (protein, fat, starch, glucose, volatile fatty acids) as inputs and contains 12 state variables divided into metabolite pools (amino acids, fatty acids, glucose, glycogen, acetyl-CoA, ATP), and body constituent pools (muscle protein, bone protein, hide protein, viscera protein, body fat, body ash). Ingested feed is partitioned into digested nutrients using digestibility coefficients from extant equine literature, and indigestible nutrients are excreted. Meta-analysis was used to develop empirical equations to predict VFA concentrations in the hindgut. VFA absorption is estimated using Michaelis-Menten kinetics including the pH and hindgut volume, assumed as a constant value for a mature horse Acetyl-CoA, a key intermediary metabolism pool, is produced from amino acid, glucose, and fatty acid catabolism and is consumed for maintenance requirements, which is accounted for in an ATP pool. The ATP pool is a ‘zero pool’, which balances the ATP producing and -consuming reactions in the model, with any remaining ATP balance required being pulled from the acetyl-CoA pool. Turnover of protein and fat is represented by differences in accretion and catabolism. Work is ongoing to evaluate the developed model for model performance using data extracted from the literature. The model will be trained and subsequently evaluated using equine studies in three main areas: growth and body composition, protein turnover and nitrogen balance, and energy metabolism. Developing this model for the equine sector will stimulate and assist in defining future research priorities, inform revisions to the nutrient requirements of horses, increase understanding of metabolic processes as well as related disorders, reduce waste via increased focus on precision feeding and support the development of new products and services to improve equine health.

470 Reducing crude protein levels with amino acid supplementation in the finishing diets of heavy Duroc sire line pigs: Effects on growth performance and nitrogen balance in males and females

Abstract Nutrition represents 70% of pig production costs, particularly protein; then, decreasing protein costs is of capital importance. Reducing crude protein (CP) contents to levels below recommended whilst supplementing with amino acids (AAs) is an interesting strategy to reduce costs without decreasing production performances with environmental benefits. It has been conducted essentially in lean genotypes during the growth stage. Few studies address heavy genotypes or differences between males and females during the finishing period. Our objective is to study productive performances of heavy [Duroc X (Landrace X Large-White)] male and female pigs during the finishing stage under a 2% CP reduction with crystalline AA supplementation, hypothesizing that both sexes will equally be affected. In total, 60 males and 60 females were used. At 9 wk of age, animals were allotted in split-sex pens (6 pigs/pen, 0.9 m2/animal) with water and dry feed ad libitum. At 15 wk of age, when pigs weighed an average of 68 kg, two isoenergetic diets with different CP levels were provided (145 and 125 g CP/kg, control and low-CP) during the last 42 d of fattening, under the ideal protein concept. In the low-CP diet, crystalline AAs were added. Feed intake was measured daily, and animals were weighed every 3 wk to calculate average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR) and N balance on d 21 and 42. Data were analyzed using the simple least squares models that included dietary treatment and sex and their interaction as fixed effects with the pen as the experimental unit. At d 21, animals weighed 90 to 95 kg with males being 5 to 6 % heavier (P < 0.01). No significant differences were recorded regarding diet. The same difference (P < 0.001) was recorded at day 42, with males (119-122 kg) being 7.25% heavier than females in both treatments. Males had 16% higher ADGs than females in both treatments (P < 0.0001) No differences were recorded for ADFI as a consequence of sex for both diets. FCRs were higher in females of both nutritional treatments (P < 0.0001). Retained N was 22% greater in males than in females for both dietary treatments. The N efficiency was greater in Low CP males by comparison with low CP females and control males, whereas control CP females had decreased N efficiency compared with all other experimental groups. Results demonstrate that the 20g/kg CP reduction supplemented with AAs can efficiently be used in heavy Duroc sire line genotypes during the finishing phase without a decrease in production parameters with females having poorer growth performances than males, whereas N efficiency was impaired when females had no limiting dietary CP.

374 Efficacy of phytase and/or chromium tripicolinate supplementation on nutrient digestibility and blood metabolites in grower pigs

Abstract Phytase supplementation is widely used in diet formulations to enhance nutrient use efficiency in pigs, while supplemental chromium tripicolinate has been shown to help optimize glucose metabolism by enhancing insulin sensitivity. Therefore, the objectives of this metabolism study were to examine potential synergies of these additives to evaluate if nutrient digestibility and/or blood metabolites could be improved in grower pigs. Grower pigs [n = 6; body weight (BW) = 21.8 ± 0.19 kg; Genesus genetics] were randomly allotted by initial BW to four treatments in a 2 x 2 factorial arrangement of treatments. Treatment (Trt) 1 consisted of a control diet without phytase while Trt 2 had decreased levels of calcium and phosphorus with added phytase (1,500 FYT/kg; HiPhorius; dsm-firmenich, Plainsboro, NJ). Treatment 3 was the control diet without phytase with added chromium from chromium tripicolinate (200 ppb; Chromax, Kent Nutrition Group, Inc., Muscatine, IA) while Trt 4 consisted of the diets with decreased levels of calcium and phosphorus with added HiPhorius (1,500 FYT/kg) and chromium tripicolinate (200 ppb). With six metabolism crates available and four treatment groups, it took a 4-wk duration to allow for each pig to be evaluated on each of the four treatments. The pigs were allowed a 4-d acclimation period followed by a 3-d collection period with the experimental diets fed at 4% BW divided into two meals each day. Water was added at 2.5 times the amount of feed fed each day. A second group of grower pigs (n = 6; BW = 19.6 ± 0.12 kg; Genesus) were utilized following the same procedures as above and pooled with the first group for data analysis. On the last day of the collection period, blood samples were collected before the meal (fasting) and then 2 h after the meal (post-meal). Added phytase resulted in a reduction (P < 0.05) in fasting blood urea nitrogen. Nitrogen digestibility and nitrogen retention were both improved (P < 0.01) with pigs fed supplemental phytase. Furthermore, dry matter digestibility was also improved (P < 0.001) in pigs fed added phytase. Supplemental chromium was without effect on any of the nitrogen and/or dry matter digestibility measurements. These data suggest that supplemental phytase has positive effects by significantly improving nitrogen and dry matter digestibility with no further improvements observed from supplemental chromium.

144 Assessing economic implications of thermal stress of Bos indicus and Bos taurus species during finishing in northern Colorado

Abstract The objective of this study was to determine the economic implications of thermal stress on climate adaptive capacity, resiliency, and impact of Bos indicus and Bos taurus finishing steers using common finishing systems. The experimental design was a completely randomized design, with a 2 by 2 factorial arrangement of finishing system (‘natural’ or ‘conventional’) and species of cattle (Bos indicus or Bos taurus). Steers [n = 200; body weight (BW) ~450 kg] were housed in 20 feedlot pens (10 steers/pen) for the first 84 d, where cattle were blocked by initial BW. For the remainder of the 180 d (96 d) finishing period, cattle were moved to four Climate Smart Research Pens (50 steers/pen, 1 pen/ treatment, and species combination). Within each Climate Smart Research Pen, five SmartFeed systems were used to evaluate individual animal feed intake, one GreenFeed emission measurement system was used to evaluate individual animal gas emissions flux of enteric CH4, O2, H2, and CO2, and were equipped for nutrient mass balance of carbon, nitrogen, and phosphorus. Animal BW were collected every 28 d for analysis of average daily gain (ADG) and feed efficiency. Thermal stress behaviors were evaluated by one trained personnel on a subset of 7 steers/treatment via the measurement of respiration rate, open mouth breathing, rumen temperature, number of daily water intake events, lying and standing behavior, and pen surface temperature for the last 96 d of the finishing period. At harvest, carcass characteristics, liver scores, and heart scores were collected. Economic analyses were conducted post-hoc to determine the profitability of each species based on economic implications, tradeoffs, carcass quality and quantity, and time to finish. Selection of cattle for climate adaptive features may involve production tradeoffs (e.g., depressed rate of gain, greater yield risk, lower technical efficiency) and adjustment costs (e.g., re-optimizing feed for a new breed), which affect the adoption of less common breeds into the US cattle supply chain. Adding to the complexity of this evaluation, consumers preferences may not adapt quickly, affecting the prospect of Bos indicus cuts of meat in the market. We also, therefore, explore the supply- and demand-side effects of climate change adaptation through breed selection in the beef industry.

Lemongrass essential oil in silage and as a feed additive has limited effect on animals feed intake and rumen fermentation

ABSTRACT 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.

Biological Nitrogen Fixation for Sustainable Agriculture Development Under Climate Change–New Insights From a Meta‐Analysis

ABSTRACTBiological nitrogen fixation (BNF) in legume crops is a crucial ecosystem service that enhances soil nitrogen and reduces the need for chemical fertilisers. This study evaluates the factors influencing the proportion of plant nitrogen derived from atmospheric fixation (Ndfa) in legume crops. We compiled a global dataset spanning from 1980 to 2018 and used the 15N method to assess the impacts of crop species, climatic conditions, stand composition and nitrogen fertilisation on Ndfa. The global meta‐analysis reveals that the percentage of nitrogen derived from atmospheric fixation (Ndfa) in legumes ranges from 5% to 99%, with an average of 68%. Fodder legumes exhibited higher Ndfa, averaging 75%, while grain legumes showed more variability, ranging from 38% to 85%, depending on species and climatic conditions. The significant variability in Ndfa underscores the complexity of the process, which is influenced by species‐specific traits, ecological conditions and competition in mixed stands. However, the current data is insufficient for precise Ndfa estimation in nitrogen balances and decision support tools. The study highlights the need for further research on the impact of nitrogen fertilisation and stand composition on Ndfa. These findings emphasise the potential of BNF to support sustainable agriculture by improving nitrogen availability and reducing dependence on synthetic fertilisers and particularly susceptibility to climate change challenges. To optimise the benefits of BNF, future research should focus on refining fertilisation regimes and exploring species‐specific responses to various ecological conditions. Exploring adaptive strategies, like selecting drought‐tolerant legumes and optimising irrigation, is essential. This will enhance the application of BNF in diverse agricultural systems, contributing to more sustainable and efficient farming practices.

Serendipita indica: A Promising Biostimulant for Improving Growth, Nutrient Uptake, and Sugar Accumulation in Camellia oleifera

Serendipita indica is a very promising root-associated endophytic fungus that is widely used on various plants; however, whether it affects the growth and physiological activity of an oilseed crop (Camellia oleifera) under field conditions remains unclear. In this study, we analyzed the effects of S. indica inoculation on root colonization rate, growth rate, photosynthetic parameters, mineral element concentrations and related gene expression, and sugar concentrations and expression of their transporter genes in four-year-old C. oleifera trees in the field. The results showed that the root colonization rate of C. oleifera increased from 3.37% to 9.42% following being inoculated with S. indica. Inoculation with S. indica significantly increased the plant height (46.81%), net photosynthetic rate (69.16%), nitrogen balance index (14.44%), chlorophyll index (21.08%), leaf K (7.4%), leaf Ca (13.52%), root P (17.75%), root K (12.80%), soil NH4+-N (17.78%), available K (26.66%), Olsen-P (184.30%), easily extractable glomalin-related soil protein (39.26%), and soil organic carbon (16.25%) concentrations compared to the uninoculated treatment. Inoculation with S. indica also significantly up-regulated the expression of CoHKT1;1 and CoCAX1;2 in the leaves and roots and CoPht1;1, CoPht1;2, and CoPht1;3 in the leaves. Plants inoculated with S. indica also presented significantly higher leaf glucose, fructose, and sucrose concentrations, accompanied by up-regulated expression of CoSWEET2a, CoSWEET7, CoSWEET9b, CoSWEET17a, and CoSWEET17b. These results suggest that S. indica has significant potential as a biostimulant for enhancing the growth and nutritional profile of C. oleifera, thereby contributing to sustainable oilseed production.

Periodic Catatonia: A Tangled Spectra within Neuropsychiatry

Catatonia was first described by Kahlbaum in 1874. Subsequently, in 1908, Kraepelin delineated a cyclical pattern of catatonia in a group of patients with Schizophrenia. Further ahead, in 1938, Gjessing demonstrated the role of nitrogen phasic change in synchronous syntonic cases of periodic catatonia. However, Stokes et al., in 1941, demonstrated it to be a result of steady accumulation rather than a phasic change in nitrogen balance. There are no reliable prevalence figures for periodic catatonia. Prominent diagnostic manuals have not given this diagnostic entity a separate nosological status, despite evidence of a discrete metabolic profile. This case series elucidates periodic catatonia in different psychiatric disorders and how a separate diagnostic criterion could help in early detection and management. We narrate three case reports of catatonic manifestations in two young adolescents and one young adult male, with no underlying medical condition. The first case report highlights intermittent brief periods of catatonic excitement beginning with acute anxiety and followed by fainting spells. The second case report narrates an acute onset manic episode which alternates with the catatonic episode. The third case report shows seasonal advents of catatonia. The pharmacological intervention itself was adequate enough to resolve the catatonic symptoms. The three cases give a purview of catatonic manifestations with differential phenomenology. The treatment of catatonia bears challenges owing to a lack of awareness and differential response to available pharmacotherapy.

A systematic review to assess the impact of amino acids or their derivatives on skeletal muscle wasting in critically ill patients

BackgroundIt is plausible that supplementation with specific amino acids or metabolites could attenuate skeletal muscle wasting during critical illness. The aim of this systematic review was to explore if amino acids or their derivatives impact skeletal muscle wastage in critically ill adults. MethodsFour databases were systematically searched to identify randomised control trials which delivered enteral supplemental amino acids, or their metabolites compared with placebo, standard care or no intervention, to critically ill patients and reported outcomes of skeletal muscle mass, plasma amino acids, nitrogen balance, or muscle strength. Two authors independently completed screening, data extraction, and risk of bias assessment using the Cochrane Risk of Bias 2 Tool. A meta-analysis was planned but heterogeneity in the type of intervention used and outcome assessment precluded this. Therefore, data were synthesised using vote counting. ResultsThirty randomised control trials, comprising 1976 patients were included. The most frequently studied interventional amino acid or metabolite was glutamine (n = 12 trials), a combination (n = 9), arginine (n = 6), β-hydroxy β-methylbutyrate (HMB) (n = 2) or ornithine (n = 1). Six trials (including 284 participants) measured skeletal muscle following supplementation, four of which used HMB alone or in combination as the intervention. Of these, one trial observed an attenuation of muscle wasting with a combination of amino acids, one observed an exacerbation of muscle wasting with HMB, three trials observed no impact on muscle wasting with HMB or a combination of amino acids and one trial reported no information. ConclusionSix trials have investigated the effect of enteral amino acid or amino acid metabolite supplementation on muscle mass in critically ill. Heterogeneity of interventions, outcome assessments and direction of effects limits the certainty regarding the effect of supplemental amino acids, or their metabolites, on skeletal muscle wasting during critical illness.The trial protocol is registered on PROSPERO (CRD42021275989).

Efficacy of L-cysteine in increasing circulatory hydrogen sulfide, nitrite, and 25(OH)VD levels in ZDF rats and in vitro treatment of H2S and NO2 in upregulating VD hydroxylase genes in monocytes

Dairy products, such as whey proteins, have been effectively utilized to enhance the effectiveness of vitamin D fortification and optimize circulating 25(OH)VD levels. Whey protein is rich in L-cysteine (LC) which is the precursor of hydrogen sulfide (H2S), enhances glutathione (GSH) biosynthesis, and promotes positive nitrogen balance. Zucker diabetic rats (ZDF) were used as a model in this study, to examine the hypothesis that LC supplementation enhances blood levels of H2S and nitrite (NO2) while reducing inflammation biomarkers. Rats were gavaged daily (orally) with either saline placebo or L-cysteine along with a high-calorie diet starting at 6 weeks of age. Fasting blood levels showed LC supplementation significantly increased circulatory levels of H2S and NO2 compared with placebo rats. LC supplementation increased plasma concentration of 25(OH)VD and vitamin C and lowered leptin and body weight gain in ZDF rats. Furthermore, to assess the impact of H2S and NO2 in raising 25(OH)VD levels, the in vitro effect of H2S/NO2 on vitamin D metabolism genes was examined using THP-1 monocytes. The exogenous H2S and NO2 treatment upregulated the relative expression of CYP2R1 and CYP27B1 genes in cultured monocytes. This study suggests a potential mechanism for the observed increase in circulating 25(OH)VD levels following L-cysteine supplementation.

Apparent metabolizable energy concentration and ileal amino acid digestibility in cereal grains fed to broiler chickens.

This study aimed to determine apparent metabolizable energy concentrations and ileal amino acid (AA) digestibility in cereal grains and to compare those metabolizable energy values between the total collection and index methods for 21-day-old broilers. On day 17 post-hatch, a total of 336 Ross 308 male broilers were assigned to 6 dietary treatments with 8 replicate cages (7 birds/cage). Five experimental diets were formulated to incorporate non-extruded corn, extruded corn, wheat, wheat flour, and barley as the sole source of AA and energy. Retention of dry matter and nitrogen, and energy concentrations in cereal grains determined by the total collection method were greater (p<0.05) than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater (p<0.05) than those of wheat, wheat flour, and barley. Wheat flour exhibited greater (p<0.05) ileal AA digestibility than non-extruded and extruded corn. Extruded corn and wheat showed comparable ileal AA digestibility values, whereas barley had the lowest among cereal grains. Energy concentrations of cereal grains determined by the total collection method were greater than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater compared to wheat, wheat flour, and barley, irrespective of the method used. The ileal AA digestibility in wheat flour was the greatest, followed by non-extruded corn, extruded corn, wheat, and barley in broilers.

Effect of dietary β-mannanase supplementation on growth performance, intestinal morphology, digesta viscosity, and nutrient utilization in broiler chickens: Meta-analysis and meta-regression.

The present study aimed to investigate the effectiveness of dietary β-mannanase supplementation on growth performance, intestinal morphology, digesta viscosity, and dietary nutrient utilization in broiler chickens through a meta-analysis. The effects were further examined by a meta-regression analysis with activity levels of β-mannanase in broiler diets. A total of 23 studies, which conducted in 11 countries and completed between December 2003 and August 2023, were finally selected for this meta-analysis. The standardized mean difference (SMD) and its 95% confidence interval (CI) were calculated as the effect size metrics using random effect model, with I2 value being utilized to measure heterogeneity. Investigated measurements included body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), villus height (VH), crypt depth (CD), VH:CD ratio, digesta viscosity, nitrogen-corrected metabolizable energy (AMEn), apparent ileal digestibility (AID), and apparent total tract retention (ATTR) of dry matter (DM), gross energy (GE), and nitrogen (N). All statistical analyses were performed using R version 4.3.3. Results revealed significant positive effects of dietary β-mannanase supplementation on BWG (P = 0.005), FCR (P < 0.001), VH (P < 0.001), VH:CD (P < 0.001), digesta viscosity (P < 0.001), AMEn (P = 0.011), AID of GE (P = 0.002) and N (P = 0.003), and ATTR of DM (P = 0.019), GE (P = 0.002), and N (P = 0.005) in broiler chickens. In the meta-regression analysis, increasing activity levels of β-mannanase in broiler diets increased VH:CD (P < 0.001, R2 = 79.2%) and AID of N (P = 0.038, R2 = 67.4%). the current meta-analysis indicates that dietary β-mannanase supplementation improves energy and nutrient utilization in broiler diets possibly by decreasing digesta viscosity and enhancing intestinal morphology in broiler chickens. These beneficial effects can contribute to improved growth performance in broiler chickens.

Microbial mechanisms of biochar addition on carbon and nitrogen synergistic retention during distilled grain waste composting: Insights from metagenomic analysis

To elucidate the mechanism of biochar addition on carbon and nitrogen retention during distilled grain (DGW) composting, this study investigated the losses of carbon and nitrogen and functional genes related to carbon and nitrogen metabolisms between biochar-treated and control composts. The addition of biochar significantly increased carbon and nitrogen retention by 13.5% and 33.8%, respectively. The difference in core carbon metabolism genes indicated that biochar addition inhibited CO2 release and promoted carbon fixation during the later composting phase, leading to improved carbon retention. Nitrogen metabolism analysis indicated that biochar addition suppressed early-phase ammoniation and late-phase denitrification and promoted nitrification and ammonia assimilation during the later stages of composting, thereby preserving nitrogen. During the later composting phase, biochar addition enhanced carbon–nitrogen coupling metabolism activity, leading to the synchronous retention of carbon and nitrogen. These findings elucidate the mechanism of biochar addition on carbon and nitrogen retention during DGW composting.