Nutrient Deposition Research Articles

Biogeochemical characteristics of brash sea ice and icebergs during summer and autumn in the Indian sector of the Southern Ocean

We analyzed biogeochemical components of brash ice, originating from sea ice and icebergs, collected in the Indian sector of the Southern Ocean during the summer and autumn of 2018–2020. Ice samples, collected from seawater by net or cage methods, were melted in the dark under cool conditions to measure physical and biogeochemical components such as salinity, stable oxygen isotopes, nutrients, and chlorophyll-a. We compared brash ice parameters with those of seawater samples from the temperature minimum layer, corresponding to the water in which the sea ice originated, to examine the effects of processes such as brine drainage, snow-ice formation, and biological activities on the biogeochemical components in sea ice. Samples from icebergs (ice formed on land) had salinity of zero and low concentrations of all other components, suggesting that the atmospheric deposition of nutrients is minimal in this clean environment. However, sea ice samples had a wide range of values for each parameter. Our results show that meteoric water makes a smaller contribution to sea ice than it typically does to multi-year landfast ice, and there is no correlation between this meteoric water contribution and nutrient concentrations, which suggests that the contribution of snow-ice formation to nutrients within sea ice is subordinate to the role of biological processes. Nutrient and chlorophyll-a concentrations in our brash ice samples are of similar magnitude to those in sea ice samples collected in the same area by coring of thick pack ice. Our data represent end-member values that may be useful to estimate the respective contributions of snow, sea ice, and seawater to surface water samples.

Dietary nano-selenium supplementation regulates lipid deposition, protein synthesis and muscle fiber formation in grass carp fed with high-fat diet.

The current study aims to confirm the positive effects of dietary nano-selenium (nano-Se) on nutrients deposition and muscle fiber formation in grass carp fed with high-fat diet (HFD) before overwintering and to reveal its possible molecular mechanism. The lipid deposition, protein synthesis and muscle fiber formation in grass carp fed with regular diet (RD), HFD or HFD supplemented with nano-Se (0.3 or 0.6 mg/kg) for 60 d were tested. Results show that nano-Se significantly reduced lipid content, dripping loss and fiber diameter (P < 0.05), but increased protein content, post-mortem pH24 h and muscle fiber density (P < 0.05) in muscle of grass carp fed with HFD. Notably, dietary nano-Se decreased lipid deposition in the muscle by regulating amp-activated protein kinase (AMPK) activity and increased protein synthesis and fiber formation in muscle by activating target of rapamycin (TOR) and myogenic determining factors (MyoD) pathways. In summary, dietary nano-Se can regulate the nutrients deposition and muscle fiber formation in grass carp fed with HFD, which exhibit potential benefit for improving flesh quality of grass carp fed with HFD.

Comparative Proximate, Vitamins, Minerals and Phytochemical Analysis of Cola rostrata K. Schum. and Cola parchycarpa K. Schum.

Cola rostrata and Cola parchycarpa are under-utilized indigenous kola plants, known as achicha by the Igbo natives in Nigeria, whose fruit pulps are edible and tasty. The proximate, vitamins, minerals and phytochemicals constituent of the fruit epicarp, fruit pulp and seed of C. rostrata and C. parchycarpa were evaluated using standard analytical laboratory procedures. The results revealed that C. rostrata and C. parchycarpa fruit pulps contained high moisture contents (56.56 % and 58.83 %) and carbohydrates (31.30 % and 55.39 %) respectively. They also contained vitamins and minerals that are required for nutrition in humans and animals. However, C. rostrata fruit pulp had higher concentrations of magnesium (80.36 mg/100g), calcium (170.31 mg/100g), vitamin A (54.53 mg/100g), vitamin C (21.41 mg/100g) and vitamin E (4.25 mg/100g), while C. parchycarpa had higher concentrations of all the phytochemicals screened. These phytochemicals, if explored further, can be implored in the treatment of certain ailments. The fruit pulp can be recommended for individuals who suffer from calcium deficiency while the seed and fruit epicarp could be used in the formulation and fortification of animal feeds due to the substantial nutrient deposits in them as revealed by this study.

Elevational gradient regulates the effects of short-term nutrient deposition on soil microorganisms and SOM decomposition in subtropical forests

Elevational gradient regulates the effects of short-term nutrient deposition on soil microorganisms and SOM decomposition in subtropical forests

Combination of Aspartame and Acesulfame Potassium Does not Alter Blood Glucose, Lipids and Cytokines of Female Rats

Cola rostrata and Cola parchycarpa are under-utilized indigenous kola plants, known as achicha by the Igbo natives in Nigeria, whose fruit pulps are edible and tasty. The proximate, vitamins, minerals and phytochemicals constituent of the fruit epicarp, fruit pulp and seed of C. rostrata and C. parchycarpa were evaluated using standard analytical laboratory procedures. The results revealed that C. rostrata and C. parchycarpa fruit pulps contained high moisture contents (56.56 % and 58.83 %) and carbohydrates (31.30 % and 55.39 %) respectively. They also contained vitamins and minerals that are required for nutrition in humans and animals. However, C. rostrata fruit pulp had higher concentrations of magnesium (80.36 mg/100g), calcium (170.31 mg/100g), vitamin A (54.53 mg/100g), vitamin C (21.41 mg/100g) and vitamin E (4.25 mg/100g), while C. parchycarpa had higher concentrations of all the phytochemicals screened. These phytochemicals, if explored further, can be implored in the treatment of certain ailments. The fruit pulp can be recommended for individuals who suffer from calcium deficiency while the seed and fruit epicarp could be used in the formulation and fortification of animal feeds due to the substantial nutrient deposits in them as revealed by this study.

Long-term concentration of tropical forest nutrient hotspots is generated by a central-place apex predator

Apex predators typically affect the distribution of key soil and vegetation nutrients through the heterogeneous deposition of prey carcasses and excreta, leading to a nutrient concentration in a hotspot. The exact role of central-place foragers, such as tropical raptors, in nutrient deposition and cycling, is not yet known. We investigated whether harpy eagles (Harpia harpyja) in Amazonian Forests—a typically low soil fertility ecosystem—affect soil nutrient profiles and the phytochemistry around their nest-trees through cumulative deposition of prey carcasses and excreta. Nest-trees occurred at densities of 1.5–5.0/100 km2, and each nest received ~ 102.3 kg of undressed carcasses each year. Effects of nests were surprisingly negative over local soil nutrient profiles, with soils underneath nest-trees showing reductions in nutrients compared with controls. Conversely, canopy tree leaves around nests showed significant 99%, 154% and 50% increases in nitrogen, phosphorus and potassium, respectively. Harpy eagles have experienced a 41% decline in their range, and many raptor species are becoming locally extirpated. These are general examples of disruption in biogeochemical cycles and nutrient heterogeneity caused by population declines in a central-place apex predator. This form of carrion deposition is by no means an exception since several large raptors have similar habits.

The Growth of the Red Lactus (Lactuca sativa L. var. Crispa) After Using Nano Technology Liquid Organic Fertilizer Hydroponically cultivated

Hydroponics is a method of agriculture in which earth is not used. Among the plants amenable to hydroponic cultivation is red lettuce. One disadvantage of hydroponic cultivation is the occurrence of nutrient deposition, particularly in the wick system, where the nutrient water does not move. A technique that can lessen the amount of nutrient deposition that occurs in hydroponic systems is required in light of the aforementioned issues. Nanotechnology is one of the technologies developed. The five treatments and four replications in this study were P1 = AB Mix 100 percent, P2 = AB Mix 75 percent + POC Nano 25 percent, P3 = AB Mix 50 percent + POC Nano 50 percent, P4 = AB Mix 25 percent + POC Nano 75 percent, and P5 = POC Nano 100 percent. ANOVA (Analysis of Variance) was used to analyze the data, and the Duncan's New Multiple Range Test (DMRT) test at level 5 followed. The effects of nanotechnology-enhanced liquid organic fertilizer on red lettuce growth, including height, leaf area, number of leaves, fresh weight, and dry weight, were examined. The highest average plant is at P3 with a plant height of 36.42 cm, the highest average number of leaves is at P3 as many as 11.25 strands, the widest average leaf is at P4 with an area of ​​40.25 cm2, the average weight The highest wet weight was P4 with a weight of 17.01 g, and the highest average dry weight was P2 with a weight of 1.32 g.

The Effect Of Nano Technology Liquid Organic Fertilizer On The Growth Of Spinach (Amaranthus hybridus l.) Cultivated Hydroponically

Hydroponic cultivation using a wick system is one of the techniques used to increase the production of spinach (Amaranthus hybridus L.). One of the disadvantages of hydroponics is the occurrence of nutrient deposition, to reduce nutrient deposition in the wick system is to apply nanotechnology to break down particles in the planting medium and nutrients used, that the particles become smaller and more easily absorbed by plants, and reduce precipitation in the wick system. This research was conducted using the RAL method (Completely Randomized Design) which consisted of 6 treatments and 4 replications and namely Control (Well water + AB Mix), P1 (Nano technology water + 100% AB Mix), P2 (nano technology water + 25% POC+75% AB Mix), P3 (nano technology water+50% POC+50% AB Mix), P4 (nano technology water+75% POC+25% AB Mix), P5 (nano technology water+100% POC). The data obtained were analyzed by means of variance (ANOVA) and followed by the DMRT test at 5% level. The results of this study are that there is an effect of the use of nano technology liquid organic fertilizer on the growth of spinach which can be seen in the highest plant at P2 with 29.975 cm, the highest number of leaves is at P2 with 34 leaves, the highest leaf area is in the control with 13,71 cm2, the wet weight the highest was on P1 with 17 gr, the highest dry weight was on P2 with 1.3 gr. The use of nano technology liquid organic fertilizer has an influence on the growth of green spinach which is cultivated hydroponically.

Exploring the mycobiome and arbuscular mycorrhizal fungi associated with the rizosphere of the genus Inga in the pristine Ecuadorian Amazon.

This study explored the composition of the mycobiome in the rhizosphere of Inga seedlings in two different but neighboring forest ecosystems in the undisturbed tropical Amazon rainforest at the Tiputini Biodiversity Station in Ecuador. In terra firme plots, which were situated higher up and therefore typically outside of the influence of river floods, and in várzea plots, the lower part of the forest located near the riverbanks and therefore seasonally flooded, tree seedlings of the genus Inga were randomly collected and measured, and the rhizosphere soils surrounding the root systems was collected. Members of the Fabaceae family and the genus Inga were highly abundant in both forest ecosystems. Inga sp. seedlings collected in terra firme showed a lower shoot to root ratio compared to seedlings that were collected in várzea, suggesting that Inga seedlings which germinated in várzea soils could invest more resources in vegetative growth with shorter roots. Results of the physical-chemical properties of soil samples indicated higher proportions of N, Mo, and V in terra firme soils, whereas várzea soils present higher concentrations of all other macro- and micronutrients, which confirmed the nutrient deposition effect of seasonal flooding by the nearby river. ITS metabarcoding was used to explore the mycobiome associated with roots of the genus Inga. Bioinformatic analysis was performed using Qiime 2 to calculate the alpha and beta diversity, species taxonomy and the differential abundance of fungi and arbuscular mycorrhizal fungi. The fungal community represented 75% of the total ITS ASVs, and although present in all samples, the subphylum Glomeromycotina represented 1.42% of all ITS ASVs with annotations to 13 distinct families, including Glomeraceae (72,23%), Gigasporaceae (0,57%), Acaulosporaceae (0,49%). AMF spores of these three AMF families were morphologically identified by microscopy. Results of this study indicate that AMF surround the rhizosphere of Inga seedlings in relatively low proportions compared to other fungal groups but present in both terra firme and várzea Neotropical ecosystems.

Impact of ocean warming on net primary production in the northern Indian Ocean: role of aerosols and freshening of surface ocean.

Warming due to climate change stratifies the upper ocean and reduces nutrient input to the photic zone resulting in a decline in net primary production (NPP). On the other hand, climate change increases both anthropogenic aerosol input into the atmosphere and the river discharge due to the melting of glaciers on land resulting in enhanced nutrient inputs to the surface ocean and NPP. To examine the balance between these two processes, spatial and temporal variations in the rate of warming, NPP, aerosol optical depth (AOD), and sea surface salinity (SSS) were studied between 2001 and 2020 in the northern Indian Ocean. Strong heterogeneity in the warming of the sea surface was observed in the northern Indian Ocean with significant warming in the south of 12°N. Insignificant trends in warming were observed in the northern Arabian Sea (AS), north of 12°N, during winter and fall, and western Bay of Bengal (BoB) during winter, spring, and fall associated with higher levels of anthropogenic AOD (AAOD) due to a reduction in incoming solar radiation. The decline in NPP was observed in the south of 12°N in both AS and BoB and correlated inversely with SST suggesting that a weak supply of nutrients due to upper ocean stratification controlled NPP. Despite warming, the weak trends in NPP in the north of 12°N were associated with higher AAOD levels and their rate of increase suggesting that the deposition of nutrients from the aerosols seems to be compensating for declining trends due to warming. The decrease in sea surface salinity confirmed an increase in river discharge, and nutrient supply led to weak NPP trends in the northern BoB. This study suggests that the enhanced atmospheric aerosols and river discharge played a significant role in warming and changes in NPP in the northern Indian Ocean, and these parameters must be included in the ocean biogeochemical models for accurate prediction of possible changes in the upper ocean biogeochemistry in the future due to climate change.

Protecting nature's most effective carbon sink: an important role for fungi in peatlands.

This article is a Commentary on Shao et al. (2023), 238: 80–95.

Synergistic effects of climate warming and atmospheric nutrient deposition on the alpine lake ecosystem in the south-eastern Tibetan Plateau during the Anthropocene

Alpine lakes on the Tibetan Plateau are highly sensitive to global change and have been recognized as the sentinel of climate warming. However, anthropogenic impacts in populated area are migrating to these remote areas via transporting particulate nutrients by atmospheric deposition. Whether warming and nutrient deposition would impose additive or synergistic effects on the lake ecosystem remains largely unknown. Here, we present multi-proxy (sediment pigment and geochemistry) records during the past two centuries at the Cuoqia Lake in the southeast Tibetan Plateau. We found that the lake exhibited rapid ecological changes since 1980 AD characterized by an increase in primary productivity due to algal proliferation, with more rapid growth of green algae and diatoms. These findings are in concert with many other lakes (e.g., Moon Lake and Shade Co) in the same area, suggesting a consistent pattern of ecosystem evolution at the region scale. Statistical analyses suggested that nutrient deposition and climate warming were strongly associated with the variations in primary productivity and algae composition, exerting both individual and interactive effects. In addition, scenario analyses with a well-established process-based ecosystem model further revealed that the two factors not only individually, but also synergistically promoted the algal proliferation and community succession. Such synergy is evident in that the effect of lake warming would be more pronounced under higher nutrient deposition scenario, which is potentially due to higher temperature-driven mineralization in warmer conditions, and higher efficiency of nutrient utilization under enhanced light availability attributing to declining ice thickness and duration in cold seasons. Overall, our study proposes the existence and quantifies the synergistic impacts of climate warming and anthropogenic activities in driving the ecological changes in remote alpine lakes on the Tibetan Plateau. The lake ecological consequences driven by individual factor would be worsen by such synergy, so that we cannot predict the lake ecosystem trajectory in the future based on each factor separately, and more efforts than previously expected would be needed for the lake restoration and management.

Mechanisms Underlying Aboveground and Belowground Litter Decomposition Converge over Time under Nutrient Deposition

Decomposition is vital for nutrient cycling and is sensitive to atmospheric nutrient depositions. However, the influences and underlying mechanisms of nutrient deposition on the long-term decomposition of leaves and absorptive roots remain unclear. Here, we explored the responses of leaves and absorptive roots to nutrient deposition (control, +N, +P, and +NP) in Pinus massoniana and Schima superba forests in subtropical China based on two stages (early-stage (1-year) and late-stage (3-year)) of a decomposition experiment. The chemical factions (acid-unhydrolysable residue (AUR), cellulose, and hemicellulose concentrations) and microbial enzymatic activities (hydrolase and oxidase) were also determined. The +N treatment had persistent negative effects on absorptive root decomposition, except for P. massoniana during the late stage. The +P treatment had a positive effect on leaf decomposition in all stages. The +NP treatment had a positive effect on leaf decomposition during the late stage. The increasing decomposition rates of foliar under +P treatment were more correlated with the increasing acid phosphatase activity than chemical factions, indicating a microbial mechanism. The decreasing decomposition rates of roots under +N treatment were weakly correlated with increasing AUR concentrations and strongly correlated with decreasing oxidase activity during the late stage, indicating both chemical and microbial mechanisms. Overall, our findings highlight that, despite contrasting responses to nutrient deposition, the mechanisms underlying aboveground and belowground decomposition tend to converge as decomposition progresses.

Distribution, source identification and ecological effects of aerosol dissolved nutrients in the Bohai Bay

The atmospheric aerosols around the Bohai Bay are affected intensively by the surrounding industrial, shipping and other human activities. Although atmospheric dry deposition is an important way for nutrients to enter the Bohai Bay, few studies explore the distribution patterns, source and deposition fluxes of typical nutrients in aerosols and their impacts on the marine ecosystem. This paper explored the spatial-temporal distribution of typical aerosol nutrients in summer and autumn, and their source and ecological effects were illustrated further. The mean concentration of dissolved total phosphorus (DTP), dissolved total nitrogen (DTN), dissolved organic nitrogen (DON), dissolved inorganic nitrogen (DIN), ammonium (NH4–N), nitrate (NO3–N), nitrite (NO2–N), silicate (SiO3–Si), phosphate (PO4–P), and dissolved organic phosphorus (DOP) were 31.22, 847.22, 288.19, 559.77, 288.19, 304.00, 253.65, 2.12, 15.74 and 15.48 nmol/m3, respectively, while their fluxes were corresponding to 0.61, 8.36, 2.52, 4.90, 1.41, 2.49, 0.02, 0.04, 0.19 and 0.26 mmol/(m2 month). Typical aerosol nutrient concentrations in autumn were mostly higher than those in summer, with high values occurring mainly in the central region. The potential sources of pollution were mainly concentrated in Shandong and Mongolia, and the sources of pollution were mainly agriculture, dust and industry. The large N:P and N:Si ratios in the dry deposition likely exacerbated Si and P limitation in the water column. These results provided the data basis for evaluating the pollution status and revealed that the dry deposition of aerosol nutrients should not be neglected by the ecological environment in the Bohai Bay.

Quantifying seaweed and seagrass beach deposits using high-resolution UAV imagery

Macroalgae and seagrass wash ashore by tidal waters and episodic events and create an ocean-to-land transport of carbon and nutrients. On land, these deposits (beach wrack) are consumed by macrofauna, remineralized by microorganisms, or washed back to the sea, during which recycling of carbon and nitrogen affect the biochemical cycles in coastal zones. Manual quantification of beach wracks is time-consuming and often difficult due to complex topography and remote locations. Here, we present a novel method using Unoccupied Aerial Vehicle (UAV) photogrammetry combined with in situ measurements of carbon and nitrogen contents of wrack to quantify marine carbon and nutrient deposits in beach zones. The UAV method was tested against placed cubes ranging from 125 to 88,218 cm3 and demonstrated a high accuracy (R2 > 0.99) for volume acquisition when compared to manual measurements. Also, the UAV-based assessments of the cross-sectional area of beach deposits demonstrated a high accuracy when compared to manual and high-precision GNSS (Global Navigation Satellite System) measurements without significant differences between the methods. This demonstrated that UAVs can provide detailed spatial maps, three-dimensional (3D) surface models, and accurate volumetric assessments of beach wrack deposits. In three case studies, combined with carbon and nitrogen measures, total organic carbon and nitrogen deposits in beach wracks were quantified ranging from 4.3 to 9.7 and from 0.3 to 0.5 kg per meter coastline, respectively. In conclusion, this UAV method demonstrated an effective tool to quantify ecosystem carbon and nitrogen deposits relevant to ecosystem assessments and quantification of blue carbon stocks. The method is optimal when the terrain below beach wrack deposits is known, as in the case with before-and-after or repeated surveys. Further, UAVs display strong time- and cost-effective advantages over manual methods which is amplified with increasing project scale. We propose it as a valuable method for multiple scientific and commercial applications related to environmental monitoring and management, including marine resource exploration and exploitation.

Dry and Wet Atmospheric Deposition Composition in Southwest Florida: Environmental and Health Implications

Southwest Florida is one of the most rapidly growing regions of the United States and has been impacted over the past decade with water-quality issues and some associated health problems. The ionic ratios of the dust measured in southwest Florida vary significantly from those on the Florida east coast and in the Caribbean. The metals concentrations reported herein are enriched in potassium and calcium from local sources. Atmospheric deposition of metals and nutrients appears to have potential impacts on both indirect health problems and environmental issues of concern, particularly harmful algal blooms. However, no significant past research has been performed on measurement of the concentration of either metals including the micronutrient iron or nutrient concentrations occurring in atmospheric dry and wet fallout in southwest Florida. Measurements of the composition of key metals and nutrients were made over a one-year period. Concentrations of total phosphorus in the dust ranged from 0–80.5 mg/kg with an average of 4 mg/kg and in rainfall from 1–15.8 чg/L with an average of 4 mg/kg. Nitrate ranged from 0–746 чg/L with an average of 114.4 чg/L in rainfall in a soluble form, and from 1.3 to 718 mg/kg with an average of 209.9 mg/kg in an insoluble form. Ammonia was measured to range from 1.4 to 658 mg/kg with an average of 101.4 mg/kg in rainfall. Iron was found in the dust at concentrations ranging from 0–81 mg/kg with an average of 3.8 mg/kg and in rainfall from 0–125.7 mg/kg with an average of 3.0 mg/kg. While the measured nutrient and iron concentrations are not likely to initiate a harmful algal bloom, they are likely to sustain an existing bloom. Global climate change may exacerbate the atmospheric aerosol issue by increased wind speeds over Africa associated with longer term drought conditions caused by atmospheric temperature increases.

A dataset of litter decomposition residual mass and nutrient concentrations under nitrogen and phosphorus addition in subtropical plantations (2016&amp;ndash;2019)

The increase in atmospheric nutrient deposition resulted from human activities and changes of natural factors have a dramatically influence on the ecosystem nutrient cycling. The subtropical plantations in the South of China account for more than 40% of the national plantation area, which have become the central zone of nutrient deposition. Therefore, the scientific understanding of nutrient cycling process in plantations is the basis of coping with global climate changes and ensuring the construction of national ecological civilization. According to the unified specification of Chinese Ecosystem Research Network, and on the basis of the long-term observation of the field plots of Qianyanzhou Ecological Research Station, Jiangxi (referred to as Qianyanzhou Station), we integrated residual mass and nutrient concentrations of leaf and absorptive roots of Pinus massoniana and Schima superba plantations under different treatments (control, lower nitrogen addition, higher nitrogen addition, phosphorus addition, adding both higher nitrogen and phosphorus) from 2016 to 2019. The production and sharing of this dataset can help to provide basic data support for the dynamic study of litter decomposition as well as for the stock of soil carbon pool under the background of global changes. Additionally, it can promote the sustainable development of subtropical plantations.

Avian Diversity in Agricultural Landscapes of SP3 Pangea Area in Gorontalo Province

An agroecosystem cannot function without birds, which perform a variety of functions, including pollination, seed dispensing, nutrient deposition, scavenging, and predatory roles for rodents and insect agricultural landscapes support a wide range of habitats and a diverse population of avifauna. A new transmigration area called SP3 Pangea has been established in the province of Gorontalo. Therefore, the SP3 Pangea’s agricultural landscapes do not support a great diversity of birds. The current study documented the abundance of avifauna in agricultural landscapes in SP3 Pangea from this perspective. In order to describe the variety and temporal fluctuation of the avifauna in the agricultural landscapes of Dusun SP3 Pangea, field surveys were carried out from December 2021 to February 2022. There were 13 different bird species in total. The IUCN Red List has one species that is classified as vulnerable. In the research area, it was regularly noted that some species had worldwide population patterns that were dropping. This underlines the fact that research locations are essential habitats for bird species with high conservation needs. Future studies on the management and conservation of existing bird species in agricultural settings are expected to use the findings of the current study as a starting point.

Interactions of diet and circadian rhythm to achieve precision nutrition of poultry

Precision nutrition regimes currently rely on the assumption that broilers will grow in a steady and predictable way on a daily basis, with the continuous deposition of nutrients into muscle or, in the case of laying hens, into an egg. However, it has been observed that this is not the case for egg production, with Ca requirements being aligned with eggshell formation. Recent research has suggested that muscle is also deposited at differing rates over a 24-h cycle. The circadian rhythm synchronises various biological processes to oscillate within a 24-h cycle. Thus, the cyclic nature of body systems should be explored, to determine whether consideration of the circadian rhythm is required for precision nutrition programs, achieving peak efficiency of performance and accurate nutrient requirement recommendations. Recent advances in nutrition have demonstrated the powerful effect of the circadian rhythm on human health and animal growth and production. Therefore, this review discusses recent circadian-rhythm research with relevance to poultry. Specific focus is given to the interaction of the circadian rhythm with diet and dietary nutrients, for the precision nutrition of poultry and optimising production.

Influence of diet formulation technique on requirement of digestible lysine for growing Japanese quail: A practical reflection

This work aimed to investigate the influence of two diet formulation techniques: supplementation and dilution, on estimates of digestible lysine requirements in growing Japanese quail. For this, 492 Japanese quails (10 to 36 days old) with initial weight of 33.7 ± 0.42 g were used, housed in overlapping cages, and distributed in a completely randomized design in a 2 × 5 factorial arrangement. Two formulation techniques (supplementation technique and dilution technique) and five levels of lysine (0.80; 0.90; 1.00; 1.10 and 1.20%) were used, thus composing 10 treatments and 6 repetitions with 8 birds each. Performance parameters, nutrient gain, and carcass components were evaluated. There was interaction (p <0.05) between the formulation techniques and the levels of digestible lysine tested for feed intake, weight gain, protein gain, fat gain, chilled carcass weight, breast weight and thigh percentage, in addition to the isolated effect of the formulation technique on feed conversion, and isolated effect of the levels of digestible lysine on feed conversion and thigh weight. The digestible lysine requirement values estimated for better performance and efficiency in nutrient deposition were 1.028% or 133 mg/day by the supplementation technique, and 1.063% or 140 mg/day by the dilution technique. It can be concluded that the requirement for digestible lysine in Japanese quail is influenced by the formulation technique, and the supplementation technique had better results.