Strategies for Healthier Meat Foods: An Overview.

Functional food products remain the focus of current market trends toward healthier nutrition. The consumption of meat-based functional foods has been a topic of interest in food innovation since some of these products generate controversy due to their possible adverse effects on health. However, studies have demonstrated that meat-based functional products are considered an opportunity to improve the nutritional profile of meat products through the addition of biologically valuable components and to meet the specific needs of consumers. In this sense, some strategies and techniques are applied for processing and developing functional meat products, such as modifying carcass composition through feeding, reformulating meat products, and processing conditions. This review focuses on presenting developed and evaluated strategies that allow the production of healthy and functional meat foods, which application has successfully achieved the sensory, nutritional, and technological parameters mainly affected by such application.

The Invasive Ailanthus altissima: A Biology, Ecology, and Control Review.

Tree of Heaven (Ailanthus altissima (Mill.) Swingle) is a tree native to China which has invaded disturbed areas in many regions worldwide. Its presence endangers natural ecosystems by displacing native species, modifying habitats, changing community structures, and affecting ecosystem processes. Its invasive nature is enhanced by its high ability to reproduce both vegetatively through root regrowth and sexually through seeds. Seeds, which are wind dispersed, are the main mechanism by which this species reaches new habitats. When they germinate and develop the root system, roots emit new shoots that contribute to a rapid increase in the tree density and the subsequent expansion of the population nearby. The contradictory results about the ecological requirements for seeds to germinate and their degree of dormancy and longevity indicate the complexity and difficulty of understanding the mechanisms that govern the biology and adaptability of this plant. The management of this weed aims at its eradication, with programs based on herbicide applications carried out by injecting the active ingredient directly to the trunk. But, not many active ingredients have shown total control, so new ones should be tested in order to increase the range of available herbicides. During the last few decades, some biological agents have been identified, but their efficacy in controlling the tree and their safety for the local flora have not yet been determined. A correct management strategy should take into account all these aspects in order to contain the expansion of this species and, ultimately, allow its eradication.

Computational Requirements for Modeling Thermal Conduction in Polymeric Phase-Change Materials: Periodic Hard Spheres Case.

This research focuses on modeling heat transfer in heterogeneous media composed of stacked spheres of paraffin as a perspective polymeric phase-change material. The main goal is to study the requirements of the numerical scheme to correctly predict the thermal conductivity in a periodic system composed of an indefinitely repeated configuration of spherical particles subjected to a temperature gradient. Based on OpenFOAM, a simulation platform is created with which the resolution requirements for accurate heat transfer predictions were inferred systematically. The approach is illustrated for unit cells containing either a single sphere or a configuration of two spheres. Asymptotic convergence rates confirming the second-order accuracy of the method are established in case the grid is fine enough to have eight or more grid cells covering the distance of the diameter of a sphere. Configurations with two spheres can be created in which small gaps remain between these spheres. It was found that even the under-resolution of these small gaps does not yield inaccurate numerical solutions for the temperature field in the domain, as long as one adheres to using eight or more grid cells per sphere diameter. Overlapping and (barely) touching spheres in a configuration can be simulated with high fidelity and realistic computing costs. This study further extends to examine the effective thermal conductivity of the unit cell, particularly focusing on the volume fraction of paraffin in cases with unit cells containing a single sphere. Finally, we explore the dependence of the effective thermal conductivity for unit cells containing two spheres at different distances between them.

Optimizing hydraulic retention time of high-rate activated sludge designed for potential integration with partial nitritation/anammox in municipal wastewater treatment.

The integration of high-rate activated sludge (HRAS), an effective carbon redirection technology, with partial nitritation/anammox (PN/A) is a novel AB treatment process for municipal wastewater. In this study, an airlift HRAS reactor was operated in the continuous inflow mode for 200 d at a wastewater treatment plant. The balance between potential PN/A system stability and peak HRAS performance under decreasing hydraulic retention time (HRT) was optimized. Energy consumption and recovery and CO2 emissions were calculated. The results showed that the optimal HRT suitable with the PN/A process was 3 h, achieving 2-3 g/L mixed liquor volatile suspended solid, 67.8 % chemical oxygen demand (COD) recovery, 81 % total COD removal efficiency, 2.27 ± 1.03 g COD/L/d organic loading rate, 62 % aeration reduction, and 0.24 kWh/m3 power recovery potential. Such findings hold practical value and contribute to the development of the optimal AB process capable of achieving energy autonomy and carbon neutrality.

Overcoming Dormancy in Prunus Species under Conditions of Insufficient Winter Chilling in Israel.

The phenomenon of dormancy and the evolutionary causes for its development are presented together with the effects of the climatic factors: temperature and light. Shade and darkness have been found to enhance bud breaking in peach. The effects of various temperatures on chilling accumulation, chilling negation and chilling enhancement are described. The way these are computed in the face of global warming is explained, using the dynamic model. When natural chilling is less than that required, there are ways of compensation, up to a certain level. Various horticultural, physical and chemical means to achieve this are described, including bending branches, reducing vegetative vigor, shading the orchard, sprinkling to reduce daytime temperature and the application of various chemicals to break dormancy. When winter chilling is markedly reduced and temperatures increase considerably, the use of dormancy avoidance is suggested in frost-free places. This technique can induce a new growing cycle by avoiding dormancy altogether. However, the best approach is to breed high-quality cultivars requiring much less chilling. Another aspect discussed in this work, independent of the chilling requirement, is the negative effect of heat spells in winter and spring on the abnormal development of flower buds, leading to a low level of the stone fruit set and a reduced yield.

Differences of nutritional intake habits and Dietary Inflammatory Index score between occupational classifications in the Korean working population.

Background: Human nutrient intake is closely related to the conditions of their workplace. Methods: This study used data from the Korean National Health and Nutritional Examination Survey (KNHANES) conducted between 2016 and 2020. The study population comprised individuals aged 19 to 65 years who were engaged in paid work, excluding soldiers (total = 12,201, male = 5,872, female = 6,329). The primary outcome of interest was the Dietary Inflammatory Index (DII) score, which was calculated using dietary intake data. Generalized linear models were used for statistical analyses. Results: Pink-collar workers had higher DII scores, indicating a potentially higher inflammatory diet than white-collar workers (mean: 2.18 vs. 1.89, p < 0.001). Green and blue-collar workers displayed lower levels of dietary inflammation (green: 1.64 vs. 1.89, p = 0.019, blue: 1.79 vs. 1.89, p = 0.022). After adjusting for sex, age, income, education, and energy intake, the sole trend that persisted was the comparison between white-collar and pink-collar workers. Conclusions: DII scores and dietary patterns differed among occupational groups and genders.

Comparative Analysis of the Minimal information for studies of extracellular vesicles Guidelines: Advancements and Implications for Extracellular Vesicle Research.

In 2014, the International Society for Extracellular Vesicles (ISEV) introduced the Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines to establish standards for extracellular vesicle (EV) research. These guidelines aimed to enhance reliability and reproducibility, addressing the expanding field of EV science. EVs, membrane-bound particles released by cells, play crucial roles in intercellular communication and are potential biomarkers for various conditions. Over the years, the EV landscape witnessed a surge in publications, emphasizing their roles in cancer and immune modulation. In response, the MISEV guidelines underwent evolution, leading to the MISEV2018 update. This version, generated through community outreach, provided a comprehensive framework for EV research methodologies, emphasizing separation, characterization, reporting standards, and community engagement. The MISEV2018 guidelines reflected responsiveness to feedback, acknowledging the evolving EV research landscape. The guidelines served as a testament to the commitment of the scientific community to rigorous standards and the collective discernment of experts. The present article compares previous MISEV guidelines with its 2023 counterpart, highlighting advancements, changes, and impacts on EV research standardization. The 2023 guidelines build upon the 2018 principles, offering new recommendations for emerging areas. This comparative exploration contributes to understanding the transformative journey in EV research, emphasizing MISEV's pivotal role and the scientific community's adaptability to challenges.

Seed biology imperative for conservation and restoration of Swertia thomsonii C.B. Clarke-an endemic medicinal plant of Himalaya.

Endemic medicinal plants deserve immediate research priorities as they typically show a limited distribution range, represent few and fragmented populations in the wild and are currently facing anthropogenic threats like overharvesting and habitat degradation. One of the important aspects of ensuring their successful conservation and sustainable utilization lies in comprehending the fundamental seed biology, particularly the dormancy status and seed germination requirements of these plants. Here, we studied the seed eco-physiology and regeneration potential of Swertia thomsonii-an endemic medicinal plant of western Himalaya. We investigated the effect of different pre-sowing treatments, sowing media and sowing depth on seed germination parameters of S. thomsonii. Seeds of S. thomsonii exhibit morphophysiological dormancy (MPD), i.e. when the embryo of the seed is morphologically and/or physiologically immature. Wet stratification at 4 °C for 20 days, pre-sowing treatment with 50 ppm GA3 and pre-sowing treatment with 50 ppm KNO3 were found ideal for overcoming dormancy and enhancing the seed germination of S. thomsonii. Furthermore, seed germination and seedling survival were significantly influenced by pre-sowing treatments, sowing media and sowing depth. The percentage of seed germination and seedling survival got enhanced up to 84-86% and 73-75% respectively when seeds were pre-treated with GA3 or KNO3 and then sown in cocopeat + perlite (1:1) at a depth of 1 cm. The information obtained in the present study outlines an efficient protocol for large-scale cultivation of S. thomsonii thereby limiting the pressure of overexploitation from its natural habitats and may also help in the restoration and conservation of this valuable plant species.

Beyond the Bowl: Understanding Amino Acid Requirements and Digestibility to Improve Protein Quality Metrics for Dog and Cat Foods.

The determination of amino acid (AA) requirements for mammals has traditionally been done through nitrogen (N) balance studies, but this technique underestimates AA requirements in adult animals. There has been a shift toward researchers using the indicator amino acid oxidation (IAAO) technique for the determination of AA requirements in humans, and recently in dogs. However, the determination of AA requirements specific to adult dogs and cats at maintenance is lacking and the current requirements outlined by the National Research Council are based on a dearth of data and are likely underreporting the requirements of indispensable AA (IAA) for the population. To ensure the physiological requirements of our cats and dogs are met, we need methods to accurately and precisely measure digestibility. In vivo methods, such as ileal cannulation, are most commonly used, however, due to ethical considerations, we are moving away from animal models and toward in vitro methods. Harmonized static digestion models have the potential to replace in vivo methods but work needs to be done to have these methods more accurately represent the gastrointestinal tract (GIT) of cats and dogs. The Digestible IAA Score (DIAAS) is one metric that can help define protein quality for individual ingredients or mixed diets that uses AA SID estimates and ideally those can be replaced with in vitro AA digestibility estimates. Finally, we need accurate and reliable laboratory AA analyses to measure the AA present in complete diets, especially those used to quantify methionine (Met) and cysteine (Cys), both often limiting AAs in cat and dog diets. Together, this will guide accurate feed formulation for our companion animals to satisfy requirements while avoiding over-supplying protein, which inevitably contributes to excess N excretion, affecting both the environment and feed sustainability.

Microsponges: Development, Characterization, and Key Physicochemical Properties.

Microsponges are promising drug delivery carriers with versatile characteristics and controlled release properties for the delivery of a wide range of drugs. The microsponges will provide an optimized therapeutic effect, when delivered at the site of action without rupturing, then releasing the cargo at the predetermined time and area. The ability of the microsponges to effectively deliver the drug in a controlled manner depends on the material composition. This comprehensive review entails knowledge on the design parameters of an optimized microsponge drug delivery system and the controlled release properties of microsponges that reduces the side effects of drugs. Furthermore, the review delves into the fabrication techniques of microsponges, the mechanism of drug release from the microsponges, and the regulatory requirements of the U.S. Food and Drug Administration (FDA) for the successful marketing of microsponge formulation. The review also examines the patented formulations of microsponges. The prospects of these sophisticated drug delivery systems for improved clinical outcomes are highlighted.

Creating augmented reality-based experiences for aviation weather training: Challenges, opportunities, and design implications for 3D authoring.

This paper examines opportunities and challenges of integrating augmented reality (AR) into education and investigates requirements to enable instructors to author AR educational experiences. Although AR technology is recognised for its potential in educational enhancement, it poses challenges for instructors creating AR-based experiences due to their limited digital skills and the complexity of 3D authoring tools. Semi-structured interviews with 17 aviation instructors identified current pedagogical approaches, gaps, and potential applications of AR in aviation weather education. Additionally, results highlighted the benefits of AR and obstacles to its integration into education, followed by outlining design priorities and user needs for educational AR authoring. For AR authoring toolkit development, this study recommended incorporating interactive AR lesson modules, early development of user requirements, and prebuilt AR modules. Findings will guide the development of a 3D authoring toolkit for non-technologist instructors, enabling wider AR use in aviation weather education and other educational fields.

Research interviews with aviation instructors were conducted to derive design implications of AR authoring toolkits for non-technologist instructors. Key findings highlighted gaps in aviation weather education, potential AR applications, and barriers to AR in education. Design recommendations emphasised incorporating interactive AR lesson modules, initial user requirements, and prebuilt AR modules.

Dataset of geomagnetic absolute measurements performed by Declination and Inclination Magnetometer (DIM) and nuclear magnetometer during the joint Croatian-Hungarian repeat station campaign in Adriatic region.

The highest level of the present-day geomagnetic recordings is presented by the absolute controlled magnetic measurements. This quality is permanently fulfilled in geomagnetic observatories (GO) only. The absolute records are based on nuclear magnetometers for the intensity measurement and on DIM (Declination and Inclination Magnetometer) instruments for the direction determination of the ambient magnetic field. Although the density of GOs is not dense enough for every scientific purpose (i.e., modelling the secular variation in detail), repeat station (RS) networks were founded in a lot of countries on the Earth. Regarding to the main task of RS measurements, almost the same requirements must be fulfilled during the fieldwork as in the GOs. Consequently, the environmental and instrumental expectations are pre-defined as well as the procedure of measurement which are generally absolute readings. After the reduction of the absolute measurements to the simultaneous record of the nearest GO is performed, the data can be represented to a relevant yearly mean value. The present article shortly summarises the environmental and the instrumental background of geomagnetic absolute measurements on reoccupations of two different RS in Croatia. In 2010 tree-days-long reoccupations were performed on the selected stations with applying an on-site magnetic variometer. One of the results of data processing pointed out the appearance of a geomagnetic sea-side effect on both of RSs. The phenomenon is the geomagnetic influence of the induced current system in the seawater near to the shore. The anomalous lateral currents are the consequence of the high conductivity contrast between the mainland and the (moving) salinity water and the induction effect of the fluctuating external geomagnetic field. The calculation steps of the geomagnetic elements will be also detailed regarding the recorded samples of a presented dataset as well as the diagnostic values (i.e., offset value and misalignment error of fluxgate probe).

Collaborative optimization of depot location, capacity and rolling stock scheduling considering maintenance requirements.

Generally, when optimizing a rolling stock schedule, the locations of the depots, or places in the network where the composition changes and maintenance occurs, are assumed known. The locations where maintenance is performed naturally influence the quality of any resulting rolling stock schedules. In this paper, the problem of selecting new depot locations and their corresponding capacities is considered. A two-stage mixed integer programming approach for rolling stock scheduling with maintenance requirements is extended to account for depot selection. First, a conventional flow-based model is solved, ignoring maintenance requirements, to obtain a variety of rolling stock schedules with multiple depot locations and capacity options. Then, a maintenance feasible rolling stock schedule can be obtained by solving a series of assignment problems by using the schedules found in the first stage. The proposed methodology is tested on real-life instances, and the numerical experiments of different operational scenarios are discussed.

Cement-based solidification of nuclear waste: Mechanisms, formulations and regulatory considerations.

This review paper provides a comprehensive analysis of cement-based solidification and immobilisation of nuclear waste. It covers various aspects including mechanisms, formulations, testing and regulatory considerations. The paper begins by emphasizing the importance of nuclear waste management and the associated challenges. It explores the mechanisms and principles in cement-based solidification, with a particular focus on the interaction between cement and nuclear waste components. Different formulation considerations are discussed, encompassing factors such as cement types, the role of additives and modifiers. The review paper also examines testing and characterisation methods used to assess the physical, chemical and mechanical properties of solidified waste forms. Then the paper addresses the regulatory considerations and compliance requirements for cement-based solidification. The paper concludes by critically elaborating on the current challenges, emerging trends and future research needs in the field. Overall, this review paper offers a comprehensive overview of cement-based solidification, providing valuable insights for researchers, practitioners and regulatory bodies involved in nuclear waste management.

Clinical Decision Support Requirements for Ventricular Tachycardia Diagnosis Within the Frameworks of Knowledge and Practice: Survey Study.

BACKGROUND: Ventricular tachycardia (VT) diagnosis is challenging due to the similarity between VT and some forms of supraventricular tachycardia, complexity of clinical manifestations, heterogeneity of underlying diseases, and potential for life-threatening hemodynamic instability. Clinical decision support systems (CDSSs) have emerged as promising tools to augment the diagnostic capabilities of cardiologists. However, a requirements analysis is acknowledged to be vital for the success of a CDSS, especially for complex clinical tasks such as VT diagnosis. OBJECTIVE: The aims of this study were to analyze the requirements for a VT diagnosis CDSS within the frameworks of knowledge and practice and to determine the clinical decision support (CDS) needs. METHODS: Our multidisciplinary team first conducted semistructured interviews with seven cardiologists related to the clinical challenges of VT and expected decision support. A questionnaire was designed by the multidisciplinary team based on the results of interviews. The questionnaire was divided into four sections: demographic information, knowledge assessment, practice assessment, and CDS needs. The practice section consisted of two simulated cases for a total score of 10 marks. Online questionnaires were disseminated to registered cardiologists across China from December 2022 to February 2023. The scores for the practice section were summarized as continuous variables, using the mean, median, and range. The knowledge and CDS needs sections were assessed using a 4-point Likert scale without a neutral option. Kruskal-Wallis tests were performed to investigate the relationship between scores and practice years or specialty. RESULTS: Of the 687 cardiologists who completed the questionnaire, 567 responses were eligible for further analysis. The results of the knowledge assessment showed that 383 cardiologists (68%) lacked knowledge in diagnostic evaluation. The overall average score of the practice assessment was 6.11 (SD 0.55); the etiological diagnosis section had the highest overall scores (mean 6.74, SD 1.75), whereas the diagnostic evaluation section had the lowest scores (mean 5.78, SD 1.19). A majority of cardiologists (344/567, 60.7%) reported the need for a CDSS. There was a significant difference in practice competency scores between general cardiologists and arrhythmia specialists (P=.02). CONCLUSIONS: There was a notable deficiency in the knowledge and practice of VT among Chinese cardiologists. Specific knowledge and practice support requirements were identified, which provide a foundation for further development and optimization of a CDSS. Moreover, it is important to consider clinicians' specialization levels and years of practice for effective and personalized support.

Operative Experience of Esophageal Surgery among General Surgery Residents in the United States: An Analysis of ACGME Operative Case Logs.

INTRODUCTION: Esophageal surgery is an essential component of general surgery training and encompasses several types of cases that are logged by general surgery residents. There is a scarcity of data on the quality and volume of esophageal surgery experience during surgical residency in the United States. We analyzed trends for 9 different esophageal procedure categories logged by residents in the United States, with the aim to identify areas for improvement in training. METHODS: We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from programs accredited by the ACGME over a fourteen-year period from 2009 to 2023. Data on mean esophageal cases reported by graduates, including mean in each procedure subcategory were retrieved. Cases were categorized as either surgeon chief or surgeon junior for each procedure category. Mann-Kendall trend test was used to obtain tau statistics and p-value for trends in mean operative surgical volume for the total number of cases in each operative category over the study period. Trends in surgeon chief and surgeon junior cases were also investigated for each operative category. RESULTS: The mean number of all esophageal procedures performed per resident during their training increased significantly from 10.5 in 2009 to 16 in 2022 (τ = 0.833, p < 0.001). This trend observed among all esophageal procedures during this 14-year study can be largely attributed to the steady increase in the number and proportion of laparoscopic esophageal antireflux procedures performed (τ = 0.950, p < 0.001). Additionally, esophagectomy procedures had a statistically significant, but modest, increase during the study period (τ = 0.505, p = 0.023), from a mean of 1 case during training in 2009 to a peak of 1.3 in 2020. Although the general trend of esophagus procedures increased during the study period, most categories (7 out of 9) either decreased or did not significantly change. Esophagogastrectomy volume decreased significantly by 30%, from 1 per resident during their training in 2009 to 0.7 in 2022 (τ = -0.510, p = 0.018), esophageal diverticulectomy procedures decreased by 50% from 0.2 to 0.1 (τ = -0.609, p = 0.009), and operations for esophageal stenosis decreased by 75% from 0.4 to 0.1 (τ = -0.734, p = 0.001). Mean number of esophageal bypasses (τ = -0.128, p = 0.584), repair of perforated esophageal disease (τ = -0.333, p = 0.156), and other major esophagus procedures (τ = 0.416, p = 0.063) did not significantly change. CONCLUSION: The operative volume of esophageal surgery that general surgery residents in the United States are exposed to has significantly risen over the past 14 years, largely driven by the increase in laparoscopic antireflux procedures. However, given the recent advances and the resultant heterogeneity in both esophageal surgery, the increase in resident operative volume is still inadequate to ensure the training of safe and adept esophageal surgeons, necessitating postresidency specialized training for trainees interested in esophageal surgery.

Open forum conference on the ICH M13A bioequivalence guideline.

The Network on Bioavailability and Biopharmaceutics of EUFEPS (European Federation for Pharmaceutical Sciences) had organised an Open Discussion Forum on the ICH M13A draft "Guideline on bioequivalence for immediate-release solid oral dosage forms". This conference was cosponsored by the Arbeitsgemeinschaft Pharmazeutische Verfahrenstechnik (APV) and the Frankfurt Foundation Quality of Medicines. Scientists from academia and industry attended this workshop on May 15, 2023, in Frankfurt/Germany, to discuss the suggested regulations with the European members of the ICH drafting group. The aim of this report is to summarise and highlight the main discussion points such as choice of study population (females and/or males), request for fasted and/or fed studies, consequences of differences in drug product content, handling of aberrant plasma profiles and additional requirements in case of pH-dependant solubility. During the discussion important arguments were presented for a revision of certain requirements suggested in the draft guideline.

Priority nutrients to address malnutrition and diet-related diseases in Australia and New Zealand.

Background: The double burden of malnutrition and diet-related disease has been attributed to diets high in ultra-processed and discretionary foods, with increased sugars, saturated fats, and sodium, and insufficient dietary fibre. There is a limited understanding of the role of other macronutrients and micronutrients. Objective: Determine the highest priority nutrients to address both malnutrition and diet-related disease in Australia and New Zealand, for each demographic group and the total population. Methods: A novel four-step methodological approach was undertaken to identify: 1. Demographic (age-sex) groups; 2. Health priorities; 3. Potential nutrients based on inadequacy, increased requirements, and health priority association; and 4. Priority nutrients. Nutrient intake data was obtained from the most recent Australian and New Zealand nutrition surveys. Health priorities were based on national statistical data and expert consultation. High-level scientific literature (systematic reviews) was scoped for associations with health priorities and the suitability of recommended intakes. A quantitative scoring matrix was developed and used to determine the highest priority nutrients, with scoring over three domains: extent of inadequacy; consensus for increased requirements; and degree of association with health priorities. Results: Nutritional inadequacies were common, with 22 of 31 essential nutrients consumed below recommended levels. Nine priority nutrients were identified across the demographic groups, with each demographic group characterised by a specific subset of these. Six nutrients were highest priority within the total population: vitamin D, calcium, omega-3 fatty acids, magnesium, folate, dietary fibre. Conclusion: The extent of nutritional inadequacies in Australia and New Zealand is high, both within each demographic group and the entire population, relative to both recommended intakes and key health outcomes. The methodology can be applied to other countries and globally. Findings make a significant contribution to understanding the nutrients to prioritise in future-proofing the health of the Australian and New Zealand populations. Guidelines and policies can target priority nutrients to address the malnutrition and diet-related disease double burden.

Residency Requirements for Medical Aid in Dying.

In 1997, when Oregon became the first U.S. jurisdiction authorizing medical aid in dying (MAID), its law included a requirement that patients be legal residents of the state. Other U.S. jurisdictions legalizing MAID followed Oregon in adopting residency requirements. Recent litigation challenges the legality, as well as the justification, for such requirements. Facing such challenges, Oregon and Vermont eliminated their MAID residency requirements. More states could follow this move, for, in certain circumstances, the U.S. Constitution's privileges and immunities clause protects citizens' right to travel to secure medical care. Policy considerations could also motivate states to reexamine whether such requirements are justified in light of existing evidence of how MAID laws have been applied.

Estimation of Protein and Amino Acid Requirements in Layer Chicks Depending on Dynamic Model.

Four trials were conducted to establish a protein and amino acid requirement model for layer chicks over 0-6 weeks by using the analytical factorization method. In trial 1, a total of 90 one-day-old Jing Tint 6 chicks with similar body weight were selected to determine the growth curve, carcass and feather protein deposition, and amino acid patterns of carcass and feather proteins. In trials 2 and 3, 24 seven-day-old and 24 thirty-five-day-old Jing Tint 6 chicks were selected to determine the protein maintenance requirements, amino acid pattern, and net protein utilization rate. In trial 4, 24 ten-day-old and 24 thirty-eight-day-old Jing Tint 6 chicks were selected to determine the standard terminal ileal digestibility of amino acids. The chicks were fed either a corn-soybean basal diet, a low nitrogen diet, or a nitrogen-free diet throughout the different trials. The Gompertz equation showed that there is a functional relationship between body weight and age, described as BWt(g) = 2669.317 × exp(-4.337 × exp(-0.019t)). Integration of the test results gave a comprehensive dynamic model equation that could accurately calculate the weekly protein and amino acid requirements of the layer chicks. By applying the model, it was found that the protein requirements for Jing Tint 6 chicks during the 6-week period were 21.15, 20.54, 18.26, 18.77, 17.79, and 16.51, respectively. The model-predicted amino acid requirements for Jing Tint 6 chicks during the 6-week period were as follows: Aspartic acid (0.992-1.284), Threonine (0.601-0.750), Serine (0.984-1.542), Glutamic acid (1.661-1.925), Glycine (0.992-1.227), Alanine (0.909-0.961), Valine (0.773-1.121), Cystine (0.843-1.347), Methionine (0.210-0.267), Isoleucine (0.590-0.715), Leucine (0.977-1.208), Tyrosine (0.362-0.504), Phenylalanine (0.584-0.786), Histidine (0.169-0.250), Lysine (0.3999-0.500), Arginine (0.824-1.147), Proline (1.114-1.684), and Tryptophan (0.063-0.098). In conclusion, this study constructed a dynamic model for the protein and amino acid requirements of Jing Tint 6 chicks during the brooding period, providing an important insight to improve precise feeding for layer chicks through this dynamic model calculation.