Quadratic Behavior Research Articles

The impact of the COVID-19 pandemic on e-learning adoption in an emerging market: a longitudinal study using the UTAUT model

Purpose The COVID-19 pandemic provided unprecedented impetus to the evolution of the e-learning learning ecosystem by compelling students to adopt e-learning systems. This paper aims to use the UTAUT model to provide insight into the differences in factors influencing the adoption of e-learning systems before and after the pandemic. Design/methodology/approach This longitudinal study uses two surveys conducted among graduate students in the city of Bengaluru in India. One prior to the start of the COVID-19 pandemic and a second in its aftermath. PLS-SEM is used to analyze both data sets to draw insights into the constructs that influence Behavioral intention to adopt e-learning systems. The moderating effect of gender is also analyzed. Findings Pre COVID-19, Facilitating Conditions, Performance Expectancy and Effort Expectancy (quadratic behavior) were dominant factors influencing the adoption of e-learning technologies. Post pandemic, Performance Expectancy and Social Influence are drivers of e-learning adoption. Effort Expectancy and Facilitating Conditions grouped as Ease of Use is a significant driver of e-learning adoption post pandemic. Gender is found to not have a moderating influence. Originality/value The unique longitudinal study of the differences in factors influencing students’ intention to adopt e-learning pre- and post-COVID-19 can prove useful to policy makers in the higher education sector. Academics can use the post-pandemic e-learning model’s findings in multiple contexts such as generational cohorts, educational contexts and social contexts.

Potassium Fertilization Alters the Morphogenetic, Structural, and Productive Characteristics of Panicum maximum Cultivars

The objective was to evaluate the effects of potassium fertilization on the morphogenetic, structural, and productive characteristics of Panicum maximum (cvs. Tanzania, Quênia, Mombaça, Zuri, Massai, and Tamani). The design was in randomized blocks with four doses of potassium (K) 0, 205, 410, and 820 mg dm−3, divided into 5 applications. The analyzed variables were leaf appearance rate (LAR), leaf elongation rate (LER), stem elongation rate (SER), leaf senescence rate (LSR), leaf life span (LLS), phyllochron (PC), number of live leaves (NLL), final leaf length (FLL), tiller population density (TPD), and forage mass (FM). LAR increased by 0.00216 leaves tiller on day-1 (p = 0.0354) and LER increased by 0.00980 cm tiller on day-1 for each milligram of K (p = 0.0402). There was an increase in FLL of 0.16, 0.08, and 0.07 days for the cultivars Mombaça, Massai, and Tamani, respectively, for each milligram of K applied (p = 0.0034). The TPD of the cultivar Tamani increased linearly by 0.074 tillers/pot for each milligram of K (p = 0.0226), and the cultivar Massai showed a quadratic behavior. The TPD of the other cultivars was not influenced by the increase in the K doses. For forage mass (FM), the cultivars Mombaça and Quênia increased by 0.16 and 0.39 g DM/pot for each milligram of K added to the soil. The cultivars Tanzânia, Zuri, Massai, and Tamani showed maximum point at doses of 261.35, 279.45, 300.57, and 275.86 mg dm−3 K, respectively. Potassium fertilization linearly increased leaf appearance and elongation, with maximum productivity reached at a K dose of 430 mg dm−3, except for the cultivars Mombaça and Quênia, which responded up to a K dose of 820 mg dm−3.

Productivity and economic performance of Nellore young bulls fed diets with increasing fiber content.

Adequate neutral detergent insoluble fiber (NDF) content in the total diet can improve intake efficiency, prevent rumen disorders, and enhance the health and performance of feedlot-finished beef cattle. We hypothesized that an increase in dietary fiber levels would decrease the productive performance but increase the economic performance of young bulls in confinement. Thus, it was aimed to evaluate the effect of increasing fiber levels on feed intake, wastage, and productive and economic performance of Nellore young bulls finished in confinement. We used 20 Nellore cattle, non-castrated males, 30 months old, and average body weight (BW) of 416.35 ± 2.2kg distributed in a completely randomized design, kept in individual stalls. Animals were divided into four treatments consisting of four levels of neutral detergent insoluble fiber (NDF) (25%, 30%, 35%, and 40% NDF) in total DM. Nutrient intake, feed conversion, feed waste, body weight (BW) at slaughter, total weight gain (TWG), average daily gain (ADG), hot carcass weight (HCW), and carcass yield (CR) were evaluated. In addition, economic parameters (revenue, food expenses, and gross margin) were calculated and compared. The dry matter (DMI), organic matter (OMI), crude protein (CPI), and ether extract (EEI) intakes showed quadratic behavior. The DMI maximum estimated was 28.5% NDF in the diet. The NDF and ADF intakes showed a positive linear effect and the starch intake had a negative linear effect. There was a significant positive linear effect (P < 0.05) for the variables total mixed ration (TMR) offered and daily and total RTM intake. Minimum RTM wastage was estimated with a diet containing 30% NDF. The maximum points for BW at slaughter, HCW, and ADG were 29.9%; 29.6%, and 25% NDF, respectively. The costs of concentrate and silage showed a positive linear behavior, as did the ADG costs and the carcass equivalent cost (P < 0.05). The maximum point of the revenue estimate (US$/animal) was 29.9% of NDF, 26.1% of NDF for the total expenditure on food (US$/animal), and 32.5% of NDF for the gross margin (U$/animal). In conclusion, the animals fed a 30% NDF diet showed the best performance and economics, in addition to less food waste. We recommend 25 to 32.5% of NDF in the diet to obtain maximum productive and economic performance when finishing Nellore young bulls in confinement.

Alchemical insights into approximately quadratic energies of iso-electronic atoms.

Accurate quantum mechanics based predictions of property trends are so important for material design and discovery that even inexpensive approximate methods are valuable. We use the alchemical integral transform to study multi-electron atoms and to gain a better understanding of the approximately quadratic behavior of energy differences between iso-electronic atoms in their nuclear charges. Based on this, we arrive at the following simple analytical estimate of energy differences between any two iso-electronic atoms, ΔE≈-(1+2γNe-1)ΔZZ̄. Here, γ ≈ 0.3766 ± 0.0020 Ha corresponds to an empirical constant, and Ne, ΔZ, and Z̄, respectively, to electron number, nuclear charge difference, and average. We compare the formula's predictive accuracy using experimental numbers and non-relativistic, numerical results obtained via density functional theory (pbe0) for the entire periodic table up to Radon. A detailed discussion of the atomic helium-series is included.

Effect of temperature on water evaporation coefficient (E) in a thermobalance: A solar-driven steam generation approach

During this investigation, the variation of the water evaporation phenomenon with the defined drying temperature and mass of water was analyzed, five levels were studied (50, 60, 70, 80 and 90 ℃), finally a correlation between temperature and evaporation rate was generated. With the study carried out, it was defined that the water evaporation velocity can be calculated with an initial mass of 35 g at 90 ℃, while the necessary time for the determination was 120 min. In addition, it was determined that the evaporation velocity follows a quadratic behavior with temperature, according to the experiments carried out with the Sartorius MA-100 balance, while the maximum deviation recorded was 0.349 mmol/m2s for a temperature of 80 ℃. It is concluded that the determination of the water evaporation velocity is highly dependent on the temperature and mass of water. Furthermore, this study can be used as a basis for future studies aimed at improving the efficiency of processes such as steam and electricity cogeneration.

Rotational holographic transport from Kerr-Newman-AdS black hole

We consider rotational holographic transport in strongly coupled 2+1-dimensional systems, from the point of view of 3+1-dimensional gravity. We consider the moment of inertia I as a kind of transport coefficient, identified with the moment of inertia of a charged rotating black hole in AdS4 background. In the low-temperature region, we find the behavior of the density I/A with temperature T and angular velocity Ω and find a quadratic behavior for ∂(I/A)/∂Ω with T, in the presence of some charge Q. Published by the American Physical Society 2024

The Ensiling melon biomass with different levels of inclusion of ground corn

The aim of this study was to evaluate silages produced with different mixtures of melon biomass and different levels of ground corn. The experiment was conducted under a completely randomized design in factorial scheme (3 × 4), with four replications. The first factor consieted of three mixtures of plant (branch and leaf) and fruit (melon; scraps) on natural matter (NM) as follows: 0, 100 and 1000 g kg-1 fruit. The second factor consisted of the use of different amounts of ground corn (0, 50, 100 and 200 g kg-1). Experimental silos with capacity for 5 kg and density of 500 kg m-3 were used. After 90 days, the silos were opened and the evaluations were carried out. The data were subjected to analysis of variance and the means were analyzed through the Tukey’s test (fermentative losses, chemical composition, aerobic stability), Scott-Knott test (microbiology and organic acids) and regression, and were compared with a significance level of p&lt;0.05. The best dry matter results were obtained in silages with 0, 100 and 1000 g kg-1 fruit combined with 200 g kg-1 ground corn, which averaged 289.4, 290.4 and 264.1 g kg-1, respectively. Quadratic behavior was observed for effluent losses in silages with 100 g kg-1 fruit presenting a minimum value of 46.8 e and a maximum 56.2 kg t-1 NM. Regarding the mold population count, the highest values were obtained in silages with 100 g kg-1 fruit and 50 g kg-1 ground corn. Silages with 100 and 1000 g kg-1 fruit in melon biomass and 200 g kg-1 ground corn presented superior quality indicators, characterizing these biomass mixtures as the most suitable for silage making.

Rheological behavior of the synovial fluid: a mathematical challenge

BackgroundSynovial fluid (SF) is often used for diagnostic and research purposes as it reflects the local inflammatory environment. Owing to its complex composition, especially the presence of hyaluronic acid, SF is usually viscous and non-homogeneous. The presence of high-molar-mass hyaluronan in this fluid gives it the required viscosity for its function as a lubricant. Viscosity is the greatest major hydraulic attribute of the SF in articular cartilage.MethodsEmpirical modeling of previously published results was performed. In this study, we explored the flow of a non-Newtonian fluid that could be used to model the SF flow. Analyzing the flow in a simple geometry can help explain the model’s efficacy and assess the SF models. By employing some viscosity data reported elsewhere, we summarized the dynamic viscosity values of normal human SF of the knee joints in terms of time after injecting hyaluronidase (HYAL) at 25°C. The suggested quadratic behavior was obtained through extrapolation. For accurate diagnosis or prediction, the comparison between three specific parameters (ai, t0, and ln η0) was made for normal and pathological cases under the same experimental conditions for treatment by addition of HYAL and for investigation of the rheological properties. A new model on the variation of viscosity on the SF of knee joints with time after injection of HYAL with respect to normal and postmortem samples at different velocity gradients was proposed using data previously reported elsewhere.ResultsThe rheological behavior of SF changes progressively over time from non-Newtonian to a Newtonian profile, where the viscosity has a limiting constant value (η0) independent of the gradient velocity at a unique characteristic time (t0 ≈ 8.5 h). The proposed three-parameter model with physical meaning offers insights into future pathological cases. The outcomes of this work are expected to offer new perspectives for diagnosis, criteria, and prediction of pathological case types through comparisons with new parameter values treated under the same experimental conditions as HYAL injection. This study also highlights the importance of HYAL treatment for better intra-assay precision.

Study of the large bending behavior of CNTs using LDTM and nonlocal elasticity theory

The general expressions for vertical deflection, horizontal displacement, and strain energy in a bent cantilevered carbon nanotube (CNT) are derived herein under a uniformly distributed load. This derivation employs nonlocal elasticity theory, crucial for understanding nanoscale mechanics due to size effects, and accounts for the nonlinear relationship between bending curvature and deflection under large bending conditions, a novel contribution. In the limiting cases, our expressions for large bending give the corresponding expressions reported in the literature for small bending. Additionally, we introduce the Laplace-Differential Transformation Method (LDTM) for the first time, providing efficient solutions to explore the influence of parameters like aspect ratio and small-scale factors on CNT bending behavior. Comparison with the analytical method validates the accuracy and efficacy of LDTM, offering a rapid solution for nonlinear equations. Our findings reveal that strain energy deviates more prominently from quadratic behavior in CNTs with high aspect ratios, while small-scale parameters have a pronounced effect on CNTs with smaller aspect ratios. These results will be relevant to designing and applying the nanoscale-sized cantilevered CNTs used in MEMs/NEMs.

New pairing mechanism via chiral electron–hole condensation for non-BCS superconductivity

A novel chiral electron–hole (CEH) pairing mechanism is proposed to account for non-BCS superconductivity. In contrast to BCS Cooper pairs, CEH pairs exhibit a pronounced affinity to antiferromagnetism for superconductivity. The gap equations derived from this new microscopic mechanism are analyzed for both s- and d-wave superconductivity, revealing marked departures from the BCS theory. Unsurprisingly, CEH naturally describes superconductivity in strongly-correlated systems, necessitating an exceedingly large coupling parameter (λ>1 for s-wave and λ>π/2 for d-wave) to be efficacious. The new mechanism provides a better understanding of various non-BCS features, especially in cuprate and iron-based superconductors. In particular, CEH, through quantitative comparison with experimental data, shows promise in solving long-standing puzzles such as the unexpectedly large gap-to-critical-temperature ratio Δ0/Tc, the lack of gap closure at Tc, superconducting phase diagrams, and a non-zero heat-capacity-to-temperature ratio C/T at T=0 (i.e., the “anomalous linear term”), along with its quadratic behavior near T=0 for d-wave cuprates.

Spread complexity in saddle-dominated scrambling

Recently, the concept of spread complexity, Krylov complexity for states, has been introduced as a measure of the complexity and chaoticity of quantum systems. In this paper, we study the spread complexity of the thermofield double state within integrable systems that exhibit saddle-dominated scrambling. Specifically, we focus on the Lipkin-Meshkov-Glick model and the inverted harmonic oscillator as representative examples of quantum mechanical systems featuring saddle-dominated scrambling. Applying the Lanczos algorithm, our numerical investigation reveals that the spread complexity in these systems exhibits features reminiscent of chaotic systems, displaying a distinctive ramp-peak-slope-plateau pattern. Our results indicate that, although spread complexity serves as a valuable probe, accurately diagnosing true quantum chaos generally necessitates additional physical input. We also explore the relationship between spread complexity, the spectral form factor, and the transition probability within the Krylov space. We provide analytical confirmation of our numerical results, validating the Ehrenfest theorem of complexity and identifying a distinct quadratic behavior in the early-time regime of spread complexity.

Crossover from Linear to Quadratic Electro-optic Behavior in BaTiO_{3} and (Ba, Sr)TiO_{3} Solid Solution.

We derive a numerical method based on coupled density functional theory and effective Hamiltonian schemes to calculate the linear and quadratic electro-optic response of ferroelectrics at finite temperature and in different frequency ranges. By applying the developed method to BaTiO_{3}, we successfully resolve apparent discrepancies in the experimental literature that reported a linear or quadratic electro-optic response when visible or terahertz radiation was employed to measure the optical index, respectively. We further demonstrate that (and explain why), in the case of the Ba_{1-x}Sr_{x}TiO_{3} disordered solid solutions, structural phase transitions not only lead to larger linear electro-optic constants, as previously demonstrated in the literature, but also significantly enhance the quadratic electro-optic constants.

Evaluation of different ratios of neutral detergent-soluble carbohydrate fractions on performance, ingestive behavior, and nitrogen balance in dairy goats.

Cell components soluble in neutral detergent are a diverse group, both compositionally and nutritionally. The present study aimed to evaluate production responses, behavior (eating, ruminating, and idling), and nitrogen balance of dairy goats fed different ratios of neutral detergent-soluble carbohydrate fractions. Five multiparous Alpine does with mean ± SD initial body mass of 49.5 ± 7.9kg and 60days of lactation were randomly assigned in a 5 × 5 Latin square design. The treatments were the ratios of starch (starch associated with soluble sugar [StSS]) to neutral detergent-soluble fiber (NDSF) (StSS:NDSF): 0.89, 1.05, 1.24, 1.73, and 2.92. No effect was observed (P > 0.05) of StSS:NDSF on the intakes of neutral detergent fiber (NDF) and NDSC. However, DM intake showed a quadratic behavior (P = 0.049). The ingestive behavior was affected by StSS:NDSF linearly increased (P = 0.002) the feeding efficiency. The increase in StSS:NDSF caused a linear increase in fecal (P = 0.011), urinary (P < 0.001), and milk nitrogen excretion (P = 0.024). The increase in StSS:NDSF affected (P = 0.048) milk yield and net energy lactation (P = 0.036). In conclusion, dairy goats experience reduced dry matter intake and milk yield when subjected to high-NDSC diets, specifically those above 1.24 StSS:NDSF ratio. Elevated NDSC levels in the diets lead to decreased feeding time, whereas rumination remains unaffected. Nitrogen losses in goats increase linearly with high-NDSC diets, and a significant impact on nitrogen balance.

Internal quality of commercial eggs subjected to different shell treatments and storage times

Five hundred sixty eggs from commercial layers aged 74 weeks were subjected to sanitization and shell-covering procedures. The treatments consisted of two egg sanitization methods, sanitized (S) and not sanitized (NS), and two methods of shell covering, not covered (NC) and covered (C) with whey protein concentrate solution, arranged in a completely randomized design in a 2 × 2 factorial scheme (sanitization × shell coating), with five replications obtained from the average of four eggs evaluated in seven storage periods (1, 7, 14, 21, 28, 35, and 42 days). Albumen pH and yolk lipid oxidation using the TBARS test were evaluated. The averages for each period were submitted to analysis of variance, any differences observed were submitted to the Tukey test (5%), and regression analysis was performed between periods for each method. Using SDS-PAGE, the protein profile of albumen at 1 and 42 days was evaluated descriptively. Using methods S and NS, the pH and TBARS of eggs did not change on any of the days evaluated (P&gt;0.05). Methods C and NC had similar pH values (P&gt;0.05) only when using fresh eggs; however, the pH was higher when using eggs from Method NC (P&lt;0.0001) compared with Method C. For all techniques, the analysis of pH regression between periods revealed quadratic behavior. While regression analysis demonstrated an increasing linear behavior for all methods, the TBARS analysis results for C and NC on all evaluated days were comparable (P&gt;0.05). Whey protein concentrate does not affect the pH of sanitized eggs. The protein profile of the albumen and TBARS values of egg yolks stored at room temperature are unaffected by sanitation and whey protein concentrate covering, and TBARS values increase over storage days in all cases.

Effect of irrigation levels on the production of Arachis hypogeaea L.

Peanuts (Arachis hypogaea L.) are a high-protein alternative for making up for nutritional deficiencies. Adequate irrigation management is essential for greater productivity of this crop, especially in Brazilian Cerrado. In this context, this study aimed to evaluate the productive characteristics of peanuts subjected to different irrigation levels under controlled conditions. The research was conducted in the Savannah region at the Federal University of Rondonópolis, in Rondonópolis - Mato Grosso, Brazil. The soil used to grow the peanuts was Oxisol. The experimental design was completely randomized with five treatments (50%, 75%, 100%, 125%, and submerging at 150% of field capacity) and five replications. The analyzed variables included the number of pods, number of grains per pod, pod dry mass, and dry mass of grains. The number of pods and the number of grains per pot fitted the increasing linear model as a function of different levels of field capacity. On the other hand, the pod dry mass and dry mass of grains per pod showed a quadratic regression behavior. Different levels of field capacity had a significant impact on peanut productivity. The treatment with 100% of field capacity yielded the best results in terms of peanut productivity and grain quality.

Bosonic and fermionic holographic fluctuation and dissipation at finite temperature and density

In this paper we investigate some general aspects of fluctuation and dissipation in the holographic scenario at zero and finite density. We model this situation with a probe string in a diagonal metric representing a black brane. The string stretches from the black brane to a probe brane, thus simulating a stochastic driven particle. In this scenario, we compute the admittance, the diffusion coefficient, the correlation functions, and the regularized mean square displacement, for bosons and fermions, all from the metric components. We check these calculations with the fluctuation-dissipation theorem. Further, we show that at finite temperature and density, the mean square displacement in the limit of short times reproduces the usual quadratic (ballistic) behavior, for bosons and fermions. For large times, we find ultraslow diffusive processes in various cases, except for bosons at the zero chemical potential. We apply this general analysis in two different models: hyperscaling violation at finite temperature and a charged dilatonic anti–de Sitter black hole, both for bosons and fermions. This is important because we found the fermionic diffusion in systems that allow the appearance of Fermi surfaces and Fermi liquids. Published by the American Physical Society 2024

Local force constants and charges of the nitrosyl ligand in photoinduced NO linkage isomers in a prototypical ruthenium nitrosyl complex.

Photoinduced linkage isomers (PLI) of the NO ligand in transition-metal nitrosyl compounds can be identified by vibrational spectroscopy due to the large shifts of the (NO) stretching vibration. We present a detailed experimental and theoretical study of the prototypical compound K2[RuCl5NO], where (NO) shifts by ≈150 cm-1 when going from the N-bound (κN) ground state (GS) to the oxygen-bound (κO) metastable linkage isomer MS1, and by ≈360 cm-1 when going to the side-on (κ2N,O) metastable linkage isomer MS2. We show that the experimentally observed N-O stretching modes of the GS, MS1, and MS2 exhibit strong coupling with the Ru-N and Ru-O stretching modes, which can be decoupled using the local mode vibrational theory formalism. From the resulting decoupled pure two-atomic harmonic oscillators the local force constants are determined, which all follow the same quadratic behavior on the wavenumber. A Bader charge analysis shows that the total charge on the NO ligand is not correlated to the observed frequency shift of (NO).

Assessment of infection of Stomoxys calcitrans larvae by entomopathogenic nematodes Heterorhabditis amazonensis NEPT11.

This study aimed to evaluate the virulence of Heterorhabditis amazonenses NEPT11 against larvae of Stomoxys calcitrans. Groups of 10 third-instar fly larvae were deposited in Petri dishes, to which were added 50, 100 and 200 EPNs/larva in 4ml of distilled water. The volume of the control group was the same as the treated group, but without EPNs. Larval mortality was observed daily, until larvae died or adults emerged. The Petri dishes were kept on laboratory shelves at 27 ± 1 °C and 70 ± 10% RH. The experiment was replicated six times. A regression analysis revealed quadratic behavior with increasing concentrations, indicating that the concentration of 200 EPNs/larva (48%) was the most efficient among the tested concentrations, while concentrations of 50 and 100 EPNs/larva killed 26.6 and 40% of larvae, respectively. In general, none of the treatments resulted in a mortality rate of more than 50%, but all the treated groups exhibited a higher mortality than that of the control group. It is concluded that the EPN H. amazonensis NEPT11 shows a promising potential to control third-instar larvae of S. calcitrans. However, further studies are needed in different situations to better understand the activity of this organism against the immature stages of the stable fly.

Grãos secos de destilaria em suplementos para bovinos a pasto

Abstract The objective was to evaluate the inclusion of increasing levels of DDG on nutrient intake and digestibility and ruminal fermentation in cattle kept on pasture. Five castrated male steers, fitted with a ruminal cannula, weighing 450±50kg, 18 months old, kept on Marandu grass pasture were used; and distributed in a 5x5 Latin square. DDG was included in the supplements in the following proportions: 0, 100, 150, 200 and 300 g/kg DM. The data were analyzed and subjected to analysis of variance, at a significance level of 5%, being evaluated by simple polynomial regression. The total availability of pasture and green matter presented averages of 2.0 Ton/ha and 1.3 Ton/ha, respectively, allowing selectivity by animals. The consumption of pasture (P=0.032), MS (P=0.041), MO (P=0.022), and PB (P=0.035) showed quadratic behavior with the inclusion of DDG in the supplements, where the highest consumption for both corresponded to the supplements with 100 and 200g/kg inclusion. The digestibility of NDF (P=0.001) and OM (P=0.046) also suffered a quadratic effect (P&lt;0.05), noting that at levels above 200g/kg it can be reduced. N-consumed also suffered a quadratic effect (P=0.032) with an increase in the inclusion of 100, 200 and 300g/kg of DDG, being linked to the protein fraction of DDG. The levels of Isovalerate (P=0.0001), AGCR (P=0.004) and CH4 production (P=0.022) decreased linearly, indicating a decrease in the energy levels of the animals. Therefore, levels between 150 and 200g/kg of DDG are recommended in supplements for cattle kept on pasture.

Body content and mineral requirements of dairy goats in early lactation

This study aimed to evaluate the dynamics mobilization of body macrominerals and estimate dairy goats' maintenance and lactation requirements at the beginning of lactation. Fifty-one goats were slaughtered to estimate the body macromineral of the animals. Three goats (baseline) and forty-eight goats, with an initial body mass of 57.19 ± 8.4 kg, were assigned to a completely randomized design in eight weeks of lactation. Six goats were slaughtered per week. The intake of dry matter and minerals presented a quadratic behavior (P < 0.05) as the lactation advanced, except for the Mg intake. Milk yield and minerals were affected throughout the 56 days of lactation. Macrominerals decreased linearly in the empty body weight (EBW) (P < 0.05) with the advance in lactation. The weeks of lactation affected only the maintenance requirement of Mg (P = 0.021) and Na (P = 0.017). When analyzing lactation requirements, macrominerals decreased (P < 0.05) over the 56 days of lactation. However, only the total P and K requirements were not affected (P > 0.05). In conclusion, dairy goats in early lactation mobilize on average 12.1 ± 0.3 g Ca, 5.7 ± 0.2 g P, 0.9 ± 0.1 g Mg, 9.1 ± 0.2 g K, and 3.4 ± 0.1 g Na from EBW/day. cc