Feed Concentration Research Articles

The effect of adding essential oils of cloves and thyme on the performance of local Iraqi goats, digestibility, and rumen fermentation

This study aimed to assess the impact of natural essential oils on the performance of native Iraqi goat youngsters, their feed intake, and apparent digestibility. The study comprised 20 male kids of indigenous Iraqi lineage. Their mean weight was 19.72 ± 2.09 kg at three months of age. They were allocated randomly and uniformly into four nutritional interventions. The subjects were provided with a standardized basic diet consisting of 40% alfalfa hay and 60% concentrated feed combination. The kids were nourished in cohorts for 195 days throughout the fattening experiment and for 10 days during the digesting experiment at the conclusion of the study. Nutritional groups comprised: control group on a basic diet, clove group on a basic diet supplemented with 2 ml clove oil, thyme group on a basic diet supplemented with 2 ml thyme oil, and a combined clove and thyme group on a basic diet supplemented with 1 ml clove oil and 1 ml thyme oil. The examined essential oils shown no substantial impact on kids' performance. Clove essential oil markedly enhanced the digestibility of dry matter, organic matter, crude protein, ether extract, acid detergent fiber, and nitrogen balance ratio. The incorporation of thyme oil resulted in a considerable increase in ammonia content within the rumen. Plasma creatinine and low-density lipoprotein concentrations elevated in the thyme group. Incorporating clove or thyme oil into the kids' diet did not enhance the animals' growth performance or blood metabolites. Clove oil exerted a substantial beneficial impact on nutrient digestion. Further investigation is required utilizing elevated doses of clove oil and extended treatment periods.

Carbon Footprint of By-Product Concentrate Feed: A Case Study

Using by-products in livestock feed can be an additional strategy for safeguarding land use in agriculture and reducing the environmental impact of animal production. Studies conducted on farms to assess the environmental impact of milk and meat production using life-cycle assessment (LCA) tools reveal that feeding accounts for approximately one-third. This study aimed to calculate the carbon footprint (CF) of three different concentrated feeds for livestock, both with and without the inclusion of by-products in the formulation. Three different formulations of concentrated feeds for dairy cows were developed homogeneously regarding energy content and crude protein. The LCA approach assessed CF in kg CO2 eq.; the functional unit was 1 kg of concentrate feed. A sensitive analysis of soybean meal’s association with deforestation was formulated. The concentrated feed with by-products demonstrated a lower impact on CF of 23.7% and 37.0% compared to concentrated feed with a mix of raw material and by-products, and solely with raw material, respectively. Using agricultural by-products to produce concentrated feed for livestock sectors can be an environmentally sound alternative in terms of carbon footprint.

Hydraulic gradient analysis in vertical hydraulic transport for coarse particles

This paper investigates the hydraulic gradient in vertical hydraulic transport (VHT) for coarse particles using a one-dimensional (1D) quasi-fluid model developed in previous work. The hydraulic gradient is divided into three key mechanisms—transport medium, mixture gravity, and particle–wall collisions—each of which is thoroughly analyzed in terms of its contribution to the overall pressure drop. The model's accuracy is validated through comparison with experimental data, yielding a mean absolute percentage error of 13.38%, indicating strong agreement. The study systematically investigates the impact of feed concentration, particle diameter, and mixture velocity on both the values of the individual hydraulic gradient components and their proportions within the total hydraulic gradient. The changes in total pressure drop predicted by the 1D model are also examined across various initial conditions, showing that the total pressure drop increases with higher feed concentration and greater mixture velocity, respectively. Additionally, the total pressure drop is insensitive to the change of particle diameter. This detailed analysis provides key insights into how each mechanism influences pressure loss in VHT systems, offering practical recommendations for enhancing the efficiency and accuracy of hydraulic transport processes in engineering applications.

Lactational performance effects of 3-nitrooxypropanol supplementation to dairy cows: A meta-regression.

A meta-regression was conducted to determine the production effects of 3-nitrooxypropanol (3-NOP) and investigate their associations with dose, dietary nutrient composition, and supplementation length in dairy cows. Forty treatment and control mean comparisons extracted from 21 studies conducted or published between 2014 to 2024 were used in the meta-regression. Response variables were DMI, milk yield (MY), ECM yield, ECM feed efficiency, BW, BW change, and concentrations of milk fat, true protein, lactose, and MUN. Treatment and control mean differences (MD) as well as standardized MD were calculated and used for data presentation and statistical analysis, respectively. Dose (± SD; 77.0 ± 33.17 mg 3-NOP/kg DMI), forage-to-concentrate ratio (FC; 58.9 ± 8.83%, expressed as average ± SD% of forage in the diet), dietary concentrations of CP, ether extract, NDF, and starch (16.3 ± 1.84%, 4.3 ± 1.03%, 33.7 ± 4.40%, and 20.9 ± 3.97%, as average ± SD% of DM, respectively), supplementation length (days), and DIM and BW of the cows at the beginning of the study were used as continuous explanatory variables. Mixed-effects models were fitted using the robust variance estimation method. Full models containing uncorrelated explanatory variables (Pearson correlation <0.50) were fitted, and variables were removed from the final model if nonsignificant using the stepwise selection approach. Compared with control, supplementation of 3-NOP decreased DMI and MY by 0.80 ± 0.149 and 0.98 ± 0.250 kg/d, respectively, but only numerically decreased ECM by 0.50 ± 0.298 kg/d. Consequently, feed efficiency was increased by 0.05 ± 0.012 kg ECM/kg DMI with 3-NOP supplementation. Body weight and BW change were not affected by 3-NOP supplementation. Milk fat, true protein, and MUN concentrations were increased by 0.09 ± 0.028%, 0.02 ± 0.006%, and 0.59 ± 0.106 mg/dL, respectively. Increasing 3-NOP dose further decreased DMI and increased milk fat and MUN concentrations. Increasing dietary NDF and FC lessened the negative effect of 3-NOP on DMI and MY, respectively, and decreased its effect on milk fat and MUN (dietary NDF concentration effect only). Similarly, increasing dietary CP lessened the negative effect of 3-NOP on DMI and decreased its effect on MUN. To explain some of the production effects herein observed, ruminal fermentation data from 6 published studies were included in the meta-regression. Supplementation of 3-NOP tended to increase rumen pH and decreased NH3 concentration. Concentrations of total VFA, acetate, and the acetate-to-propionate ratio were decreased, whereas the concentration of propionate was increased, and that of butyrate was numerically increased by 3-NOP supplementation. Overall, 3-NOP supplementation of dairy cow diets decreased DMI and MY but did not affect ECM because of increased milk fat and true protein contents. Increased milk fat and MUN responses can be explained by shifted ruminal fermentation, and the increased milk true protein response may be explained by increased rumen propionate molar proportion by 3-NOP supplementation.

Development and approbation of a full-ration apicultural products based concentrated feed for the lagomorphs

The current situation in the Russian economy and international politics is very difficult, the problem of import substitution is acute. Therefore, the purposes of our research are to develop a functional full-ration concentrated feed for the lagomorphs based on the local low-budget environmentally friendly natural raw materials as well as biologically active ingredients, to elaborate a method of its manufacture and use, to test and to study its impact on biological and economically positive indicators of rabbits. The article presents the results of studies conducted on the rabbits of the Soviet chinchilla breed. Chemical composition and nutritional value of a traditional and a functional concentrated feed has been studied, a comparative analysis has been done. The effect of a functional concentrated feed use on the weight of some internal organs of rabbits as well as on the main exterior indicators, zootechnical indicators, and the quality of rabbit meat has been defined.

ВЛИЯНИЕ ЖМЫХА КОНОПЛЯНОГО НА ПЕРЕВАРИМОСТЬ И РУБЦОВЫЙ МЕТАБОЛИЗМ IN VITRO

The purpose of research is to study the effect of various doses of hempseed cake on the in vitro digestibility of the dry matter of concentrated feed and rumen metabolism. The experiment was carried out on the basis of the Center for Collective Use of the Federal Scientific Center of the BST RAS on the "artificial scar" model using the ANKOM Daisy II incubator (modifications D200 and D200I). 4 samples were prepared in three repetitions: Control group – grain mixture 100 %; Group I – grain mixture 86 % + hemp cake 14 %; Group II – grain mixture 80 % + hemp cake 20 %; Group III – grain mixture 74 % + hemp cake 26 %. It was found that the introduction of hemp cake in different dosages into a sample with dry matter of barley grain contributed to its digestibility by 1.5 %, 3.81 and 4.82 % compared to the control. At the same time, the sample in group III, containing 26 % hemp cake, was distinguished by the best digestibility. The content of total nitrogen in the rumen fluid of group III was 36.4 mg/%, 37.8 and 35.0 mg/% more than in the control, I and II groups, respectively. The control sample was inferior to I and III groups by 8.28 and 17.14 %. The largest amount of ammonia nitrogen was noted in the rumen fluid from group III, by 0.7 mg/% relative to the control. content by 41.71 %. As for the protozoa, there is a consistent increase in their number in all experimental groups – by 24.24 %, 52.27 and 139.39 %, in comparison with the control.

Structural Properties and Problems of Dairy Cattle Farms in Çanakkale-Yenı̇ce

This study was conducted to determine the current situation and care-feeding practices in dairy farms in Çanakkale-Yenice. The main material of the study consisted of surveys conducted with producers in dairy farms in Yenice. The surveys were conducted on 238 businesses determined by sampling from a total of 783 businesses. According to the findings, it was determined that the ages of the breeders varied between 26-66 and the average was 49.5 years, while the breeding period varied between 2-51 years and the average was 25.8 years. It was determined that the number of dairy cows in the examined enterprises varied between 6-24 heads and the average was 10.90 heads, while the total number of cattle varied between 12-28 heads and the average was 18.28 heads. It has been determined that dairy cattle breeding in enterprises is generally done with their own breeding Holsteins. It was determined that the daily average milk yield per cattle was 17.77 liters. It was determined that concentrated feed was not made in 72.7% of the farms examined, in 24.4% concentrated feed was made in the farms and in 2.9% outside the farms. It was determined that 87% of the animals in the farms were fed mixed and 13% were fed individually. While the rate of animals being taken to pasture was 21.8%, the rate of not being taken to pasture was determined as 78.2%. It was determined that feeding was done in the morning and evening hours in almost all of the farms. As a result, it was understood that the breeders in the enterprises examined had some deficiencies in the care and nutrition of dairy cattle and that these deficiencies needed to be eliminated. For this purpose, the training provided to producers, especially by unions and cooperatives, will make significant contributions to increasing the productivity of enterprises.

Effect of Concentrate Feed Supplementation on Performance of Indigenous Grazing Sheep

Sheep may not receive enough nutrition by grazing poor pastures, particularly during the dry season. Supplementing concentrate feed may be a useful approach to maximize rumen microbial activity by providing a balanced amount of energy and protein. Thus, the experiment was carried out to optimize the supplementation of concentrate feed for native coastal sheep in southwest Bangladesh. Five treatment groups consisting of twenty female sheep each were randomly assigned to receive five different degrees of concentrate feed. A randomized complete block design (RCBD) was the basis for the experimental setup. The five treatment groups were assigned a concentrate mix of 0, 100, 150, 200, and 250 g sheep-1 day-1, respectively. The energy and crude protein content of the concentrate mixture were 12.00MJ and 219.0g kg DM-1. Every day, from 8 a.m. to 6 p.m., all groups of sheep were permitted to graze for ten hours. Before allowing them to concentrate feeding and grazing, empty body weight measurements were recorded every two weeks. The results revealed that body weight increased with increasing concentrate feed supplementation but the mean difference did not vary significantly. In most of the cases, the numerically highest body weight was observed in sheep fed concentrate @ 250g sheep-1 day-1. The growth rate varied significantly among different concentrate supplemented group only at the sixth and eighth weights and at other weights the growth rate was statistically similar which indicates that the nutrient requirements was almost fulfilled from the grazing.

Experimental Study on the Thickening Characteristics of Ultrafine Tailings

To investigate the thickening characteristics of ultrafine tailings and the relationship between bed height and underflow concentration, a series of experiments, including graduated cylinder sedimentation tests, small-scale dynamic thickening, and semi-industrial experiments, were conducted. The results show that adding flocculants accelerates settling velocity, with a significant change occurring at 50 g/t when the bridging effect weakens. Solid flux increases initially with feed concentration but decreases after reaching a peak at 8%, where the maximum solid flux is 0.322 t·m−2·h−1. Reducing solid flux, lowering flocculant dosage, and increasing bed height all contribute to higher underflow concentration, while reducing solid flux and increasing flocculant dosage lowers overflow turbidity. The variation in underflow concentration in the deep cone thickener (DCT) occurs in three phases: continuous feeding with no discharge, dynamic equilibrium with a stable bed height, and bed descent with increasing underflow discharge. At the same bed height, underflow concentration is lower during the bed descent phase compared to the continuous feeding phase. This study offers valuable insights for the precise control of underflow concentration in ultrafine tailing thickening processes.

Relationship between Forage Particle Size and Rate of in vitro Digestion Parameters of Alfalfa-based Lamb in Complete Pelleted Diets

Background: Intensive feeding systems for lamb production are based on high concentrations of feed, depending on the type of forage, which can cause digestive disturbances; however, forage particle length (FPL) and size (FPS) can affect the fermentation process and the productive performance of lambs. Intensive feeding systems for lamb production are based on high concentrations of feed, depending on the type of forage, which can cause digestive disturbances; however, forage particle length (FPL) and size (FPS) can affect the fermentation process and the productive performance of lambs. Understanding how the lambs meet these challenges requires a conceptual integration of forage structure, mechanical particle size of forage and microbial fermentation. This synthesis will hopefully contribute to the development of a biomimetic co-treatment process for translating the unique characteristics of digestion into an effective component of biorefineries for the industrial conversion of cellulosic in forage biomass to useful products. Therefore, this study aimed to evaluate the relationship among FPL, degradability of feed in vitro and digestibility of organic materials. Methods: As a laboratory simulation of rumen functions, four alfalfa FPS lengths were studied within the components of integrated feed pellets 0.1 mm, common in the Saudi animal feed market, 5, 10 and 15 mm using the same feed composition, but with different lengths. Result: Cumulative gas production in PSL8 and PSL12 lambs was higher compared with the other two groups, indicating that lengths greater than 15 mm and less than 5 mm affected gas production rates. The effect of FPL on rumen parameters had no effect on the pH of the rumen fluid. There were no significant differences in all values of the main volatile fatty acids acetate, propionate and butyrate and digestibility increased when the FPL ranged from 5 to 10 mm as in the PSL5 and PSL10 groups. Hydrogen levels were significantly higher in the PSL1 and PSL10 groups than in the PSL5 and PSL15 groups. Based on forage size, groups PSL5 to PSL10 showed the possibility of using this type of feed for growing lambs and small ruminants.

Low-Density Polyethylene Microplastics in the Rumen: Implications for Rumen Fermentation Dynamics and Utilization of Concentrate Feed

Microplastics (MPs) have emerged as a significant environmental threat, infiltrating livestock systems. This study presents the first in vitro investigation of the effects of low-density polyethylene (LDPE) MP contamination on rumen fermentation dynamics and feed utilization in a simulated ruminal digestive system. Concentrate feed was incubated in buffered rumen fluid collected from lambs, supplemented with LDPE MPs at concentrations of 3.3 g/L and 6.6 g/L and compared to the concentrate incubated in the buffered rumen fluid without MP contamination. The results demonstrate that both levels of LDPE MPs significantly altered rumen fermentation dynamics by reducing asymptotic gas production by 11% and 15% and increasing the constant rate of gas production by 16% and 19% at low and high addition levels, respectively, compared to the control. However, the early-stage fermentation dynamics remained unaffected. Furthermore, both levels of LDPE MPs reduced rumen protozoal populations (20% and 23%) and ammonia-nitrogen levels by 11% at both of addition levels. Despite these disruptions, rumen pH remained unaffected. Increasing the addition level of LDPE from 3.3 to 6.6 g/L did not exacerbate the disruptions. The results of this study highlight the potential risks posed by LDPE MPs in ruminal nutrition. Further in vivo investigations are essential to validate these findings and assess their impact on animal performance.

Polymer-Free Electrospinning of β-Cyclodextrin-Oligolactide for Magnolol and Honokiol Pharmaceutical Formulations.

Background: Magnolol (MG) and honokiol (HK) are bioactive compounds extracted from Magnolia obovata and Magnolia Officinalis trees with significant pharmacological properties, including antioxidant and antibacterial activity. However, their poor water solubility and low bioavailability limit the therapeutic potential. Methods: To address these limitations, this study aims to develop MG and HK formulations by co-electrospinning using custom-synthesized β-cyclodextrin-oligolactide (β-CDLA) derivatives. MALDI MS and NMR were employed for the structural assessment of the β-CDLA derivatives. This polymer-free electrospinning technique utilizes the high solubility of β-CDLA to incorporate MG and HK into fibrous webs. The morphology of the resulting fibers is established by SEM and further characterized using FTIR and NMR spectroscopy to confirm the successful incorporation of MG and HK. The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, while the antimicrobial activity was evaluated against several standard microorganisms (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans). Results: The MG and HK electrospun formulations were prepared using highly concentrated feed solutions in dimethylformamide (180% w/v). The resulting β-CDLA fibers, with diameters above 400 nm and an active compound content of 7% wt., exhibited enhanced long-term antioxidant activity and improved antimicrobial efficacy, including notable activity against Escherichia coli. Conclusions: This study demonstrates the potential of MG and HK-loaded β-CDLA fibrous formulations as delivery systems with prolonged antioxidant activity and notable antibacterial efficacy, providing a promising platform for biomedical applications.

Unlocking the phosphorus circularity potential of corn belt watersheds with biorefinery phosphorus recovery incentives.

As global phosphorus (P) stores rapidly decline, P fed algal blooms continue to threaten critical freshwater resources across the globe. In the Midwestern United States (US), particularly the Corn Belt, biorefineries could play a key role in addressing this issue. By recovering P from the byproducts of ethanol production these facilities could reduce the P content of distillers grain feed, thereby reducing P excreted in manures. This process could potentially divert P away from concentrated animal feeding operations (CAFOs) and toward renewable P (rP) fertilizer production utilizing the recovered P. To foster the inclusion of P recovery incentives in state nutrient reduction strategies, this study elucidates the cascading benefits of rP recovery from corn biorefineries in watersheds across six Upper Midwestern states. Incentivizing P recovery in watersheds that contain both biorefineries and CAFOs could foster the production of 107,500 metric tons (MT) rP fertilizer while diverting 26,800MTP from CAFO wastes each year, nearly double the estimated P reduction potential for municipal wastewater in the analysis region. These estimates can inform nutrient reduction analysts and policymakers in determining P load reduction potential. To further guide incentive strategies, four priority watersheds are highlighted to illustrate P reduction and circularity typologies across the region.

Constraining CO2 Coverage on Copper Promotes CO2 Electroreduction to Multi‐carbon Products in Strong Acid

AbstractElectrocatalytic CO2 reduction (CO2R) to multi‐carbon (C2+) products in strong acid presents a promising approach to mitigate the CO2 loss commonly encountered in alkaline and neutral systems. However, this process often suffers from low selectivity for C2+ products due to the competing C1 (e.g., CO and HCOOH) formation and complex C−C coupling kinetics. In this work, we report a CO2 coverage constraining strategy by diluting CO2 reactant feed to modulate the intermediate distribution and C−C coupling pathways for an enhanced electrosynthesis of C2+ products in strong acid. Lowering the CO2 feed concentration reduces CO2 coverage on copper catalyst, enriching the surface coverage and optimizing the adsorption configuration of the key CO intermediate for C−C coupling. This approach efficiently suppresses the formation of undesired C1 products. By employing a 20 % CO2 feed, we achieved a significant improvement in C2+ Faradaic efficiency, reaching 68 % at 100 mA cm−2, approximately 1.7 times higher than the 41 % obtained using pure CO2. We demonstrated the direct electroreduction of a 30 % CO2 feed—representative CO2 concentration of typical industrial flue gases—in a full electrolyzer, achieving a C2+ selectivity of 78 % and an energy efficiency of 23 % at 200 mA cm−2.

Influence of feed flow rate and feed concentration on the ammonia absorption refrigeration system

The absorption refrigeration system is a type of heat-driven system. The working pairs used most commonly are the lithium bromide-water and the ammonia-water pairs. Compared to the lithium bromide-water pair, the ammonia-water pair can achieve lower evaporation temperature and has a wider range of applications in industry. Feed flow rate and feed concentration are key factors affecting the system's performance, which have significant effects on the ammonia concentration and flow rate at the outlet of the distillation tower, as well as the COP of the system. In this paper, the relationship between feed concentration, feed flow rate, and system performance is investigated by numerical simulation and experimental study. The results show that increased feed concentration can effectively improve the ammonia concentration at the outlet of the distillation tower. At the same time, there is an optimal feed flow rate in the system, and when the feed flow rate rises gradually to the optimal value, the COP of the system also increases. When the feed flow rate exceeds the optimal value, the ammonia concentration at the outlet of the distillation tower will be rapidly reduced, as well as the COP of the system.

Purification of mesenchymal stromal cell-derived small extracellular vesicles using ultrafiltration.

Mesenchymal stromal cell-derived small extracellular vesicles (MSC-sEVs) are pivotal for the curative effects of mesenchymal stromal cells, but their translation into clinical products is hindered by the technical challenges of scaled production and purification. Ultrafiltration, a pressure-driven membrane separation method, is well known as an efficient, scalable, and cost-effective approach for bioseparation. However, there has been little study so far that comprehensively evaluates the potential application of ultrafiltration for scaled sEV isolation and purification. In this study, the feasibility and effectiveness of ultrafiltration for MSC-sEV isolation and purification are studied, and the effects of key process design and operational parameters, including the membrane pore size, transmembrane pressure (TMP), stirring speed (shear rate), feed concentration, are quantified using a stirred cell setup. Results revealed that 500kDa molecular weight cut-off (MWCO) polyethersulfone membrane demonstrated superior suitability for MSC-sEV separation, yielding higher purity and productivity compared to 100 and 300kDa MWCO membranes of the same material. The MSC-sEV productivity and purity could also be improved by applying a moderate stirring speed and lower operational pressure, respectively. Isovolumetric diafiltration was incorporated to enhance the purity of MSC-sEVs, successfully removing about 99% of protein contaminants by six diafiltration volumes (DVs). Subsequently, a fed-batch ultra-diafiltration (UF/DF) process with optimised filtration parameters was developed and compared with the currently most used ultracentrifugation (UC) method, showing exceptional effectiveness and performance in the isolation of MSC-sEVs: it increased the recovery of MSC-sEV from 20.59% to 60.88% (about three folds increase) and nearly doubled the purity, while also reducing processing time from over 4h to 3.5h, with a potential further reduction to less than 2.5h through automation. The study concludes that ultrafiltration could be a promising method for both lab-scale preparation and industrial-scale manufacture of MSC-sEVs, offering advantages of high recovery, scalability, fast, and cost-effectiveness.

Thermal treatment and densification of manure and biomass blends to produce stabilized soil amendments.

Land application of dairy manure is the most common practice for disposal of this waste. Agricultural fields surrounding concentrated animal feeding operations (CAFOs) often have high levels of N and P because of manure over-application. However, its low bulk density limits the amount of manure that can be profitably transported for use as fuel or fertilizer. As an alternative, selective carbonization can be used to create densified-stabilized N-containing products that can be delivered to regions with low soil N and P contents. This research reports developing a biomass (Douglas fir)/manure thermally treated product containing a maximum fraction of N integrated into the biochar structure. Response Surface Methodology (RSM) was used to identify processing conditions resulting in high C and N conversion efficiencies. Experimental results show maximum N conversion efficiencies were achieved at Douglas fir contents higher than 50wt % and temperatures close to 260°C. H3PO4 levels at 2wt % seems to be sufficient to catalyze the desired reactions. The KOH treatment did not significantly affect product yield and the efficiency of C and N conversion. The structural strength of densified char was evaluated using dynamic rheometric (amplitude sweep test).

Enhancing the efficiency of the cultivation of cladocerans (Moina sp. and Diaphanosoma sp.) through dietary diversification strategies.

The establishment of a feeding regimen for cladocerans is crucial in contemporary aquaculture due to their significance as nutrient-rich live feeds for various aquatic species. Three experiments were conducted to optimize the growth and reproduction rates of cladocerans (Moina sp. and Diaphanosoma sp.) using various stocking densities, types of food, and feeding regimens, emphasizing the importance of Haematococcus sp. in enhancing aquaculture productivity. In the first experiment, five different initial stocking densities: 1×103 indv. L-1 (T1), 3×103 indv. L-1 (T2), 6×103 indv. L-1 (T3), 9×103 indv. L-1 (T4), and 12×103 indv. L-1 (T5) of cladocerans were tested over a 10-day culture period, where T3 demonstrated the best growth. Using the best initial stocking density from experiment 1, the second experiment assessed varying concentrations of Haematococcus sp.: 1×105, 5×105, 10×105, 15×105, and 20×105cells mL-1 in T1, T2, T3, T4 and T5, respectively as feed of cladocerans; among them, T3 exhibited the highest population density. Experiment 3 evaluated the effects of three different diets including live Haematococcus sp. (T1), baker's yeast (Saccharomyces cerevisiae) (T2), and Haematococcus sp.+baker's yeast (Saccharomyces cerevisiae) (T3) on the growth of cladocerans over 10 days. The study employed the optimal initial stocking density of cladocerans and the feeding concentration of Haematococcus sp. as determined from the prior two experiments. Notably, T3 yielded the highest zooplankton density in this investigation. These findings indicate that elevating the initial stocking density of cladocerans and increasing the concentrations of Haematococcus sp. as feed up to an optimal level can effectively enhance the population growth of cladocerans. Both very low and excessively high initial stocking density, as well as suboptimal and excessively high concentrations of Haematococcus sp., negatively impact the growth of cladocerans. Moreover, using Haematococcus sp. alone or in combination with baker's yeast (Saccharomyces cerevisiae) enhances the growth and reproduction rates of cladocerans, indicating potential benefits for aquaculture systems.

Mathematical and experimental study of the direct contact membrane distillation method for desalination using a hydrophobic electrospun nanofibers membrane

This paper examines the performance of a Direct Contact Membrane Distillation (DCMD) system experimentally and theoretically. The system uses a super hydrophobic electrospun nanofiber membrane to desalinate water. Investigations were carried out into how the feed concentration, feed flow rate, and feed temperature affected permeate flux. as system operating parameters to aid in comprehending the factors impacting the DCMD process. The application of DOE and Taguchi methods achieved statistical optimization of the DCMD process's performance. In addition, the study of mass and heat transport in DCMD was described by a theoretical model. While the feed concentration (0- 210 g/L) significantly affected flux, the feed's temperature (35-55 °C) and flow rate (0.2-0.6 L/min) mostly dominated the impact on system performance. The created model numerically solved the DCMD process using MATLAB software, describing it as a system of nonlinear equations. Various operating conditions were used to investigate the efficiency of the superhydrophobic electrospun nanofiber membrane in treating 210 g/L NaCl salt water. Changing the feed temperature and concentration affected the hypothetically suggested path across the membrane, according to the simulation results presented in this paper. Excellent agreement was observed between the experiment results and the constructed model's predicted results. Every instance maintained a high salt rejection rate (over 99.9%). The DCMD produced a gain output ratio (GOR) of 0.87 and a temperature polarization coefficient of 0.78 to 0.91. The system achieved a maximum thermal efficiency of 73.5%. The optimal parameters, which are 70 g/L, 0.6 L/min, and 55°C.

Case study of nutritional supplement for livestock, result of the pecan nut process in the state of Chihuahua, Mexico

The south-central region of the State of Chihuahua is characterized by being a walnut producing area, in Cd. Delicias. There are ten companies of international stature dedicated to processing pecan nuts. Analyzing the feasibility of using the scrap that these companies discard when breaking the nut and converting it into a useful product such as concentrated livestock feed, which can be marketed, in addition to the nutritional contributions it has. This city is identified as being an important dairy basin, which is why cattle need molasses, mineral salts and some other types of nutrients, which is why this work was developed dedicated to the study of the scrap content that results at the end of the process of cracking the pecan nut in the processing companies, being an area of interest, in which the innovation of using very small parts of the walnut kernel, mixed with other waste produced by this agroindustrial process, taking advantage of this value chain, is analyzed the probability of manufacturing a feed supplement for livestock, converting what they consider waste into a marketable product. To prepare the nutritional table, different statistical studies were developed, which supported the theory and unconditional advice of the Center for Research in Food and Development A.C. Cd. Delicias, Chihuahua, attached to CONAHCYT.