Dietary organic acids ameliorate high stocking density stress-induced intestinal inflammation through the restoration of intestinal microbiota in broilers

Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty acid production to inhibit the TLR4/NF-κB signaling pathway.These findings demonstrated the critical role of intestinal microbiota in mediating the HSD-induced inflammatory responses,contributing to exploring nutritional strategies to alleviate HSD-induced stress in animals.

Optimization of Stocking Density for the Sea Cucumber, Apostichopus japonicus Selenka, Under Feed-Supplement and Non-Feed-Supplement Regimes in Pond Culture

Optimal stocking densities were investigated for the sea cucumber Apostichopusjaponicus Selenka under feed-supplement and non-feed-supplement regimes in net enclosures for 333 d. Substantial weight loss occurred during the aestivation phase （AE）. Decreased growth rates were also observed during the winter phase （WT）. In contrast, sea cucumbers showed rapid growth during the spring （SP） and autumn （AU） phases. Feeding regimes considerably influenced the growtb performance, i.e., sea cucumbers grew faster under feed-supplement regime than under non-feed-supplement regime （P 〈 0.05）. The average survival rates of sea cucumbers under feed-supplement regime were higher than those under non-feed-supplement regime for both the autumn phase and spring phase, but the differences were only significant for the latter phase （P〈 0.05）. The fitted B-N curves showed that the optimal stocking densities, in terms of net production, were 22.3 ind. m^-2 for feed-supplement regime and 14.1 ind. m^-2 for non-feed-supplement regime.

Influence of stocking density on growth, body composition and energy budget of Atlantic salmon Salmo salar L. in recirculating aquaculture systems

Atlantic salmon Salmo salar were reared at four stocking densities--high density D1 （final density -39 kg/m^3）, medium densities DE （-29 kg/m^3） and D3 （~19 kg/m^3）, and low density D4 （-12 kg/m^3）- for 40 days to investigate the effect of stocking density on their growth performance, body composition and energy budgets. Stocking density did not significantly affect specific growth rate in terms of weight （SGRw） but did affect specific growth rate in terms of energy （SGRe）. Stocking density significantly influenced the ration level （RLw and RLe）, feed conversion ratio （FCRw and FCRe） and apparent digestibility rate （ADR）. Ration level and FCRw tended to increase with increasing density. Fish at the highest density D~ and lowest density D4 showed lower FCRe and higher ADR than at medium densities. Stocking density significantly affected protein and energy contents of the body but did not affect its moisture, lipid, or ash contents. The expenditure of energy for metabolism in the low-density and high-density groups was lower than that in the medium-density groups. Stocking density affected energy utilization from the feces but had no effect on excretion rate. The greater energy allocation to growth at high density and low density may be attributed to reduced metabolic rate and increased apparent digestibility rate. These findings provide information that will assist selection of suitable stocking densities in the Atlantic-salmon-farming industry.

Effect of stocking density on performances of juvenile turbot (Scophthalmus maximus) in recirculating aquaculture systems

Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems （RAS）. In this study, turbot （13.84±2.74 g; average weigh±SD） were reared at four different initial densities （low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m^2） for 10 weeks in RAS at 23±1℃ Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m^2, respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate （SGR）, and voluntary feed intake significantly decreased and the coefficient of variation （CV） of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate （FCR）, feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower （not significantly） at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher （but not significantly） at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m^2. With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m^2 （final： 7.25 and 14.16 kg/m^2） would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition.

Effects of dietary tryptophan and stocking density on the performance,meat quality,and metabolic status of broilers

Background： Highly automated cage-rearing systems are becoming increasingly popular in China. However, a high stocking density can cause oxidative stress and decrease broiler performance. The tryptophan （TRP） derivative 5-hydroxytryptophan （5-HT） has been shown to preserve membrane fluidity in birds suffering from oxidative stress Therefore, this experiment was conducted to determine the effects of dietan/TRP supplementation on performance, breast meat quality and oxidative stress in broilers reared in cages with a high or low stocking density. Methods： Female Arbor Acres broilers （25-d-old, n = 144） were randomly allocated to 1 of 4 treatments. The birds were fed a diet based on corn, soybean meal, cottonseed meal and corn gluten meal containing either 0.18 or 0.27% TRP and were housed with stocking densities of 11 or 15.4 birds/m2 in a 2 x 2 factorial experiment. Broiler performance was evaluated from d 25 to 42. Eight birds from each treatment were slaughtered on d 42 and plasma and breast muscle samples were collected to measure biochemical indices. Results： A higher stocking density tended to be associated with reduced weight gain （P 〈 0.10）, and significantly increased plasma glutamic-pyruvic transaminase （GPT） activity （P 〈 0.001）. Increased dietary TRP significantly reduced the activities of lactic dehydrogenase and GPT while increasing total cholesterol in the plasma （P 〈 0.01）, reducing drip loss of breast muscle （P 〈 0.10） and improving feed efficiency （P 〈 0.10）. Conclusions： An increase in dietary TRP, ].S-fold higher than the standard supplementation level, can alleviate oxidative stress as well as improve welfare and feed efficiency in broilers reared in cages with a high stocking density.

Effects of stocking density on the growth and immunity of Atlantic salmon salmo salar reared in recirculating aquaculture system(RAS)

Atlantic salmon reared in recirculating aquaculture system(RAS) may lead to inappropriately high stocking density, because ?sh live in a limited space. Finding the suitable stocking density of Atlantic salmon reared in RAS is very important for RAS industry. In this paper, the in?uence of stocking density on growth and some stress related physiological factors were investigated to evaluate the ef fects of stocking density. The ?sh were reared for 220 days at ?ve densities(A: 24 kg/m^3; B: 21 kg/m^3; C: 15 kg/m^3; D: 9 kg/m^3 and E: 6 kg/m^3). The results show that 30 kg/m^3 might be the maximum density which RAS can af ford in China. The stocking densities under 30 kg/m^3 have no ef fect on mortality of Atlantic salmon reared in RAS. However, the speci?c growth rate(SGR), ?nal weight and weight gain in the high density group were signi?cantly lower than the lower density groups and middle density groups. Moreover, feed conversion rate(FCR) had a negative correlation with density. Plasma hormone T_3 and GH showed signi?cant decrease with the increase of the stocking density of the experiment. Furthermore, thyroid hormone(T 3), GH(growth hormone) activities were decreased with stocking density increase. However, plasma cortisol, GOT(glutamic oxalacetic transaminase) and GPT(glutamic pyruvic transaminase) activities were increase with stocking density increase. And the stocking density has no ef fects on plasma lysozyme of Atlantic salmon reared in RAS. These investigations would also help devise effcient ways to rear adult Atlantic salmon in China and may, in a way, help spread salmon mariculture in China.

REDUCED GROWTH IN HYBRID TILAPIA (OREOCHROMIS MOSSAMBICUS×O. NILOTICUS) AT INTERMEDIATE STOCKING DENSITY

Hybrid tilapia were reared at densities of 1, 5 or 10 fish per tank for four weeks. Mortality was 0 at 1 and 10 fish per tank, but was 25% at 5 fish per tank. Specific growth rate was highest at 1 fish per tank, and lowest at 5 fish per tank. The lower growth rate at the intermediate stocking density was associated with reduced feed efficiency, but there was no reduction in feed intake or digestibility. The results suggested increased metabolic cost caused by aggressive behaviour at intermediate stocking density, which can be suppressed by a further increase in density.

Stocking density affects the growth performance and metabolism of Amur sturgeon by regulating expression of genes in the GH/IGF axis

The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three dif ferent stocking densities(low stocking density, LSD: 5.5 kg/m^3; medium stocking density, MSD: 8.0 kg/m^3; and high stocking density, HSD: 11.0 kg/m^3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower fi nal body weight and specifi c growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2(IGF-2), while the concentrations of serum growth hormone(GH) and insulin-like growth factor 1(IGF-1) decreased in the HSD group. The full-length cDNAs of G H and IGF-2 genes(995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor( GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively af fects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.

Permanence and global attractivity of stage-structured predator-prey model with continuous harvesting on predator and impulsive stocking on prey

We investigate a stage-structured delayed predator-prey model with impulsive stocking on prey and continuous harvesting on predator. According to the fact of biological resource management, we improve the assumption of a predator-prey model with stage structure for predator population that each individual predator has the same ability to capture prey. It is assumed that the immature and mature individuals of the predator population are divided by a fixed age, and immature predator population does not have the ability to attach prey. Sufficient conditions are obtained, which guarantee the global attractivity of predator-extinction periodic solution and the permanence of the system. Our results show that the behavior of impulsive stocking on prey plays an important role for the permanence of the system, and provide tactical basis for the biological resource management. Numerical analysis is presented to illuminate the dynamics of the system.

Research Progress on Effects of Stocking Density on Performance, Health and Welfare of Duck

Stocking density is an important factor for animal production performance.It appears particularly urgent and important to research systematically on stocking density for the dual restriction of environmental protection and animal welfare.This review dealt with the influence of stocking density on ducks'productivity and health through production performance,animal behavior and animal welfare,and analyzed the possible mechanism of high stocking density reducing production performance,resulting in abnormal behavior and stress,causing welfare and health problems.We consider that it might be associated with heat stress,more spatial competition(to gather the food,drinking water,sports area,etc.),as well as the quality deterioration of litter and house air caused by high stocking density.Finally,we put forward some suggestions on the study of stocking density's effects on ducks,and proposed the future work that need to be studied and problems that need to be solved imminently.

Stocking density effects on growth and stress response of juvenile turbot(Scophthalmus maximus) reared in land-based recirculating aquaculture system

Stocking density is widely recognized as a critical factor in aquaculture and a potential source of long-term stress.The influence of stocking density on growth and stress response of juvenile turbot（Scophthalmus maximus, ~3–75g, initial to final weight） was examined in fish held under low（LD, ~0.21–5.31 kg/m^2, initial to final density）,medium（MD, ~0.42–10.81 kg/m^2） and high stocking density（HD, ~0.63–14.27 kg/m^2） for 120 days in a recirculating aquaculture system（RAS）. In this trial, the growth curve for weight of juvenile turbot in RAS, all fitted by the Schnute model. No significant difference was found in growth performance among the three densities until at the final sampling（Day 120）. The final weight and body weight increase（BWI） in the HD group were significantly lower than in other groups（P〈0.05, weight：（75.83±2.49） g,（75.39±2.08） g,（65.72±2.86） g and BWI：（2 436.12±28.10）%,（2 421.29±4.64）%,（2 097.88±20.99）% in LD, MD and HD groups, respectively）. Similarly, the specific growth rate（SGR）, feed conversion ratio（FCR） and coefficient of variation for weight（CV_w） were adversely affected by high stocking density（P〈0.05）. However, there was no difference in survival and Fulton＇s condition factor（K） of turbot among the different groups. Physiological analyses demonstrated a clear increase in the plasma cortisol level and an obvious decrease in growth hormone（GH） concentration in the HD group on Day120（P〈0.05）. There was no significant effect of stocking density on plasma glucose, Cl– and protein levels. All these findings would provide a reference for selecting the optimal stocking density of juvenile turbot in RAS.

Lake-Based Nursery Rearing of Nile Tilapia (Oreochromis niloticus) Fingerlings in Nylon Hapas: Effects of Stocking Density on Growth, Survival and Profitability

The inadequate supply of tilapia fingerling is a major limitation to cage culture development in Ghana. Lake-based hapa systems are very efficient in nursing fingerlings although the process can be tricky due to inherent effects of stocking densities and environmental factors. This study aimed at assessing the growth, survival and profitability of Nile tilapia (Oreochromis niloticus) fingerlings of the Akosombo strain reared in nine 1 m3 Lake-based hapas at different densities. Each hapa was stocked with 2.12 ± 0.14 g sex-reversed tilapia fingerlings at varying stocking densities of 400 fish/m3, 800 fish/m3 and 1200 fish/m3 serving as treatments T1, T2 and T3 respectively. Each treatment was replicated thrice. Bi-weekly samplings were done and water quality parameters were measured. After the experiment, analysis of variance showed significant differences (p

Effects of Temperature,Salinity and Stocking Density on Larval Survival and Growth of Reciprocal Crosses Between Two Strains of Pacific Oysters,Crassostrea gigas

The Pacific oyster Crassostrea gigas is one of the most widely cultivated aquaculture species and contributes signifi-cantly to total seafood production for human beings.However,mass mortality occurred frequently,and in some regions almost all oysters died during seed production and grow-out stage.In order to explore whether hybridization breeding can improve its growth and survival,a complete diallel cross between a selected strain‘Haida No.1’(S)and an orange shell variant(O)of C.gigas was carried out.The larval growth and survival were compared among hybrids and purebred strains at temperatures of 16,20,24,28 and 32℃;salinities of 15,20,25,30 and 35;and stocking densities of 0.5,1,2,4 and 8 larvae mL−1.Under different environments,the hybridization between two strains of C.gigas showed the heterosis of growth and survival.The mean shell height and survival rate of the two reciprocal crosses(OS,SO)were significantly higher than those of the two purebred strains(SS,OO)under all environ-mental conditions.In particular,OS showed greater heterosis than the purebred strains and SO progeny.The results showed that the productive traits of the‘Haida No.1’could be improved by crossing with the orange shell line.Meanwhile,the results from this study also indicated that hybridization between the two strains of C.gigas may be a promising way for breeding new variety with high survival rate.

Effects of feeding and stocking density on digestion of cultured Atlantic salmon Salmo salar L.

The combined effects of feeding rate(0.8%,1.0%,and 1.2%initial body weight/day),feeding frequency(two,three,and four times/day) and stocking density(10,15,and 20 kg/m3) in recirculating aquaculture systems(RAS) on growth performance,digestion and waste generation of Atlantic salmon(Salmo salar L.) were investigated in an 8-week orthogonal experiment(L9(3)3) with a constant daily water renewal at 7.50%of total volume.No mortality occurred during the experimental period.Feed conversion ratio(FCR) varied from 0.90 to 1.13 and specific growth rate(SGR) ranged from 0.48%to 0.69%/day.SGR,thermal growth coefficient(TGC) and FCR were not significantly(P>0.05) affected by the three factors,while net protein utilization(NPU) was significantly(P<0.05) affected.Apparent digestibility coefficients(ADC) of dry matter in the present study were in the range 66.12%-73.55%.ADC in protein,lipid and energy were statistically different among all treatments and in the range of 90.07%-93.67%,81.54%-89.15%,and67.55%-71.87%,respectively.The proportion of mean total ammonia nitrogen excreted ranged from 1.37%to 1.64%of feed nitrogen at steady state,and the concentration of nitrogenous and phosphorus compounds were differently correlated to the three factors.The results will provide valuable reference data for culture management decisions in the Atlantic salmon farming industry.

Turbot Scophthalmus maximus: stocking density on growth, pigmentation and feed conversion

Juvenile turbot （Scophthalmus maximus） the initial stock densities at 0.28, 0.87, 1.12, 1.16, 2.75 were reared in five different experiment groups in kg/m^2 respectively for the study of the density effect on growth, pigmentation and feed coefficient rate. The experiment lasted for 60 days with final stock densities at 1.91, 6.31, 8.86, 11.97, 17.67 kg/m^2 respectively. Result showed that, in the same experiment condition, the stocking density has a positive effect on growth in low density and negative in high density. The SGR （special growth rate） was 3.189, 3.304, 3.447, 3.341, and 3.087 respectively. The uniformity of weight distributing among experiment groups decreased with increasing density. The stocking density had positive effect on feed coefficient rate. Group 1 had the least feed coefficient rate 0.96, and highest at 1.25 in Group 5, the highest density group. High stocking density inhibited the growth and increased the feed coefficient rate. The stocking density had negative relationship to pigmentation improvement for whitened fish.

The influence of stocking levels,clone,fertilization,and weed control on surface CO_(2)efflux in a mid-rotation Pinus radiata D.Don plantation in Canterbury,New Zealand

Silvicultural practices applied in managed forest plantations may help counteract the effects of climate change by influencing soil surface CO_(2)efflux(Fs).Understanding the effects of silvicultural practices on Fs will provide unbiased estimates of carbon fluxes and allow better silvicultural decisions for carbon sequestration.Therefore,we assessed how Fs differed seasonally across silvicultural practices(i.e.,stocking levels,clone,fertilization and weed control treatments)and evaluated the effects of soil temperature(Ts)and soil volumetric water content(θv)on Fs across these practices for a mid-rotation(14 year-old)Pinus radiata plantation in the Canterbury region of New Zealand.There were significant differences in Fs(p<0.05)over the four seasons,three levels of stocking,and five clones.The effects of fertilization and weed control applied 12 years previously on Fs were insignificant.Annual estimate of Fs(mean±1 standard deviation)from the study site was 22.7±7.1 t ha^(-1)a^(-1)in the form of CO_(2)(6.2±2.1 t ha^(-1)a^(-1)in the form of C).Fs values were consistently higher in plots with 1250 stems ha^(-1)compared to 2500 stems ha^(-1),which may be related to a strong soil resource limitation because of the close spacing in the latter plantation.Significant differences in Fs across clones suggest that variations in carbon partitioning might explain their growth performance.Silvicultural treatments influenced Fs response to soil temperature(p<0.05),resulting in models explaining 28-49%of the total variance in Fs.These findings provide insights into how silvicultural management decisions may impact Fs in mid-rotation radiata pine plantations,contributing towards developing more precise and unbiased plantation carbon budgets.

Effect of Alum-Amended Litter and Stocking Density on Ammonia Release and Footpad and Hock Dermatitis of Broilers

Two experiments were conducted to evaluate the effect of alum on ammonia emission,live performance,and health of broilers.In experiment 1,the effect of alum （0,2,and 4%） supplementation on the emission of ammonia was measured.The effects of alum-treated litter and stocking density （12,16,and 20 birds m-2） on the live performance and incidence of footpad and hock dermatitis were investigated in experiment 2.Alum supplementation in chicken excreta significantly decreased pH from 8.06 to 5.27 and 3.62 by 2 and 4% alum treatments,respectively.Ammonia emission rate was reduced 73.0 and 75.8% by 2 and 4% alum treatments,respectively.The suppressed litter urease activity was detected in 4% alum treatment.Alum-amended litter （1 kg m-2） decreased atmosphere ammonia concentrations by 30% in broiler house.Alum-amended litter maintained a lower pH until 35 d of age.Body weight （BW） gain was decreased by alum treatment in the period of 4-7 wk of age.Higher stocking density （20 birds m-2） increased BW gain in the first 3 wk of age but decreased BW gain during the period of 4-7 wk of age.Neither alum nor stocking density treatments had a significant effect on feed intake and feed efficiency.Alum-treated litter had no detrimental effect on the development of footpad and hock burns.In contrast,high stocking density （20 bird m-2） increased the incidence of footpad and hock lesion.The result suggests that the decreased litter pH and suppressed bacterial urease activity by alum treatment is responsible for the decreased ammonia emission.At high stocking density,the increased litter moisture content should be responsible,at least partially,for the development of footpad and hock lesions.

Effects of osmotic pressure, temperature and stocking density on survival and sexual reproduction of Craspedacusta sowerbii

The effects of osmotic pressure, temperature and stocking density on medusae survival of Craspedacusta sowerbii were examined. The medusae were shown to be sensitive to the variations of osmotic pressure. And the survival time was 〈90 h at 34 mOsm/L and it declined rapidly with rising osmotic pressure. The peak survival time of 〉200 h was recorded at 0.2 mOsm/L. Comparing with 27℃ and 32 ℃ treatments, 23 ℃ treatment yielded lower activities at a range of 8-13/min. However, there was a longer survival time. A non-linear relationship existed between survival time and stocking density. Lower density resulted in larger body size. And sexual reproduction resumed after breeding for 〉22 days. Newly-formed polyps and medusae appeared subsequently but only in the higher-density groups of 10, 14 and 18 ind./L. It suggested that the number of newly-formed polyps and medusae was highly dependent on stocking density. That is, a higher stocking density produced more organisms. However, newly-formed medusae died within one month and none grew a diameter of 〉5 mm.

STUDY ON RELATIONSHIPS AMONG SEEDLING QUALITY AND SURVIVAL RATE, STOCKING PERCENTAGE AND GROWTH

Effects of various seedling classes and root cutting treatments on the survival rate, stocking Percentage and the growth of height and collar diameter in young stands of korean pine (Pinus koraiensis), mongolian scots pine (Pin us sylvestris var.mangolica),Dahurian larch (Larix gmelini), korean spruce (Picea koraiensis), anur cork tree(Phellodendron amurensis). manchurian ash (Fradinus mandshurica) and anur linden (Tilia amurensis) were studied in this paper. The results show that the survival rate, stocking Percentage and the growth of height and collar diameter of the I class seedlings are better than that of the n and III classes seedlings. so it is very important to select I class seedlings for increasing the quality of afforestation.

Comparative Study on Various Methods of Pressure in Compression Stockings

A series of self-designed and woven compression stockings were used in this pressure comparison experiment. In order to compare the differences of the garment pressure values exerted by the compression stockings with different structure parameters among three methods. The experiments were carried out with Flexi force sensors. The pressure value of nine pairs of compression stockings on five subjects and the model leg was collected, and the tensile force of the every section of these stockings was collected to calculate the pressure according to Laplace's equation. The data analysis results show that the pressure values of the compression stockings obtained by comparing the three methods have great differences in various testing methods. There is a significant correlation between processing parameters and stitch density(SD). The pressure design of the compression stockings should be based on the actual wearing of the pressure.