Experiment of dynamic seepage of tight/shale oil under matrix fracture coupling

A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance(NMR)and CT scanning.The microscopic production mechanism of tight/shale oil in pore throat by dynamic imbibition and the influencing factors on the development effect of dynamic imbibition were analyzed.The dynamic seepage process of fracking-soaking-backflow-production integration was simulated,which reveals the dynamic production characteristics at different development stages and their contribution to enhancing oil recovery(EOR).The seepage of tight/shale reservoirs can be divided into three stages:strong displacement and weak imbibition as oil produced rapidly by displacement from macropores and fractures,weak displacement and strong imbibition as oil produced slowly by reverse imbibition from small pores,and weak displacement and weak imbibition at dynamic equilibrium.The greater displacement pressure results in the higher displacement recovery and the lower imbibition recovery.However,if the displacement pressure is too high,the injected water is easy to break through the front and reduce the recovery degree.The higher the permeability,the greater the imbibition and displacement recovery,the shorter the time of imbibition balance,and the higher the final recovery.The fractures can effectively increase the imbibition contact area between matrix and water,reduce the oil-water seepage resistance,promote the oil-water displacement between matrix and fracture,and improve the oil displacement rate and recovery of the matrix.The soaking after fracturing is beneficial to the imbibition replacement and energy storage of the fluid;also,the effective use of the carrying of the backflow fluid and the displacement in the mining stage is the key to enhancing oil recovery.

Effect of perforation density distribution on production of perforated horizontal wellbore

To address the issue of horizontal well production affected by the distribution of perforation density in the wellbore,a numerical model for simulating two-phase flow in a horizontal well is established under two perforation density distribution conditions(i.e.increasing the perforation density at inlet and outlet sections respectively).The simulation results are compared with experimental results to verify the reliability of the numerical simulation method.The behaviors of the total pressure drop,superficial velocity of air-water two-phase flow,void fraction,liquid film thickness,air production and liquid production that occur with various flow patterns are investigated under two perforation density distribution conditions based on the numerical model.The total pressure drop,superficial velocity of the mixture and void fraction increase with the air flow rate when the water flow rate is constant.The liquid film thickness decreases when the air flow rate increases.The liquid and air productions increase when the perforation density increases at the inlet section compared with increasing the perforation density at the outlet section of the perforated horizontal wellbore.It is noted that the air production increases with the air flow rate.Liquid production increases with the bubble flow and begins to decrease at the transition point of the slug-stratified flow,then increases through the stratified wave flow.The normalized liquid flux is higher when the perforation density increases at the inlet section,and increases with the radial air flow rate.

Effects of Supplementation with <i>Saccharomyces cerevisiae</i>and Its Fermentation Products on Production Performance and Its Mechanism in Perinatal Dairy Cows

The aim of this study was to investigate the effects of Saccharomyces cerevisiae and its fermentation products on performance, blood hormone levels and rumen floral composition in peripartum dairy cows. Sixty perinatal cows were selected and allocated to two groups according to parity and expected date of delivery. Each group was supplemented with Saccharomyces cerevisiae and its fermentation product 0 or 100 g. The results showed that Saccharomyces cerevisiae and its fermentation products could significantly increase the feed intake of peripartum dairy cows (P < 0.01), increase the lactose content after 21 days postpartum (P < 0.01), and tend to increase milk production (P = 0.052). There was no significant effect on other milk components, the apparent digestibility of nutrients. There was a tendency to increase milk production and reduce the number of somatic cells in milk;increase blood levels of glucagon (P < 0.01) and β-hydroxybutyrate (P = 0.01), reducing the insulin content (P = 0.02). Saccharomyces cerevisiae reduced the abundance of rumen microbes in peripartum dairy cows but had no effect on rumen microbial diversity. Compared with the control group, the supplemented group showed reductions in the abundance of genera Bacillus (P = 0.03), Butyrivibrio (P = 0.01), Denitrobacterium (P = 0.01), and Mogibacterium (P < 0.01), Porphyromonas (P = 0.05), Saccharofermentans (P < 0.01), Sphaerochaeta (P = 0.02), Streptococcus (P = 0.04) and other genera. There were significant increase in the content of Acidaminococcus (P = 0.03), Allisonella (P < 0.01), Bulleidia (P < 0.01), Corynebacterium (P = 0.01), Dialister (P < 0.01), Faecalibacterium (P = 0.02), Faekalitalea (P = 0.03), Fibrobacter (P = 0.04), Flavobacterium (P = 0.03), Kandleria (P < 0.01), Paraprevotella (P < 0.01), Pyramidobacter (P = 0.05), Roseburia (P < 0.01), Succinivibrio (P < 0.01) and other genera. The main metabolic pathways such as tryptophan metabolism and steroid hormone biosynthesis in perinatal dairy cows were determined for Saccharomyces cerevisiae and its fermentation products.

Hybrid data-driven framework for shale gas production performance analysis via game theory, machine learning, and optimization approaches

A comprehensive and precise analysis of shale gas production performance is crucial for evaluating resource potential,designing a field development plan,and making investment decisions.However,quantitative analysis can be challenging because production performance is dominated by the complex interaction among a series of geological and engineering factors.In fact,each factor can be viewed as a player who makes cooperative contributions to the production payoff within the constraints of physical laws and models.Inspired by the idea,we propose a hybrid data-driven analysis framework in this study,where the contributions of dominant factors are quantitatively evaluated,the productions are precisely forecasted,and the development optimization suggestions are comprehensively generated.More specifically,game theory and machine learning models are coupled to determine the dominating geological and engineering factors.The Shapley value with definite physical meaning is employed to quantitatively measure the effects of individual factors.A multi-model-fused stacked model is trained for production forecast,which provides the basis for derivative-free optimization algorithms to optimize the development plan.The complete workflow is validated with actual production data collected from the Fuling shale gas field,Sichuan Basin,China.The validation results show that the proposed procedure can draw rigorous conclusions with quantified evidence and thereby provide specific and reliable suggestions for development plan optimization.Comparing with traditional and experience-based approaches,the hybrid data-driven procedure is advanced in terms of both efficiency and accuracy.

Utilizing Dynamic Data to Quickly Evaluate Advantageous Channels and Applications

In response to the high cost and difficulty of high-speed development and testing data in offshore oil fields, this paper proposes to use the most easily available production performance data as the basis and use the grey correlation method to calculate the correlation coefficient between oil and water wells to characterize the degree of development of advantageous channels. The consistency between the calculated results of this method and the tracer test results is over 80%. Based on the fitting results, the correlation coefficient exceeds 0.74 to determine the existence of an advantageous channel. According to the research results of grey correlation method, Bohai K oilfield has completed the combined profile control and flooding measures, and the daily oil production has increased by 20 m3/d. This method is simple, fast, and can achieve quantitative evaluation, which saves time and investment compared to offshore testing. It has strong application and reference value for the development of other offshore water injection oilfields.

纯中药添加剂对肉杂鸡促生产效果及其作用机理的研究

[ Objective] The aim was to study the effects of Chinese medicine additive HMS on promoting the production of meat hybrid chicken and its action mechanism, so as to provide a scientific basis for the promotion effects of Chinese medicine additive on production. [ Method] Meat hybrid chickens, 7 day-old with similar weight, were randomly divided into four groups. And Chinese medicine feed additive HMS was added to the diet of each group at different proportions. All the chickens were weighed before the test as well as at the end of the 2nd, 3rd, 4^th and 5^th week. The feed consumption was also recorded during the test. Before slaughter, serum samples were collected from the randomly selected chickens for the deter- mination of serum biochemical indexes. Their bursae of Fabdcius and spleens were collected and weighed in order to determine the indexes, of im- mune organs. [ Result] HMS significantly reduced the feed conversion ratio （ P 〈 0.05 ）, very significantly reduced the feed consumptioh （ P 〈 0.01 ）, very significantly improve the content of serum high-density lipoprotein （ P 〈 0.01 ）, significantly increased the activity of serum alkaline phos- phatase （ P 〈 0.05）, very significantly reduced the content of serum urea nitrogen and uric acid （ P 〈 0.01 ）, and significantly reduced the level of serum cholesterol （ P 〈0.05）. There were no significant difference between the test groups and the control group （ P 〉 0.05） in the increase of im- mune organ indexes, but the index of immune organs has increasing trend. [ Conclusion] HMS reduces feed consumption and feed conversion rati- o, improves the feed utilization, and has a role in promoting production. The possible mechanism may be HMS improving the activity of serum alka- line phosphatase and the level of serum high-density lipoprotein, as well as reducing the content of serum cholesterol, urea nitrogen and uric acid in meat hybrid chickens.

天祝白牦牛的毛绒生产性能

[ Objective ] To analyze the hair and villus production performance of Tianzhu white yak and thus provide conditions for the genetic breed ing and product development. [Method] The hair and villus yield as well as villus rate of male and female Tianzhu white yaks from one year to six years old was detected and the villus yield was also determined. And these indexes of hair and villus were analyzed to evaluate the production per formance. [ Result] In Tianzhu white yaks from one year to two years old, the hair and villus yield was lower, but the villus rate and yield were high er. The hair and villus yield, villus rate, and villus yield were all higher in Tianzhu white yaks from three years to six years old but significantly de creased in 7yearold Tianzhu white yaks. In addition, the hair and villus yield was significantly （ P 〈 0.05） or very significantly （ P 〈 0.01 ） higher in male yaks than in female yaks. The villus rate was very significantly （ P 〈0.01 ） higher than in female yaks from five years to seven years old than in male yaks at the same age. [ Conclusion] Tianzhu white yaks from one year to two years old have the best hair and villus production perform ance; Tianzhu white yaks from three years to six years old are in the main phase of hair and villus production; Tianzhu white yaks older than seven years old should not be used for hair and villus production.

Raising on Water Stocking Density Reduces Geese Reproductive Performances via Water Bacteria and Lipopolysaccharide Contaminations in “Geese-Fish” Production System

This study was carried out to unravel the mechanism of reductions in production performances in high stocking density geese flocks during summer months in ＂geese-fish＂ production system. Experiment 1 observed the water bacterial growth, lipopolysaccharde concentrations in water and geese blood, and geese reproductive performances from summer to winter, in two flocks with varying on water stocking densities. Results showed that counts of total bacteria, Escherichia coli and Salmonella in water, as well as water and geese plasma LPS concentrations, exhibited a tendency decreasing from the highest levels in summer, to intermediate levels in autumn, and to the lowest values in winter. Such seasonal decreases in bacteria and LPS concentrations were associated with similar seasonal decreases in embryo mortality during incubation. In addition, embryos dead or showing development retardation by day 25 of incubation contained copious LPS in allantoic fluid, in contrast to the negligible amount in normal developing embryos. Raising on water stocking density elevated bacteria counts, LPS concentrations in water and geese plasma, and decreased egg fertility but increased embryo mortality during incubation. In experiment 2, exogenous LPS treatment to the geese depressed egg laying, reduced egg hatchability, caused sickness behavior in the goslings hatched. In experiment 3, exogenous LPS directly administered to day 8 and 18 embryos during incubation dose dependently increased mortality and decreased hatchability, and caused sickness behavior in the goslings hatched. It is concluded that the raising on water geese stocking density stimulates pathogenic bacteria growth in water, which via LPS contamination impaires embryo development in incubation and therefore reduces geese reproductive performance and gosling quality during the hot summer months.

Association of polymorphisms of Nramp1 gene with immune function and production performance of large white pig

The present research was designed to study the association of polymorphism of natural resistance-associated macrophage proteinl （Nrampl） with some immune function and the production performance in Large White pig. The PCR-RFLP technique was applied to analyze the correlation between the polymorphisms of Nrampl gene and immune function [value of Polymorphonuclear Leukocytes （PMN） obtained by Nitroblue Tetrazolium （NBT） Reduction and effect of Cytotoxin in Monocyte] and production performance in 165 Large White pigs. The results showed that there was one Nde I restriction locus in Large White pig, and both values of PMN by NBT Reduction and effect of Cytotoxin in Monocyte in genotype BB were higher than those in genotype AB （P〈0.05）. Simultaneously, the weight of 180-day-old pigs with genotype BB was higher than that with genotype AB （P〈0.05）. The results indicated that there was a significant correlation between different genotypes of Nrampl gene and Immune function and production performance, and it can be regarded as a candidate gene of disease resistance. All these results provide valuable reference to further studies of pig disease resistance.

Improving Geese Production Performance in “Goose-Fish” Production System by Competitive Reduction of Pathogenic Bacteria in Pond Water

This study investigated whether competitive reduction of pathogenic bacteria growth in pond water alleviates lipopolysaccharide （LPS） contamination and improves geese production performances in the ＂goose-fish＂ production system, thereby providing the potential for an improved technique for ecological water fowl production. In the first experiment, 240 Magang goslings of 15-d age were randomly and equally allocated into 16 ＂yard and pond＂ pens using a 2-2 factorial design with 4 replications per treatment. In the 55-d experimental period, the goslings received 2 main treatments： supplementation of Bacillus subtilis spores in the feed and addition of photosynthetic bacteria （PSB） to the pond water. Both B. subtilis spores and PSB treatments significantly suppressed water counts of Gram-negative bacteria Escherichia coli, Salmonella and Shigella, and LPS concentrations in pond water and in gosling blood （P〈0.05）. As the result, the two treatments significantly improved gosling weight gain and carcass quality, marked by enhanced breast and leg muscle percentages and reduced subcutaneous fat proportions （P〈0.05）. Moreover, the improved effects of B. subtilis spores and PSB treatments were additive. In the second experiment, 1 160 adult geese were induced to start egg laying from May throughout the summer months. The geese were separated equally into control and experimental flocks to fit into 2 integration production units, with a density of 1 bird m-2 meter on pond water. Experimental flock geese were treated with B. subtilis spores in feed and PSB in the pond water for the duration of the study. Such treatment combination significantly depressed the growth of E. coli, Salmonella and Shigella in the pond water and reduced LPS concentrations both in pond water and in geese blood （P〈0.01）. As a result, egg fertility, fertile and set egg hatchabilities were all improved in the treated flock. Results from both growing goslings and breeding geese demonstrated that water bacteria pollution can be competitively reduced by supplementation with B. subtilis spores via the feed and addition of PSB in pond water, each of which reduces LPS contamination to geese and improves production performances. Micro- ecological agents such as B. subtilis spores and PSB improve water quality and provide a simple ecological technique for the ＂water fowl-fish＂ integrative production system.

Phenolic compounds as natural feed additives in poultry and swine diets:a review

Due to ban on using antibiotics in feed industry,awareness of using natural feed additives have led to a great demand.The interest of plants phenolic compounds as a potential natural antioxidant source has been considered in research community due to their predictable potential role as feed additives in poultry and swine production.However,the mode of action for their functional role and dosage recommendation in animal diets are still remain indistinct.Taking into account,the present review study highlights an outline about the mode of action of phenolic compound and their experimental uses in poultry and swine focusing on the growth performance,antioxidant function,immune function,antimicrobial role and overall health status,justified with the past findings till to date.Finally,the present review study concluded that supplementation of phenolic compounds as natural feed additives may have a role on the antioxidant,immunity,antimicrobial and overall production performance in poultry and swine.

Effects of Fermentation Product Containing Phytase on Productive Performance,Egg Quality,and Phosphorous Apparent Metabolism of Laying Hens Fed Different Levels of Phosphorus

This study investigated the effects of fermentation product containing phytase （FPP） that was fermented using waste vinegar residue （WVR） as substrate from Aspergillusficuum NTG-23 on productive performance, egg quality, and phosphorus apparent metabolism of laying hens. First, 375 22-wk-old Jinghong hens were allocated into 5 treatments （5 replicates of 15 hens each） in an 8-wk experiment for evaluating the parameters of productive performance, egg quality, serum, and tibia. Experimental diets contained 4% FPP and 96% corn-soybean diet. The levels of dicalciurn phosphate （DCP） were 1.34, 1.01, 0.67, 0.34 and 0%. Next, thirty 31-wk-old Jinghong hens were fed 5 types of diets for evaluating phosphorous apparent metabolism rate. Egg productive rate, egg weight, feed conversion ratio, Haugh unit, egg albumen height, serum calcium, tibia ash, tibia ash calcium and tibia breaking strength were not different significantly among 5 treatments. The significant difference of average daily feed intake was not appeared when the DCP content of corn-soybean-FPP diet was reduced to 0.67%; the eggshell hardness, eggshell thickness and serum phosphorus were not reduced significantly until the DCP content of corn-soybean-FPP diet was reduced to 0.34%. The yolk color was improved when the laying hens fed deficient DCP corn-soybean-FPP diet. A 22.14% reduction in excreta phosphorus was observed when the laying hens fed low phosphorus （0.67% DCP） corn-soybean-FPP diet. A 30% elevation of phosphorus apparent metabolism rate was obtained when the DCP content of corn-soybean-FPP diet was decreased from 1.34 to 1.01%. The reducing cost of layer diet was totalized about 120 CNY 1000 kg1 diet when the content of DCP was 0.67% in corn-soybean-FPP diet. These results indicated that FPP could be applied in laying hen as a potential, cost-effective and rational application of WVR.

Physical simulation of fluid flow and production performance in extra-low permeability porous media

For extra-low permeability reservoirs, with a permeability of about 0.3×10?3 μm2, fluid flow and production performance in cores were studied. A long core holder with a multi-location piezometric measurement was specially designed. An artificial long core, about 700 mm long and with a cross section of 45mm×45mm, was used. In the experiment, pressure distribution along the core can be measured in real time. Single phase flow in the core was investigated. Different modes of production in long cores were also simulated including natural depletion, water flooding, and advanced water flooding. Through physical simulation, flow parameters were collected and production characteristics in extra-low permeability cores were studied. From experimental results, it can be seen that fluid flow in extra-low permeability cores is different from that in high permeability cores. Transmission of pressure in extra-low permeability cores is very slow, and it needs a long time for the pressure to become stable. The distribution curve of pressure along the core is nonlinear and the production rate in extra-low permeability reservoirs decreases sharply. The development effects of different production modes in extra-low permeability cores were compared with one another. Among the production modes, advanced water flooding has much potential for effective development of extra-low permeability reservoirs. Natural depletion and conventional water flooding can also be used in early production periods. In addition, the countermeasures and some ideas especially for the potential development of extra-low permeability reservoirs are suggested.

Characterization and mitigation option of greenhouse gas emissions from lactating Holstein dairy cows in East China

Background:This study investigated greenhouse gas(GHG)emission characteristics of lactating Holstein dairy cows in East China and provided a basis for formulating GHG emission reduction measures.GreenFeed system was used to measure the amount of methane(CH_(4))and carbon dioxide(CO_(2))emitted by the cows through respiration.Data from a commercial cow farm were used to observe the effects of parity,body weight,milk yield,and milk component yield on CH_(4) and CO_(2) emissions.Results:Mean herd responses throughout the study were as follows:111 cows completed all experimental processes,while 42 cows were rejected because they were sick or had not visited the GreenFeed system 20 times.On average,lactating days of cows was 138±19.04 d,metabolic weight was 136.5±9.5 kg,parity was 2.8±1.0,dry matter intake(DMI)was 23.1±2.6 kg/d,and milk yield was 38.1±6.9 kg/d.The GreenFeed system revealed that CH_(4) production(expressed in CO_(2) equivalent,CO_(2)-eq)was found to be 8304 g/d,CH_(4)_(CO_(2)−eq)/DMI was 359 g/kg,CH_(4)_(CO_(2)−eq)/energy-corrected milk(ECM)was 229.5 g/kg,total CO_(2) production(CH_(4) production plus CO_(2) production)was 19,201 g/d,total CO_(2)/DMI was 831 g/kg,and total CO_(2)/ECM was 531 g/kg.The parity and metabolic weight of cows had no significant effect on total CO_(2) emissions(P>0.05).Cows with high milk yield,milk fat yield,milk protein yield,and total milk solids yield produced more total CO_(2)(P<0.05),but their total CO_(2) production per kg of ECM was low(P<0.05).The total CO_(2)/ECM of the medium and high milk yield groups was 17%and 27%lower than that of the low milk yield group,respectively.Conclusions:The parity and body condition had no effect on total CO_(2) emissions,while the total CO_(2)/ECM was negatively correlated with milk yield,milk fat yield,milk protein yield,and total milk solids yield in lactating Holstein dairy cows.Measurement of total CO_(2) emissions of dairy cows in the Chinese production system will help establish regional or national GHG inventories and develop mitigation approaches to dairy production regimes.

Effects of Low Protein Diets Supplemented with Ami-no Acids on Production Performance,Carcass Qual-ity and Input-output Ratio of Pigs

[ Objectives ] To study the effects of low-protein diets supplemented with amino acids on the production performance, carcass quality and input-output ratio of fattening pigs and growing-finishing pigs. [ Methods] Two studies were conducted on fattening pigs and growing pigs respectively. Pigs in two experimental groupswere fed with low-protein diets supplemented with amino acids and normal diets respectively, and the initial weight, final weight, feed consumption and car- cass index of the tested pigs were measured. [ Results] The average final weight of fattening pigs in test group was 2.4 kg lower than that in control group, while the difference was not significant （P 〉 0.05 ）. The average daily gain of fattening pigs in test group was 60 g lower than that in control group, indicating that low protein diets had a tendency to decrease the growth rate （P 〉 0.05 ）, and reduction of daily weight gain in low protein diet pigs reached 7.6%. The development of pigs in low protein diet group was poor, however, the difference was not significant. Carcass backfat thickness in low-protein diet group was slightly higher than that in control group, the difference was significant （ P 〈 0.05 ）. There was no significant difference in input-output ratio between low-protein diet group and control group. Finalweight of growing-finishing pigs in low-protein diet group was 3.22 % lower than that in control group, the average daily weight gainwas 6.91% lower than that in control group, feed intake in test group was 5.48% lower than that in control group, and difference between the two treatments was significant （P 〈 0.05 ）. Feed meat ratio in low-protein diet group improved, however, the difference was not significant（P 〉0.05）. [ Conclusions] Production performance of the pigs would be decreasedand the input-output ratio could not be improvedwhen the adding contents of crude protein in diets was reduced 3% -4%. Therefore, it is recommended that the crude protein level should be enough when pigs were fed with low-protein diets.

Application of Several Additives Instead of Antibiotics in the Production of Laying Hens

[ Objective ] The test was conducted to study the effect of three different additives instead of antibiotics in the production of laying hens. [ Method ] Basal diets in four test groups were added with 0. 015 % oxytetracycline, 0. 01% microecological preparation, 0.2% fulvic acid, and 0. 1% Chinese herbal medi- cine extract respectively, and laying hens in control group were fed with basal diets. Effect of four different additives on performance and egg quality were studied under the temperature of 28.6℃. [ Result] The average egg-laying rate and feed-egg ratio in groups 2, 3 and 4 were significantly better than those in control group and group 1 （P 〈 0.05 ）. The contents of fat and cholesterol in eggs in groups 2, 3 and 4 were lower than those in control group and group 1. And the fat content of eggs in group 4 was 13.42% lower than that in control group, the difference was significant （ P 〈 0.05 ）. The protein contents in groups 2, 3 and 4 were signifi- cantly higher than those in control group and group 1 （P 〈 0.05 ）. [Condusion ] Microecological preparation, fulvic acid and Chinese herbal medicine extract could replace antibiotics to be applied in the production of laying hens.

Preparation and Performance Research of Cement-based Grouting Materials with High Early Strength and Expansion

Main performance of the cement grouting materials made up by Portland cement（PC） and sulphoaluminate cement（SAC） was investigated in this program, a kind of expanding agent（EA） which was mainly constituted by metakaolin and alunite was utilized for the compensation of the shrinkage, the hydration products and micro structure of the grouting materials were researched by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The results showed that a high expansion rate of the grouting materials could be reached as the expanding agent mixed in 6% of PC mass; the addition of SAC in the S2（PC：SAC：EA=34：6：2.25） brought a further improvement of the expansion rate of the grouting materials, the analysis of XRD and SEM showed that due to the reaction of expanding agent and SAC in the grouting materials, more ettringite crystal was generated, which resulted in a higher early strength, the addition of SAC played an expansion and strength reinforcement role in the grouting materials.

Chinese herbal formulae defend against Mycoplasma gallisepticum infection

Mycoplasma gallisepticum HS strain(MG-HS)is a pathogen that causes chronic respiratory disease(CRD)in chicken,which is characterized by host respiratory inflammatory damage,brings huge economic losses to the poultry industry.Recently,emerging Chinese herbal medicines(CHM)have been used to treat CRD.This study was aimed to investigate the preventive and therapeutic effects and their potential mechanisms of Chinese herbal medicinal formulae(CHMF),which consisted of 10 kinds of Chinese herbal medicine including Scutellaria,Houttuynia cordate and licorice,on MGinduced CRD in chickens.With respect to the preventive effect,the results showed that CHMF could effectively recover the MG-induced decrease on body weight and feed conversion ratio.Histopathological analysis showed that both prevention and treatment of CHMF could significantly alleviate the severe respiratory inflammation induced by MG infection.Moreover,compared with the MG infection group,both the prevention groups and the treatment groups of CHMF could effectively reduce the expression of MG adhesion protein(p MGA1.2)to inhibit the proliferation of MG,and thus effectively inhibit the expression of MG-induced inflammatory factors interleukin-1β(IL-1β)and tumour necrosis factor-α(TNF-α).In summary,these findings confirm that CHMF can protect chickens from various tissue damage caused by MG infection and has no adverse effects on the performance of chickens in the short term.And its efficacy against MG is equal to or better than that of tiamulin.

Production Performance of Root Systems of Four Forage Legume Species and Their Development Characteristics in Loess Plateau,China

Production performance of four forage legumes species of Medicago sativa,Onobrychis viciifolia,Lotus corniculatus and Galega officinalis were determined,including plant height,above-ground biomass per unit area,tillers per unit area,fertile tillers per unit area,shoot /leaf ratio and fresh /dry matter weight ratio,and the distribution characteristics of their root systems in 0- 100 cm soil layers with 10 cm interval were studied. Results showed that the average aboveground fresh biomass(4 a and 5 a) of four forage legumes species successively were L. corniculatus 】 M. sativa 】 O. viciifolia 】 G. officinalis. The average plant heights in two years successively were O. viciifolia 】 M. sativa 】 G. officinalis 】 L. corniculatus. Tillers per unit area of four forage legume species in two years successively were M. sativa 】 L. corniculatus 】 O. viciifolia 】 G. officinalis. Fertile tillers per unit area in two years were O. viciifolia 】 M. sativa 】 L. corniculatus 】 G. officinalis. Average shoot /leaf ratio in two years were G. officinalis 】 M. sativa 】 O. viciifolia 】 L. corniculatus. Average moisture contents of four forage legume species in two years successively were G. officinalis 】 L. corniculatus 】 M. sativa = O. viciifolia. The distribution characteristics of root systems of four forage legumes species in 0- 100 cm soil layers were as follows: the root weights of M. sativa in 0- 40 cm soil layers accounted for about 98. 3% of total root weight,that of O. viciifolia in 0- 30 cm soil layers was 85. 8%,that of L. corniculatus in 0- 10 cm soil layers was 80%,and that of G. officinalis in 0- 40 cm soil layers was 81. 4%. The results suggested that L. corniculatus was suited to plant in slighter degraded pasture to control water and soil erosion in early stage,G. officinalis with strong lateral roots was adapted to degraded grassland in the Loess Plateau where soil nutrient was poor,while O. viciifolia and M. sativa with potentially strong main root were fit for water and soil conservation in the losses plateau for long term.

Mechanism of the Effect of Bacillus coagulans on Production Performance of Laying Hens in Late Laying Period

[Objective]The paper was to investigate the mechanism of Bacillus coagulans preparation in improving production performance of laying hens in late period of laying.[Method]A total of 648 individuals of"Jingfen 1"laying hens(66 weeks of age)in late period of laying were randomly divided into four groups,six replicates each group,and each group had 27 individuals of laying hens.The laying hens in control group were fed with basal diet,and those in experimental groupsⅠ,Ⅱ and Ⅲ were fed with the basal diets added with 3.33×10^6,1×10^7,3.33×10^7 CFU/g B.coagulans,respectively.The pretrial lasted one week,and the formal test lasted eight weeks.[Result]Compared with the control group,the laying rate in group Ⅰ increased significantly,and the feed-gain ratio in experimental group Ⅱ decreased noticeably while the spleen index increased remarkably;the alkaline phosphatase activities and blood calcium content in experimental groups Ⅰ,Ⅱ and Ⅲ increased significantly(P<0.05),while the triglyceride content decreased remarkably(P<0.05);the urea content in experimental groups Ⅰ and Ⅱ decreased obviously(P<0.05).Adding B.coagulans significantly increased the specific activity of amylase,lipase and protease in various intestinal mucosa of small intestine(P<0.05);adding B.coagulans significantly increased the content of follicle-stimulating hormone(FSH)and estradiol(E2),and significantly increased the mRNA expression of follicle stimulating hormone receptor gene(FSHR).[Conclusion]B.coagulans preparation could significantly improve the production performance of laying hens in late period of laying;appropriately enhance the immune capacity of laying hens;improve the serum biochemical indicators;increase the activity of digestive enzymes in the small intestine;and promote the release of gonadal hormone and the mRNA expression of FSHR gene in the ovary.