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.

Total Tract Apparent Digestibility, Serum Fatty Acid Profile, and Productive Performances of Mid-lactating Dairy Cows Fed with Dietary Betaine

It is hypothesized that betaine supplementation improves production performance in mid-lactation dairy cows.Twenty-one mid-lactation dairy cows were assigned to a 3×3 Latin square design with three periods of 28 d each and fed three treatments of betaine(0,100,and 200 g/d).Milk samples were collected on day 21 and day 28 of each period.During days 21 to 28,cows were fed with chromic oxide(15 g/d per cow).On days 26 to 28,fecal samples were collected to determine apparent total tract nutrient digestion.Blood samples were obtained on days 26 to 28 of each period for fatty acid(FA)analysis.Data were analyzed using the Proc Mixed in SAS.Apparent total tract dry matter(DM)digestibility tended to be greater for cows supplemented with 100 g betaine as compared to no dietary betaine(61 vs.58±1%;p=0.1).In contrast,DM intake(DMI),milk fat percent,milk yield,energy-corrected milk(ECM)yield,and milk FA composition did not differ among treatments.Supplementation of betaine can decrease the serum saturated FA C11,C12,C15 and C17,total monounsaturated FA,and C18:2 all trans-9,12.In addition,total serum n-3 polyunsaturated FA was significantly increased.This result can decrease total serum n-6 to n-3 ratio(6.80,7.07,and 6.50±0.16%,for 0,100,and 200 g betaine,respectively;p=0.04).Overall,even betaine supplementation did not change DMI or production,betaine could affect the DM digestibility and serum FA biosynthesis.

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 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.

Effect of Dietary Mulberry Leaves on Productive Performance,Egg Quality and Blood Biochemistry in Laying Hens

[Objective] The aim was to provide more information about the possible use of mulberry leaves in hen diets.[Method] Two hundred ninety two Hyline Gray laying hens, 48 wk old, were randomly allotted into four groups with 73 chickens per group. Each group was fed for 6 wk with diets that contained dried mulberry leaves at 0, 5, 10, or 15%. [ Result] The rate of egg production, egg weight, egg mass, feed intake, body weight, blood glucose level, total blood cholesterol, and triglyeride, and cholesterol of egg yolk in the dietary mulberry leaf groups were lower than the 0% mulberry leaves group. Compared with the 0% group, the feed required to produce 1 kg of eggs was 12.8% more in the 15% dietary mul- berry leaf group. Body weight and cholesterol of egg yolk decreased significantly in this group （P 〈0.05）. Blood glucose and triglyerides in the 15% dietary mulberry leaf group were significantly lower than in the 0 and 5% dietary mulberry leaf groups （P 〈0.05）. Yolk color in all treatments was higher than in the 0% group （P 〈0.05）, and Roche pigmentation score increased by 2 -2.9. One -deoxynojirimycin was detected from egg white in all treatments, and its content varied significantly between groups （ P 〈0.05）. E Conclusion] This study reflected the hypoglycemic and lipid -low- ering effects of mulberry leaves on productive performance and egg quality in laying hens. The suggested proportion of dietary mulberry leaves was 5% -10%.

Effects of Chinese Herbal Additive on Immunologic Functions and Productive Performance of Dairy Cows during Heat Stress

[Objective] To study effects of Chinese herbal additive on immunologic functions and productive performance of dairy cows, [Method] A total of 20 healthy dairy cows were randomly divided into control group and experimental group. They were respectively fed a common basal diet and the basal diet containing 100 g Chinese herbal additives. The trial lasted for 49 d. [ Result] The 4% fat corrected milk yield （FCM） production, milk yield after weight correction, quantity of solid-not-fat and ash content in the experimental group were significantly higher than those in the control group （ P 〈 0.01 ）. The total lymphocytes （LYM） number of peripheral blood, the percentage of lymphocytes, and IgG concentration in the experimental group were significantly higher than those in the control group on Day 14, 28 and 42 （ P 〈 0.01 ）. [ Conclusion] The Chinese herbal additive can enhance the lactation performance and immunologic function of dairy cows.

Performances Analysis and Developmental Strategy of Hexi Cashmere Goats

The productive performances of Hexi cashmere goats for breeding nucleus groups and producing groups in different production areas were reviewed. At the same time, the productive performances were analyzed. Moreover, the existing problems and solving methods were put forward. In addition, the Hexi cashmere goats was an ancient and native breed, and it was necessary to further improve its productive performance to protect and utilize the breed resource effectively.

Productive Performance of Giant Freshwater Prawn （Macrobrachium rosenbergi） Fed Diet Containing Silkworm Pupae （Bombyx mon~ Replacing for Fish Meal

The productive performance of giant freshwater prawn （Macrobrachium rosenbergii de Man） fed diet containing silkworm pupae （Bombyx mori） replacing for fish meal was conducted by focusing on digestibility, growth performance and feed utilization. Five diets of an isonitrogenous of 35 ：e 1% crude protein and isocaloric of digestible energy of 3,200 ±100 kcal/kg were formulated by using silkworm pupae, 0%, 8.6%, 17.2%, 25.8% and 34.7% by weight, replaced for fish meal. Giant freshwater prawn of 19 ± 2.0 g were stocked at 5 ind./m3 in concrete tank of 2.25 ton for three months. The protein digestibility by pepsin enzyme was evaluated in fish meal, silkworm pupae, soybean meal and shrimp meal. The digestibility was significantly difference （P 〈 0.05）. The protein digestibility of fishmeal and soybean meal was higher than silkworm pupae and shrimp meal. The productive performance of prawn in terms of growth rate and feed utilization were not significantly different （P 〉 0.05）. Therefore, silkworm pupae can be replaced for fishmeal in giant freshwater prawn （Macrobrachium rosenbergii de Man） without any adverse effects on productive performance.

Study on Reproductive Performance of Improved Hybrid from Chinese Holstein Cattle

In order to overcome the problems such as decline in adaptability, low fertility and few utilization years due to continuously increasing coefficient of inbreeding of Chinese Holstein cattle, three dairy-beef dual-purpose cattle varieties （purebred Simmental, Montbeliard and Fleckvieh） were introduced as the male parents to be hybridized with Chinese Holstein cattle, so as to study the improvement effect in the reproduction performance and milk production performance of the hybrid cattle. The results showed that the first-filial generation of Montbeliard had a very significant difference in gestation period from Chinese Holstein cattle （ P 〈0.01）. The parity of Fleckvieh s first-filial generation had a very significant effect on 305 d milk yield （ P 〈0.01）; and for the first-filial generation of Montbeliard, mating times and open days significantly affected 305 d milk yield （ P 〈0.05）, and its total milk yield had a significant difference from Chinese Holstein cattle （ P 〈0.05）. Comprehensively, the reproduction traits of Montbeliard s first-filial generation are better than other two varieties.

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.

Effects of Feed-grade Proteinase on the Production Performance of Piglets

In this study, feed-grade proteinase was added into conventional diets of three-line crossbred （Duroc x Landrace x Large White） piglets, to investigate the effects of feed-grade proteinase on anti-diarrhea capacity, daily weight gain, feed intake and feed conversion ratio of piglets. The results showed that adding feed-grade proteinase in diets enhanced anti-diarrhea capacity of piglets and improved signifi- cantly production performance and breeding efficiency of piglets. This study provided the reference for rational utilization of feed-grade proteinase in actual production.

Effects of Different Padding on Air Quality in Broiler House and Growth Physiological Index of Broilers

[Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817 broilers were selected. They were randomly divided into four groups with different paddings, and each group was in triplicate. The weights of broilers and feed were weighed weekly. The growth performance of broilers was determined. On day 30, the ammonia concentra- tions in broiler houses were determined. On day 35, 6 broilers were randomly se- lected from each group, and their vein blood was sampled. In the sampled vein blood, the concentrations of ammonia, glucose, globulin, serum total protein and urea nitrogen were determined. [Result] There were significant differences in ammo- nia concentration among broiler houses laid with different paddings （P〈0.05）. The ammonia concentration in group 1 was significantly lower than those in group 3 and group 4 （P〈0.05）. No significant difference was found in ammonia concentrations in broiler houses between group 2 and group 3 （P〉0.05）. The ammonia concentration in group 4 was significantly higher than those in group1, group 2 and group 3 （,0〈 0.05）. There were also significant differences in blood indicators among different groups （P〈0.05）. The blood ammonia, blood glucose and serum urea nitrogen con- centrations in group 1 were significantly lower than those in other groups （P〈0.05）, the serum total protein concentration was significantly higher than those in group 3 and group 4 （P〈0.05）, and the serum globulin concentration was significantly higher than those in group 2, group 3 and group 4 （P〈0.05）. Significant differences were observed in feed intake, body weight gain and slaughter weight between different groups （P〈0.05）, but there were no significant differences in feed to grain ratio （P〉 0.05）. [Conclusion] Under the experimental conditions, the padding of Chinese medicine residue showed better effect on reducing ammonia concentration in broiler house, which was conducive to play of production potential of broilers.

Study on the Correlation between Blood Enzyme Activity and Production Performance in Tibetan Yaks

Yak ( Bos grunniens ) is classified as Bovine genus,they live in Qingzang Plateau with elevation more than 3500m and it's neighbor highland,where the weather is high chilly,short of oxygen and large difference of temperature between day and night.But yak have adapted that circumstance after thousands of years' artificial and natural selection and has great anti adversity capacity.Yak is an important sustenance and means of production to Tibetan.China is a country with the largest number of yak,whose amount of livestock on hand accounts for 95% of the world and Tibet region takes the second place next to Qinghai in the number of yak.Tibetan yak has formed some groups for Tibetan's large area,complicated geological ecosystem conditions,geological isolation.The typical better groups are Yadong yak,Jiali yak and Sibu yak. Study about yak fell behind other animals due to the restriction of inconvenient transportation,difficult sampling and poor experimental technology.Study about the relationship between yak blood enzyme activities and milk production was little,only Jing (1992) studied correlation of milk production with serum amylase,esterase in Gansu Jiulong yak,Maiwa yak and no report was found in other groups.This study discussed six Jiali yak blood enzyme activities lactate dehydrogenase (LDH),alkaline phosphatases (AKP),acid phosphatase (ACP),catalase (CAT),amylase (Amy) and superoxide dismutase (SOD),and explored their relationship with milk production in Jiali yak,so as to supply with theoretical evidence by using blood enzyme activity as biochemical assisted selection marker in the breeding of Tibetan yak milk yield. This experiment investigated activity of six blood enzymes from 28 Tibetan yaks and explored its relationship to production performance.The results showed a extremely positive significant difference ( P <0.01) between activity of LDH and milk yield,CAT activity and length of belly hair respectively,while a positive significant difference ( P <0.05) was observed between AKP activity and body weight,Amy activity and body weight and a negative significant difference ( P <0.05) for SOD activity and body weight.Stepwise Regression Analysis showed that activity of LDH could be used for the prediction of milk yield,AKP,CAT,Amy for body weight,CAT,Amy for length of belly hair.So it is expected to use activity of LDH,AKP,CAT,Amy as biochemical genetic marker in the selection of milk yield,body weight and length of belly hair.

Effects of Chinese Medicine Additive on Promoting Production of Meat Hybrid Chicken and Its Action Mechanism

[ 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.

Production Performance and Development Strategies of Double-cropping Rice in Hunan Province

ln the research, an empirical analysis was performed on production per-formance and influential factors of rice in Changsha County and Liling City. The re-sults showed that production scale has been closely linked to age and education level of farmers. The larger scale, the higher comprehensive performance, but rele-vant efficiency tends to be lower. Sowing area and yield per unit area are major in-fluential factors of production performance of double-cropping rice, but the rest influ-ential factors are different upon production scale. Final y, developmental strategies are proposed for development of double-cropping rice.

Hair and Villus Production Performance of Tianzhu White Yak

[ 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.

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.

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.