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 ca...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.展开更多
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 perf...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.展开更多
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,...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.展开更多
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 o...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.展开更多
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 ...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.展开更多
[ 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 vil...[ 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.展开更多
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 wa...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.展开更多
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" pr...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.展开更多
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. T...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.展开更多
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...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.展开更多
[ 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...[ 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.展开更多
Twenty lactating cows of two to five parity having an average live weight of 290.00 to 330.00 kg and an average milk production of 4.54 kg/head/day to 4.66 kg/head/day were selected from the Central Cattle breeding St...Twenty lactating cows of two to five parity having an average live weight of 290.00 to 330.00 kg and an average milk production of 4.54 kg/head/day to 4.66 kg/head/day were selected from the Central Cattle breeding Station and Dairy Farm. The four dietary treatment were: SlooTo (Straw 100: Triticale 0 as control); $5oT5o (Straw 50: Triticale 50); $25T75 (Straw 25: Triticale 75) and SoTloo (Straw 0: Triticale 100). It was observed that the roughage dry matter intake (DMI) (2.61 ~ 0.07 kg) in percent live weight was significantly (P 〈 0.05) higher in $25T75 and the lowest (1.76 ~ 0.018 kg) in the control group (SlooTo) and the differences were significant among the dietary treatments except $5oT5o and SoTloo. The total DMI was significantly (P 〈 0.05) higher in SoT^oo (13.36 i 0.13 kg) followed by $25T75, $5oT5o and SlooTo, respectively. The digestibility of crude protein (CP) was slightly higher in $25T75 (75.48 ~ 0.96) compared to SoTtoo (75.31 ~ 1.45) and the difference was non-significant (P 〉 0.05). Milk production was significantly (P 〈 0.05) the highest in $5oT5o and the lowest in SlooTo followed by SoTloo, $25T75, respectively. The percent increased in milk yield was also the highest in $5oT5o (67.68%) and the lowest in SlooTo (28.85%). The 4% fat corrected milk was also significantly (P 〈 0.05) higher in $5oT5o followed by SoTloo, $25T75 and SlooTo, respectively. Therefore, it can be concluded that triticale and straw at a ratio of 50:50 may be fed for better production performance of dairy cows.展开更多
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,tiller...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.展开更多
[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&...[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.展开更多
Using the DEA analysis method,on the basis of the national panel data from 2002 to 2014,this paper made a comparative analysis on the rice production performance before and after the implementation of direct grain sub...Using the DEA analysis method,on the basis of the national panel data from 2002 to 2014,this paper made a comparative analysis on the rice production performance before and after the implementation of direct grain subsidy policy,and made an empirical analysis on the relationship between the direct grain subsidy policy and the changes in the rice production performance. The results showed that the effect of the direct grain subsidy policy on promoting the rice production performance is declining year by year,largely because drop of scale efficiency. Besides,there are problems of serious redundancy in agricultural subsidy,unreasonable resource allocation,leading to low performance and resource waste of rice production.展开更多
Domestic and foreign researches on triticale mainly focus on hereditary traits and excellent characteristics,but there are few reports on triticale yield and quality in the severe cold pastoral areas of Gansu and Qing...Domestic and foreign researches on triticale mainly focus on hereditary traits and excellent characteristics,but there are few reports on triticale yield and quality in the severe cold pastoral areas of Gansu and Qinghai.In this study,Gannong 2 triticale cultivars have been bred and planted in typical ecological areas according to the characteristics of different ecological regions.By studying the relationship between quality traits and various ecological factors,the effects of different ecological factors on the quality of Triticale hay have been clarified,which provides a reasonable basis for future triticale breeding and large-scale and targeted planting layout.The production performance and nutritional qualities of Triticale Trial in Maqu County,Gansu Province and Gannong No.2 in Dulan County,Qinghai Province are obviously superior to other pilot sites.Through reasonable fertilization,the production performance and nutritional quality of triticale are the best.Triticale production performance is significantly related to climatic factors in different pilots.The most suitable planting area for Gannong 2 is Maqu County,Gansu Province.展开更多
[Objective]In order to research on effect of different content of cottonseed meals on production performance and egg quality of Hisex laying hens. [Methods]120 Hisex laying hens of 37 weeks old are chosen,randomly div...[Objective]In order to research on effect of different content of cottonseed meals on production performance and egg quality of Hisex laying hens. [Methods]120 Hisex laying hens of 37 weeks old are chosen,randomly divided into four groups and three repetitions are set in each group,there are 10 hens in each repetition. Group I is the control group,II,III and IV are experimental groups. Cottonseed meal contents are respectively 5%,10% and 15%,with test cycle of 10 weeks,effects of different cottonseed meal dosages on Hisex laying hens production performance and egg quality are observed. [Results]When the diet is added with 5% to 15% of cottonseed meal,the average laying rate,average egg weight and feed-gain ratio all show downward trends when compared with that of the control group,but with no significant difference( P 〉 0. 05); eggshell strength,eggshell thickness,Haugh unit,egg shape index all show no significant difference( P 〉0. 05),with the increasement of cottonseed meal,the color of egg yolk got brighter,egg yolk color of 15% added group increased by 12%,show a significant difference with that of control group( P 〈0. 05). [Conclusion]When the feed was added with 15% cottonseed meals,it has an unconspicuous effect on laying performance and egg quality of Hisex laying hens,but whether it had an effect on animal health and food safety or not,a further systematic research is needed.展开更多
healthy periparturient cows were randomly allocated into three groups and fed 100% energy diet (NRC standard diets), 120% energy diet and 80% energy diet, respectively, beginning at 28 days prior to anticipated partur...healthy periparturient cows were randomly allocated into three groups and fed 100% energy diet (NRC standard diets), 120% energy diet and 80% energy diet, respectively, beginning at 28 days prior to anticipated parturition. After parturition, all the cows were provided with the lactation ration ad libitum until the day 56 postpartum. The objectives of the study were to investigate the effect of energy intake during the dry period on the production performance in the postpartum cows. The results indicated that the cows fed with high energy diet during the dry period had a lower dry material intake (DMI) and reduced milk production and a significant body weight (BW) loss compared with the cows fed with 80% energy diet and 100% energy diet. The results suggested that energy intake during the dry period was an important factor that influences and regulates DMI, milk production and energy equilibration of postparturient cows.展开更多
Using a multi-input multi-output production technology and survey data from Jinzhai County, western Anhui Province, China, the author first measured the production performance of rural households their efficiency, ec...Using a multi-input multi-output production technology and survey data from Jinzhai County, western Anhui Province, China, the author first measured the production performance of rural households their efficiency, economy of scale, and productivity during 19781997, and then related the measured production performance with institutional change, market access, and other factors. Preliminary results show that: 1) performance differs a great deal across households and over time; 2) institutional changes and market accessibility have played a major role in improving performance; 3) depending on the specific resources, their effects are variable.展开更多
[Objective] To study the effects of plant oil mixture on production performance, carcass and beef quality in beef cattle. [Method] Single-factor randomized blocks design was used. Sixteen healthy Yanbian yellow bulls ...[Objective] To study the effects of plant oil mixture on production performance, carcass and beef quality in beef cattle. [Method] Single-factor randomized blocks design was used. Sixteen healthy Yanbian yellow bulls having close body weight were selected and randomly divided into four groups, four cattle per group. Been oil, safflower oil and sunflower oil were mixed respectively at a volume ratio of 11:5:4. The oil blend was added to the daily diets of beef cattle respectively at a proportion of 4%, 5% and 6%. The effects of the plant oil mixture on production performance, carcass and beef quality were investigated. [ Result.] Compared with the control cattle, the experimental cattle had significantly lower feed intake (P 〈 0.05), non-significantly higher efficiency of feed utilization, and significantly lower digestibility of crude fiber and calcium (P 〈 0.05). With the increasing level of plant oil, the digestibility of dry matter showed a decreasing trend. The digestibility of dry matter was significantly lower in the cattle fed on the plant oil mixture at a level of 6% than in the control ( P 〈 0.05). The plant oil mixture had no effect on the digestibility of crude protein, ether extract, crude ash, nitrogen-free extract and phosphorus. With the increasing level of plant oil, the serum content of high-density lipoprotein showed an increasing trend. The serum content of high-density lipoprotein was significantly higher in the cattle fed on the plant oil mixture at a level of 6% than in the control ( P 〈 0.05). With the increasing level of plant oil, the content of total cholesterol showed an increasing trend, whereas the content of low-density lipoprotein showed a decreasing trend. Moreover, other indicators did not change significantly. The experimental cattle had larger eye muscle area and better beef quality than the control group. The content of crude protein and ether extract in beef increased with the increasing level of plant oil. [ Conclusion] The plant oil mixture added to the daily feed decreases intake and digestibility of crude fiber and calcium but has no remarkable effect on production performance of beef cattle. The addition also increases eye muscle area and improves beef quality, thereby improving quality of carcass and beef. The proportion of the plant oil mixture should be added at a proportion lower than 5%.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.42050104)the Science Foundation of SINOPEC Group(Grant No.P20030).
文摘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.
基金the financial support from the Ministry of Education Malaysia under the Fundamental Research Grant Scheme(FRGS)scheme(20180110FRGS)。
文摘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.
文摘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.
文摘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.
基金Supported by Key Financial Program of Hunan Province([2014]74)National Natural Science Foundation of China(41601097)Science&Technology Innovation Project of Hunan Academy of Agriculture Sciences(2016JC08)~~
文摘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.
文摘[ 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.
基金supported by the National Natural Science Foundation of China (30871795)the Earmarked Fund for Modern Agro-Industry Technology Research System, China (nycytx-45-13)
文摘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.
基金supported by the National Natural Science Foundation of China (30871795)the Earmarked Fund for Modern Agro-Industry Technology Research System,China (CARS-43-16)the Guangdong Provincial Science and Technology Research Grant, China (2010B020306004)
文摘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.
文摘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.
基金supported by China National Program on Key Basic Research Project (973 Program) (Grant No. 2006CB705805)National Key Scientific and Technological Project (Grant No. 2008ZX05009-004)
文摘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.
基金Supported by"Pig-based Eco-friendly Feed Research and Demonstration"of Science and Technology Department in Hebei Province(11220422)Technology Research on Application of"Animal-derived Active Red Gold Protein Peptide"in Pig Breeding(16226601D)
文摘[ 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.
文摘Twenty lactating cows of two to five parity having an average live weight of 290.00 to 330.00 kg and an average milk production of 4.54 kg/head/day to 4.66 kg/head/day were selected from the Central Cattle breeding Station and Dairy Farm. The four dietary treatment were: SlooTo (Straw 100: Triticale 0 as control); $5oT5o (Straw 50: Triticale 50); $25T75 (Straw 25: Triticale 75) and SoTloo (Straw 0: Triticale 100). It was observed that the roughage dry matter intake (DMI) (2.61 ~ 0.07 kg) in percent live weight was significantly (P 〈 0.05) higher in $25T75 and the lowest (1.76 ~ 0.018 kg) in the control group (SlooTo) and the differences were significant among the dietary treatments except $5oT5o and SoTloo. The total DMI was significantly (P 〈 0.05) higher in SoT^oo (13.36 i 0.13 kg) followed by $25T75, $5oT5o and SlooTo, respectively. The digestibility of crude protein (CP) was slightly higher in $25T75 (75.48 ~ 0.96) compared to SoTtoo (75.31 ~ 1.45) and the difference was non-significant (P 〉 0.05). Milk production was significantly (P 〈 0.05) the highest in $5oT5o and the lowest in SlooTo followed by SoTloo, $25T75, respectively. The percent increased in milk yield was also the highest in $5oT5o (67.68%) and the lowest in SlooTo (28.85%). The 4% fat corrected milk was also significantly (P 〈 0.05) higher in $5oT5o followed by SoTloo, $25T75 and SlooTo, respectively. Therefore, it can be concluded that triticale and straw at a ratio of 50:50 may be fed for better production performance of dairy cows.
基金Supported by National Basic Research Program(2014CB138704)National Natural Science Foundation of China(31302023)
文摘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.
文摘[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.
文摘Using the DEA analysis method,on the basis of the national panel data from 2002 to 2014,this paper made a comparative analysis on the rice production performance before and after the implementation of direct grain subsidy policy,and made an empirical analysis on the relationship between the direct grain subsidy policy and the changes in the rice production performance. The results showed that the effect of the direct grain subsidy policy on promoting the rice production performance is declining year by year,largely because drop of scale efficiency. Besides,there are problems of serious redundancy in agricultural subsidy,unreasonable resource allocation,leading to low performance and resource waste of rice production.
基金Natural Science Foundation of Qinghai Province(2020-ZJ-957Q)Qinghai University for Nationalities 2020 High-level Talent(PhD)Project(2020XJG14)。
文摘Domestic and foreign researches on triticale mainly focus on hereditary traits and excellent characteristics,but there are few reports on triticale yield and quality in the severe cold pastoral areas of Gansu and Qinghai.In this study,Gannong 2 triticale cultivars have been bred and planted in typical ecological areas according to the characteristics of different ecological regions.By studying the relationship between quality traits and various ecological factors,the effects of different ecological factors on the quality of Triticale hay have been clarified,which provides a reasonable basis for future triticale breeding and large-scale and targeted planting layout.The production performance and nutritional qualities of Triticale Trial in Maqu County,Gansu Province and Gannong No.2 in Dulan County,Qinghai Province are obviously superior to other pilot sites.Through reasonable fertilization,the production performance and nutritional quality of triticale are the best.Triticale production performance is significantly related to climatic factors in different pilots.The most suitable planting area for Gannong 2 is Maqu County,Gansu Province.
基金Supported by Modern Agricultural Industry Technology System Construction Special Fund(nycytx-41-2B)Social Development Project of Yangzhou(yz2010080)
文摘[Objective]In order to research on effect of different content of cottonseed meals on production performance and egg quality of Hisex laying hens. [Methods]120 Hisex laying hens of 37 weeks old are chosen,randomly divided into four groups and three repetitions are set in each group,there are 10 hens in each repetition. Group I is the control group,II,III and IV are experimental groups. Cottonseed meal contents are respectively 5%,10% and 15%,with test cycle of 10 weeks,effects of different cottonseed meal dosages on Hisex laying hens production performance and egg quality are observed. [Results]When the diet is added with 5% to 15% of cottonseed meal,the average laying rate,average egg weight and feed-gain ratio all show downward trends when compared with that of the control group,but with no significant difference( P 〉 0. 05); eggshell strength,eggshell thickness,Haugh unit,egg shape index all show no significant difference( P 〉0. 05),with the increasement of cottonseed meal,the color of egg yolk got brighter,egg yolk color of 15% added group increased by 12%,show a significant difference with that of control group( P 〈0. 05). [Conclusion]When the feed was added with 15% cottonseed meals,it has an unconspicuous effect on laying performance and egg quality of Hisex laying hens,but whether it had an effect on animal health and food safety or not,a further systematic research is needed.
文摘healthy periparturient cows were randomly allocated into three groups and fed 100% energy diet (NRC standard diets), 120% energy diet and 80% energy diet, respectively, beginning at 28 days prior to anticipated parturition. After parturition, all the cows were provided with the lactation ration ad libitum until the day 56 postpartum. The objectives of the study were to investigate the effect of energy intake during the dry period on the production performance in the postpartum cows. The results indicated that the cows fed with high energy diet during the dry period had a lower dry material intake (DMI) and reduced milk production and a significant body weight (BW) loss compared with the cows fed with 80% energy diet and 100% energy diet. The results suggested that energy intake during the dry period was an important factor that influences and regulates DMI, milk production and energy equilibration of postparturient cows.
文摘Using a multi-input multi-output production technology and survey data from Jinzhai County, western Anhui Province, China, the author first measured the production performance of rural households their efficiency, economy of scale, and productivity during 19781997, and then related the measured production performance with institutional change, market access, and other factors. Preliminary results show that: 1) performance differs a great deal across households and over time; 2) institutional changes and market accessibility have played a major role in improving performance; 3) depending on the specific resources, their effects are variable.
文摘[Objective] To study the effects of plant oil mixture on production performance, carcass and beef quality in beef cattle. [Method] Single-factor randomized blocks design was used. Sixteen healthy Yanbian yellow bulls having close body weight were selected and randomly divided into four groups, four cattle per group. Been oil, safflower oil and sunflower oil were mixed respectively at a volume ratio of 11:5:4. The oil blend was added to the daily diets of beef cattle respectively at a proportion of 4%, 5% and 6%. The effects of the plant oil mixture on production performance, carcass and beef quality were investigated. [ Result.] Compared with the control cattle, the experimental cattle had significantly lower feed intake (P 〈 0.05), non-significantly higher efficiency of feed utilization, and significantly lower digestibility of crude fiber and calcium (P 〈 0.05). With the increasing level of plant oil, the digestibility of dry matter showed a decreasing trend. The digestibility of dry matter was significantly lower in the cattle fed on the plant oil mixture at a level of 6% than in the control ( P 〈 0.05). The plant oil mixture had no effect on the digestibility of crude protein, ether extract, crude ash, nitrogen-free extract and phosphorus. With the increasing level of plant oil, the serum content of high-density lipoprotein showed an increasing trend. The serum content of high-density lipoprotein was significantly higher in the cattle fed on the plant oil mixture at a level of 6% than in the control ( P 〈 0.05). With the increasing level of plant oil, the content of total cholesterol showed an increasing trend, whereas the content of low-density lipoprotein showed a decreasing trend. Moreover, other indicators did not change significantly. The experimental cattle had larger eye muscle area and better beef quality than the control group. The content of crude protein and ether extract in beef increased with the increasing level of plant oil. [ Conclusion] The plant oil mixture added to the daily feed decreases intake and digestibility of crude fiber and calcium but has no remarkable effect on production performance of beef cattle. The addition also increases eye muscle area and improves beef quality, thereby improving quality of carcass and beef. The proportion of the plant oil mixture should be added at a proportion lower than 5%.