The tobacco growers with the growing area of greater than or equal to 100 mu,have become an important subject of tobacco production in Weng'an County of Guizhou Province. Regulating and developing the production a...The tobacco growers with the growing area of greater than or equal to 100 mu,have become an important subject of tobacco production in Weng'an County of Guizhou Province. Regulating and developing the production and business activities of large-scale tobacco growers, plays an important role in stabilizing tobacco production,reducing costs and increasing efficiency in Weng'an County. Through the field survey of large-scale growers' production activities,this article analyzes the input and output levels,and explores the key factors influencing benefit, in order to provide a basis for further regulating the tobacco growing practices and improving the flue-cured tobacco production benefit.展开更多
A degree centigrade fall or rise in body temperature of broiler chickens is sufficient to reduce performance, alter sound physiological state and divert nutritional metabolism in quest for ensuring thermal balance. Th...A degree centigrade fall or rise in body temperature of broiler chickens is sufficient to reduce performance, alter sound physiological state and divert nutritional metabolism in quest for ensuring thermal balance. Thermoregulatory mechanisms of newly hatched chicks are poorly developed, and fluctuations in brooding temperature coupled with severe environmental temperatures in the tropics could threaten the survivability, production and economic integrity of fast-growing strains of broilers. However, information on the effect of sharp fluctuations in body temperature on nutrient intake and European production index (EPI) of broilers fed dietary electrolytes is scanty and thus investigated. Using a total of 300, one-day-old unsexed broiler chicks (Arbor Acre) that were randomly allotted to six dietary treatments (T1-210, T2-240, T3270, T4-300, T5-330 and T6-360 mEq/kg electrolyte balance), data on performance characteristics and their correlations with body temperature and EPI at prestarter, starter and finisher phases were determined using standard procedures. Data were analysed using descriptive statistics and ANOVA at α = 0.05. At prestarter phase, feed intake (FI) had a strong and positive relationship with protein intake (r = 1.00;p < 0.01), EPI (r = 0.96;p < 0.01) and potassium (K) intake (r = 0.66;p < 0.01), but was negatively correlated with temperature change (r = ?0.39;p < 0.05). However, FI was not significantly correlated with body weight (BW), body weight gain (BWG), sodium (Na) and water intake. At starter phase, EPI was positively correlated to K intake (r = 0.38;p < 0.05), but not Na and chloride (Cl) intake. European production index of starter chicks could be enhanced by increasing the level of K intake through dietary supplementation up to 1.02%. Weight gain was adversely affected by sharp changes in temperature at finisher phase. Increase in water intake may not be a remedial tool in lowering sharp fluctuations in body temperature. However, sharp fluctuation in body temperature of broilers was reduced with DEB of 330, 270 and 240 mEq/kg at prestarter, starter and finisher phases, respectively.展开更多
Recently, interest in animal production and poultry production in particular has increased, because poultry meat and eggs and their products are more widely consumed than other products. Human health is also considere...Recently, interest in animal production and poultry production in particular has increased, because poultry meat and eggs and their products are more widely consumed than other products. Human health is also considered one of the priorities. Nowadays, the fermentation industry has become very popular due to its great benefits in the pharmaceutical industry, the improvement of foodstuffs and the animal feed industry and its improvement. Moreover, microbial fermentation can enhance the content and digestibility of nutrients in nontraditional diets while decreasing the quantity of crude fiber and anti-nutritional elements such as tannins. The functional components (organic acids, bioactive peptides, lactic acid bacteria) found in microbial fermented feed can increase meat production in cattle, pigs, and sheep, and broiler productivity, carcass quality, intestinal health, immunological function, and so on. This paper examines the application study of microbial fermented feed in broiler production and serves as a resource for microbial fermented feed promotion and use in broiler production.展开更多
The production performance of broilers fed with silkworm pupa (Bombyx mori) was studied by focusing on growth, feed utilization, carcass composition and meat quality. There were two difference sources of silkworm p...The production performance of broilers fed with silkworm pupa (Bombyx mori) was studied by focusing on growth, feed utilization, carcass composition and meat quality. There were two difference sources of silkworm pupa: (1) silkworm pupa from spun silk industry (SSP) and (2) silkworm pupa from silk yam reeling industry (RSP) were mixed into five isonitrogenous (20% CP) and isocaloric (ME = 3,150 kcal/kg feed) diet. The 195 chickens at three weeks old were equally distributed to 15 pens in the closed housing. The experiment was divided into five dietary treatments (three replications each): treatment 1 (10% fishmeal, FM and 0% silkworm pupae) (control)), treatment 2 (0% FM and 10% SSP), treatment 3 (0% FM and 20% SSP), treatment 4 (0% FM and 5% SSP + 5% RSP), and treatment 5 (0% FM and 10% SSP + 10% RSP). Daily weight gain was 0.069, 0.060, 0.051, 0.065 and 0.061 kg/chick in treatments 1, 2, 3, 4 and 5, respectively. It is indicated that replacing fishmeal with silkworm pupa (5%SSP + 5%RSP) performed the same daily weight gain as control but exhibited the higher feed conversion ratio (1.87) than control (1.68). Carcass muscle of control treatment 1 (58.26%) was the highest (P 〈 0.05) and closed to treatment 4 and 5 (57.62% and 57.83%, respectively). Sensory evaluation was not significantly differences (P 〉 0.05). Therefore, treatment 4 (5%SSP + 5%RSP) could be substituted FM with little adverse effect on broiler growth but without any adverse effect on percentage of muscle and sensory test. However, further supplemental silkworm pupa performed reduction in dietary utilization and carcass muscle.展开更多
[ Objective] To investigate the effects of non-starch polysaccharide (NSP) enzyme products on meat performance of broilers and thus to provide a scientific basis for their rational use. [Method] Two hundred 21-day-o...[ Objective] To investigate the effects of non-starch polysaccharide (NSP) enzyme products on meat performance of broilers and thus to provide a scientific basis for their rational use. [Method] Two hundred 21-day-old Ross broilers were assigned to five groups. The broilers in group Ⅰ and group Ⅱ were fed positive control diet and negative control diet, respectively, which were slightly different. The broilers in group Ⅲ, Ⅳ and V were fed the negative control diet respectively supplemented with different commercial NSP enzyme products. The broilers were slaughtered at 56 days old, and their meat yield was determined. [ Result] The percentage of carcass yield and percentage of abdominal fat were significantly higher in the group Ⅲ than in the group Ⅱ (P 〈 0.05). The percentage of small intestine weight in slaughter weight was lower in the group Ⅱ than in other groups. [ Conclusion] Diets supplemented broad-rang and highly active NSP enzyme products can promote absorption of routine feed ingredients, increase meat yield, and improve meat performance.展开更多
Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The pres...Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The present study aimed,therefore,to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance,breast meat quality attributes,incidence and severity of breast muscle myopathies and foot pad dermatitis(FPD),and plasma and muscle metabolomics profile in fast-growing broilers.Results: A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet(CON,digestible Arg:Lys ratio of 1.05,1.05,1.06 and 1.07 in each feeding phase,respectively) or the same basal diet supplemented on-top with crystalline L-arginine(ARG,digestible Arg:Lys ratio of 1.15,1.15,1.16 and 1.17,respectively).Productive parameters were determined at the end of each feeding phase(12,22,33,43 d).At slaughter(43 d),incidence and severity of FPD and breast myopathies were assessed,while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonancespectroscopy.The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d(1.352 vs.1.401,P < 0.05),22 d(1.398 vs.1.420; P < 0.01) and 33 d(1.494 vs.1.524; P < 0.05),and also tended to improve it in the overall period of trial(1.646 vs.1.675; P = 0.09).Body weight was significantly increased in ARG compared to CON group at 33 d(1,884 vs.1,829 g; P < 0.05).No significant effect was observed on meat quality attributes,breast myopathies and FPD occurrence.ARG birds showed significantly higher plasma concentration of arginine and leucine,and lower of acetoacetate,glutamate,adenosine and proline.Arginine and acetate concentrations were higher,whereas acetone and inosine levels were lower in the breast of ARG birds(P < 0.05).Conclusions: Taken together,these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism.展开更多
Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product s...Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product system de-sign in China. Therefore,in terms of a concept of product generation and product interaction we are in a weak position compared with the requirements of global markets. Today,the idea of serial product design has attracted much attention in the design field and the definition of product generation as well as its parameters has already become the standard in serial product designs. Although the design of a large-scale NC machine tool is complicated,it can be further optimized by the precise exercise of object design by placing the concept of platform establishment firmly into serial product de-sign. The essence of a serial product design has been demonstrated by the design process of a large-scale NC machine tool.展开更多
Nanoparticles provide great advantages but also great risks. Risks associating with nanoparticles are the problem of all technologies, but they increase in many times in nanotechnologies. Adequate methods of outgoing ...Nanoparticles provide great advantages but also great risks. Risks associating with nanoparticles are the problem of all technologies, but they increase in many times in nanotechnologies. Adequate methods of outgoing production inspection are necessary to solve the problem of risks, and the inspection must be based on the safety standard. Existing safety standard results from a principle of “maximum permissible concentrations or MPC”. This principle is not applicable to nanoparticles, but a safety standard reflecting risks inherent in nanoparticles doesn’t exist. Essence of the risks is illustrated by the example from pharmacology, since its safety assurance is conceptually based on MPC and it has already come against this problem. Possible formula of safety standard for nanoparticles is reflected in many publications, but conventional inspection methods cannot provide its realization, and this gap is an obstacle to assumption of similar formulas. Therefore the development of nanoparticle industry as a whole (also development of the pharmacology in particular) is impossible without the creation of an adequate inspection method. There are suggested new inspection methods founded on the new physical principle and satisfying to the adequate safety standard for nanoparticles. These methods demonstrate that creation of the adequate safety standard and the outgoing production inspection in a large-scale manufacturing of nanoparticles are the solvable problems. However there is a great distance between the physical principle and its hardware realization, and a transition from the principle to the hardware demands great intellectual and material costs. Therefore it is desirable to call attention of the public at large to the necessity of urgent expansions of investigations associated with outgoing inspections in nanoparticles technologies. It is necessary also to attract attention, first, of representatives of state structures controlling approvals of the adequate safety standard to this problem, since it is impossible to compel producers providing the safety without the similar standard, and, second, of leaders of pharmacological industry, since their industry already entered into the nanotechnology era, and they have taken an interest in a forthcoming development of inspection methods.展开更多
Poultry is a light-sensitive animal and the light environment has an important influence on the growth and development of these animals.Previous studies have mainly focused on the effects of the light environment on v...Poultry is a light-sensitive animal and the light environment has an important influence on the growth and development of these animals.Previous studies have mainly focused on the effects of the light environment on various physiological indicators of poultry but seldom explored the light demand characteristics of broilers under free selection.This experiment mainly studied the light demand characteristics of broilers under a yellow LED light environment and the influence of different breeding densities[low-density(2.5 broilers/m^(2)),high-density(7.5 broilers/m^(2))]on the production performance and diet characteristics of broilers.Studies showed that the production performance indexes of low-density groups are higher than those of high-density groups.The feed and water consumption in the light area of the two experimental groups were significantly higher than those in the dark area,which means that the broilers showed a great preference for the light area.However,as the age of the broilers increased,the food and water consumption of the broilers decreased,indicating that broilers had a lower preference for light in the middle and late stages of growth.The statistical results for the residence frequency distribution characteristics showed that broiler chickens had different light requirements at different growth stages under the condition of active selection:1)low-density breeding environment:23.8L(light):0.2D(dark)for chicks and 22.3L:1.7D for adult broilers;2)high-density breeding environment:22.6L:1.4D for chicks and 15.0L:9.0D for adult broilers.This study will provide a reference for the optimization and control of light environment in broiler breeding.展开更多
Large-scale gold production(LSGP) is one of the five convention-related atmospheric mercury(Hg) emission sources in the Minamata Convention on Mercury. However, field experiments on Hg flows of the whole process o...Large-scale gold production(LSGP) is one of the five convention-related atmospheric mercury(Hg) emission sources in the Minamata Convention on Mercury. However, field experiments on Hg flows of the whole process of LSGP are limited. To identify the atmospheric Hg emission points and understand Hg emission characteristics of LSGP, Hg flows in two gold smelters were studied. Overall atmospheric Hg emissions accounted for 10%–17% of total Hg outputs and the Hg emission factors for all processes were 7.6–9.6 kg/ton. There were three dominant atmospheric Hg emission points in the studied gold smelters, including the exhaust gas of the roasting process, exhaust gas from the environmental fog collection stack and exhaust gas from the converter of the refining process. Atmospheric Hg emissions from the roasting process only accounted for 16%–29% of total emissions and the rest were emitted from the refining process. The overall Hg speciation profile(gaseous elemental Hg/gaseous oxidized Hg/particulate-bound Hg) for LSGP was 34.1/57.1/8.8. The dominant Hg output byproducts included waste acid, sulfuric acid and cyanide leaching residue. Total Hg outputs from these three byproducts were 80% in smelter A and 84% in smelter B. Our study indicated that previous atmospheric Hg emissions from large-scale gold production might have been overestimated.Hg emission control in LSGP is not especially urgent in China compared to other significant emission sources(e.g., cement plants). Instead, LSGP is a potential Hg release source due to the high Hg output proportions to acid and sludge.展开更多
The present study was designed to evaluate Dioscarea bulbifera flour as potential feed ingredient in broilers diets. For this purpose, 256-day-old Cobb 500 broiler chicks, were divided into 4 groups replicated 4 times...The present study was designed to evaluate Dioscarea bulbifera flour as potential feed ingredient in broilers diets. For this purpose, 256-day-old Cobb 500 broiler chicks, were divided into 4 groups replicated 4 times in a completely randomized design. A control ration (R0) containing maize as the main energy source was compared to three other rations in which 50%, 75% and 100% maize were substituted with Dioscarea bulbifera flour. The main results showed that, the increasing rate of Dioscarea bulbifera flour had no significant (p > 0.05) effect on the digestibility of feed components. Feed intake was higher with 50% and 75% Dioscarea bulbifera flour inclusion levels. As compared to the control ration, a significant (p < 0.05) drop in live weight and weight gain was recorded with 50% substitution while feed conversion ratio increased significantly with increasing level of Dioscarea bulbifera flour in the ration. Dioscarea bulbifera flour induced a linear and significant (p < 0.05) increase in the relative weight of the gizzard, liver and production cost. It was concluded that, substituting 50% maize with Dioscarea bulbifera flour could be a sustainable solution to palliate the growing inflation of maize as animal feed ingredient. However, the incorporation level of Dioscarea bulbifera as feed ingredient in substitution of maize must not exceed 50% at the risk of depreciating growth performance of broilers.展开更多
This experiment was conducted at the poultry farm, poultry research station, state board of agriculture research, ministry of agriculture to study the effect of supplemental anise seed on broiler diets. A total of 640...This experiment was conducted at the poultry farm, poultry research station, state board of agriculture research, ministry of agriculture to study the effect of supplemental anise seed on broiler diets. A total of 640 of one-day old unsexed broiler chicks (Cobb) were used in this study. They were randomly distributed to four treatments. Anise seeds were supplemented at the levels of 0.2%, 0.4% and 0.6% compared with the control group for 49 days. The results showed: there was a significant (P 〈 0.05) increase in the rate of body weight for the two treatments 0.6% and 0.4% of the anise seeds compared with 0.2% and control treatments, body weight gain take the same direction, like in body weight, the highest treatment was 0.6% followed by treatment 0.4% as well as the feed consumption has increased in these treatments than in 0.2% and control treatments, so about feed conversion ratio the treatment 0.6% of the anise seeds recorded the best feed conversion ratio compared with other treatments. Significant decreased in mortality and significant increased in production index by increasing the level of anise seeds in feed. Dressing percentage increased significantly for all treatments using anise seeds and treatment 0.6% recorded highest dressing percentage, from the other hand percentage of abdominal fat decreased significantly by increasing anise seed levels and no significant difference in the percentages of liver, gizzard and heart were recorded in this study. About carcass cuts, the weights of primary cuts (thigh, drum stick, breast) relative to body weight recorded significant increase in the treatments using anise seeds at the expense of secondary cuts (neck, wings, back). There was a significant decline (P 〈 0.05) for total bacterial (E. coli and Staphylococci) in small intestine in all level of anise seeds (0.2%, 0.4%, 0.6%) in ration while the decline of two types of bacteria in colon recorded in 0.4% and 0.6% treatments compared with 0.2~/0 and control treatments. Conclude from this study the possibility of using anise seeds at all levels used in the experiment and the best level that can be used to get the best performance of the positive results of broiler chickens is 0.6%.展开更多
After 1500 male and female broiler chickens from a pure line were selected on the basis of plasma very low density lipoprotein (VLDL) concentration at 8 weeks of age,abdominal fat(AF),liver fat,body weight,meat traits...After 1500 male and female broiler chickens from a pure line were selected on the basis of plasma very low density lipoprotein (VLDL) concentration at 8 weeks of age,abdominal fat(AF),liver fat,body weight,meat traits and plasma lipids were determined,and effects of interaction between genotype and nutrition on AF and its correlated traits were studied.1) It was efficient to select against AF on the basis of plasma VLDL concentration.The indirect response of gizzard fat was the greatest,and that of liver fat was the second.AF was decreased,whereas liver fat was increased,feed conversion efficiency during growing period were improved, body weight and meat traits were both not influenced by selecting for low plasma VLDL concentration.2) Nutrition had significant effect on fat deposition and growth performance.Interaction between line and diet had evident effect on AF and its correlated traits.In general,diet had greater effect on H-VLDL line than L-VLDL line,namely chickens of L-VLDL line were less sensitive to diet than those of H-VLDL line.3) Due to high coefficients of variation of plasma VLDL and AF in H-VLDL and L-VLDL lines in the first generation.It will be possible that plasma VLDL is to be selected continuously to breed low fat line of broiler chickens of which the feed conversion efficiency is much better.Moreover,family combined with individual selection should be adopted during future generation selection and breeding because of significant family difference in plasma VLDL concentration.展开更多
文摘The tobacco growers with the growing area of greater than or equal to 100 mu,have become an important subject of tobacco production in Weng'an County of Guizhou Province. Regulating and developing the production and business activities of large-scale tobacco growers, plays an important role in stabilizing tobacco production,reducing costs and increasing efficiency in Weng'an County. Through the field survey of large-scale growers' production activities,this article analyzes the input and output levels,and explores the key factors influencing benefit, in order to provide a basis for further regulating the tobacco growing practices and improving the flue-cured tobacco production benefit.
文摘A degree centigrade fall or rise in body temperature of broiler chickens is sufficient to reduce performance, alter sound physiological state and divert nutritional metabolism in quest for ensuring thermal balance. Thermoregulatory mechanisms of newly hatched chicks are poorly developed, and fluctuations in brooding temperature coupled with severe environmental temperatures in the tropics could threaten the survivability, production and economic integrity of fast-growing strains of broilers. However, information on the effect of sharp fluctuations in body temperature on nutrient intake and European production index (EPI) of broilers fed dietary electrolytes is scanty and thus investigated. Using a total of 300, one-day-old unsexed broiler chicks (Arbor Acre) that were randomly allotted to six dietary treatments (T1-210, T2-240, T3270, T4-300, T5-330 and T6-360 mEq/kg electrolyte balance), data on performance characteristics and their correlations with body temperature and EPI at prestarter, starter and finisher phases were determined using standard procedures. Data were analysed using descriptive statistics and ANOVA at α = 0.05. At prestarter phase, feed intake (FI) had a strong and positive relationship with protein intake (r = 1.00;p < 0.01), EPI (r = 0.96;p < 0.01) and potassium (K) intake (r = 0.66;p < 0.01), but was negatively correlated with temperature change (r = ?0.39;p < 0.05). However, FI was not significantly correlated with body weight (BW), body weight gain (BWG), sodium (Na) and water intake. At starter phase, EPI was positively correlated to K intake (r = 0.38;p < 0.05), but not Na and chloride (Cl) intake. European production index of starter chicks could be enhanced by increasing the level of K intake through dietary supplementation up to 1.02%. Weight gain was adversely affected by sharp changes in temperature at finisher phase. Increase in water intake may not be a remedial tool in lowering sharp fluctuations in body temperature. However, sharp fluctuation in body temperature of broilers was reduced with DEB of 330, 270 and 240 mEq/kg at prestarter, starter and finisher phases, respectively.
文摘Recently, interest in animal production and poultry production in particular has increased, because poultry meat and eggs and their products are more widely consumed than other products. Human health is also considered one of the priorities. Nowadays, the fermentation industry has become very popular due to its great benefits in the pharmaceutical industry, the improvement of foodstuffs and the animal feed industry and its improvement. Moreover, microbial fermentation can enhance the content and digestibility of nutrients in nontraditional diets while decreasing the quantity of crude fiber and anti-nutritional elements such as tannins. The functional components (organic acids, bioactive peptides, lactic acid bacteria) found in microbial fermented feed can increase meat production in cattle, pigs, and sheep, and broiler productivity, carcass quality, intestinal health, immunological function, and so on. This paper examines the application study of microbial fermented feed in broiler production and serves as a resource for microbial fermented feed promotion and use in broiler production.
文摘The production performance of broilers fed with silkworm pupa (Bombyx mori) was studied by focusing on growth, feed utilization, carcass composition and meat quality. There were two difference sources of silkworm pupa: (1) silkworm pupa from spun silk industry (SSP) and (2) silkworm pupa from silk yam reeling industry (RSP) were mixed into five isonitrogenous (20% CP) and isocaloric (ME = 3,150 kcal/kg feed) diet. The 195 chickens at three weeks old were equally distributed to 15 pens in the closed housing. The experiment was divided into five dietary treatments (three replications each): treatment 1 (10% fishmeal, FM and 0% silkworm pupae) (control)), treatment 2 (0% FM and 10% SSP), treatment 3 (0% FM and 20% SSP), treatment 4 (0% FM and 5% SSP + 5% RSP), and treatment 5 (0% FM and 10% SSP + 10% RSP). Daily weight gain was 0.069, 0.060, 0.051, 0.065 and 0.061 kg/chick in treatments 1, 2, 3, 4 and 5, respectively. It is indicated that replacing fishmeal with silkworm pupa (5%SSP + 5%RSP) performed the same daily weight gain as control but exhibited the higher feed conversion ratio (1.87) than control (1.68). Carcass muscle of control treatment 1 (58.26%) was the highest (P 〈 0.05) and closed to treatment 4 and 5 (57.62% and 57.83%, respectively). Sensory evaluation was not significantly differences (P 〉 0.05). Therefore, treatment 4 (5%SSP + 5%RSP) could be substituted FM with little adverse effect on broiler growth but without any adverse effect on percentage of muscle and sensory test. However, further supplemental silkworm pupa performed reduction in dietary utilization and carcass muscle.
基金funded by the Action Project of Scientists and Technicians Serving Enterprises of the Ministry of Science and Technology (2009GJF30046)Key Technology R&D Program of Yunnan Province (2008LA006 )+1 种基金Kunming Science and Technology Project (08G100112)Yunnan Innovative Enterprise Pilot Project
文摘[ Objective] To investigate the effects of non-starch polysaccharide (NSP) enzyme products on meat performance of broilers and thus to provide a scientific basis for their rational use. [Method] Two hundred 21-day-old Ross broilers were assigned to five groups. The broilers in group Ⅰ and group Ⅱ were fed positive control diet and negative control diet, respectively, which were slightly different. The broilers in group Ⅲ, Ⅳ and V were fed the negative control diet respectively supplemented with different commercial NSP enzyme products. The broilers were slaughtered at 56 days old, and their meat yield was determined. [ Result] The percentage of carcass yield and percentage of abdominal fat were significantly higher in the group Ⅲ than in the group Ⅱ (P 〈 0.05). The percentage of small intestine weight in slaughter weight was lower in the group Ⅱ than in other groups. [ Conclusion] Diets supplemented broad-rang and highly active NSP enzyme products can promote absorption of routine feed ingredients, increase meat yield, and improve meat performance.
文摘Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The present study aimed,therefore,to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance,breast meat quality attributes,incidence and severity of breast muscle myopathies and foot pad dermatitis(FPD),and plasma and muscle metabolomics profile in fast-growing broilers.Results: A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet(CON,digestible Arg:Lys ratio of 1.05,1.05,1.06 and 1.07 in each feeding phase,respectively) or the same basal diet supplemented on-top with crystalline L-arginine(ARG,digestible Arg:Lys ratio of 1.15,1.15,1.16 and 1.17,respectively).Productive parameters were determined at the end of each feeding phase(12,22,33,43 d).At slaughter(43 d),incidence and severity of FPD and breast myopathies were assessed,while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonancespectroscopy.The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d(1.352 vs.1.401,P < 0.05),22 d(1.398 vs.1.420; P < 0.01) and 33 d(1.494 vs.1.524; P < 0.05),and also tended to improve it in the overall period of trial(1.646 vs.1.675; P = 0.09).Body weight was significantly increased in ARG compared to CON group at 33 d(1,884 vs.1,829 g; P < 0.05).No significant effect was observed on meat quality attributes,breast myopathies and FPD occurrence.ARG birds showed significantly higher plasma concentration of arginine and leucine,and lower of acetoacetate,glutamate,adenosine and proline.Arginine and acetate concentrations were higher,whereas acetone and inosine levels were lower in the breast of ARG birds(P < 0.05).Conclusions: Taken together,these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism.
文摘Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product system de-sign in China. Therefore,in terms of a concept of product generation and product interaction we are in a weak position compared with the requirements of global markets. Today,the idea of serial product design has attracted much attention in the design field and the definition of product generation as well as its parameters has already become the standard in serial product designs. Although the design of a large-scale NC machine tool is complicated,it can be further optimized by the precise exercise of object design by placing the concept of platform establishment firmly into serial product de-sign. The essence of a serial product design has been demonstrated by the design process of a large-scale NC machine tool.
文摘Nanoparticles provide great advantages but also great risks. Risks associating with nanoparticles are the problem of all technologies, but they increase in many times in nanotechnologies. Adequate methods of outgoing production inspection are necessary to solve the problem of risks, and the inspection must be based on the safety standard. Existing safety standard results from a principle of “maximum permissible concentrations or MPC”. This principle is not applicable to nanoparticles, but a safety standard reflecting risks inherent in nanoparticles doesn’t exist. Essence of the risks is illustrated by the example from pharmacology, since its safety assurance is conceptually based on MPC and it has already come against this problem. Possible formula of safety standard for nanoparticles is reflected in many publications, but conventional inspection methods cannot provide its realization, and this gap is an obstacle to assumption of similar formulas. Therefore the development of nanoparticle industry as a whole (also development of the pharmacology in particular) is impossible without the creation of an adequate inspection method. There are suggested new inspection methods founded on the new physical principle and satisfying to the adequate safety standard for nanoparticles. These methods demonstrate that creation of the adequate safety standard and the outgoing production inspection in a large-scale manufacturing of nanoparticles are the solvable problems. However there is a great distance between the physical principle and its hardware realization, and a transition from the principle to the hardware demands great intellectual and material costs. Therefore it is desirable to call attention of the public at large to the necessity of urgent expansions of investigations associated with outgoing inspections in nanoparticles technologies. It is necessary also to attract attention, first, of representatives of state structures controlling approvals of the adequate safety standard to this problem, since it is impossible to compel producers providing the safety without the similar standard, and, second, of leaders of pharmacological industry, since their industry already entered into the nanotechnology era, and they have taken an interest in a forthcoming development of inspection methods.
基金financially supported by the National Natural Science Foundation of China(Grant No.31972609)the China Agriculture Research System(CARS-40).
文摘Poultry is a light-sensitive animal and the light environment has an important influence on the growth and development of these animals.Previous studies have mainly focused on the effects of the light environment on various physiological indicators of poultry but seldom explored the light demand characteristics of broilers under free selection.This experiment mainly studied the light demand characteristics of broilers under a yellow LED light environment and the influence of different breeding densities[low-density(2.5 broilers/m^(2)),high-density(7.5 broilers/m^(2))]on the production performance and diet characteristics of broilers.Studies showed that the production performance indexes of low-density groups are higher than those of high-density groups.The feed and water consumption in the light area of the two experimental groups were significantly higher than those in the dark area,which means that the broilers showed a great preference for the light area.However,as the age of the broilers increased,the food and water consumption of the broilers decreased,indicating that broilers had a lower preference for light in the middle and late stages of growth.The statistical results for the residence frequency distribution characteristics showed that broiler chickens had different light requirements at different growth stages under the condition of active selection:1)low-density breeding environment:23.8L(light):0.2D(dark)for chicks and 22.3L:1.7D for adult broilers;2)high-density breeding environment:22.6L:1.4D for chicks and 15.0L:9.0D for adult broilers.This study will provide a reference for the optimization and control of light environment in broiler breeding.
基金supported by the National basic Research Program (973) of China (No.2013CB430001)the National Natural Science Foundation of China (No.21077065)the China Postdoctoral Science Foundation (2016T90103,2016M601053)
文摘Large-scale gold production(LSGP) is one of the five convention-related atmospheric mercury(Hg) emission sources in the Minamata Convention on Mercury. However, field experiments on Hg flows of the whole process of LSGP are limited. To identify the atmospheric Hg emission points and understand Hg emission characteristics of LSGP, Hg flows in two gold smelters were studied. Overall atmospheric Hg emissions accounted for 10%–17% of total Hg outputs and the Hg emission factors for all processes were 7.6–9.6 kg/ton. There were three dominant atmospheric Hg emission points in the studied gold smelters, including the exhaust gas of the roasting process, exhaust gas from the environmental fog collection stack and exhaust gas from the converter of the refining process. Atmospheric Hg emissions from the roasting process only accounted for 16%–29% of total emissions and the rest were emitted from the refining process. The overall Hg speciation profile(gaseous elemental Hg/gaseous oxidized Hg/particulate-bound Hg) for LSGP was 34.1/57.1/8.8. The dominant Hg output byproducts included waste acid, sulfuric acid and cyanide leaching residue. Total Hg outputs from these three byproducts were 80% in smelter A and 84% in smelter B. Our study indicated that previous atmospheric Hg emissions from large-scale gold production might have been overestimated.Hg emission control in LSGP is not especially urgent in China compared to other significant emission sources(e.g., cement plants). Instead, LSGP is a potential Hg release source due to the high Hg output proportions to acid and sludge.
文摘The present study was designed to evaluate Dioscarea bulbifera flour as potential feed ingredient in broilers diets. For this purpose, 256-day-old Cobb 500 broiler chicks, were divided into 4 groups replicated 4 times in a completely randomized design. A control ration (R0) containing maize as the main energy source was compared to three other rations in which 50%, 75% and 100% maize were substituted with Dioscarea bulbifera flour. The main results showed that, the increasing rate of Dioscarea bulbifera flour had no significant (p > 0.05) effect on the digestibility of feed components. Feed intake was higher with 50% and 75% Dioscarea bulbifera flour inclusion levels. As compared to the control ration, a significant (p < 0.05) drop in live weight and weight gain was recorded with 50% substitution while feed conversion ratio increased significantly with increasing level of Dioscarea bulbifera flour in the ration. Dioscarea bulbifera flour induced a linear and significant (p < 0.05) increase in the relative weight of the gizzard, liver and production cost. It was concluded that, substituting 50% maize with Dioscarea bulbifera flour could be a sustainable solution to palliate the growing inflation of maize as animal feed ingredient. However, the incorporation level of Dioscarea bulbifera as feed ingredient in substitution of maize must not exceed 50% at the risk of depreciating growth performance of broilers.
文摘This experiment was conducted at the poultry farm, poultry research station, state board of agriculture research, ministry of agriculture to study the effect of supplemental anise seed on broiler diets. A total of 640 of one-day old unsexed broiler chicks (Cobb) were used in this study. They were randomly distributed to four treatments. Anise seeds were supplemented at the levels of 0.2%, 0.4% and 0.6% compared with the control group for 49 days. The results showed: there was a significant (P 〈 0.05) increase in the rate of body weight for the two treatments 0.6% and 0.4% of the anise seeds compared with 0.2% and control treatments, body weight gain take the same direction, like in body weight, the highest treatment was 0.6% followed by treatment 0.4% as well as the feed consumption has increased in these treatments than in 0.2% and control treatments, so about feed conversion ratio the treatment 0.6% of the anise seeds recorded the best feed conversion ratio compared with other treatments. Significant decreased in mortality and significant increased in production index by increasing the level of anise seeds in feed. Dressing percentage increased significantly for all treatments using anise seeds and treatment 0.6% recorded highest dressing percentage, from the other hand percentage of abdominal fat decreased significantly by increasing anise seed levels and no significant difference in the percentages of liver, gizzard and heart were recorded in this study. About carcass cuts, the weights of primary cuts (thigh, drum stick, breast) relative to body weight recorded significant increase in the treatments using anise seeds at the expense of secondary cuts (neck, wings, back). There was a significant decline (P 〈 0.05) for total bacterial (E. coli and Staphylococci) in small intestine in all level of anise seeds (0.2%, 0.4%, 0.6%) in ration while the decline of two types of bacteria in colon recorded in 0.4% and 0.6% treatments compared with 0.2~/0 and control treatments. Conclude from this study the possibility of using anise seeds at all levels used in the experiment and the best level that can be used to get the best performance of the positive results of broiler chickens is 0.6%.
文摘After 1500 male and female broiler chickens from a pure line were selected on the basis of plasma very low density lipoprotein (VLDL) concentration at 8 weeks of age,abdominal fat(AF),liver fat,body weight,meat traits and plasma lipids were determined,and effects of interaction between genotype and nutrition on AF and its correlated traits were studied.1) It was efficient to select against AF on the basis of plasma VLDL concentration.The indirect response of gizzard fat was the greatest,and that of liver fat was the second.AF was decreased,whereas liver fat was increased,feed conversion efficiency during growing period were improved, body weight and meat traits were both not influenced by selecting for low plasma VLDL concentration.2) Nutrition had significant effect on fat deposition and growth performance.Interaction between line and diet had evident effect on AF and its correlated traits.In general,diet had greater effect on H-VLDL line than L-VLDL line,namely chickens of L-VLDL line were less sensitive to diet than those of H-VLDL line.3) Due to high coefficients of variation of plasma VLDL and AF in H-VLDL and L-VLDL lines in the first generation.It will be possible that plasma VLDL is to be selected continuously to breed low fat line of broiler chickens of which the feed conversion efficiency is much better.Moreover,family combined with individual selection should be adopted during future generation selection and breeding because of significant family difference in plasma VLDL concentration.