Background Body weight is an important indicator of the overall health and production efficiency in broiler chickens.In broiler houses,body weight of chicks is variable despite the same genetics,hatching and feeding p...Background Body weight is an important indicator of the overall health and production efficiency in broiler chickens.In broiler houses,body weight of chicks is variable despite the same genetics,hatching and feeding practices within a production system.The objective of this study was to investigate the intestinal microbiota and bile salt hydrolase(BSH)activity in slow and fast growing broiler chickens,which belonged to the 10th and 90th percentile body weight groups,respectively.Methods A total of 300 Ross 308 broiler chickens(100 per cohort from three independent cohorts)were selected and mucosal samples from the jejunum,ileum,and cecum were collected at day of arrival,11 and 25(n=450).Then,bacterial counts,16S rRNA amplicon sequencing,species specific real-time qPCR,as well as BSH activity were analyzed.Results Results of bacterial counts showed no significant difference between slow and fast growing cohorts(P>0.05),but they tended to be higher in the slow growing chickens in all measured bacterial groups in cecum.The 16S rRNA amplicon sequencing revealed higher relative abundance of E.coli-Shigella(71.3%−79.8%)at day of arrival,while the most abundant microorganisms at d 25 was Candidatus Arthromitus(slow:44.5%;fast:27.4%)in small intestine.qPCR results indicated significant differences in bacterial populations between the slow and fast growing chickens,especially higher total bacteria,Enterococcus,and Clostridium cluster I in the slow growing chickens at d 25.BSH activity was higher in the slow growing chickens than the fast growing chickens[slow:0.476ΔOD/protein(μg/mL);fast:0.258ΔOD/protein(μg/mL);P<0.0001],and correlation analysis highlighted associations between BSH activity,body weight,feed intake,body weight gain,and bacterial counts.Conclusions We postulate that high total bacteria and Enterococcus abundance are associated with high BSH activity,impacting low feed intake and body weight gain,ultimately resulting in separation into slow and fast growing birds.The findings of this study contribute to understanding the relationship between gut microbiota,BSH activity,and host physiology in broiler chickens,with potential implications for poultry production.展开更多
Background There is a growing focus on using various plant-derived agricultural by-products to increase the benefits of pig farming,but these feedstuffs are fibrous in nature.This study investigated the relationship b...Background There is a growing focus on using various plant-derived agricultural by-products to increase the benefits of pig farming,but these feedstuffs are fibrous in nature.This study investigated the relationship between dietary fiber physicochemical properties and feedstuff fermentation characteristics and their effects on nutrient utilization,energy metabolism,and gut microbiota in growing pigs.Methods Thirty-six growing barrows(47.2±1.5 kg)were randomly allotted to 6 dietary treatments with 2 apparent viscosity levels and 3β-glucan-to-arabinoxylan ratios.In the experiment,nutrient utilization,energy metabolism,fecal microbial community,and production and absorption of short-chain fatty acid(SCFA)of pigs were investigated.In vitro digestion and fermentation models were used to compare the fermentation characteristics of feedstuffs and ileal digesta in the pig’s hindgut.Results The production dynamics of SCFA and dry matter corrected gas production of different feedstuffs during in vitro fermentation were different and closely related to the physical properties and chemical structure of the fiber.In animal experiments,increasing the dietary apparent viscosity and theβ-glucan-to-arabinoxylan ratios both increased the apparent ileal digestibility(AID),apparent total tract digestibility(ATTD),and hindgut digestibility of fiber components while decreasing the AID and ATTD of dry matter and organic matter(P<0.05).In addition,increasing dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased gas exchange,heat production,and protein oxidation,and decreased energy deposition(P<0.05).The dietary apparent viscosity andβ-glucanto-arabinoxylan ratios had linear interaction effects on the digestible energy,metabolizable energy,retained energy(RE),and net energy(NE)of the diets(P<0.05).At the same time,the increase of dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased SCFA production and absorption(P<0.05).Increasing the dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios increased the diversity and abundance of bacteria(P<0.05)and the relative abundance of beneficial bacteria.Furthermore,increasing the dietaryβ-glucan-to-arabinoxylan ratios led to a linear increase in SCFA production during the in vitro fermentation of ileal digesta(P<0.001).Finally,the prediction equations for RE and NE were established.Conclusion Dietary fiber physicochemical properties alter dietary fermentation patterns and regulate nutrient utilization,energy metabolism,and pig gut microbiota composition and metabolites.展开更多
Acrylamide(AA)is a harmful substance widely found in infant and child biscuits;however,the health hazards of AA,especially endogenous AA,in the biscuit matrix is poorly understood.This study aimed to determine the eff...Acrylamide(AA)is a harmful substance widely found in infant and child biscuits;however,the health hazards of AA,especially endogenous AA,in the biscuit matrix is poorly understood.This study aimed to determine the effects of endogenous(0.11 mg/(kg bw·day))and exogenous(1.31,5.23,and 10.13 mg/(kg bw·day))AA exposure from biscuit diet on the hematology,hormone levels,immune function,and liver and kidney damage in growing female rat pups.For the hematological indices,a quadratic reduction was observed in percentage of neutrophils(Neu%)and percentage of eosinophils(Eos%)in the leukograms and in mean corpuscular hemoglobin concentration and platelet in the erythrograms in all the AA-exposed groups.In terms of hormones,extremely remarkably elevations in estradiol(E_(2))and growth hormone(GH)levels were associated with exogenous AA,and a significant increase in GH levels was noted in the endogenous AA group.Regarding immune function,endogenous and exogenous AA showed a dose-dependent immunotoxic effect on lysozyme(LYSO),nitric oxide(NO),immunoglobulin(Ig)G,and IgM.In particular,the lactate dehydrogenase(LDH)activity was significantly high in the exogenous medium dose(Exo-M)and exogenous high dose(Exo-H)groups,and the percentage of CD3^(+)T cells in the blood and CD8^(+)expression levels in the spleen were significantly elevated in the Exo-H group.For liver and kidney function,exogenous AA had a dose-dependent effect on alanine aminotransferases(ALT),aspartate transferases(AST),alkaline phosphatase(ALP),urea nitrogen(UREA),and creatinine(CREA-S).In addition to the dose-dependent effect on the pathological changes in the liver and kidneys,the endogenous AA group presented with hepatocellular steatosis,kidney inflammatory infiltrates,and glomerular and tubular atrophy.Overall,our findings suggested the dose-dependent harmful effect of endogenous and exogenous AA.Special attention should be paid to the damage caused by exposure to endogenous AA.Stringent AA intake guidelines and measures are required to minimize AA levels in the food matrix.展开更多
Peanuts are widely produced and commonly eaten in China.They grow well in warm climates with moderate rainfall and sandy soil,and they have a relatively long growing season.In China,the main peanut-producing areas are...Peanuts are widely produced and commonly eaten in China.They grow well in warm climates with moderate rainfall and sandy soil,and they have a relatively long growing season.In China,the main peanut-producing areas are Henan,Shandong,and Hebei provinces.From planting to harvest,peanuts go through five main stages.展开更多
By using asymptotic method,we verify the existence on the slowly growing solutions to second order difference equations discussed by Ishizaki-Yanagihara’s Wiman-Valiron method and Ishizaki-Wen’s binomial series meth...By using asymptotic method,we verify the existence on the slowly growing solutions to second order difference equations discussed by Ishizaki-Yanagihara’s Wiman-Valiron method and Ishizaki-Wen’s binomial series method.The classical problem on finding conditions on the polynomial coefficients P_(j)(z)(j=0,1,2)and F(z)to guarantee that all nontrivial solutions of complex second order difference equation P_(2)(z)f(z+2)+P_(1)(z)f(z+1)+P_(0)(z)f(z)=F(z)has slowly growing solutions with order 1/2 is detected.展开更多
Researching into changes in thermal growing season has been one of the most important scientific issues in studies of the impact of global climate change on terrestrial ecosystems. However, few studies investigated th...Researching into changes in thermal growing season has been one of the most important scientific issues in studies of the impact of global climate change on terrestrial ecosystems. However, few studies investigated the differences under various definitions of thermal growing season and compared the trends of thermal growing season in different parts of China. Based on the daily mean air temperatures collected from 877 meteorological stations over northern China from 1961 to 2015, we investigated the variations of the thermal growing season parameters including the onset, ending and duration of the growing season using the methods of differential analysis, trend analysis, comparative analysis, and Kriging interpolation technique. Results indicate that the differences of the maximum values of those indices for the thermal growing season were significant, while they were insignificant for the mean values. For indices with the same length of the spells exceeding 5°C, frost criterion had a significant effect on the differences of the maximum values. The differences of the mean values between frost and non-frost indices were also slight, even smaller than those from the different lengths of the spells. Temporally, the starting date of the thermal growing season advanced by 10.0–11.0 days, while the ending dates delayed by 5.0–6.0 days during the period 1961–2015. Consequently, the duration of the thermal growing season was prolonged 15.0–16.0 days. Spatially, the advanced onset of the thermal growing season occurred in the southwestern, eastern, and northeastern parts of northern China, whereas the delayed ending of the thermal growing season appeared in the western part, and the length of the thermal growing season was prolonged significantly in the vast majority of northern China. The trend values of the thermal growing season were affected by altitude. The magnitude of the earlier onset of the thermal growing season decreased, and that of the later ending increased rapidly as the altitude increased, causing the magnitude of the prolonged growing season increased correspondingly. Comparing the applicability of selected indices and considering the impacts of frost on the definitions are important and necessary for determining the timing and length of the thermal growing season in northern China.展开更多
[Objective] The aims were to understand variation characteristics of water resources and provide theoretical guidance for the formulation of agricultural irrigation methods.[Method] Taking the precipitation records du...[Objective] The aims were to understand variation characteristics of water resources and provide theoretical guidance for the formulation of agricultural irrigation methods.[Method] Taking the precipitation records during crop growing season（from April to September）observed by 177 weather stations from 1971 to 2008 in the three provinces of Northeast China（Heilongjiang,Jilin and Liaoning）as research data,annual change and spatial distribution characteristics of precipitation during crop growing season were analyzed by means of small grid interpolation and climatic trend rate.[Result] The precipitation during crop growing season general exhibited the decreasing trend and the precipitation trend rate was-8.6 mm/10a in Northeast China.In addition,there was lack of rain from 1971 to 1980 and relatively abundant of rain during 1981 and 1990 respectively.Moreover,the precipitation obviously exhibited decreasing trend from 1991 to 2008.But the decreasing trend was inconsistent in spatial distributions,that was,the precipitation slightly increased in relatively rainless areas and obviously decreased in relatively rainy areas.[Conclusion] The areas with obvious decreasing trend of precipitation during crop growing season are the main grain producing zones in Northeast China,so the problem of food production security caused by the precipitation changes should be paid enough attention.展开更多
The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data colle...The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity.To solve the critical problems of estimating air temperature(T a) and filling in missing pixels due to cloudy and low-quality images in growing degree days(GDDs) calculation from remotely sensed data,a novel spatio-temporal algorithm for T a estimation from Terra and Aqua moderate resolution imaging spectroradiometer(MODIS) data was proposed.This is a preliminary study to calculate heat accumulation,expressed in accumulative growing degree days(AGDDs) above 10 ℃,from reconstructed T a based on MODIS land surface temperature(LST) data.The verification results of maximum T a,minimum T a,GDD,and AGDD from MODIS-derived data to meteorological calculation were all satisfied with high correlations over 0.01 significant levels.Overall,MODIS-derived AGDD was slightly underestimated with almost 10% relative error.However,the feasibility of employing AGDD anomaly maps to characterize the 2001-2010 spatio-temporal variability of heat accumulation and estimating the 2011 heat accumulation distribution using only MODIS data was finally demonstrated in the current paper.Our study may supply a novel way to calculate AGDD in heat-related study concerning crop growth monitoring,agricultural climatic regionalization,and agro-meteorological disaster detection at the regional scale.展开更多
Based on the conventional meteorological data of temperature,accumulated temperature,precipitation,sunshine,frozen soil and frost-free period from five stations(including Liaozhong,Kaiyuan,Dawa,Donggang and Zhuanghe)i...Based on the conventional meteorological data of temperature,accumulated temperature,precipitation,sunshine,frozen soil and frost-free period from five stations(including Liaozhong,Kaiyuan,Dawa,Donggang and Zhuanghe)in Liaoning Province from April to September during 1960-2009,the climatic changes in growing season in rice producing area of Liaoning Province were analyzed.The results showed that average temperature,frost-free period and accumulated temperature showed increase trend in growing season in rice producing area over the past 50 years,while average maximum depth of frozen soil,precipitation and sunshine duration went down with fluctuation.展开更多
The soybean, cotton, maize and sorghum were planted in pot under low nitrogen, high nitrogen treatments, the soil available nitrogen constitution and con- version and utilization of nitrogen fertilizer were determined...The soybean, cotton, maize and sorghum were planted in pot under low nitrogen, high nitrogen treatments, the soil available nitrogen constitution and con- version and utilization of nitrogen fertilizer were determined, so as to provide techni- cal guidance for reasonable use and improving use efficiency of nitrogen fertilizer for different types of crops. Compared with the control with nitrogen but unplanted crop, growing soybean, cotton, maize, sorghum significantly decreased the soil available N contents by 53. 48%, 51.54%, 33.10%, 55.03%,and influenced the constitution of soil available N. Thereinto, growing soybean, cotton, maize and sorghum significantly decreased soil inorganic N contents by 85.41%, 83.09%, 70.89% and 83.35%,but increased soil hydrolysable organic N contents by 1.41, 1.53, 2.11 and 1.28 times, respectively; growing soybean, cotton, maize and sorghum significantly decreased the rate of soil inorganic N to available N by 68.61%, 65.09%, 56.47% and 63.00%, but increased the rate of soil hydrolysable organic N to available N by 4.18, 4.21, 3.66 and 4.08 times, respectively. Compared with the control, growing soybean, cotton, maize and sorghum significantly increased the transform rate of ammonium nitrogen fertilizer by 93.66%, 38.19%, 32.58% and 38.31% respectively, and growing soybean treatment had the highest increasing range; the nitrification rates of ammo- nium nitrogen fertilizer of growing soybean, cotton, maize and sorghum treatments were negative values, and growing soybean treatment had the highest decreasing amplitude. The ammonium nitrogen fertilizer use efficiency of growing soybean, cot- ton, maize and sorghum treatments were 52.01%, 28.31%, 24.16% and 28.40% re- spectively and growing soybean treatment had the highest value. In conclusion, growing crops suppressed the soil nitrification and accelerated the development of soil hydrolysable organic nitrogen by the utilization of soil available nitrogen and the alteration of soil environment, and hence impacted the constitution of soil available nitrogen and the transform and use of ammonium nitrogen applied in soil. Legumi- nous crops had stronger ability of suppressing nitrification, making use of ammonium compared with non-Leguminous crops.展开更多
The climate change in Alaska has caused earlier spring snowmelt and the growing season expanded. However, the effect of climate change on crop phenological stages, heading (BBCH 55) and maturity (BBCH 85), is unknown....The climate change in Alaska has caused earlier spring snowmelt and the growing season expanded. However, the effect of climate change on crop phenological stages, heading (BBCH 55) and maturity (BBCH 85), is unknown. In this study, the trends of growing-season length (GSL), phenological stages of crops and climatic parameters, and the correlations between climatic parameters and the phenological stages were analyzed using the climate data and crop data over the period of 1978 to 2016. The longer GSL was found in Fairbanks (64.83<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span></span>N, 147.77<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span></span>W) and in Delta Junction (64.05<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>N, 145.60<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>W) but not in Palmer (61.60<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>N, 149.11<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>W). Sowing dates did not change significantly in three locations. The decreasing trends of heading and maturity of crops were observed but varied with location. Heading of barley and oat significantly advanced 3 and 3.1 d decade<sup>-1</sup>, respectively from 1989 to 2016 in Fairbanks while no change of heading was observed in Delta Junction and Palmer. Maturity of barley, oat and wheat significantly advanced 2.6, 3.8 and 3.9 d decade<sup>-1</sup>, respectively from 1978 to 2016 in Fairbanks (<em>P</em> < 0.05);maturity of oat and wheat significantly advanced 4.4 and 3.4 d decade<sup>-1</sup> from 1978 to 2015, respectively in Delta Junction (<em>P</em> < 0.05). The increasing temperature trends and decreasing precipitation trends were found in Fairbanks and Delta Junction but varied with phenological stages of crops. Sowing was more important for heading than for maturity of crops. The effect of climate change on heading was less important than that on maturity. Earlier maturity of crops in Fairbanks may be attributed to increased temperatures, that in Delta Junction to both increased minimum temperature and decreased precipitation and that in Palmer to temperature and precipitation.展开更多
Background: Two experiments were conducted to estimate the net energy(NE) of corn, soybean meal, expel er-pressed rapeseed meal(EP-RSM) and solvent-extracted rapeseed meal(SE-RSM) using indirect calorimetry and to val...Background: Two experiments were conducted to estimate the net energy(NE) of corn, soybean meal, expel er-pressed rapeseed meal(EP-RSM) and solvent-extracted rapeseed meal(SE-RSM) using indirect calorimetry and to validate the NE of these four ingredients using pig growth performance.Methods: In Exp.1, 24 barrows(initial BW = 36.4 ± 1.6 kg) were allotted to 1 of 4 diets which included a corn basal diet,a corn-soybean meal basal diet and two rapeseed meal diets containing 20% EP-RSM(9.5% ether extract) or SE-RSM(1.1% ether extract) substituted for corn and soybean meal. The design allowed the calculation of NE values of corn,soybean meal and rapeseed meals according to the difference method. In Exp.2, 175 growing pigs(initial BW = 36.0± 5.2 kg) were fed 1 of 5 diets for 28 d, with five pigs per pen and seven replications(pens) per treatment in order to validate the measured energy values. Diets were a corn-soybean meal diet and four diets including 10% or 20% EP-RSM and 10% or 20% SE-RSM.Results: The NE of corn, soybean meal, EP-RSM and SE-RSM were 12.46, 11.34, 11.71 and 8.83 MJ/kg DM, respectively. The NE to ME ratio of corn(78%) was similar to tabular values, however, the NE to ME ratios of soybean meal(70%) and rapeseed meal(76%) were greater than tabular values. The greater NE value in EP-RSM than in SE-RSM is consistent with its higher EE content. Increasing EP-RSM or SE-RSM did not affect the growth performance of pigs and the caloric efficiency of NE was comparable for al diets.Conclusions: The NE of EP-RSM was similar to soybean meal, and both were greater than SE-RSM. The DE, ME and NE values measured in Exp.1 are confirmed by results of Exp. 2 with comparable caloric efficiencies of DE, ME or NE for all diets.展开更多
Daily and ten-day Normalized Difference Vegetation Index( NDVI) of crops were retrieved from meteorological satellite NOAA AVHRR images. The temporal variations of the NDVI were analyzed during the whole growing seaso...Daily and ten-day Normalized Difference Vegetation Index( NDVI) of crops were retrieved from meteorological satellite NOAA AVHRR images. The temporal variations of the NDVI were analyzed during the whole growing season, and thus the principle of the interaction between NDVI profile and the growing status of crops was discussed. As a case in point, the relationship between integral NDVI and winter wheat yield of Henan Province in 1999 had been analyzed. By putting integral NDVI values of 60 sample counties into the winter wheat yield-integral NDVI coordination, scattering map was plotted. It demonstrated that integral NDVI had a close relation with winter wheat yield. These relation could be described with linear, cubic polynomial, and exponential regression, and the cubic polynomial regression was the best way. In general, NDVI reflects growing status of green vegetation, so crop monitoring and crop yield estimation could be realized by using remote sensing technique on the basis of time serial NDVI data together with agriculture calendars.展开更多
In this study, we have used four methods to investigate the start of the growing season （SGS） on the Tibetan Plateau （TP） from 1982 to 2012, using Normalized Difference Vegetation Index （NDVI） data obtained from...In this study, we have used four methods to investigate the start of the growing season （SGS） on the Tibetan Plateau （TP） from 1982 to 2012, using Normalized Difference Vegetation Index （NDVI） data obtained from Global Inventory Modeling and Mapping Studies （GIMSS, 1982-2006） and SPOT VEGETATION （SPOT-VGT, 1999-2012）. SGS values esti- mated using the four methods show similar spatial patterns along latitudinal or altitudinal gradients, but with significant variations in the SGS dates. The largest discrepancies are mainly found in the regions with the highest or the lowest vegetation coverage. Between 1982 and 1998, the SGS values derived from the four methods all display an advancing trend, however, according to the more recent SPOT VGT data （1999-2012）, there is no continu- ously advancing trend of SGS on the TP. Analysis of the correlation between the SGS values derived from GIMMS and SPOT between 1999 and 2006 demonstrates consistency in the tendency with regard both to the data sources and to the four analysis methods used. Com- pared with other methods, the greatest consistency between the in situ data and the SGS values retrieved is obtained with Method 3 （Threshold of NDVI ratio）. To avoid error, in a vast region with diverse vegetation types and physical environments, it is critical to know the seasonal change characteristics of the different vegetation types, particularly in areas with sparse grassland or evergreen forest.展开更多
Late-maturity type of Yongyou japonica/indica hybrids series(LMYS)have shown great yield potential,and are being widely planted in the lower reaches of Yangtze River,China.Knowledge about suitable growing zone and eva...Late-maturity type of Yongyou japonica/indica hybrids series(LMYS)have shown great yield potential,and are being widely planted in the lower reaches of Yangtze River,China.Knowledge about suitable growing zone and evaluation of yield advantage is of practicall importance for LMYS in this region.Fifteen LMYS,two high-yielding inbred japonica check varieties(CK-J)and two high-yielding hybrid indica check varieties(CK-I)were grown at Xinghua(119.57°E,33.05°N)of Lixiahe region,Yangzhou(119.25°E,32.30°N)of Yanjiang region,Changshu(120.46°E,31.41°N)of Taihu Lake region,and Ningbo(121.31°E,29.45°N)of Ningshao Plain in 2013 and 2014.The results showed that maturity dates of the 15 were later than the secure maturity date at Xinghua and 6,14 and 15 LMYS were mature before the secure maturity date at Yangzhou,Changshu and Ningbo,respectively.One variety was identified as high-yielding variety among LMYS(HYYS)at Yangzhou,8 HYYS in 201:3 and 9 HYYS in 2014 at Changshu,9 HYYS at Ningbo.HYYS here referred to the variety among LMYS that was mature before the secure maturity date and had at least 8%higher grain yield than both CK-J and CK-I at each experimental site.Grain yield of HYYS at each experimental site was about 12.0 t ha-1 or higher,and was significantly higher than CK varieties.High yield of HYYS was mainly attributed to larger sink size due to more spikelets per panicle.Plant height of HYYS was about 140 cm,and was significantly higher than check varieties.Significant positive correlations were recorded between duration from heading to maturity stage and grain yield,and also between whole growth periods and grain yield.HYYS had obvious advantage over check varieties in biomass accumulation and leaf area duration from heading to maturity stage.Comprehensive consideration about safe matudty and yield performance of LMYS at each experimental site,Taihu Lake region(representative site Changshu)and Ningshao Plain(representative site Ningbo)were thought suitable growing zones for LMYS in the lower reaches of Yangtze River.The main factors underlying high yield ofHYYS were larger sink size,higher plant height,longer duration from heading to maturity stage and whole growth periods,and higher biomass accumulation and leaf area duration during grain filling stage.展开更多
This study analyzed the spatial-temporal heterogeneity of green development efficiency and its influencing factors in the growing Xuzhou Metropolitan Area for the period 2000–2015.The slacks-based measure(SBM)model,s...This study analyzed the spatial-temporal heterogeneity of green development efficiency and its influencing factors in the growing Xuzhou Metropolitan Area for the period 2000–2015.The slacks-based measure(SBM)model,spatial autocorrelation,and the geographically weighted regression(GWR)model were used to conduct the analysis.The conclusions were as follows:first,the overall efficiency of green development of the Xuzhou Metropolitan Area decreased,the regional differences and spatial agglomeration shrunk and differences within the region were the main contributors to the regional differences of green development efficiency.Second,the counties with high-efficiency green development were distributed along the coast,and along the routes of the Beijing-Shanghai and the Eastern Longhai railways.A developing axis of the high-efficiency counties was the main feature of the spatial pattern for green development efficiency.Third,regarding spatial correlation and green development efficiency,the High-High type counties in the Xuzhou Metropolitan Area formed a centralized distribution corridor along the inter-provincial border areas of Henan and Jiangsu,whereas the Low-Low type counties were concentrated in the external,marginal parts of the metropolitan area.Fourth,the major factors(ranked in decreasing order of impact)influencing green development efficiency were innovation,government regulations,the economic development level,energy consumption,and industrial structure.These factors exerted their influence to varying extents;the influence of the same factor had different effects in different regions and obvious spatial differences were observed for the different regions.展开更多
The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble die...The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.展开更多
Two experiments were conducted to investigate the effect of dietary supplementation with phytase transgenic corn （PTC） on growth performance,phosphorus （P） utilization and excretion in growing pigs.In Exp.1,180 pi...Two experiments were conducted to investigate the effect of dietary supplementation with phytase transgenic corn （PTC） on growth performance,phosphorus （P） utilization and excretion in growing pigs.In Exp.1,180 pigs （Large White × Landrace,BW=37.7 kg） were randomly allotted to 4 treatments with 5 replicates of 9 pigs each in order to evaluate the effect of PTC supplementation in low-P diets on growth performance.Four corn soybean meal-based diets consisted of a positive control （PC） diet,a diet containing 500 units （U） of exogenous phytase kg-1 （EP） on the basis of low-P （inorganic P reduced by 0.05% from PC diet） and the low-P＋500 （PTC1） or 750 （PTC2） phytase U of PTC kg-1.In Exp.2,20 barrows （Large White×Landrace,BW=31 kg,4 treatments with 5 replicates of 1 pig each） were randomly selected to evaluate the effect of PTC in low-P diets on serum parameters and nutrient utilization.Diets in Exp.2 were similar to those in Exp.1 except that the EP group was replaced by a low-P diet without exogenous phytase supplementation as a negative control （NC） group.The results from Exp.1 showed that the average daily gain （ADG） in the PTC2 group was significantly higher （P〈0.05） than that in the EP group over all periods.On the other hand,the feed：gain （F：G） ratio of the EP group was significantly higher （P〈0.05） than that of the PTC2 group during 1-21 and 1-42 d,respectively.There were no differences in average daily feed intake （ADFI） among all treatments （P〉0.05）.The results from Exp.2 showed that the concentration of serum Ca in the NC group was the highest （P〈0.05）,while the concentration of serum P in the PTC2 group was the highest （P〈0.05） among all treatments.There was a significant decrease （P〈0.05） in the P apparent digestibility of the NC group compared with the other groups,and that of PTC2 group was the best.Furthermore,fecal P excretion was reduced （P〈0.05） from 1.80 g d-1 in the PC group to 1.28 g d-1 in the PTC2 group.In conclusion,dietary supplementation with PTC could reduce the application of inorganic P,decrease fecal P excretion,and improve the growth performance of growing pigs.展开更多
The objective of this study was to investigate pig fed by Bacillus coagulans-fermented distillers＇ dried grains with solubles （DDGS） on the faecal microbial composition and diversity using 454 pyrosequencing. Healt...The objective of this study was to investigate pig fed by Bacillus coagulans-fermented distillers＇ dried grains with solubles （DDGS） on the faecal microbial composition and diversity using 454 pyrosequencing. Healthy crossbred （Durocx Yorkshirex Landrace） growing and fattening pigs （n=48）, with an average initial body weight of 65 kg, were divided into two groups （24 replicates per group; four pens per group; six pigs per pen）, and given either DDGS feed as the control, or B. coagulans-fermented DDGS feed as the treatment. Faecal samples were collected on day 0, 7, 14, 21, and 28. DNA was extracted, and the V3-V6 region of the 16S rRNA gene was amplified. The fermented DDGS feed affected the relative abundance of bacteria populations at the phylum, genus, and species levels. At the genus level, the consumption of fermented DDGS feed led to higher relative abundances of faecal Prevotella, Lactobacillus, Clostridium, Bifidobacterium, Roseburia, and Bacillus, and lower relative abundances of faecal Escherichia, Ruminococcus, Dialister, unclassified Lachnospiraceae, unclassified Ruminococcaceae, and unclassified Enterobacteriaceae than in the control. At the species level, the consumption of fermented DDGS feed led to higher relative abundances of faecal Prevotella sp., Lactobacillus johnsonii, Lactobacillus fermentum, Lactobacillus mucosae, Lactobacillus reuteri, Clostridium butyricum, Bifidobacterium sp., and Roseburia sp., and lower relative abundances of faecal Prevotella copri, Escherichia coil, Ruminococcus gnavus, Ruminococcus flavefaciens, and Dialister sp. than in the control. Principal coordinates analysis indicated a distinct separation in the faecal microbial communities of pigs that were fed the fermented and unfermented DDGS feed. Fermented DDGS feed significantly increased the average daily gain （ADG） of pigs, and significantly decreased the average daily feed intake （ADFI） of feed and feed/gain （F/G）. Thus, our results demonstrate a beneficial shift in the faecal microbiota of pigs consuming fermented DDGS feed, with potential applications in livestock production.展开更多
To provide base for adjusting the sowing date,achieving the yield potential of wheat cultivars with different growth characteristics,and improving the utilization rate of natural resource in the North China Plain （NC...To provide base for adjusting the sowing date,achieving the yield potential of wheat cultivars with different growth characteristics,and improving the utilization rate of natural resource in the North China Plain （NCP）,a 4-yr field experiment of growing degree-days （GDD） before winter （realized through different sowing dates） with three wheat （Triticum aestivum L.） cultivars of each type of semi-winterness and weak springness was carried out at 20 test experimental sites （32°4’N36°1’N） of Henan Province in the NCP.The results showed that：（i） yield of semi-winterness wheat was significantly higher than weak springness wheat （P〈0.01）;（ii） there was a quadratic regression between the yield and GDD before winter.According to the regression equation,the optimum GDD range with high yield of semi-winterness and weak springness wheats was 750-770 and 570-590°C d,respectively;（iii） under the optimum GDD condition,the foliar age on the main stem of semi-winterness and weak springness wheats was 7.67-7.91 and 6.36-6.86 leaves,respectively,calculated by the linear regression equation between foliar age and GDD before winter;（iv） both semi-winterness and weak springness wheats were in the double ridge stage of spike differentiation under the condition of the optimum GDD range,and at this time,the foliar age on the main stem of semi-winterness and weak springness wheats was about 7.80 and 6.07 leaves,respectively,which was consistent with the results calculated by the liner regression equation.Therefore,we could consider that the sowing date is appropriate if the foliar age is about 7.8 and 6.3 leaves for semi-winterness and weak springness wheats,respectively.According to the results of this study,choosing semi-winterness wheat and planting 710 d earlier would improve yield and natural resource utilization in NCP.展开更多
基金supported by research funding provided by Arm&Hammer Animal and Food Production,Waukesha,WI 53186,USA.
文摘Background Body weight is an important indicator of the overall health and production efficiency in broiler chickens.In broiler houses,body weight of chicks is variable despite the same genetics,hatching and feeding practices within a production system.The objective of this study was to investigate the intestinal microbiota and bile salt hydrolase(BSH)activity in slow and fast growing broiler chickens,which belonged to the 10th and 90th percentile body weight groups,respectively.Methods A total of 300 Ross 308 broiler chickens(100 per cohort from three independent cohorts)were selected and mucosal samples from the jejunum,ileum,and cecum were collected at day of arrival,11 and 25(n=450).Then,bacterial counts,16S rRNA amplicon sequencing,species specific real-time qPCR,as well as BSH activity were analyzed.Results Results of bacterial counts showed no significant difference between slow and fast growing cohorts(P>0.05),but they tended to be higher in the slow growing chickens in all measured bacterial groups in cecum.The 16S rRNA amplicon sequencing revealed higher relative abundance of E.coli-Shigella(71.3%−79.8%)at day of arrival,while the most abundant microorganisms at d 25 was Candidatus Arthromitus(slow:44.5%;fast:27.4%)in small intestine.qPCR results indicated significant differences in bacterial populations between the slow and fast growing chickens,especially higher total bacteria,Enterococcus,and Clostridium cluster I in the slow growing chickens at d 25.BSH activity was higher in the slow growing chickens than the fast growing chickens[slow:0.476ΔOD/protein(μg/mL);fast:0.258ΔOD/protein(μg/mL);P<0.0001],and correlation analysis highlighted associations between BSH activity,body weight,feed intake,body weight gain,and bacterial counts.Conclusions We postulate that high total bacteria and Enterococcus abundance are associated with high BSH activity,impacting low feed intake and body weight gain,ultimately resulting in separation into slow and fast growing birds.The findings of this study contribute to understanding the relationship between gut microbiota,BSH activity,and host physiology in broiler chickens,with potential implications for poultry production.
基金supported by the National Key Research and Development Program(No.2021YFD1300201)Jilin Provincial Department of Science and Technology Innovation Platform and Talent Special Project(No.20230508090RC).
文摘Background There is a growing focus on using various plant-derived agricultural by-products to increase the benefits of pig farming,but these feedstuffs are fibrous in nature.This study investigated the relationship between dietary fiber physicochemical properties and feedstuff fermentation characteristics and their effects on nutrient utilization,energy metabolism,and gut microbiota in growing pigs.Methods Thirty-six growing barrows(47.2±1.5 kg)were randomly allotted to 6 dietary treatments with 2 apparent viscosity levels and 3β-glucan-to-arabinoxylan ratios.In the experiment,nutrient utilization,energy metabolism,fecal microbial community,and production and absorption of short-chain fatty acid(SCFA)of pigs were investigated.In vitro digestion and fermentation models were used to compare the fermentation characteristics of feedstuffs and ileal digesta in the pig’s hindgut.Results The production dynamics of SCFA and dry matter corrected gas production of different feedstuffs during in vitro fermentation were different and closely related to the physical properties and chemical structure of the fiber.In animal experiments,increasing the dietary apparent viscosity and theβ-glucan-to-arabinoxylan ratios both increased the apparent ileal digestibility(AID),apparent total tract digestibility(ATTD),and hindgut digestibility of fiber components while decreasing the AID and ATTD of dry matter and organic matter(P<0.05).In addition,increasing dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased gas exchange,heat production,and protein oxidation,and decreased energy deposition(P<0.05).The dietary apparent viscosity andβ-glucanto-arabinoxylan ratios had linear interaction effects on the digestible energy,metabolizable energy,retained energy(RE),and net energy(NE)of the diets(P<0.05).At the same time,the increase of dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios both increased SCFA production and absorption(P<0.05).Increasing the dietary apparent viscosity andβ-glucan-to-arabinoxylan ratios increased the diversity and abundance of bacteria(P<0.05)and the relative abundance of beneficial bacteria.Furthermore,increasing the dietaryβ-glucan-to-arabinoxylan ratios led to a linear increase in SCFA production during the in vitro fermentation of ileal digesta(P<0.001).Finally,the prediction equations for RE and NE were established.Conclusion Dietary fiber physicochemical properties alter dietary fermentation patterns and regulate nutrient utilization,energy metabolism,and pig gut microbiota composition and metabolites.
文摘Acrylamide(AA)is a harmful substance widely found in infant and child biscuits;however,the health hazards of AA,especially endogenous AA,in the biscuit matrix is poorly understood.This study aimed to determine the effects of endogenous(0.11 mg/(kg bw·day))and exogenous(1.31,5.23,and 10.13 mg/(kg bw·day))AA exposure from biscuit diet on the hematology,hormone levels,immune function,and liver and kidney damage in growing female rat pups.For the hematological indices,a quadratic reduction was observed in percentage of neutrophils(Neu%)and percentage of eosinophils(Eos%)in the leukograms and in mean corpuscular hemoglobin concentration and platelet in the erythrograms in all the AA-exposed groups.In terms of hormones,extremely remarkably elevations in estradiol(E_(2))and growth hormone(GH)levels were associated with exogenous AA,and a significant increase in GH levels was noted in the endogenous AA group.Regarding immune function,endogenous and exogenous AA showed a dose-dependent immunotoxic effect on lysozyme(LYSO),nitric oxide(NO),immunoglobulin(Ig)G,and IgM.In particular,the lactate dehydrogenase(LDH)activity was significantly high in the exogenous medium dose(Exo-M)and exogenous high dose(Exo-H)groups,and the percentage of CD3^(+)T cells in the blood and CD8^(+)expression levels in the spleen were significantly elevated in the Exo-H group.For liver and kidney function,exogenous AA had a dose-dependent effect on alanine aminotransferases(ALT),aspartate transferases(AST),alkaline phosphatase(ALP),urea nitrogen(UREA),and creatinine(CREA-S).In addition to the dose-dependent effect on the pathological changes in the liver and kidneys,the endogenous AA group presented with hepatocellular steatosis,kidney inflammatory infiltrates,and glomerular and tubular atrophy.Overall,our findings suggested the dose-dependent harmful effect of endogenous and exogenous AA.Special attention should be paid to the damage caused by exposure to endogenous AA.Stringent AA intake guidelines and measures are required to minimize AA levels in the food matrix.
文摘Peanuts are widely produced and commonly eaten in China.They grow well in warm climates with moderate rainfall and sandy soil,and they have a relatively long growing season.In China,the main peanut-producing areas are Henan,Shandong,and Hebei provinces.From planting to harvest,peanuts go through five main stages.
文摘By using asymptotic method,we verify the existence on the slowly growing solutions to second order difference equations discussed by Ishizaki-Yanagihara’s Wiman-Valiron method and Ishizaki-Wen’s binomial series method.The classical problem on finding conditions on the polynomial coefficients P_(j)(z)(j=0,1,2)and F(z)to guarantee that all nontrivial solutions of complex second order difference equation P_(2)(z)f(z+2)+P_(1)(z)f(z+1)+P_(0)(z)f(z)=F(z)has slowly growing solutions with order 1/2 is detected.
基金supported by the National Natural Science Foundation of China(41571044,41401661,41001283)the Climate Change Special Fund of the China Meteorological Administration(CCSF201716)the China Clean Development Mechanism(CDM)Fund Project(2012043)
文摘Researching into changes in thermal growing season has been one of the most important scientific issues in studies of the impact of global climate change on terrestrial ecosystems. However, few studies investigated the differences under various definitions of thermal growing season and compared the trends of thermal growing season in different parts of China. Based on the daily mean air temperatures collected from 877 meteorological stations over northern China from 1961 to 2015, we investigated the variations of the thermal growing season parameters including the onset, ending and duration of the growing season using the methods of differential analysis, trend analysis, comparative analysis, and Kriging interpolation technique. Results indicate that the differences of the maximum values of those indices for the thermal growing season were significant, while they were insignificant for the mean values. For indices with the same length of the spells exceeding 5°C, frost criterion had a significant effect on the differences of the maximum values. The differences of the mean values between frost and non-frost indices were also slight, even smaller than those from the different lengths of the spells. Temporally, the starting date of the thermal growing season advanced by 10.0–11.0 days, while the ending dates delayed by 5.0–6.0 days during the period 1961–2015. Consequently, the duration of the thermal growing season was prolonged 15.0–16.0 days. Spatially, the advanced onset of the thermal growing season occurred in the southwestern, eastern, and northeastern parts of northern China, whereas the delayed ending of the thermal growing season appeared in the western part, and the length of the thermal growing season was prolonged significantly in the vast majority of northern China. The trend values of the thermal growing season were affected by altitude. The magnitude of the earlier onset of the thermal growing season decreased, and that of the later ending increased rapidly as the altitude increased, causing the magnitude of the prolonged growing season increased correspondingly. Comparing the applicability of selected indices and considering the impacts of frost on the definitions are important and necessary for determining the timing and length of the thermal growing season in northern China.
基金Supported by Special Fund for Climate Change of China Meteorological Administration(CCSF-09-13)Special Fund for Researchof Nonprofit Sector(meteorology)(GYHY200706030)~~
文摘[Objective] The aims were to understand variation characteristics of water resources and provide theoretical guidance for the formulation of agricultural irrigation methods.[Method] Taking the precipitation records during crop growing season（from April to September）observed by 177 weather stations from 1971 to 2008 in the three provinces of Northeast China（Heilongjiang,Jilin and Liaoning）as research data,annual change and spatial distribution characteristics of precipitation during crop growing season were analyzed by means of small grid interpolation and climatic trend rate.[Result] The precipitation during crop growing season general exhibited the decreasing trend and the precipitation trend rate was-8.6 mm/10a in Northeast China.In addition,there was lack of rain from 1971 to 1980 and relatively abundant of rain during 1981 and 1990 respectively.Moreover,the precipitation obviously exhibited decreasing trend from 1991 to 2008.But the decreasing trend was inconsistent in spatial distributions,that was,the precipitation slightly increased in relatively rainless areas and obviously decreased in relatively rainy areas.[Conclusion] The areas with obvious decreasing trend of precipitation during crop growing season are the main grain producing zones in Northeast China,so the problem of food production security caused by the precipitation changes should be paid enough attention.
基金Project supported by the National Key Technology R&D Program of China (No. 2012BAH29B02)the PhD Programs Foundation of Ministry of Education of China (No. 200100101110035)
文摘The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity.To solve the critical problems of estimating air temperature(T a) and filling in missing pixels due to cloudy and low-quality images in growing degree days(GDDs) calculation from remotely sensed data,a novel spatio-temporal algorithm for T a estimation from Terra and Aqua moderate resolution imaging spectroradiometer(MODIS) data was proposed.This is a preliminary study to calculate heat accumulation,expressed in accumulative growing degree days(AGDDs) above 10 ℃,from reconstructed T a based on MODIS land surface temperature(LST) data.The verification results of maximum T a,minimum T a,GDD,and AGDD from MODIS-derived data to meteorological calculation were all satisfied with high correlations over 0.01 significant levels.Overall,MODIS-derived AGDD was slightly underestimated with almost 10% relative error.However,the feasibility of employing AGDD anomaly maps to characterize the 2001-2010 spatio-temporal variability of heat accumulation and estimating the 2011 heat accumulation distribution using only MODIS data was finally demonstrated in the current paper.Our study may supply a novel way to calculate AGDD in heat-related study concerning crop growth monitoring,agricultural climatic regionalization,and agro-meteorological disaster detection at the regional scale.
文摘Based on the conventional meteorological data of temperature,accumulated temperature,precipitation,sunshine,frozen soil and frost-free period from five stations(including Liaozhong,Kaiyuan,Dawa,Donggang and Zhuanghe)in Liaoning Province from April to September during 1960-2009,the climatic changes in growing season in rice producing area of Liaoning Province were analyzed.The results showed that average temperature,frost-free period and accumulated temperature showed increase trend in growing season in rice producing area over the past 50 years,while average maximum depth of frozen soil,precipitation and sunshine duration went down with fluctuation.
基金Supported by National Natural Science Foundation of China(41371259)Hubei Natural Science Foundation(2014CFB545)~~
文摘The soybean, cotton, maize and sorghum were planted in pot under low nitrogen, high nitrogen treatments, the soil available nitrogen constitution and con- version and utilization of nitrogen fertilizer were determined, so as to provide techni- cal guidance for reasonable use and improving use efficiency of nitrogen fertilizer for different types of crops. Compared with the control with nitrogen but unplanted crop, growing soybean, cotton, maize, sorghum significantly decreased the soil available N contents by 53. 48%, 51.54%, 33.10%, 55.03%,and influenced the constitution of soil available N. Thereinto, growing soybean, cotton, maize and sorghum significantly decreased soil inorganic N contents by 85.41%, 83.09%, 70.89% and 83.35%,but increased soil hydrolysable organic N contents by 1.41, 1.53, 2.11 and 1.28 times, respectively; growing soybean, cotton, maize and sorghum significantly decreased the rate of soil inorganic N to available N by 68.61%, 65.09%, 56.47% and 63.00%, but increased the rate of soil hydrolysable organic N to available N by 4.18, 4.21, 3.66 and 4.08 times, respectively. Compared with the control, growing soybean, cotton, maize and sorghum significantly increased the transform rate of ammonium nitrogen fertilizer by 93.66%, 38.19%, 32.58% and 38.31% respectively, and growing soybean treatment had the highest increasing range; the nitrification rates of ammo- nium nitrogen fertilizer of growing soybean, cotton, maize and sorghum treatments were negative values, and growing soybean treatment had the highest decreasing amplitude. The ammonium nitrogen fertilizer use efficiency of growing soybean, cot- ton, maize and sorghum treatments were 52.01%, 28.31%, 24.16% and 28.40% re- spectively and growing soybean treatment had the highest value. In conclusion, growing crops suppressed the soil nitrification and accelerated the development of soil hydrolysable organic nitrogen by the utilization of soil available nitrogen and the alteration of soil environment, and hence impacted the constitution of soil available nitrogen and the transform and use of ammonium nitrogen applied in soil. Legumi- nous crops had stronger ability of suppressing nitrification, making use of ammonium compared with non-Leguminous crops.
文摘The climate change in Alaska has caused earlier spring snowmelt and the growing season expanded. However, the effect of climate change on crop phenological stages, heading (BBCH 55) and maturity (BBCH 85), is unknown. In this study, the trends of growing-season length (GSL), phenological stages of crops and climatic parameters, and the correlations between climatic parameters and the phenological stages were analyzed using the climate data and crop data over the period of 1978 to 2016. The longer GSL was found in Fairbanks (64.83<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span></span>N, 147.77<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span></span>W) and in Delta Junction (64.05<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>N, 145.60<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>W) but not in Palmer (61.60<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>N, 149.11<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>W). Sowing dates did not change significantly in three locations. The decreasing trends of heading and maturity of crops were observed but varied with location. Heading of barley and oat significantly advanced 3 and 3.1 d decade<sup>-1</sup>, respectively from 1989 to 2016 in Fairbanks while no change of heading was observed in Delta Junction and Palmer. Maturity of barley, oat and wheat significantly advanced 2.6, 3.8 and 3.9 d decade<sup>-1</sup>, respectively from 1978 to 2016 in Fairbanks (<em>P</em> < 0.05);maturity of oat and wheat significantly advanced 4.4 and 3.4 d decade<sup>-1</sup> from 1978 to 2015, respectively in Delta Junction (<em>P</em> < 0.05). The increasing temperature trends and decreasing precipitation trends were found in Fairbanks and Delta Junction but varied with phenological stages of crops. Sowing was more important for heading than for maturity of crops. The effect of climate change on heading was less important than that on maturity. Earlier maturity of crops in Fairbanks may be attributed to increased temperatures, that in Delta Junction to both increased minimum temperature and decreased precipitation and that in Palmer to temperature and precipitation.
基金supported by the Modern Agricultural Industry Technology System(CARS-36)Developing key equipment for digital management and monitoring environment in animal production(2013AA10230602)+1 种基金National Natural Science Foundation of China(31372317)the 111 Project(B16044)
文摘Background: Two experiments were conducted to estimate the net energy(NE) of corn, soybean meal, expel er-pressed rapeseed meal(EP-RSM) and solvent-extracted rapeseed meal(SE-RSM) using indirect calorimetry and to validate the NE of these four ingredients using pig growth performance.Methods: In Exp.1, 24 barrows(initial BW = 36.4 ± 1.6 kg) were allotted to 1 of 4 diets which included a corn basal diet,a corn-soybean meal basal diet and two rapeseed meal diets containing 20% EP-RSM(9.5% ether extract) or SE-RSM(1.1% ether extract) substituted for corn and soybean meal. The design allowed the calculation of NE values of corn,soybean meal and rapeseed meals according to the difference method. In Exp.2, 175 growing pigs(initial BW = 36.0± 5.2 kg) were fed 1 of 5 diets for 28 d, with five pigs per pen and seven replications(pens) per treatment in order to validate the measured energy values. Diets were a corn-soybean meal diet and four diets including 10% or 20% EP-RSM and 10% or 20% SE-RSM.Results: The NE of corn, soybean meal, EP-RSM and SE-RSM were 12.46, 11.34, 11.71 and 8.83 MJ/kg DM, respectively. The NE to ME ratio of corn(78%) was similar to tabular values, however, the NE to ME ratios of soybean meal(70%) and rapeseed meal(76%) were greater than tabular values. The greater NE value in EP-RSM than in SE-RSM is consistent with its higher EE content. Increasing EP-RSM or SE-RSM did not affect the growth performance of pigs and the caloric efficiency of NE was comparable for al diets.Conclusions: The NE of EP-RSM was similar to soybean meal, and both were greater than SE-RSM. The DE, ME and NE values measured in Exp.1 are confirmed by results of Exp. 2 with comparable caloric efficiencies of DE, ME or NE for all diets.
基金Under the auspices of Beijing Precision Agriculture Project of the State Development Planning Commission(A00300100584-RS02).
文摘Daily and ten-day Normalized Difference Vegetation Index( NDVI) of crops were retrieved from meteorological satellite NOAA AVHRR images. The temporal variations of the NDVI were analyzed during the whole growing season, and thus the principle of the interaction between NDVI profile and the growing status of crops was discussed. As a case in point, the relationship between integral NDVI and winter wheat yield of Henan Province in 1999 had been analyzed. By putting integral NDVI values of 60 sample counties into the winter wheat yield-integral NDVI coordination, scattering map was plotted. It demonstrated that integral NDVI had a close relation with winter wheat yield. These relation could be described with linear, cubic polynomial, and exponential regression, and the cubic polynomial regression was the best way. In general, NDVI reflects growing status of green vegetation, so crop monitoring and crop yield estimation could be realized by using remote sensing technique on the basis of time serial NDVI data together with agriculture calendars.
基金Strategic Priority Research Program of the Chinese Academy of Sciences, No.XDB03030500 National Natural Science Foundation of China, No.41201095+1 种基金 No.41171080 No.413711 20
文摘In this study, we have used four methods to investigate the start of the growing season （SGS） on the Tibetan Plateau （TP） from 1982 to 2012, using Normalized Difference Vegetation Index （NDVI） data obtained from Global Inventory Modeling and Mapping Studies （GIMSS, 1982-2006） and SPOT VEGETATION （SPOT-VGT, 1999-2012）. SGS values esti- mated using the four methods show similar spatial patterns along latitudinal or altitudinal gradients, but with significant variations in the SGS dates. The largest discrepancies are mainly found in the regions with the highest or the lowest vegetation coverage. Between 1982 and 1998, the SGS values derived from the four methods all display an advancing trend, however, according to the more recent SPOT VGT data （1999-2012）, there is no continu- ously advancing trend of SGS on the TP. Analysis of the correlation between the SGS values derived from GIMMS and SPOT between 1999 and 2006 demonstrates consistency in the tendency with regard both to the data sources and to the four analysis methods used. Com- pared with other methods, the greatest consistency between the in situ data and the SGS values retrieved is obtained with Method 3 （Threshold of NDVI ratio）. To avoid error, in a vast region with diverse vegetation types and physical environments, it is critical to know the seasonal change characteristics of the different vegetation types, particularly in areas with sparse grassland or evergreen forest.
基金financed by the Special Program of Super Rice of Ministry of Agriculture,China(02318802013231)the National Public Services Sectors(Agricultural)Research Projects,China(201303102)+1 种基金the Major Scientific and Technological Projects,Bureau of Science and Technology of Ningbo,China(2013C11001)the Innovative Training Program of Yangzhou University,China(KYLX15_1371)
文摘Late-maturity type of Yongyou japonica/indica hybrids series(LMYS)have shown great yield potential,and are being widely planted in the lower reaches of Yangtze River,China.Knowledge about suitable growing zone and evaluation of yield advantage is of practicall importance for LMYS in this region.Fifteen LMYS,two high-yielding inbred japonica check varieties(CK-J)and two high-yielding hybrid indica check varieties(CK-I)were grown at Xinghua(119.57°E,33.05°N)of Lixiahe region,Yangzhou(119.25°E,32.30°N)of Yanjiang region,Changshu(120.46°E,31.41°N)of Taihu Lake region,and Ningbo(121.31°E,29.45°N)of Ningshao Plain in 2013 and 2014.The results showed that maturity dates of the 15 were later than the secure maturity date at Xinghua and 6,14 and 15 LMYS were mature before the secure maturity date at Yangzhou,Changshu and Ningbo,respectively.One variety was identified as high-yielding variety among LMYS(HYYS)at Yangzhou,8 HYYS in 201:3 and 9 HYYS in 2014 at Changshu,9 HYYS at Ningbo.HYYS here referred to the variety among LMYS that was mature before the secure maturity date and had at least 8%higher grain yield than both CK-J and CK-I at each experimental site.Grain yield of HYYS at each experimental site was about 12.0 t ha-1 or higher,and was significantly higher than CK varieties.High yield of HYYS was mainly attributed to larger sink size due to more spikelets per panicle.Plant height of HYYS was about 140 cm,and was significantly higher than check varieties.Significant positive correlations were recorded between duration from heading to maturity stage and grain yield,and also between whole growth periods and grain yield.HYYS had obvious advantage over check varieties in biomass accumulation and leaf area duration from heading to maturity stage.Comprehensive consideration about safe matudty and yield performance of LMYS at each experimental site,Taihu Lake region(representative site Changshu)and Ningshao Plain(representative site Ningbo)were thought suitable growing zones for LMYS in the lower reaches of Yangtze River.The main factors underlying high yield ofHYYS were larger sink size,higher plant height,longer duration from heading to maturity stage and whole growth periods,and higher biomass accumulation and leaf area duration during grain filling stage.
基金Under the auspices of the National Natural Science Foundation of China(No.41671123,41971158,41671122)Major Project of Philosophy and Social Science Research of Jiangsu Universities(No.2018SJZDA010).
文摘This study analyzed the spatial-temporal heterogeneity of green development efficiency and its influencing factors in the growing Xuzhou Metropolitan Area for the period 2000–2015.The slacks-based measure(SBM)model,spatial autocorrelation,and the geographically weighted regression(GWR)model were used to conduct the analysis.The conclusions were as follows:first,the overall efficiency of green development of the Xuzhou Metropolitan Area decreased,the regional differences and spatial agglomeration shrunk and differences within the region were the main contributors to the regional differences of green development efficiency.Second,the counties with high-efficiency green development were distributed along the coast,and along the routes of the Beijing-Shanghai and the Eastern Longhai railways.A developing axis of the high-efficiency counties was the main feature of the spatial pattern for green development efficiency.Third,regarding spatial correlation and green development efficiency,the High-High type counties in the Xuzhou Metropolitan Area formed a centralized distribution corridor along the inter-provincial border areas of Henan and Jiangsu,whereas the Low-Low type counties were concentrated in the external,marginal parts of the metropolitan area.Fourth,the major factors(ranked in decreasing order of impact)influencing green development efficiency were innovation,government regulations,the economic development level,energy consumption,and industrial structure.These factors exerted their influence to varying extents;the influence of the same factor had different effects in different regions and obvious spatial differences were observed for the different regions.
基金financially supported by the National Key Technology R&D Program in the 11th Five Yr Plan of China(2006BAD12B01)Special Public Sector Fund in Agriculture(200903006)
文摘The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.
基金supported by the Key Program of Transgenic Plant Breeding,China (2008ZX08003-002)the Major Special Project of Guangdong Province,China(2009A080303009)+1 种基金the National Major Science Research Program of China (2009CB941601)the Special Fund for Agro-Scientific Research in the Public Interest,China (Agriculture,201003011)
文摘Two experiments were conducted to investigate the effect of dietary supplementation with phytase transgenic corn （PTC） on growth performance,phosphorus （P） utilization and excretion in growing pigs.In Exp.1,180 pigs （Large White × Landrace,BW=37.7 kg） were randomly allotted to 4 treatments with 5 replicates of 9 pigs each in order to evaluate the effect of PTC supplementation in low-P diets on growth performance.Four corn soybean meal-based diets consisted of a positive control （PC） diet,a diet containing 500 units （U） of exogenous phytase kg-1 （EP） on the basis of low-P （inorganic P reduced by 0.05% from PC diet） and the low-P＋500 （PTC1） or 750 （PTC2） phytase U of PTC kg-1.In Exp.2,20 barrows （Large White×Landrace,BW=31 kg,4 treatments with 5 replicates of 1 pig each） were randomly selected to evaluate the effect of PTC in low-P diets on serum parameters and nutrient utilization.Diets in Exp.2 were similar to those in Exp.1 except that the EP group was replaced by a low-P diet without exogenous phytase supplementation as a negative control （NC） group.The results from Exp.1 showed that the average daily gain （ADG） in the PTC2 group was significantly higher （P〈0.05） than that in the EP group over all periods.On the other hand,the feed：gain （F：G） ratio of the EP group was significantly higher （P〈0.05） than that of the PTC2 group during 1-21 and 1-42 d,respectively.There were no differences in average daily feed intake （ADFI） among all treatments （P〉0.05）.The results from Exp.2 showed that the concentration of serum Ca in the NC group was the highest （P〈0.05）,while the concentration of serum P in the PTC2 group was the highest （P〈0.05） among all treatments.There was a significant decrease （P〈0.05） in the P apparent digestibility of the NC group compared with the other groups,and that of PTC2 group was the best.Furthermore,fecal P excretion was reduced （P〈0.05） from 1.80 g d-1 in the PC group to 1.28 g d-1 in the PTC2 group.In conclusion,dietary supplementation with PTC could reduce the application of inorganic P,decrease fecal P excretion,and improve the growth performance of growing pigs.
基金the Open Funding Project of the Key Laboratory of Systems Bioengineering,Ministry of Education of China,Tianjin,China(20160315)
文摘The objective of this study was to investigate pig fed by Bacillus coagulans-fermented distillers＇ dried grains with solubles （DDGS） on the faecal microbial composition and diversity using 454 pyrosequencing. Healthy crossbred （Durocx Yorkshirex Landrace） growing and fattening pigs （n=48）, with an average initial body weight of 65 kg, were divided into two groups （24 replicates per group; four pens per group; six pigs per pen）, and given either DDGS feed as the control, or B. coagulans-fermented DDGS feed as the treatment. Faecal samples were collected on day 0, 7, 14, 21, and 28. DNA was extracted, and the V3-V6 region of the 16S rRNA gene was amplified. The fermented DDGS feed affected the relative abundance of bacteria populations at the phylum, genus, and species levels. At the genus level, the consumption of fermented DDGS feed led to higher relative abundances of faecal Prevotella, Lactobacillus, Clostridium, Bifidobacterium, Roseburia, and Bacillus, and lower relative abundances of faecal Escherichia, Ruminococcus, Dialister, unclassified Lachnospiraceae, unclassified Ruminococcaceae, and unclassified Enterobacteriaceae than in the control. At the species level, the consumption of fermented DDGS feed led to higher relative abundances of faecal Prevotella sp., Lactobacillus johnsonii, Lactobacillus fermentum, Lactobacillus mucosae, Lactobacillus reuteri, Clostridium butyricum, Bifidobacterium sp., and Roseburia sp., and lower relative abundances of faecal Prevotella copri, Escherichia coil, Ruminococcus gnavus, Ruminococcus flavefaciens, and Dialister sp. than in the control. Principal coordinates analysis indicated a distinct separation in the faecal microbial communities of pigs that were fed the fermented and unfermented DDGS feed. Fermented DDGS feed significantly increased the average daily gain （ADG） of pigs, and significantly decreased the average daily feed intake （ADFI） of feed and feed/gain （F/G）. Thus, our results demonstrate a beneficial shift in the faecal microbiota of pigs consuming fermented DDGS feed, with potential applications in livestock production.
基金supported by the Key Technologies R&D Program of China during the 11th and 12th Five-Year Plan periods(2006BAD02A07,2011BAD16B07)
文摘To provide base for adjusting the sowing date,achieving the yield potential of wheat cultivars with different growth characteristics,and improving the utilization rate of natural resource in the North China Plain （NCP）,a 4-yr field experiment of growing degree-days （GDD） before winter （realized through different sowing dates） with three wheat （Triticum aestivum L.） cultivars of each type of semi-winterness and weak springness was carried out at 20 test experimental sites （32°4’N36°1’N） of Henan Province in the NCP.The results showed that：（i） yield of semi-winterness wheat was significantly higher than weak springness wheat （P〈0.01）;（ii） there was a quadratic regression between the yield and GDD before winter.According to the regression equation,the optimum GDD range with high yield of semi-winterness and weak springness wheats was 750-770 and 570-590°C d,respectively;（iii） under the optimum GDD condition,the foliar age on the main stem of semi-winterness and weak springness wheats was 7.67-7.91 and 6.36-6.86 leaves,respectively,calculated by the linear regression equation between foliar age and GDD before winter;（iv） both semi-winterness and weak springness wheats were in the double ridge stage of spike differentiation under the condition of the optimum GDD range,and at this time,the foliar age on the main stem of semi-winterness and weak springness wheats was about 7.80 and 6.07 leaves,respectively,which was consistent with the results calculated by the liner regression equation.Therefore,we could consider that the sowing date is appropriate if the foliar age is about 7.8 and 6.3 leaves for semi-winterness and weak springness wheats,respectively.According to the results of this study,choosing semi-winterness wheat and planting 710 d earlier would improve yield and natural resource utilization in NCP.
