The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, ...The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.展开更多
Although the effect of animal and diet factors on enteric methane （CH4） emissions from confined cattle has been extensively examined, less data is available regarding CH4 emissions from grazing young cattle. A study...Although the effect of animal and diet factors on enteric methane （CH4） emissions from confined cattle has been extensively examined, less data is available regarding CH4 emissions from grazing young cattle. A study was undertaken to evaluate the effect of the physiological state of Holstein-Friesian heifers on their enteric CH4 emissions while grazing a perennial ryegrass sward. Two experiments were conducted： Experiment 1 ran from May 2011 for 11 weeks and Experiment 2 ran from August 2011 for 10 weeks. In each experiment, Holstein-Friesian heifers were divided into three treatment groups （12 animals/group） consisting of calves, yearling heifers, and in-calf heifers （average ages： 8.5, 14.5, and 20.5 months, respectively）. Methane emissions were estimated for each animal in the final week of each experiment using the sulfur hexafluoride tracer technique. Dry matter （DM） intake was estimated using the calculated metabolizable energy （ME） requirement divided by the ME concentration in the grazed grass. As expected, live weight increased with increasing animal age （P 〈 0.001）; however, there was no difference in live weight gain among the three groups in Experiment 1, although in Experiment 2, this variable decreased with increasing animal age （P 〈 0.001 ）. In Experiment 1, yearling heifers had the highest CH4 emissions （g·d^-1） and in-calf heifers produced more than calves （P 〈 0.001 ）. When expressed as CH4 emissions per unit of live weight, DM intake, and gross energy （GE） intake, yearling heifers had higher emission rates than calves and in-calf heifers （P 〈 0.001）. However, the effects on CH4 emissions were different in Experiment 2, in which CH, emissions （g·d^-1） increased linearly with increasing animal age （P 〈 0.001）, although the difference between yearling and in-calf heifers was not significant. The CH4/live weight ratio was lower in in-calf heifers than in the other two groups （P 〈 0.001 ）, while CH4 energy output as a proportion of GE intake was lower in calves than in yearling and in-calf heifers （P 〈 0.05）. All data were then pooled and used to develop prediction equations for CH4 emissions. All relationships are significant （P 〈 0.001）, with R2 values ranging from 0.630 to 0.682. These models indicate that CH4 emissions could be increased by 0.252 g.d-1 with an increase of I kg live weight or by 14.9 g·d^-1 with an increase of 1 kg·d^-1 of DM intake; or, the CH4 energy output could be increased by 0.046 MJ·d^-1 with an increase of 1 MJ·d^-1 of GE intake. These results provide an alternative approach for estimating CH4 emissions from grazine dairy heifers when actual CH, emission data are not available.展开更多
Cattle may improve their feeding efficiency by altering their ingestive behaviour in response to changes in the quality of their pastoral environments. To test this hypothesis, an experiment was conducted in a native ...Cattle may improve their feeding efficiency by altering their ingestive behaviour in response to changes in the quality of their pastoral environments. To test this hypothesis, an experiment was conducted in a native pasture that has been managed in continuous stocking at different daily forage allowances （4%, 8%, 12%, and 16% of live weight） for twenty two years thus creating different pastoral environments. For the current experiment, the animals were allocated to their respective experimental units on April 27, 2007. Two experiments were conducted; one was performed at the end of winter （experiment 1）, and the other was undertaken at the end of spring （experiment 2）. Four tester animals were observed per experimental unit （3-5 ha each）. The animals increased their daily grazing time when forage allowance decreased. Most of this increased time was devoted to harvesting, whereas searching was reduced to a few minutes per day. Under conditions of ideal range of forage allowance （between 12% and 14%）, the grazing time was reduced, and the search activity increased. These results suggest that the monitoring of indicators of ingestive behaviour can be used to determine the attributes of forage resources.展开更多
Increased sedimentation rates have been attributed to increased anthropogenic activity in watersheds throughout Florida and many parts of the world. The Manatee River, located on the west coast of Florida （USA）, lik...Increased sedimentation rates have been attributed to increased anthropogenic activity in watersheds throughout Florida and many parts of the world. The Manatee River, located on the west coast of Florida （USA）, like many other coastal watersheds, has experienced depletion in natural resources, increased nutrient loading, and increased pollution. LARs （linear accumulation rates） from watersheds throughout Florida suggest that anthropogenic activity increased bulk sedimentation by as much as 4-fold. The objective of this study was to construct a record of sedimentation and improve upon previous studies by determining individual sedimentary constituent MARs （mass accumulation rates） based on short lived radioisotopes （2~~pb and 234Th） to characterize changes in sedimentation attributed to increased anthropogenic development. This study constructed records of sedimentary accumulation rates to compare pre-development records to the past 100 years of anthropogenic development and identified specific changes in sedimentation attributed to anthropogenic activity. Anthropogenic development increased deposition of terrigenous material into the river from 2-fold to I 0-fold （0.3-2.0 g/cm2/yr） over three periods： （1） predevelopment period （1900-1941）; （2） agricultural development period （1941-1970）; （3） urban development period （1970-2010）. The mobilization of this amount of terrigenous material has implications for effects on water quality and biological communities within the river.展开更多
After the reform and opening up, especially in recent years. Dairy farming has a rapid development in our country, however, the dairy farming link in our country also is in a small scale, and dairy cows yield at lower...After the reform and opening up, especially in recent years. Dairy farming has a rapid development in our country, however, the dairy farming link in our country also is in a small scale, and dairy cows yield at lower levels, based on the present situation of dair farming in our country, This article mainly analysis the problems of dairy farming link, and puts torward the corresponding countermeasures and suggestions to solve these problems.展开更多
This study was carried out to investigate if on-farm cut vs. grazed pastures differed in soil fertility and species density in the temperate Himalayan highlands. Soil fertility and species relative density were measur...This study was carried out to investigate if on-farm cut vs. grazed pastures differed in soil fertility and species density in the temperate Himalayan highlands. Soil fertility and species relative density were measured from 30 cut and 30 grazed dairy pastures. In both types of pasture, soil pH, available phosphorus(P) and exchangeable potassium(K) were negatively correlated with pasture age and slope. In cut pasture, cocksfoot(Dactylis glomerata) and pasture age were positively correlated,whereas in grazed pasture, they were negatively correlated. In grazed pasture, unsown species and pasture age were positively correlated. Soil available P was significantly greater in cut pastures whereas soil exchangeable K was significantly greater in grazed pastures. In terms of species density, cut pasture had greater densities of cocksfoot and Italian ryegrass(Lolium multiflorum), whereas grazed pasture showed greater densities of white clover, sedge and local grass. Our study suggests that, if there are no improvements in the current method of pasture management, the cut pastures in the future are likely to have a simple pasture mixture constituting only cocksfoot and white clover(Trifolium repens).Whereas in grazed pasture, the pasture mixture is likely to be comprised of white clover and unsown species such as sedge, local grass and broadleaf weeds.展开更多
The aim of this study was to evaluate the feed consumption and weight gain in calves fed with a nutritional block made of white mulberry （Morus alba） for a 90-day-period, involving dry season months （March-May） in...The aim of this study was to evaluate the feed consumption and weight gain in calves fed with a nutritional block made of white mulberry （Morus alba） for a 90-day-period, involving dry season months （March-May） in Tuxpan, Veracruz, Mexico. A total of 45 growing Zebu x Swiss calves with an average weight of 200 kg were assigned randomly in three groups of 15 animals, and the following treatments of nutritional block were offered to each group： grazing animals （To）, grazing animals plus nutritious block with white mulberry （T1）, and grazing animals plus nutritious block without white mulberry （T2）. A consumption of 0.545 kg/d from block in treatment T1 was observed, significantly improving calves growing and showing a weight gain of 0.933 kg/d. Use of white mulberry in nutritional blocks is a good alternative for growing calves, as a feeding strategy given the seasonality of pasture production in the tropics.展开更多
A change in the European Union energy policy has markedly promoted the expansion of biogas production. Consequently, large amounts of nutrient-rich residues are being used as organic fertilizers. In this study, a pot ...A change in the European Union energy policy has markedly promoted the expansion of biogas production. Consequently, large amounts of nutrient-rich residues are being used as organic fertilizers. In this study, a pot experiment was conducted to simulate the high-risk situation of enhanced greenhouse gas （GHG） emissions following organic fertilizer application in energy maize cultivation. We hypothesized that cattle slurry application enhanced CO2 and N20 fluxes compared to biogas digestate because of the overall higher carbon （C） and nitrogen （N） input, and that higher levels of CO2 and N20 emissions could be expected by increasing soil organic C （SOC） and N contents. Biogas digestate and cattle slurry, at a rate of 150 kg NH＋-N ha-1, were incorporated into 3 soil types with low, medium, and high SOC contents （Cambisol, Mollic Gleysol, and Sapric Histosol, termed Clow, Cmedium, and Chigh, respectively）. The GHG exchange （CO2, CH4, and N20） was measured on 5 replicates over a period of 22 d using the closed chamber technique. The application of cattle slurry resulted in significantly higher CO2 and N20 fluxes compared to the application of biogas digestate. No differences were observed in CH4 exchange, which was close to zero for all treatments. Significantly higher CO2 emissions were observed in Chigh compared to the other two soil types, whereas the highest N20 emissions were observed in Cmedium. Thus, the results demonstrate the importance of soil type-adapted fertilization with respect to changing soil physical and environmental conditions.展开更多
文摘The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.
基金funded by the Department for Environment Food & Rural Affairsthe Scottish Government+2 种基金the Department of Agriculture and Rural Development for Northern Irelandthe Welsh Government as part of the UK’s Agricultural GHG Research Platform initiative
文摘Although the effect of animal and diet factors on enteric methane （CH4） emissions from confined cattle has been extensively examined, less data is available regarding CH4 emissions from grazing young cattle. A study was undertaken to evaluate the effect of the physiological state of Holstein-Friesian heifers on their enteric CH4 emissions while grazing a perennial ryegrass sward. Two experiments were conducted： Experiment 1 ran from May 2011 for 11 weeks and Experiment 2 ran from August 2011 for 10 weeks. In each experiment, Holstein-Friesian heifers were divided into three treatment groups （12 animals/group） consisting of calves, yearling heifers, and in-calf heifers （average ages： 8.5, 14.5, and 20.5 months, respectively）. Methane emissions were estimated for each animal in the final week of each experiment using the sulfur hexafluoride tracer technique. Dry matter （DM） intake was estimated using the calculated metabolizable energy （ME） requirement divided by the ME concentration in the grazed grass. As expected, live weight increased with increasing animal age （P 〈 0.001）; however, there was no difference in live weight gain among the three groups in Experiment 1, although in Experiment 2, this variable decreased with increasing animal age （P 〈 0.001 ）. In Experiment 1, yearling heifers had the highest CH4 emissions （g·d^-1） and in-calf heifers produced more than calves （P 〈 0.001 ）. When expressed as CH4 emissions per unit of live weight, DM intake, and gross energy （GE） intake, yearling heifers had higher emission rates than calves and in-calf heifers （P 〈 0.001）. However, the effects on CH4 emissions were different in Experiment 2, in which CH, emissions （g·d^-1） increased linearly with increasing animal age （P 〈 0.001）, although the difference between yearling and in-calf heifers was not significant. The CH4/live weight ratio was lower in in-calf heifers than in the other two groups （P 〈 0.001 ）, while CH4 energy output as a proportion of GE intake was lower in calves than in yearling and in-calf heifers （P 〈 0.05）. All data were then pooled and used to develop prediction equations for CH4 emissions. All relationships are significant （P 〈 0.001）, with R2 values ranging from 0.630 to 0.682. These models indicate that CH4 emissions could be increased by 0.252 g.d-1 with an increase of I kg live weight or by 14.9 g·d^-1 with an increase of 1 kg·d^-1 of DM intake; or, the CH4 energy output could be increased by 0.046 MJ·d^-1 with an increase of 1 MJ·d^-1 of GE intake. These results provide an alternative approach for estimating CH4 emissions from grazine dairy heifers when actual CH, emission data are not available.
文摘Cattle may improve their feeding efficiency by altering their ingestive behaviour in response to changes in the quality of their pastoral environments. To test this hypothesis, an experiment was conducted in a native pasture that has been managed in continuous stocking at different daily forage allowances （4%, 8%, 12%, and 16% of live weight） for twenty two years thus creating different pastoral environments. For the current experiment, the animals were allocated to their respective experimental units on April 27, 2007. Two experiments were conducted; one was performed at the end of winter （experiment 1）, and the other was undertaken at the end of spring （experiment 2）. Four tester animals were observed per experimental unit （3-5 ha each）. The animals increased their daily grazing time when forage allowance decreased. Most of this increased time was devoted to harvesting, whereas searching was reduced to a few minutes per day. Under conditions of ideal range of forage allowance （between 12% and 14%）, the grazing time was reduced, and the search activity increased. These results suggest that the monitoring of indicators of ingestive behaviour can be used to determine the attributes of forage resources.
文摘Increased sedimentation rates have been attributed to increased anthropogenic activity in watersheds throughout Florida and many parts of the world. The Manatee River, located on the west coast of Florida （USA）, like many other coastal watersheds, has experienced depletion in natural resources, increased nutrient loading, and increased pollution. LARs （linear accumulation rates） from watersheds throughout Florida suggest that anthropogenic activity increased bulk sedimentation by as much as 4-fold. The objective of this study was to construct a record of sedimentation and improve upon previous studies by determining individual sedimentary constituent MARs （mass accumulation rates） based on short lived radioisotopes （2~~pb and 234Th） to characterize changes in sedimentation attributed to increased anthropogenic development. This study constructed records of sedimentary accumulation rates to compare pre-development records to the past 100 years of anthropogenic development and identified specific changes in sedimentation attributed to anthropogenic activity. Anthropogenic development increased deposition of terrigenous material into the river from 2-fold to I 0-fold （0.3-2.0 g/cm2/yr） over three periods： （1） predevelopment period （1900-1941）; （2） agricultural development period （1941-1970）; （3） urban development period （1970-2010）. The mobilization of this amount of terrigenous material has implications for effects on water quality and biological communities within the river.
文摘After the reform and opening up, especially in recent years. Dairy farming has a rapid development in our country, however, the dairy farming link in our country also is in a small scale, and dairy cows yield at lower levels, based on the present situation of dair farming in our country, This article mainly analysis the problems of dairy farming link, and puts torward the corresponding countermeasures and suggestions to solve these problems.
文摘This study was carried out to investigate if on-farm cut vs. grazed pastures differed in soil fertility and species density in the temperate Himalayan highlands. Soil fertility and species relative density were measured from 30 cut and 30 grazed dairy pastures. In both types of pasture, soil pH, available phosphorus(P) and exchangeable potassium(K) were negatively correlated with pasture age and slope. In cut pasture, cocksfoot(Dactylis glomerata) and pasture age were positively correlated,whereas in grazed pasture, they were negatively correlated. In grazed pasture, unsown species and pasture age were positively correlated. Soil available P was significantly greater in cut pastures whereas soil exchangeable K was significantly greater in grazed pastures. In terms of species density, cut pasture had greater densities of cocksfoot and Italian ryegrass(Lolium multiflorum), whereas grazed pasture showed greater densities of white clover, sedge and local grass. Our study suggests that, if there are no improvements in the current method of pasture management, the cut pastures in the future are likely to have a simple pasture mixture constituting only cocksfoot and white clover(Trifolium repens).Whereas in grazed pasture, the pasture mixture is likely to be comprised of white clover and unsown species such as sedge, local grass and broadleaf weeds.
文摘The aim of this study was to evaluate the feed consumption and weight gain in calves fed with a nutritional block made of white mulberry （Morus alba） for a 90-day-period, involving dry season months （March-May） in Tuxpan, Veracruz, Mexico. A total of 45 growing Zebu x Swiss calves with an average weight of 200 kg were assigned randomly in three groups of 15 animals, and the following treatments of nutritional block were offered to each group： grazing animals （To）, grazing animals plus nutritious block with white mulberry （T1）, and grazing animals plus nutritious block without white mulberry （T2）. A consumption of 0.545 kg/d from block in treatment T1 was observed, significantly improving calves growing and showing a weight gain of 0.933 kg/d. Use of white mulberry in nutritional blocks is a good alternative for growing calves, as a feeding strategy given the seasonality of pasture production in the tropics.
文摘A change in the European Union energy policy has markedly promoted the expansion of biogas production. Consequently, large amounts of nutrient-rich residues are being used as organic fertilizers. In this study, a pot experiment was conducted to simulate the high-risk situation of enhanced greenhouse gas （GHG） emissions following organic fertilizer application in energy maize cultivation. We hypothesized that cattle slurry application enhanced CO2 and N20 fluxes compared to biogas digestate because of the overall higher carbon （C） and nitrogen （N） input, and that higher levels of CO2 and N20 emissions could be expected by increasing soil organic C （SOC） and N contents. Biogas digestate and cattle slurry, at a rate of 150 kg NH＋-N ha-1, were incorporated into 3 soil types with low, medium, and high SOC contents （Cambisol, Mollic Gleysol, and Sapric Histosol, termed Clow, Cmedium, and Chigh, respectively）. The GHG exchange （CO2, CH4, and N20） was measured on 5 replicates over a period of 22 d using the closed chamber technique. The application of cattle slurry resulted in significantly higher CO2 and N20 fluxes compared to the application of biogas digestate. No differences were observed in CH4 exchange, which was close to zero for all treatments. Significantly higher CO2 emissions were observed in Chigh compared to the other two soil types, whereas the highest N20 emissions were observed in Cmedium. Thus, the results demonstrate the importance of soil type-adapted fertilization with respect to changing soil physical and environmental conditions.
