[Objectives]To make targeted breeding of new type of Shuxuan beef cattle,study and determine the breeding target traits of new type of Shuxuan beef cattle.[Methods]The difference method was used to calculate the margi...[Objectives]To make targeted breeding of new type of Shuxuan beef cattle,study and determine the breeding target traits of new type of Shuxuan beef cattle.[Methods]The difference method was used to calculate the marginal benefit of each target trait,and the economic weight of the corresponding breeding target trait was obtained.[Results]The marginal benefits of weaning weight,fattening daily gain,18-month weight,carcass quality,dressing percentage,pure meat percentage,age at first calving,calving interval and stay group time were 35.86,13.76,13.05,421.96,375.55,22.58,-4.45,-27.53,and 1555.24,respectively.The relative economic weight ratio of growth traits,carcass traits,and reproductive traits was close to 4∶1∶5.Through marginal benefit analysis,the economic benefits obtained by improving carcass quality,dressing percentage and stay group time were significantly higher than other traits.[Conclusions]It is expected to provide a theoretic basis for establishing the target trait selection indicators for the new type of Shuxuan beef cattle.展开更多
More attention has been paid to the cost of intensive but sporadic floods than the cost of extensive but frequent events.To examine the impacts of intensive versus extensive events,we investigated the loss structure o...More attention has been paid to the cost of intensive but sporadic floods than the cost of extensive but frequent events.To examine the impacts of intensive versus extensive events,we investigated the loss structure of global flood-induced mortality by using the cumulative loss ratio,marginal benefit chart,and cumulative loss plot.Drawing on the flood-induced mortality data for four decades(1976–2016)from the international disaster database EM-DAT,we defined the levels of flood loss according to the frequency of flood-induced deaths,and calculated the cumulative mortality and the marginal benefits of flood loss prevention practices at different levels.Our analysis showed that for the world’s leading 30 countries with large flood-induced mortality and different levels of development:(1)70%of them have the cumulative deaths from extensive floods exceeding half of those caused by intensive floods in the study’s four data decades;and(2)80%of them tend to gain less marginal benefit with increasing levels of flood prevention,with their marginal benefits peaking at loss prevention levels of 2-year or 5-year flood-induced mortality.These results indicate that,in the long run,the cumulative deaths of extensive floods are comparable to that of intensive events,and prevention of loss from extensive events can be an efficient way to reduce the total loss.For flood risk management under conditions of climate change,extensive loss events deserve more consideration.展开更多
基金Key Technology R&D Program of Sichuan Province(2019YFD0123)Key R&D Project of Sichuan Science and Technology Plan(2021YFYZ0001)Sichuan Beef Cattle Innovation Team of Modern Agricultural Industrial Technology System(SCCXTD-2021-13).
文摘[Objectives]To make targeted breeding of new type of Shuxuan beef cattle,study and determine the breeding target traits of new type of Shuxuan beef cattle.[Methods]The difference method was used to calculate the marginal benefit of each target trait,and the economic weight of the corresponding breeding target trait was obtained.[Results]The marginal benefits of weaning weight,fattening daily gain,18-month weight,carcass quality,dressing percentage,pure meat percentage,age at first calving,calving interval and stay group time were 35.86,13.76,13.05,421.96,375.55,22.58,-4.45,-27.53,and 1555.24,respectively.The relative economic weight ratio of growth traits,carcass traits,and reproductive traits was close to 4∶1∶5.Through marginal benefit analysis,the economic benefits obtained by improving carcass quality,dressing percentage and stay group time were significantly higher than other traits.[Conclusions]It is expected to provide a theoretic basis for establishing the target trait selection indicators for the new type of Shuxuan beef cattle.
基金partial financial support provided by the projects of the National Key Research and Development Program(Grant No.2016YFA0602404 and 2017YFA0604903)National Science Foundation of China(Grant No.41501020)partial financial support provided by the Science and Technology Planning Project of Guangdong Province,China(Grant No.2017B020244002 and 2019A070716007)。
文摘More attention has been paid to the cost of intensive but sporadic floods than the cost of extensive but frequent events.To examine the impacts of intensive versus extensive events,we investigated the loss structure of global flood-induced mortality by using the cumulative loss ratio,marginal benefit chart,and cumulative loss plot.Drawing on the flood-induced mortality data for four decades(1976–2016)from the international disaster database EM-DAT,we defined the levels of flood loss according to the frequency of flood-induced deaths,and calculated the cumulative mortality and the marginal benefits of flood loss prevention practices at different levels.Our analysis showed that for the world’s leading 30 countries with large flood-induced mortality and different levels of development:(1)70%of them have the cumulative deaths from extensive floods exceeding half of those caused by intensive floods in the study’s four data decades;and(2)80%of them tend to gain less marginal benefit with increasing levels of flood prevention,with their marginal benefits peaking at loss prevention levels of 2-year or 5-year flood-induced mortality.These results indicate that,in the long run,the cumulative deaths of extensive floods are comparable to that of intensive events,and prevention of loss from extensive events can be an efficient way to reduce the total loss.For flood risk management under conditions of climate change,extensive loss events deserve more consideration.
