Based on annual pork yield of each province in 1996-2014,using Gini coefficient and spatial polarization index model,empirical analysis was carried out for spatial imbalance and polarization degree of swine production...Based on annual pork yield of each province in 1996-2014,using Gini coefficient and spatial polarization index model,empirical analysis was carried out for spatial imbalance and polarization degree of swine production distribution. Results indicate that there is high imbalance in spatial distribution of swine production. The imbalance takes on first rise then declines with fluctuation,largely because of inter-group gap. From the perspective of regions,the regions with balanced grain production have the highest imbalance in swine production,followed by main sales regions,and the main grain production regions have the lowest imbalance. The polarization index indicates that the overall polarization degree of the spatial distribution of swine production takes on a growing trend,and that of each functional region of grain production is also growing.展开更多
Tryptophan(Trp)is an essential amino acid that cannot be synthesized by animals.It has been characterized into two different isomers,levorotation-Trp(L-Trp)and dextrorotation-Trp(D-Trp),based on their distinct molecul...Tryptophan(Trp)is an essential amino acid that cannot be synthesized by animals.It has been characterized into two different isomers,levorotation-Trp(L-Trp)and dextrorotation-Trp(D-Trp),based on their distinct molecule orientation.Intestinal epithelial cells and gut microbiota are involved in metabolizing L-Trp in the gut via the activation of the kynurenine,serotonin,and indole pathways.However,knowledge regarding D-Trp metabolism in the gut remains unclear.In this review,we briefly update the current understanding of intestinal L/D-Trp metabolism and the function of their metabolites in modulating the gut physiology and diseases.Finally,we summarize the effects of Trp nutrition on swine production at different stages,including growth performance in weaned piglets and growing pigs,as well as the reproduction performance in sows.展开更多
基金Supported by Key Project of National Social Science Foundation(12&ZD048)
文摘Based on annual pork yield of each province in 1996-2014,using Gini coefficient and spatial polarization index model,empirical analysis was carried out for spatial imbalance and polarization degree of swine production distribution. Results indicate that there is high imbalance in spatial distribution of swine production. The imbalance takes on first rise then declines with fluctuation,largely because of inter-group gap. From the perspective of regions,the regions with balanced grain production have the highest imbalance in swine production,followed by main sales regions,and the main grain production regions have the lowest imbalance. The polarization index indicates that the overall polarization degree of the spatial distribution of swine production takes on a growing trend,and that of each functional region of grain production is also growing.
基金supported by the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-CXRC-038)the National Natural Science Foundation of China(U20A2054)the Earmarked Fund for China Agriculture Research System(CARS-35).
文摘Tryptophan(Trp)is an essential amino acid that cannot be synthesized by animals.It has been characterized into two different isomers,levorotation-Trp(L-Trp)and dextrorotation-Trp(D-Trp),based on their distinct molecule orientation.Intestinal epithelial cells and gut microbiota are involved in metabolizing L-Trp in the gut via the activation of the kynurenine,serotonin,and indole pathways.However,knowledge regarding D-Trp metabolism in the gut remains unclear.In this review,we briefly update the current understanding of intestinal L/D-Trp metabolism and the function of their metabolites in modulating the gut physiology and diseases.Finally,we summarize the effects of Trp nutrition on swine production at different stages,including growth performance in weaned piglets and growing pigs,as well as the reproduction performance in sows.
