基于物种生态位与物质能量流互动机制对外来入侵植物的探讨

The current study was to investigate the effects of cysteamine （CS） on carcass characteristics, meat quality, and antioxidant status in finishing pigs. A total of 24 crossbred （PIC variety） finishing pigs （60.05±1.24 kg, 12 gilts and 12 barrows） were assigned randomly to one of the three dietary groups, with four pens/group （one gilt and one barrow per pen）. Pigs were fed with a basal diet containing 0 （control）, 70, or 140 mg/kg CS for 47 days. The results indicated that dietary CS supplementation increased （P〈0.05） the average daily gain and feed intake with optimal responses occurring at 70 mg/kg. Dietary supplementation of CS increased （P〈0.05） the dressing percentage and lean percentage of finishing pigs with optimal responses occurring at 140 mg/kg. The CS supplementation, however, had no effect （P〉0.05） on meat quality. Dietary CS supplementation increased （P〈0.05） total antioxidant capacity （T-AOC） and decreased malondialdehyde （MDA） with optimal responses occurring at 70 mg/kg. CS supplementation at both 70 mg/kg and 140 mg/kg doses improved （P〈0.05） the muscle RNA/DNA ratio. Collectively, the results suggest dietary supplementation of 70 mg/kg CS could significantly improve growth performance and antioxidant status without adverse effects on the gastrointestinal tracts in finishing pigs while the 140 mg/kg CS supplementation improved the carcass quality. However, meat quality was not affected by CS supplementation.

A Study on Alien Invasive Plants from the Interactive Mechanism between Species Niche and Material/Energy Flow

Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic mechanism of alien plants invasion.Result]Most of the invasive plants have not been explicitly defined and their effective control methods not brought forward.Conclusion]Overrun of alien invasive plants depends on whether the niche of a species could be continuously met at spatial level.Based on this we put forward corresponding control measures,proposed an assumption to establish a cylinder-network model and discussed the definition of alien invasive plants.