PDF(Pubmed)
Abstract：
Many theoretical treatments of foraging use energy as currency, with carbohydrates and lipids considered interchangeable as energy sources. However, herbivores must often synthesize lipids from carbohydrates since they are in short supply in plants, theoretically increasing the cost of growth. We tested whether a generalist insect herbivore (Locusta migratoria) can improve its growth efficiency by consuming lipids, and whether these locusts have a preferred caloric intake ratio of carbohydrate to lipid (C : L). Locusts fed pairs of isocaloric, isoprotein diets differing in C and L consistently selected a 2C : 1L target. Locusts reared on isocaloric, isoprotein 3C : 0L diets attained similar final body masses and lipid contents to locusts fed the 2C : 1L diet, but they ate more and had a ~12% higher metabolic rate, indicating an energetic cost for lipogenesis. These results demonstrate that some animals can selectively regulate carbohydrate-to-lipid intake and that consumption of dietary lipids can improve growth efficiency.
摘要：
许多理论上的觅食方法都使用能量作为货币，碳水化合物和脂质被认为是可互换的能源。然而,草食动物必须经常从碳水化合物中合成脂质，因为它们在植物中供应短缺，理论上增加增长成本。我们测试了通才昆虫食草动物（Locustamigratoria）是否可以通过消耗脂质来提高其生长效率，以及这些蝗虫是否具有碳水化合物与脂质的首选热量摄入比（C：L）。蝗虫喂养成对等热量，C和L不同的异蛋白饮食始终选择2C：1L目标。蝗虫等热量饲养，同工蛋白3C：0L饮食获得与2C：1L饮食喂养的蝗虫相似的最终体重和脂质含量，但是他们吃得更多，代谢率高12%，表明脂肪生成的能量成本。这些结果表明，一些动物可以选择性地调节碳水化合物对脂质的摄入，并且食用膳食脂质可以提高生长效率。
