Menzies Brandon R, Shaw Geoff, Fletcher Terry P, Renfree Marilyn B
Department of Zoology, University of Melbourne, Vic. 3010, Australia.
Reprod Fertil Dev. 2007;19(8):976-83. doi: 10.1071/rd07142.
Cross-fostering of marsupial young between species can potentially facilitate propagation of endangered or rare marsupial species by artificially increasing the number of progeny produced. The present study compares the growth and development of normal and cross-fostered tammar and parma wallabies. Tammars cross-fostered into the pouches of parmas grew at a similar rate to naturally reared tammar young and had developmental milestones at a similar age. However, parma young cross-fostered between the day of birth and 15 days post-partum into tammars that were carrying young of equivalent developmental stages did not grow normally and were lost from the pouch. Parma young cross-fostered at 30 days survived, but had significantly reduced growth rates and their developmental milestones were delayed compared with normally reared parma young. Thus, growth can be affected by cross-fostering, even between species like tammars and parmas that are of similar size and have similar lactation lengths. The results of the present study suggest that maternal milk regulates the timing of development of each species and a mis-match in the time that each young receives critical milk components can have a marked effect on their growth and development.
有袋动物幼崽在物种间的交叉寄养有可能通过人为增加后代数量来促进濒危或稀有有袋动物物种的繁衍。本研究比较了正常饲养和交叉寄养的帚尾袋鼩和帚尾岩袋鼠幼崽的生长与发育情况。寄养在帚尾岩袋鼠育儿袋中的帚尾袋鼩幼崽生长速度与自然饲养的帚尾袋鼩幼崽相似，且在相似年龄达到发育里程碑。然而，在出生当天至产后15天之间交叉寄养到携带发育阶段相当的幼崽的帚尾袋鼩育儿袋中的帚尾岩袋鼠幼崽生长不正常，会从育儿袋中丢失。在30天时交叉寄养的帚尾岩袋鼠幼崽存活了下来，但与正常饲养的帚尾岩袋鼠幼崽相比，其生长速度显著降低，发育里程碑也有所延迟。因此，即使在像帚尾袋鼩和帚尾岩袋鼠这样体型相似、哺乳期长度相近的物种之间进行交叉寄养，生长也可能受到影响。本研究结果表明，母兽乳汁调节着每个物种的发育时间，幼崽接受关键乳汁成分的时间不匹配会对其生长和发育产生显著影响。
