Thiels E, Alberts J R
J Comp Psychol. 1985 Dec;99(4):447-56.
Two experiments were conducted to investigate the role of milk availability in the development of independent feeding and drinking in the Norway rat pup. Beginning on Day 14 postnatally, pups were exposed to different levels of milk supply by changing litter size from 8 to 4 versus 12 pups (Experiment 1) or limiting temporally the pups' access to a lactating dam to 8, 14, or 24 hr daily (Experiment 2). Both manipulations accelerated weaning in milk-poor pups in comparison with same-age pups with relatively greater milk supplies. By adding solid food and water to their diet, early weaning pups compensated for the negative energy consequences of milk reduction and achieved premanipulation growth rates. Milk availability thus appears to affect weaning, and it is suggested that the developmental changes in the nutritive energy balance between mother and offspring contribute to the emergence of independent ingestion.
进行了两项实验，以研究乳汁供应在挪威大鼠幼崽自主进食和饮水发育过程中的作用。从出生后第14天开始，通过将窝仔数从8只改为4只或12只（实验1），或在一段时间内将幼崽接触哺乳母鼠的时间限制为每天8小时、14小时或24小时（实验2），使幼崽接触到不同水平的乳汁供应。与乳汁供应相对较多的同龄幼崽相比，这两种操作都加速了乳汁供应不足的幼崽的断奶过程。通过在饮食中添加固体食物和水，早期断奶的幼崽弥补了乳汁减少带来的负能量影响，并达到了操作前的生长速度。因此，乳汁供应似乎会影响断奶，并且有人提出，母鼠和幼崽之间营养能量平衡的发育变化有助于自主摄食行为的出现。
