Hudson Robyn, Raihani Gina, González Daniel, Bautista Amando, Distel Hans
Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, DF, Mexico.
Dev Psychobiol. 2009 May;51(4):322-32. doi: 10.1002/dev.20371.
We studied the development of suckling behavior and weight gain in 11 litters (52 kittens) of free-ranging domestic cats until postnatal day 28 just before the start of weaning. In six of these litters, we also recorded milk intake and contests for access to nipples. Already within 12 hr of birth kittens showed a preference for posterior nipples, and by postnatal day 3 each had developed a preference for particular nipples. In fact, 86% of kittens used one particular nipple most often, and even when the mother changed the side she lay on to nurse. Contests for access to nipples occurred throughout the study period at an average rate of one to two contests per kitten per hour of nursing. Contrary to suggestions in the literature that kittens compete for more productive nipples, we found no relation between kittens' use of particular nipples and their weight gain, milk intake, or involvement in contests during suckling. We suggest that kittens' preference for posterior nipples as well as their establishment of an individual "teat order" might function to optimize the number of nipples remaining productive across lactation, and to reduce energetically costly scrambles and potentially injurious contests among littermates.
我们研究了11窝（52只小猫）自由放养的家猫从出生到出生后第28天（断奶开始前）的吮乳行为发展和体重增加情况。在其中6窝小猫中，我们还记录了它们的乳汁摄入量以及争夺乳头的情况。出生后12小时内，小猫就表现出对后部乳头的偏好，到出生后第3天，每只小猫都对特定的乳头产生了偏好。事实上，86%的小猫最常使用一个特定的乳头，即使母猫改变哺乳时躺的一侧也是如此。在整个研究期间，争夺乳头的情况平均每只小猫每小时哺乳时发生一到两次。与文献中认为小猫会争夺产奶量更高的乳头的观点相反，我们发现小猫对特定乳头的使用与其体重增加、乳汁摄入量或哺乳期间参与争夺乳头的情况之间没有关联。我们认为，小猫对后部乳头的偏好以及它们建立个体“乳头顺序 ”可能有助于优化整个哺乳期仍能产奶的乳头数量，并减少同窝小猫之间消耗能量的争抢以及可能造成伤害的争斗。
