Nonnutritive sucking: One of the major determinants of filial love

Abstract

The present study investigated the rewarding effects of nonnutritive sucking on the development of a filial preference. Two experiments were conducted to test whether nonnutritive visceral and oral stimuli have reinforcing properties independent from each other or act in synergy. Lambs could interact freely with their dam but were deprived of suckling by covering the udder for the first 12 hr. In Experiment 1, suckling was prevented and replaced by human giving, in the presence of the mother, either a bottle of water (B5 and B2.5: 5% or 2.5% birth weight, BW, divided into seven portions over 12 hr) or water via tube-feeding (I5 and I2.5: 5% or 2.5% BW, also divided into seven portions over 12 hr). During a two-choice test performed at 12 hr after birth, only B5 and I5 lambs preferred their mother to an alien ewe however, B5 were faster at choosing their mother at the beginning of the test. B2.5 and I2.5 lambs made a random choice. In Experiment 2, suckling was prevented and replaced by human giving, in the presence of the mother, either a bottle of water (B2.5: 2.5% BW, divided into seven portions over 12 hr) or water via tube-feeding (I10 and I2.5: 10% or 2.5% BW, also divided into seven portions over 12 hr). During a two-choice test at 12 hr, tube-fed lambs (I10 and I2.5) preferred their mother to a human. B2.5 lambs were equally attracted to both partners and spent more time near the human than lambs from the other groups. In a test of reactivity to a human performed on neonates isolated from their mother, B2.5 lambs explored the human much more than the other lambs. The presence of the human had soothing properties in B2.5 lambs and once the human left, they were the only lambs displaying enhanced vocal and locomotor activity. In these experiments, nonnutritive gastrointestinal stimuli induced a preference for the mother whereas nonnutritive sucking led to a strong positive relationship with the human. These results suggest that when lambs suckle their dam, the development of filial bonding is facilitated through the combined effects of oral and gastrointestinal stimuli.

Mother–Young Relationships in Sheep: A Model for a Multidisciplinary Approach of the Study of Attachment in Mammals

“…Using the same paradigm of suckling deprivation, it was shown that several aspects of the neonatal suckling activity could facilitate the development of a preference for the mother. Replacing suckling by repeated infusions of colostrum into the lamb’s stomach through a nasogastric canula triggers a preference for the mother (60, 61). The same behavioural outcome is obtained with infusions of a non‐nutritive liquid such as saline, although only when it is given in twice the volume required for colostrum.…”

From birth to colostrum: early steps leading to lamb survival

“…Through the cascade of neurophysiological events that are triggered during suckling, colostrum ingestion also shapes the behaviour of the neonate with biochemical and visceral mechanical stimulation. Recent studies have also demonstrated that non nutritive sucking facilitated early filial bonding [80].…”

Exposure to dietary mercury alters cognition and behavior of zebra finches

“…A 30-min social dominance trial began when all six birds were released into the experimental arena. We video recorded all interactions and noted the order in which birds fed from the food dish ( Boogert et al 2006 ; Val-Laillet et al 2006 ; David et al 2011 ), the number of aggressive interactions initiated by each bird, as well as all displacements between birds. From these latter observations we constructed a matrix of wins and losses and assigned a rank score based on wins minus losses, with lower numbers indicating higher social rank.…”