A Cineradiographic Study of Bottle Feeding

Abstract

Cineradiographic films have been taken of babies, lambs and kid goats, taking a mixture of milk and barium from a bottle. The various types of teat supplied for feeding babies were comparatively ineffective when compared with the soft veterinary rubber teats used for feeding the animals; the performance of the babies was thus not so good as that of the lambs or kid goats. Our conclusions are: 1. The influence of gravity is important in bottle feeding. It ensures that the bulb of the teat fills. If the hole in the teat is large anough milk drips into the mouth; when rigid teats are used this may be the only way the child can obtain an adequate supply of milk. 2. The lambs and kid goats take one teat full of milk with each jaw and tongue movement; the neck of the teat is completely occluded by approximation of the jaws and the contents of the bulb are expressed into the mouth by elevation of the tongue towards the soft palate, the tongue indenting the bulb from before backwards. Babies usually attempt this movement but in most instances are only partly successful; the teats normally supplied are too rigid and the hole is too small. 3. Following compression of the bulb of the teat by the squeezing action of the tongue, the lowering of the jaw and tongue must cause some degree of suction which may aid in the refilling of the bulb and it may also draw milk into the mouth; the amount of milk obtained in this manner may in favourable circumstances equal the amount obtained by expression. 4. During the phase of compression of the bulb of the teat by elevation of the tongue in the forepart of the mouth there is also taking place simultaneously a lowering of the tongue behind the teat which must cause some suction. 5. Factors relating to the design of different teats have been considered. 6. When milk is swallowed, naso-pharyngeal closure is made by elevation of the soft palate against the adenoidal pad on the roof of the epipharynix, the mode of closure differing from that seen in adults. The relevant variations in anatomy between infants and adults are discussed. 7. The bolus passes through the pharynx on both sides of the superior laryngeal aperture. The larynx is closed as each bolus is expressed from the pharynx and reopened just before the next bolus enters. The theory that young babies and members of the herbivora are able to continue feeding by passing food down into the oesophagus on either side of the laryngeal aperture without closing the airway is disproved.