Infant pigs demonstrate motor adaptation across multiple physiologic functions during feeding in response to dynamic changes in milk flow rate

Safe and effective infant feeding requires precise coordination of sucking, swallowing, and breathing, yet disruptions in this coordination affect a significant number of infants. Altering sensory input, such as bottle nipple flow rate, is used to address poor coordination in infants. However, prior studies often compare different nipples used across different feeds, which introduces confounding variables and limits insight into neuromotor responses. To address this, we used infant pigs as a validated animal model to assess real-time neuromotor responses to dynamic changes in flow rate within a single feeding session using a custom, computer-controlled nipple. We collected high-speed biplanar videofluoroscopy, intraoral pressure, and respiratory data to evaluate kinematics, physiology, and coordination patterns. We found that while sucking and breathing rates remained stable, higher flow rates elicited greater tongue, hyoid, and thyroid translations, larger bolus sizes, and lower intraoral pressures. Notably, swallow rate increased, resulting in a shift to suck-swallow-breathe coordination, with swallows occurring earlier in the suck cycle and more frequently per breath. These changes suggest that infants rapidly adapt their motor output to changing sensory conditions. This study demonstrates that real-time flow variation significantly impacts feeding mechanics and coordination, highlighting the potential for sensory-based interventions rooted in motor learning and neuromotor rehabilitation principles. Understanding how infants dynamically adjust to sensory changes offers critical insights into feeding development and provides a framework for developing more effective interventions for infants with feeding disorders.