Bolus versus continuous feedings stimulate small-intestinal growth and development in the newborn pig

Although bolus and continuous tube feedings are common, little is known about their effect on the developing small intestine. To compare their effect on small-intestinal growth and differentiation, six pairs of 3-day-old piglet littermates were randomized to receive similar volumes of sow milk replacer, either by bolus (four times daily, group B) or continuous feedings (over 24 h, group C) for 7 days. The piglets were then killed and small-intestinal length, weight, protein mass, and disaccharidase activities were determined. Small-intestinal mucosal weight and ileal protein mass were greater in group B than in group C (p = 0.0024 and 0.019, respectively). No differences were noted between groups in jejunal mucosal protein mass. Ileal maltase activity also was greater in group B than group C (p = 0.02). Although ileal lactase activity in group B was twice that in group C, the differences did not quite reach statistical significance (p = 0.11). No differences between groups were noted in ileal or jejunal sucrase activity. Our study demonstrated that bolus feedings increased mucosal mass, protein mass, and maltase activity to a greater degree than continuous feedings. These results may have clinical significance for infants receiving long-term tube feedings.