Developmental study of digestive motor response to dietary pattern in young broilers

Abstract

1. 1. Gastrointestinal (GI) morphometry and motility were measured in young broilers (3, 8 and 15 days old) when they were submitted to three dietary patterns ( ad libitum food, acute 48-hr fast and cumulative semi-starvation). 2. 2. All GI regions were hypertrophied when acute or intermittent starvation were applied; lightly when acute starvation was applied and strongly with intermittent starvation. 3. 3. All the 3-, 8- and 15-day-old acutely and intermittently starved chickens increased GI motility at the shortest times (0.5 and 1 hr) after the marker administration, but decreased GI motility at the longest times (2 and 4hr). 4. 4. The GI motor response of intermittently starved chicks was faster than the observed one in acutely starved chicks. The GI tract of intermittent starved chicks increased its motor response proportionally to the broilers age, while acutely starved chicks decreased their GI motility when the broilers age was increased. 5. 5. A relationship between morphometrical and motor GI responses to dietary pattern has been inferred. From the gizzard and small bowel hypertrophy caused by intermittent starvation, an increased reflex GI motor response can be expected. Acute starvation only caused a light increase of GI motility, because it only increased the gizzard morphometry. 6. 6. We concluded that young chicks respond to acute starvation by means of a short-term mechanism (an increase of GI motor reflexes) and responds to intermittent starvation by means of a medium- and long-term mechanism (a hypertrophy of GI tract and its subsequent increase of GI motor reflexes).