Rate of Passage of Corn-Canola Meal and Corn-Soybean Meal Diets Through the Gastrointestinal Tract of Broiler and White Leghorn Chickens

Abstract

The effect of corn-canola meal and corn-soybean meal diets on the form and function of the gastrointestinal tract of broiler (meat-type) and White Leghorn (egg-type) cockerels was measured from 14 to 44 and 14 to 86 days of age or 203 to 1,844 and 115 to 1,777 g of body weight, respectively. Dry weights of the empty crop (P<.01), gizzard (P<.001), and ceca (P<.001) relative to live body weight (g/kg) were lighter in broilers than in Leghorns. Canola meal at 370 g/kg diet was associated with increased (P<.001) dry weight of the gizzard and jejunum relative to body weight. Soybean meal at 370 g/kg diet was associated with increased (P<.001) dry weight of the ceca relative to body weight. The lengths, relative to a power of body weight of the duodenum (cm/g.187) and jejunum plus ileum (cm/g.240), were longer (P<.001) in broilers than in Leghorns. The canola meal diet was associated with an increase (P<.001) in length of the jejunum plus ileum (cm/g.240) relative to a power of body weight. Mean retention time (MRT) of a particle marker, 103 ruthenium phenanthroline, increased with body weight in the entire gastrointestinal tract (P<.001) and in each of its segments except in the proventriculus, where it was not affected by body weight (P>.05), and in the gizzard, where it decreased (P<.05) with body weight. The MRT, adjusted for body weight in the entire gastrointestinal tract of broilers (338.0 ± 10.8 min) and Leghorns (359.9 ± 10.8 min), was similar (P>.05) but varied significantly in segments of the gut for both type of chicken and diet. Adjusted MRT was shorter in the crop (P<.001) and gizzard (P<.001) and longer in the duodenum (P<.001) and ileum (P<.01) of broilers than Leghorns. The soybean meal diet was retained for 2.3 min longer in the duodenum (P<.001) and 84.2 min longer in the ceca (P<.001) than the canola meal diet, which accounted for the longer (P<.001) retention of the soybean meal diet in the entire gastrointestinal tract (388.0 ± 10.6 vs. 309.8 ± 10.8 min). Segments of the gastrointestinal tract vary in length, weight, and MRT of digesta with dietary composition and type and body weight of chicken.