Spatiotemporal mapping of the motility of the isolated chicken caecum

We studied the caecal contractile activity of the chicken (Gallus gallus) using single caeca that had been cannulated at their proximal and distal ends, and in paired caeca, maintained in situ on excised segments of gut that were cannulated at the colonic and small intestinal ends. Longitudinal and circular contractile patterns were characterised using high-definition spatiotemporal mapping. Low amplitude longitudinal contraction waves of frequency 14.1 cycles/min occurred in the absence of major contractile events. These were termed fast phasic and appeared to be mediated by slow waves. The nature of major spontaneous contractions occurring in the single caecum varied with the level of caecal distension. Type A contractions occurred when the caecum was not distended, originated from variable sites and propagated in both directions. Type B or C contractile events occurred when the caecum was moderately or fully distended, originated from a predominantly distal site and propagated proximally. On diameter maps, each type B event comprised a succession of contractions which had similar propagation speeds, frequency and direction to fast phasic contractions. Type C events were comprised of a succession of higher amplitude contractions with no appreciable propagation. Perfusion of saline via the colon resulted in fluid entering both caeca and the onset of aborad contractions in their proximal canals. Saline was also seen to flow between caeca during contractile events however no saline was seen to enter the small intestine as has been postulated by other workers.

Effect of dietary carbohydrates and biotin level on cecal size and biotin concentration of growing chickens

Growing chickens were fed three levels of biotin, 0, 20, and 100 micrograms/kg diet, and four different carbohydrates, glucose, dextrin, sucrose, and sorbitol, in order to study the effect of dietary carbohydrates on the level of cecal biotin. Dietary sorbitol was found to enhance the concentration of cecal biotin at suboptimal levels of dietary biotin, while dietary dextrin had the opposite effect. When the dietary requirement of biotin was met, cecal biotin greatly increased in the presence of dietary glucose, sorbitol, and sucrose but remained at a low level when dextrin was the dietary carbohydrate. Dietary sorbitol increased significantly the dry weight of ceca over those of birds fed other carbohydrates.