Reverse Peristalsis in Intermittent and Ad Libitum Fed Broiler Chickens Raised on Diets of Varying Form and Insoluble Fiber Content

Abstract

A study was conducted to investigate the effect of feeding pattern, feed form and insoluble fiber content of diets on the occurrence of reverse peristalsis, or reflux, in broiler chickens. One hundred and two Ross 308 birds were raised to 18 days of age in 6 groups and then transferred to individual cages, while maintaining the same 6 treatment groups: 1) ad libitum fed Basal diet, 2) ad libitum fed Basal diet + 15% hulls (7.5% barley, 7.5% oat) coarse ground, 3) ad libitum fed Basal diet + 15% hulls fine ground, 4) intermittent fed Basal diet, 5) intermittent fed Basal diet +15% hulls coarse ground, 6)intermittent fed Basal diet +15% hulls fine ground. The birds in groups 4, 5 and 6 had access to feed for one hour followed by three hours fasting throughout the day until midnight when they had two hours to feed before the lights went off. At 31 days of age, 9 birds from each treatment group were given access to feed for one hour followed by one hour of fasting. Subsequently birds were inoculated with CrEDTA via the cloaca, returned to their cages and appropriate feeding regime for two hours, and then slaughtered. Digesta samples were taken from the gizzard, duodenum, jejunum, and ileum. This process was repeated on the remaining birds (8 birds per treatment) on day 32. The dried digesta samples were analysed for chromium content using inductively coupled plasma - mass spectrometry (ICP). Although not significant there was a general trend (p=0.0688) for higher chromium levels in the dry matter contents of gizzards from ad libitum fed birds. A tendency (p=0.1655) for elevated levels of chromium was observed in the gizzard contents of birds raised on hulled diets compared to birds fed the control diets. In addition, the gizzards of these birds were significantly larger (p<0.0001) than those from the control diets. This supports the hypothesis that gizzard development and reflux from the duodenum is increased by the inclusion of insoluble fiber (Hetland et al, 2003). Occurrence of ileal-jejunal reflux was illustrated by the presence of chromium in these sections with a strong tendency (p=0.0585) for higher levels in the jejunum contents of ad libitum fed birds. The presence of chromium in the gizzard, duodenum, jejunum and ileum of birds from all six treatment groups, illustrates that reflux occurs along the entire length of the gastro intestinal tract, irrespective of insoluble fiber content of the feed or feeding regime.