This study was conducted to record the histological features of the gastrointestinal tract of wild Indonesian shortfin eel, Anguilla bicolor bicolor (McClelland, 1844), captured in Peninsular Malaysia. The gastrointestinal tract was segmented into the oesophagus, stomach, and intestine. Then, the oesophagus was divided into five (first to fifth), the stomach into two (cardiac and pyloric), and the intestine into four segments (anterior, intermediate, posterior, and rectum) for histological examinations. The stomach had significantly taller villi and thicker inner circular muscles compared to the intestine and oesophagus. The lamina propria was thickest in stomach, significantly when compared with oesophagus, but not with the intestine. However, the intestine showed significantly thicker outer longitudinal muscle while gastric glands were observed only in the stomach. The histological features were closely associated with the functions of the different segments of the gastrointestinal tract. In conclusion, the histological features of the gastrointestinal tract of A. b. bicolor are consistent with the feeding habit of a carnivorous fish.
Partial ablation of the uropygial gland is being used in the poultry industry as a new way to enhance body performance of chickens. However, limited data are available estimating the efficacy of partial uropygialectomy (PU) to improve body organ activity. The present study evaluated the effect of partial ablation of the uropygial gland on the serum growth hormone concentration level and digestive system histology of 120 Akar Putra chickens in 5 trials with 3 replicates per trial. The experimental treatments consisted of a control treatment T1; partial ablation of the uropygial gland was applied in the T2, T3, T4, and T5 treatments at 3, 4, 5, and 6 wk of age, respectively. Feed and water were provided ad libitum. All treatment groups were provided the same diet. Venous blood samples were collected on wk 7, 10, and 12 to assay the levels of growth hormone concentration. On the last d of the experiment, 4 birds per replicate were randomly isolated and euthanized to perform the necropsy. Digestive system organs' cross sections were measured by a computerized image analyzer after being stained with haematoxylin and eosin. In comparison with the control group, surgical removal of the uropygial gland, especially at wk 3, had a greater (P<0.01) effect on the total duodenum, jejunum, and ilium wall thickness. In addition, effects (P<0.05) were observed on the wall thickness of males' cecum and colon. Moreover, the wall layers of the esophagus, proventriculus, gizzard, and rectum were not affected by the treatment. However, removing the uropygial gland showed significant impact (P<0.05) in males' growth hormone concentration level at wk 7 and (P<0.01) effects at wk 12 in both sexes. This study provides a novel and economic alternative to enhance the body performance of poultry in general and Akar Putra chickens particularly.
Digestive tract measurements are often considered species specific, but little information exists on the degree to which they change during ontogeny within a species. Additionally, access to anatomical material from nondomestic species is often limited, with fixed tissues possibly representing the only available source, though the degree to which this material is representative in terms of dimensions and weight is debatable. In the present study, the macroscopic anatomy of the digestive tract (length of intestinal sections, and tissue weights of stomach and intestines) of 58 Lemur catta [ranging in age from 1 month (neonates) to 25 years], which had been stored frozen (n = 27) or fixed in formalin (n = 31), was quantified. Particular attention was paid to the caecum and the possible presence of an appendix. The intraspecific allometric scaling of body mass (BM)0.46[0.40;0.51] for total intestine length and BM0.48[0.41;0.54] for small intestine length was higher than the expected geometric scaling of BM0.33, and similar to that reported in the literature for interspecific scaling. This difference in scaling is usually explained by the hypothesis that, to maintain optimal absorption, the diameter of the intestinal tube cannot increase geometrically. Therefore, geometric volume gain of increasing body mass is accommodated for by more-than-geometric length scaling. According to the literature, not all L. catta have an appendix. No appendix was found in the specimens in the present study. The proportions of length measurements did not change markedly during ontogeny, indicating that the proportions of the foetus are representative of those of the adult animal. By contrast, width and tissue-mass scaling of the caecum indicated disproportionate growth of this organ during ontogeny that was not reflected in its length. Compared to overall intraspecific variation, the method of storage (frozen vs. formalin) had no relevant impact on length or weight measurements.