RESUMO
The objective of this study was to investigate development of the weight and the morphological development of the rectum in broiler chickens. Twenty broiler chickens (Ross 308) were used in this experiment and they were 12, 20, 35 and 44 days of age. Samples from the rectum of chicks were sectioned in an unbiased manner and examined quantitatively using stereology. In addition, the weight of both body (BW) and rectum and also rectum weight as a proportion of BW, height and width of the villi and thickness of rectum wall were measured. The results revealed that the body and rectum weight were increased with age. The greatest rectum weight as a proportion of BW was observed on day 20. An increase in height and width of the villi during the study period were obtained. The increase was more significant on days 35 and 44 than on days 12 and 20 (p < 0.05). There were significant difference in thickness of tunica mucosa, submucosa and muscular layer of the rectum on day 20 compared to day 35 (p < 0.05). The increase in the volume density of the wall, tunica mucosa and tunica muscular was greater on day 20 than on day 35. However, significant differences were observed in volume density of this layers between days 35 and 44 compared to days 12 and 20 (p < 0.05).
RESUMO
In pancreatic survey, quantitative and morphological characteristics could be fundamental variables for the evaluation of some structures. The aim of this study was the application of stereological methods for estimation of quantitative parameters and morphological evaluation of the pancreas in chickens. Ten adult male and ten adult female native chickens were used in this study. Routine tissue processing was carried out for all samples. The sections were stained with hematoxylin and eosin and Gomori's aldehyde-fuchsin. Stereological examinations were performed according to systemic uniform random sampling as well as Cavalieri and point counting method. The morphological results showed that in both sexes, pancreas of chickens was composed of four main pancreatic lobes and contained two distinct islet types. Alpha islets consisted of alpha and a few delta cells and beta islets contained beta and seldom delta cells. Stereological results showed that in both sexes, there were significantly distinctive regional differences in the volume of islet and the numerical density of cells among some lobes with highest values in third and splenic lobes, respectively (p < 0.05). The nuclear volume was lowest in ventral lobe either males (80.60 ± 33.50) or females (84.20 ± 44.10). Beside, in the islets diameter of splenic lobe, there were significant differences in males as compared with females (p < 0.05). In splenic lobe, a significant difference was observed in the nuclear diameter in males than to females (p < 0.05). The results indicated that although there were not morphological changes between sexes in pancreatic lobes, however, some stereological parameters could be affected by sex.
