Cell morphology and epithelial development of the rumen in cattle fetus and newborn calves

• Grant number: 14/16677-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2014
• End date: September 30, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine
• Principal Investigator: Francisco Javier Hernandez Blazquez
• Grantee: Letícia Palmeira Pinto
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The stomach of ruminants is a complex organ divided into four compartments: the rumen, the reticulum, the omasum and the abomasum, with the first three forming the pre-stomachs or pro ventricles. The pre-stomachs have an important role in digestive physiology of ruminants, once they consist the local where physical and biochemical processes related to rumination occur and, particularly, where symbiotic bacteria carry an intense fermentation activity of cellulose digestion. Moreover, each of the three compartments has its own characteristic, responsible for essential mechanisms of rumination. During the third month of pregnancy, the relative sizes of the four stomach compartments of the bovine fetus are comparable to those observed in adults. Subsequently, however, the abomasum develops at a high rate and at birth is responsible for about half of the total volume of the stomach. This is due to the necessity of the abomasum to make use of the liquid diet during the first weeks after birth; liquids bypass the rumen, reticulum and omasum through the esophageal groove to gain direct access to the abomasum. With the change in diet from liquid to solid, the rumen, reticulum and omasum become functional and increase in size. The study of junction protein is necessary for a better understanding of the rumen cell-cell functions and behaviors during their fetal development and newborn calf. The family of cadherins, consisting of a number of single chain transmembrane glycoproteins with similar structures and functions, is primarily responsible for mediating intercellular adhesions of calcium-dependent homotipes. The purpose of this study is to evaluate the cell morphology of the rumen of bovine fetuses and newborn calves, focusing on the structure of the rumen epithelium, basement membrane and cell morphometry, once the rumen is an organ of extreme importance for this animal species, because it is an organ that undergoes phenotypic and physiological changes during its development. For this purpose, techniques of histology and staining, as well as immunohistochemistry for PCNA and E-cadherin will be held. (AU)