Aspectos bioquímicos do colostro e do leite de peixe-boi da Amazônia Trichechus inunguis (Natterer, 1883)

Abstract

The Amazon manatee is an aquatic mammal that possesses the placenta of the zonary and endotheliochorial type. This placental conformation partially blocks the passage of antibodies, increasing the need for immediate colostrum intake by the offspring. In this context, knowing the biochemical composition properties of the colostrum of this aquatic mammal is very important for the understanding of the physiology of the species and for guiding management measures to guarantee the health of captive T.inunguis in the early stages of development. The objective of this study was to characterize the proteins and amino acid composition in the colostrum of the Amazonian manatee Trichechus inunguis kept in captivity. Two samples of colostrum from a captive female were collected at the Center for the Preservation and Research of Aquatic Mammals, Balbina-AM, on two consecutive days, corresponding to the first 24 and 48 hours after delivery. Protein and free amino acids from "in nature" colostrum were analyzed by High Efficiency Liquid Chromatography by ion exchange. Proteins were determined by means of SDS PAGE followed by MALDI-TOF-MS analysis. The most abundant amino acids in colostrum in the first 24 hours were: glutamic acid (20.4%) and proline (13.7%). The lowest available amino acids were: arginine (0.9%), glycine (1.1%). Aspartic acid and serine were the amino acids that suffered the greatest decreases in their total concentrations between the samples of 24 and 48 hours (reduction of 6.4% and 0.9%, respectively) after delivery. The most abundant free amino acids in colostrum were aspartic acid (18%) and proline (15%). Four major proteins were identified in colostrum (bovine serum albumin, Apolipoprotein E, zinc finger protein and DREBRIN protein) and a polypeptide rich in proline and serine. Colostrum for this species does not appear to be related to the specific function of transmitting immunity but rather to act as a promoter of the infant's immune development by providing necessary subsidies capable of ensuring the synthesis of the infant's own immunity. In addition, the proteins identified in this study suggest preparing the newborn to metabolize mature, lipid-rich milk and providing subsidies for the neonatal development of the newborn