Effect of humic acids on intestinal viscosity, leaky gut and ammonia excretion in a 24 hr feed restriction model to induce intestinal permeability in broiler chickens

Abstract

The purpose of this study was to evaluate the effect of humic acids (HA) on intestinal viscosity, leaky gut and ammonia excretion in a 24 hr feed restriction (FR) model to induce intestinal permeability in chickens. One-day-old male Cobb-Vantress broilers were randomly allocated to one of two groups (n = 25 chickens), with or without 0.2% of isolated HA from worm-compost, and placed in brooder batteries. Chicks had ad libitum access to water and feed for 14 days. Intestinal permeability was induced by 24 hr FR starting at 14 days. At 15 days of age, chickens in both groups were given an appropriate dose of fluorescein isothiocyanate dextran (FITC-d) by oral gavage. Intestine and liver samples were also collected to evaluate viscosity and bacterial translocation (BT), respectively. An increase (p < .05) in intestinal viscosity was observed in the experimental group consuming 0.2% of HA and was confirmed in a published in vitro digestion model that simulates the chemical and physical conditions of the crop, proventriculus and intestine of chickens. Furthermore, the treated group also showed a significant reduction in FITC-d, liver BT and ammonia in the manure. These results suggest that HA have a positive impact in intestinal integrity in chickens.

Effect of the Addition of Humic Substances as Growth Promoter in Broiler Chickens Under Two Feeding Regimens

“…In previous research [5] chicks fed with HA extracted from the same worm compost as the one used in this study and subjected to REST for 24 h showed higher intestinal viscosity and lowered bacterial liver translocation and serum FTIC-d compared to control chicks. Higher intestinal viscosity, and hence, the ability of HS to create protective layers, have been linked to the high capacity of HS to form aggregates within solutions [10].…”

“…Several mechanisms of action have been proposed to explain the benefits observed in broiler chickens supplemented with HS, including the ability to create protective layers over the epithelial mucosal membrane of the digestive tract against the penetration of toxic and other bacterial contaminated substances [4,5,8]; whilst, feed restriction for 24 h has been successfully used to induce intestinal inflammation as a means to disrupt the tight junctions of enterocytes [13,14].…”

“…In previous studies, HS derived from a worm compost was supplemented to broilers through the drinking water or feeds with encouraging results [4,5]. Broilers added with a worm compost leachate in the drinking water showed lower feed conversion ratio (FCR) and higher energy digestibility and higher retention of dried matter, ashes, nitrogen, and energy [4].…”

“…Farm animals are an essential component of this triad because they are exposed to growth promoter antibiotics (GPA) to improve animal health, welfare, and productivity, and act as reservoirs and vectors of resistance genes [1,3]. For this reason, several new additives have been tested as growth promoters to reduce or alternate the inclusion of GPA in feeds, while maintaining an efficient animal production to obtain safe edible products [4][5][6].…”

“…The main substances that make up the HS are the humic acids (HA), fulvic acids (FA), and humins, and hence, they are a complex mixture of aliphatic chains or aromatic rings with specific content of functional groups, but the concentration of these substances differs according to the raw materials that they originate from [8][9][10]. Leonardite and lignites, two non-renewable resources, are the primary commercial sources of HS, while compost and worm compost, especially those produced with animal manure, are two environmentally friendly sources of HS [4][5][6].…”