Phenol-rich fulvic acid as a water additive enhances growth, reduces stress, and stimulates the immune system of fish in aquaculture by Thora Lieke, Christian E. W. Steinberg, Bo Pan, Irina V. Perminova, Thomas Meinelt, Klaus Knopf, Werner Kloas
Aquaculture has become imperative to cover the demands for dietary animal protein. Simultaneously, it has to overcome prejudices from excessive use of antibiotics and environmental impacts. Natural supplements are traditionally applied orally. In this study, we demonstrated another pathway: the gills. Humic substances are immunostimulants and a natural part of every aquatic ecosystem, making them ideal to be used as bath stimulants. Five and 50 mg C/L of a fulvic acid-rich humic substance was added for 28 days to the water of juvenile rainbow trout (Oncorhynchus mykiss). This fulvic acid is characterized by a high content of phenolic moieties with persistent free radicals and a high electron exchange capacity. The high concentration of the fulvic acid significantly increased growth and reduced the food conversion ratio and the response to a handling-stressor. Phagocytosis and potential killing activity of head kidney leukocytes were increased, as well as the total oxyradical scavenging capacity (TOSC) and lysozyme activity in the gills. In conclusion, immunostimulation via gills is possible with our fulvic acid, and the high phenolic content improved overall health and stress resistance of fish. More
Humic substances are an important biogeochemical ecological factor that can initiate chemical stress in exposed organisms. The effects of stress by humic substances on Darwinian fitness are the subject of this thesis. Lifespan and fertility of the cosmopolitan water flea Moina macrocopa were examined under exposure of humic substances at environmentally realistic concentrations. More
The effects of diets containing different levels of humic acid (HA) were determined on several blood and milk parameters in dairy goats. Eighteen Saanen goats (2 years old, 52 kg body weight) were fed three diets containing: 0 g HA/kg body weight (T1 ), 1 g HA/kg – (T2 ) or 3 g HA/kg – (T3 ) in a 3x3 latin square experimental design. Each period consisted of 21 days preliminary period and 7 days collection phase. More
Humic substances (HS) are ubiquitous natural products of decomposition of dead organic matter. HS is present in most freshwaters at concentrations ranging from 0.5 to 50 mg L1 . Organic carbon can represent 20% dry weight of sediments. Recently, the interaction of dissolved HS with the aryl hydrocarbon receptor (AhR) has been demonstrated. More
Humic acids (НА), а class of compounds resulting from decomposition of organic matter, particularly plants аге natural constituents of drinking water, soil and lignite. lt inhibit bacterial and fungal growth, thus decrease levels of mycotoxins in feed. More
Peat is an easily available natural material and a source of biologically active substances widely used, not only in agriculture but in human and animal medicine as well. In recent years, interest in the use of peat as a feed supplement has increased, particularly due to its capability to prevent enteric diseases and to stimulate growth in piglets and pigs. More
Humic acids are a class of compounds resulting from decomposition of organic matter, particularly plants, and are natural components of drinking water, soil and lignite. They are three dimensional macrocolloidal molecules with a polyaromatic center containing iso- and heterocyclic structures and peripheral side-chains. More
This study was designed to investigate the effect of addition humic acid to the developed laying hen diets on egg production, egg quality and some physiological traits. More