Mechanisms of Action of Humic Substances as Growth Promoters in Animals

Abstract

A review of the latest research on the addition of humic substances (HSs) in the drinking water or feed of farm animals including poultry, pigs, dairy cows and calves, goats, and rabbits was carried out. The results reinforces the promoted protective action of HS on the digestive mucosa, their antioxidant properties, immunomodulatory, and anti-inflammatory attributes, the suggested microbial shift to a probiotic-type bacteria in the gut, including antiparasitic and antifungal effects, as well as their influence on the higher efficient of minerals, proteins, and lipids utilization within the body. The outstanding improvements in health, productivity, and meat and milk quality obtained from animals supplemented with HS are common features in the majority of available research. The main benefits in the gastrointestinal tract stem from the formation of protective barriers on the epithelial mucosa due to its colloidal properties and stimulation of mucin production. HS also promotes the development of probiotic microbiota and positive changes in bacterial fermentation patterns, which results in improved intestinal health and integrity. As a result, a cascade of benefits is derived within the body, reinforcing antioxidant protection responses, immunomodulation, and anti-inflammation mechanisms, as well as improving nutrient utilization efficiency. However, the truly molecular mechanisms of action of HS in the intestine and throughout the body remain unknown.

The Effect of Sodium Humate Feed Additives in Diets for Holstein Breed Heifers

“…Research studies on humic substances added to drinking water for animals have reported an increase in live weight gain for various species of productive animals, including heifers [72], which was consistent with the findings of the present research. In addition, de Lourdes Angeles et al ( 2022) indicated an improvement in the welfare of heifers and a decrease in the incidence of diarrhea in heifers [78]. The present research on the NaHum additive included in the diet for breeding heifers found that the breeding heifers displayed an improvement in their welfare, activity, and coat condition, which was fully consistent with the findings made by and De Lourdes Angeles et al (2022) [18,78].…”

“…In addition, de Lourdes Angeles et al ( 2022) indicated an improvement in the welfare of heifers and a decrease in the incidence of diarrhea in heifers [78]. The present research on the NaHum additive included in the diet for breeding heifers found that the breeding heifers displayed an improvement in their welfare, activity, and coat condition, which was fully consistent with the findings made by and De Lourdes Angeles et al (2022) [18,78].…”

Humic Substances as a Versatile Intermediary

“…The final meat quality of broiler chickens, which was favourably impacted by increased protein, decreased fat content and showed lower lipid oxidation was the major benefit of the broiler's diet supplemented with HSs [93,94]. HSs not only have a positive effect as a growth promoter, but can also reduce the mortality of farm animals [95].…”

Humic Acids Preparation, Characterization, and Their Potential Adsorption Capacity for Aflatoxin B1 in an In Vitro Poultry Digestive Model

“…Recently, our research group studied an extract of HA from vermicompost under different experimental conditions to clarify its mechanism of action [ 12 , 13 , 14 ]. In previous in vitro and in vivo studies, several sources of HS containing mixtures of HA and FA have been used as mycotoxin binders [ 15 ]; however, purified HA from vermicompost has never been tested against AFB 1 . HAs extracted from vermicompost are still in an early humification process and are considered immature; this factor may cause structural differences compared to HA extracted from lignites, leonardites, or other HA-aged sources.…”