Humic substances are chemical compounds that are formed during the decay of plant and animal material in the soil. This process produces a transformation product that is commonly known as humus.
Humic acids are mainly composed of structural elements based on phenols, carbohydrates and amino acids that are arranged in much more complex compounds. The use of humic acids in animal nutrition has advantages for animal health and growth. Most of the scientific literature available focuses on livestock, and here mainly on egg production and egg traits of laying hen. Studies for the use of humic acid in aquaculture nutrition are limited and scarcely available.
The objective of this study was to test whether this class of organic compounds has beneficial effects on performance and survival of Red Nile Tilapia for a more sustainable production.
For this purpose, a study was conducted in the aquaculture trial facility of Dr. Eckel Animal Nutrition GmbH & Co. KG (Niederzissen, Germany).
The fish were fed a diet based on commercial feed for tilapia as control and three treatment diets that included humic acid at different dosages: 1,00 ppm, 1,000 ppm, 1,0000 ppm, named A1, A2, and A3, respectively. Twelve tanks were allocated to the trial, six replicates for the control and two replicates for each treatment.
Each tank was stocked with Red Nile Tilapia (Oreochromis niloticus) at a density of 1 fish/l and an initial body weight of 0.56 g ± 0.07. The feed allocated per day was supplied in 5 portions at 8 a.m., 9.30 a.m., 11.30 a.m., 1.30 p.m. and 4.30 p.m. by broadcasting the powdered feed over the water surface.
The trial was completed after 60 days, and performance parameters were assessed. The final average body weight (Fig. 1) did not show a significant difference when compared to the control. Survival (Fig. 2) was numerically improved which demonstrates that the use of humic acid was not harmful to the animal. Moreover, the feed conversion rate (FCR) was significantly improved (Fig. 3).
The outcome clearly shows the potential of this additive for the improvement of animal health and performance in terms of feed efficiency.
- ALEX DIANA (e-mail: firstname.lastname@example.org), TILMAN WILKE and DZENAN HOZIC, Dr. Eckel Animal Nutrition GmbH & Co. KG