Research article

EFFECT OF REPLACING SOYBEAN MEAL WITH DUCK WEED GROWN ON DOMESTIC WASTE WATER ON PRODUCTIVE TRAITS AND BIOACCUMULATION OF SOME HEAVY METALS IN COMMON CARP FISH

Nidhal T. AL-Taee

Online First: November 11, 2022


Soybean meal is a major source of protein in the feed for common carp Cyprinus carpio L, which is imported in hard currency from outside the country and raises the prices of fish feed. The study attempts to exploit duckweed (Lemna sp.) as a protein source, partially replacing soybeans. To save the cost of fish feed. The research was conducted in the fish laboratory of the Department of Animal Production in the College of Agriculture and Forestry, University of Mosul. The experiment included feeding common carp fish with five experimental diets including duckweed in different amounts (0, 5, 10, 15, 20, 25, 30) % as an alternative to soybean meal in the total percentage. Within glass basins of size 40 x 40 x 60 cm. The statistical examination of the values of final weight gain and total weight gain (g/fish), percentage of relative growth rate, and specific growth showed that the experimental treatments differed significantly (P 0.05), where the first treatment (control) was highly significant compared to the other treatments, and it was (49.26 and 20). .53 and 0.88) g/fish, 71.48% and 1.09, respectively. The values of temperature and pH showed significant differences (P 0.05) between treatments, and the temperature for the first and second treatments (5% duckweed) was superior to the rest of the treatments, and it reached (25.80, 25.91) degrees Celsius, and pH (7.71, 7.70), respectively. Temperature affects the growth of fish by increasing their feed intake, and the pH on the physiological and growth activities of fish. The results showed that there were significant differences (P 0.05) for the concentration of dissolved oxygen between the treatments, as the concentration of dissolved oxygen decreased for the first and second treatment and reached (4.92 and 4.97 mg/L, respectively), and the highest concentration reached 5.65 mg/L for the fourth treatment (15% duckweed). The successful management of fish provides the necessary oxygen for respiration, maintenance of vital activities, growth and health of fish. The water temperature, dissolved oxygen and pH are related to each other to provide the appropriate environment for fish growth. duckweed were grown on domestic waste water, and the results of the study showed that there was no sensitivity to lead and copper concentrations by the atomic spectrometer, to ensure that there was no bioaccumulation of them in the plant and the food chain. It is inferred that silts are safe for use as a feed source and a partial substitute for soybean meal in fish diet in order to reduce feed costs. Good management of the pond environment is to monitor temperature, pH and dissolved oxygen concentration for their effect on the growth of common carp fish.

Keywords

Duckweed; temperature; pH; carp; dissolved oxygen