A PhD thesis at the Department of Fish and Marine Resources - College of Agriculture - University of Basrah on the feeding efficiency, growth and health status of common carp fingerlings as life indicators in evaluating the addition of some probiotics and synergistic mixtures to diets was discussed on Monday 6/26/2023.
The thesis of the student, Muhammad Salih Qadouri, which was supervised by: Prof. Dr. Salah Mahdi Negm and Prof. Dr. Khaleda Salem Khudair, included two laboratory experiments, the first experiment was the use of the Iraqi booster, the commercially imported booster Suntypo, and the commercially imported synergistic mixture Biomin and compared it with the synergistic mixture prepared from lactic acid bacteria (Lactococcusbulgaricus and Streptococcus themophilus) and the second experiment included increasing the percentage of adding the prepared synergistic mixture and knowing its effect on productive performance and healthy fingerlings of common carp (Cyprinus carpio) cultured in a closed water recirculation system for 70 days.
The study aimed to identify the effect of adding lactic acid bacteria (Lactococcus bulgaricus and Streptococcus themophilus) on stimulating growth and improving the nutritional value of the diet and the health status of the fish.
The researcher concluded that the addition of the synergistic mixture with lactic acid bacteria (Lactococcusbulgaricus and Streptococcus themophilus) improved growth performance, diet evaluation and health status of fish, especially at 0.15% concentration.
The process of forming the synergistic mixture by fermentation method and adding it to the fish diet led to a decrease in the concentration of phytic acid, which worked to increase the minerals and the availability of amino acids and improve the nutritional value of the diet and also increased the intestinal bacteria beneficial to the fish in the treatment of the synergistic mixture, and no presence of Escherichia coli bacteria was recorded, which led to an increase in diet and growth parameters, as well as the results showed an increase in the concentration of intestinal enzymes α-amylase and lipase in the blood serum and an improvement in the histological picture of the intestine in the treatment of the synergistic mixture prepared with lactic acid bacteria, and a significant decrease (positive result) was recorded in the level of the picture of fats in the blood serum of fish. In addition to an improvement in the level of liver enzymes in blood serum and an increase in the level of total protein, albumin, globulin, red blood cell count, hemoglobin, and the volume of compact cells (a positive result) compared to other experimental treatments.
The researcher recommended the use of a synergistic mixture with lactic acid bacteria at a concentration of 0.15% as a food additive for farmed fish. He also recommended that more studies should be conducted on other types of beneficial bacteria in the preparation of the synergistic mixture, in addition to other studies on reducing anti-nutritional factors to improve the nutritional value of the diet and study the environmental benefits. This could include an assessment of its impact on water quality, as well as the potential for waste reduction and increased sustainability in the aquaculture sector.
