Effects of dietary supplementation of a mixture heat-killed Lactobacillus plantarum L-137 and propionic acid calcium on growth performance and feed utilization efficiency of striped catfish (Pangasianodon hythpothalmus) at juvenile stage

Abstract

The purpose of this study was to determine the effects of adding propionic acid calcium (PA) and heat-killed Lactobacillus plantarum (HK L-137) to the diet on the growth performance and feed utilization efficiency of juvenile striped catfish (Pangasianodon hypophthalmus). The experiment was carried out in a recirculating system with 6 dietary treatments, including a control diet and 5 treatments with varying doses of HK L-137 (LP20) or PA supplements, with each treatment replicated four times. In comparison to the control diet, diets supplemented with HK L-137 or HK L-137 combined with PA dietary demonstrated significantly improved weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), feed conversion ratio (FCR), and survival rate after 60 days. Fish in treatment 3 (2 ppm HK L-137) had the highest growth rate (through WG, SGR, and FCR) and feed utilization efficiency (PER, FCR), but treatment 6 (2 ppm HK L-137 and 1000 ppm PA) had the highest survival rate. Additionally, the activities of the digestive enzymes (α - amylase, trypsin, and chymotrypsin) in fish gut given HK L-137 or HK L-137 combined with PA supplement significantly increased, especially in the treatment 3. These results showed that adding HK L-137 at a dosage of 2 ppm to the diet of striped catfish had improved growth performance and feed utilization efficiency