The Effect of Ag Nanoparticles and Multimicrobial Preparation as Factors Stabilizing the Microbiological Homeostasis of Feed Tables for Cornu aspersum (Müller) Snails on Snail Growth and Quality Parameters of Carcasses and Shells

SIMPLE SUMMARY: The farming of snails, unlike that of large farm animals, requires less space and financial resources, and snails are not as demanding. In field husbandry conditions, snails have access to green forage and are given concentrated mixtures on feed tables. In this maintenance system, it is important to carry out treatments stabilizing the microbiological balance of feed tables, where snail feces and feed refusals accumulate. This study analyzed the effect of paint with silver nanoparticles (nano-Ag) or a multimicrobial preparation applied to feed tables on the microbiological composition of the feed table environment, the growth and mortality of snails, and parameters assessing the quality of carcasses and snail shells. Results showed that the use of nano-Ag paint reduced the growth of bacteria, while the multimicrobial preparation reduced mold and yeast. Spraying feed tables with the multimicrobial preparation had a better effect on the growth of snails, while the use of nano-Ag paint reduced the mortality of the animals. The factors used did not have a negative effect on the quality of shells. The snails that had contact with nano-Ag paint showed a higher content of Ag in the carcasses and a greater degree of lipid peroxidation. ABSTRACT: The aim of this research was to evaluate the effect of Ag nanoparticles (nano-Ag) used in the paint covering feed tables or a multimicrobial preparation applied to feed tables on the microbiological composition of the feed table environment, the growth and mortality of snails, and selected parameters for assessing the quality of carcasses and snail shells. The research was carried out in a farm of Cornu aspersum (Müller) snails. In the control (K) group, paint without nano-Ag was used. In two other groups (N-Ag and N-Ag + effective microorganisms (EM)), the feed tables were covered with the same paint as in the control group but with the addition of 100 mg/L of nano-Ag it (N-Ag group). Additionally, multimicrobial preparation (EM Bokashi(®)) at a concentration of 10% was spread on the tables in the N-Ag + EM group. In the last group (EM), the feed tables were covered with paint without nano-Ag, and only multimicrobial preparation was applied at a concentration of 10%. During the tests, the body weight of snails was measured three times, and swab samples were taken from the feed tables for the examination of microbiological composition. At the end of the experiment, the snails were killed, and the weight of the carcass and the size of the shell were measured. The content of Ag and the degree of lipid oxidation (thiobarbituric acid reactive substances (TBARS)) in the carcasses were analyzed, and the content of Ca and the crushing strength of the shells were determined. In the N-Ag and N-Ag + EM groups, a significant reduction in the total number of bacteria, fecal streptococci, and Escherichia coli was found, while there was also a reduction in mold and fungi in the N-Ag + EM and EM groups. In the K and EM groups, the mortality of animals was higher than in the nano-Ag groups. In subsequent weight checks, the highest body weight was found in the EM group and the lowest in the N-Ag and N-Ag + EM groups. In addition, the carcass weight and shell size in the N-Ag group was significantly lower compared to the K and EM groups. In the N-Ag and N-Ag + EM groups, a higher Ag content in the carcasses and a greater degree of lipid peroxidation were found. The Ca content of the shells was the highest in the N-Ag group, and the hardness of shells was the highest in the N-Ag and N-Ag + EM groups.