Fuel Cells Bulletin ISSN: 1464-2859 527 Vol: 2024|Iss: 7|2024|© 2024 Fuel Cells Bulletin Evaluation of Fermented Apple Bagasse (Manzarine) In Tilapia Feed (Oreochromis Niloticus, Rocky Mountain Variety) In a Semi-Controlled System José Luis Guevara Valdez 1 , Daniel Díaz Plascencia 1 *, José Antonio Arzaga Becerra 1 , Perla Lucía Ordoñez Baquera 1 , América Chávez-Martínez 1 , Joel Domínguez Viveros 1 , Yamicela Castillo Castillo 1 , Octavio Villalobos Cano 2 1 Universidad Autónoma de Chihuahua, Facultad de Zootecnia y Ecología. Periférico Francisco R. Almada Km 1. CP. 33820. Chihuahua, Chihuahua, México. 2 Universidad Autónoma de Chihuahua, Facultad de Ciencias Agricolas y Forestales. Km. 2.5 carretera a Rosales, Poniente, CP. 33000 Ciudad Delicias, Chihuahua, México. ∗Correspondence author: dplascencia@uach.mx SUMMARY The objective of this work was to evaluate the use of a fermented apple (manzarine) compound rich in functional compounds and yeasts in the behavior of Tilapia (Oreochromis niloticus) Rocky Mountain variety in a semi-controlled aquaculture system. The variables evaluated were weight gain, length, width and height of the fish, as well as dissolved oxygen, temperature and pH. They were separated into two diets, including 10% Manzarina (MAN Treatment), comparing it against a control food. During the study, 210 three-week-old fingerlings were used, which for evaluation 21 fish tanks in the growth stage and two 1,800-liter Rotoplás ® containers for the development stage were used. For the statistical analysis of the data, an ANOVA analysis of variance was used to evaluate the productive variables. In all variables, the interaction of treatment with the covariates "day, oxygen, pH, and temperature" was tested. There was no statistical difference between treatments based on fish growth (P > 0.05), however, there was a statistical difference in the influence of the environment on growth (P ≤ 0.05), where dissolved oxygen had a significant influence (P ≤ 0.05) with daily gain in weight, length and height, and temperature and pH significantly influenced (P < 0.05) the width of the fish. Keywords: Oregano essential oil, zeolite, yeast, molasses. INTRODUCTION Aquaculture plays a key role in the growth and stability of the food system, contributing to the conservation of aquatic species, increasing nutrition levels, reducing environmental impacts, producing raw materials for industry and pharmacology, as well as promoting self-employment. Aquaculture is the development of aquatic organisms under controlled or semi-controlled conditions, this being one of the most economical options for obtaining protein of animal origin. In the production of fish by aquaculture, 50% or more of the expenditures are destined for feed, so it is necessary to develop feed alternatives with high digestibility with added nutritional benefits, economic and high protein quality, as well as nutraceutical supplements that optimize the health and growth of the fish, thus achieving a greater productive benefit. Thiessen et al., 2003; Kaiser et al., 2022. The main challenge in aquaculture lies in the fact that this sector is experiencing very rapid growth, currently being the one with the highest rate of expansion within food production. It is estimated that, by 2050, the world's population will reach 9 billion people, which will generate greater pressure on the food supply chain Sadigov, (2022). However, fishing, as a source of protein for both human consumption and animal production, is not a long-term sustainable solution, as there are no fish stocks capable of supporting COMEPESCA, (2022). Therefore, there are protein sources of vegetable origin available on the market such as soybean paste, which has an excellent amino acid profile which represents an excellent opportunity as a source of food for fish but unfortunately due to its high demand it is expensive and scarce, Dong et al., 2013; FAO, 2020. Manza fruit waste has a high nutritional value; however, it is still little explored, so it is a source of current study by researchers to quantify its nutritional potential and how nutritionists use it as a strategy in aquaculture diets. Fermented apple