Key Factors Determining Growth and Feed Efficiency in Aquaculture

By: Victor Vargas Zelaya.

Modern aquaculture is far more complex than simply feeding fish and waiting for growth outcomes. Achieving optimal performance—particularly in terms of growth and feed efficiency, known as the Feed Conversion Ratio (FCR)—requires a comprehensive integration of biological understanding, nutritional precision, operational execution, and strategic decision-making (FAO, 2020). Every operational choice, from ration timing to genetic strain selection, can determine whether a farming system advances toward profitability or drifts into inefficiency. To clarify the hierarchy of these influences, experts often employ the Analytic Hierarchy Process (AHP), a structured decision-support method capable of quantifying the relative importance of each contributing factor (Saaty, 2008).

Fig. 1 : Factors affecting fish growth and feed conversion efficiency.

Source: Own research and elaboration

Within this framework, five principal categories emerge: management, biological, nutritional, environmental, and socio-cultural. Among them, management consistently stands out as the most decisive, accounting for approximately 53% of overall impact on growth and FCR (Timmons & Ebeling, 2013). Management, however, is not limited to feeding; it embodies the precision of feed delivery relative to biomass, the timing and frequency of distribution, and the choice of pellet size to minimize waste. Misaligned feeding schedules often result in uneaten feed, deteriorating water quality, and inflated FCR values (Bregnballe, 2015). Alongside feeding, robust control practices—such as continuous monitoring of biomass, stocking density, and fish distribution—are essential to detect deviations before they escalate into crises. Operational husbandry, including net maintenance, sanitary protocols, and harvest planning, reinforces these efforts, yet even the most sophisticated protocols are rendered ineffective without skilled and motivated personnel. Ultimately, human execution remains the critical link between planning and performance.

Biological factors, estimated to contribute around 22% of influence, encompass species selection, genetic resilience, metabolic growth potential, and overall physiological health (FAO, 2020). Fish with strong genetic traits and low susceptibility to stress convert feed more efficiently and exhibit better growth consistency under variable farming conditions. Nutritional factors, contributing roughly 15%, underscore the pivotal role of diet quality. A balanced amino acid profile, ingredient digestibility, pellet stability, and proper storage all shape how effectively feed is converted into biomass (NRC, 2011). Even when feeding practices are sound, suboptimal formulation can undermine performance at the metabolic level.

Environmental conditions, though assigned a lower relative weight of about 8%, exert direct physiological pressure. Temperature, dissolved oxygen, salinity, turbidity, and photoperiod collectively dictate metabolic rate, feeding behavior, and immune function (Timmons & Ebeling, 2013). Unlike genetics or nutrition, environmental variables can sometimes be managed through technological intervention—such as aeration or thermal regulation—which partly explains their reduced weight within the AHP hierarchy. Finally, socio-cultural factors, contributing around 3%, shape the broader implementation environment. Community acceptance, labor culture, regulatory compliance, and local traditions may not influence metabolism directly, yet they determine how effectively best practices are adopted and sustained (FAO, 2018).

Fig. 2 : Analytical Hierarchy Process (AHP) Matrix Showing Relative Weight of Each Factor

Source: Own research and elaboration

The critical insight that emerges from this analytical approach is that no factor operates in isolation. A drop in water temperature, for example, slows metabolic processes and demands a reduction in feeding to prevent waste. Likewise, poor feed quality cannot be compensated for by excellent management, just as superior genetics cannot overcome chronic environmental stress. Feed efficiency, therefore, is not the outcome of a singular intervention but the result of harmonizing biological potential with environmental stability, nutritional precision, and operational discipline (Bregnballe, 2015). Rather than searching for a single “magic factor,” successful aquaculture relies on prioritizing managerial excellence, investing in trained personnel, selecting genetically robust stock, and utilizing high-quality feeds. By applying structured tools like the Analytic Hierarchy Process, producers gain clarity on where to allocate attention and resources, ultimately maximizing growth, minimizing waste, and steering production toward long-term sustainability and profitability.

At Pinuer Consulting, we help aquaculture operations turn complex biological and managerial interactions—such as those that drive growth and feed efficiency—into clear, actionable strategies. Modern farming systems require more than good feed and favorable environments: they demand precise management, nutritional optimization, environmental control, and data-driven decision-making aligned with the realities of each production model.

Our team works with producers to identify the key factors affecting their FCR and growth performance using structured methodologies such as the Analytic Hierarchy Process (AHP). By quantifying the influence of management, biology, nutrition, environment, and socio-cultural conditions, we help operations understand where improvements will have the highest return on investment.

Whether you aim to reduce feed waste, enhance feeding protocols, strengthen husbandry practices, or refine genetic and nutritional strategies, we provide the technical guidance needed to harmonize these variables and elevate overall system productivity.

If you are ready to transform the complexity of aquaculture into repeatable, profitable performance, reach out to us for a strategic and operational consultation.