Comparative Performance of Renewable Protein Concentrates in Animal Feeds Across Regions

Thesis Abstract

The rapid growth of plant- and insect-based protein concentrates as alternatives to conventional soybean meal has heightened concerns about regional supply reliability, nutritional variability, and environmental footprints in animal feeding systems. This study addresses the problem of inconsistent performance of renewable protein concentrates (RPCs) across regions, which impedes their adoption by livestock producers and feeds manufacturers. The aim is to evaluate and compare the nutritional adequacy, growth performance, and product-to-feed efficiency of RPCs derived from legume seeds, algae biomass, and insect frass, across temperate, tropical, and semi-arid regions. Specific objectives are to (i) quantify proximate composition, amino acid profiles, and anti-nutritional factors of RPCs from three feed materials; (ii) assess feed formulateability and cost implications using region-specific ingredient price data; (iii) evaluate animal performance (growth rate, feed conversion ratio, and nitrogen retention) in broiler chickens and growing pigs fed RPC-based diets; (iv) determine digestibility coefficients and ileal amino acid availability through meta-analysis of digestibility trials; and (v) model regional variation in environmental performance indicators (life-cycle greenhouse gas emissions, land use, and water use) associated with RPC substitution. The study adopts a multi-site, cross-regional design combining experimental feeding trials with a meta-analytic synthesis of existing digestibility data. The population includes 540 one-day-old broiler chicks and 360 weaned pigs, allocated to a randomized complete block design across three regions (temperate, tropical, semi-arid) with factorial inclusion levels of RPCs (0%, 10%, 20%). Data collection instruments comprise standardized proximate and amino acid analyses (AOAC 2005 methods, UPLC-MS for amino acids), anti-nutritional factor assays (phytates, tannins, trypsin inhibitors), feed formulation software for cost optimization, growth performance monitoring, and digestibility trials using standardized total collection (broilers) and marker-based methods ( pigs). The study employs regression analyses to relate RPC composition to growth and digestibility, ANOVA to compare treatment effects across regions, and the Derivative-N equation to estimate nitrogen retention. A mixed-effects model will account for regional and farm-level random effects. The theoretical framework integrates the Nutrient Balance Theory and the Resource-Use Efficiency model to elucidate how RPCs influence nutritional adequacy and environmental outcomes under different production constraints. The research will also apply the OECD environmental accounting framework to estimate regional life-cycle assessment metrics. Expected findings include region-specific variations in RPC nutritional value due to intrinsic ingredient quality and processing differences, with legume-based RPCs showing higher lysine but elevated phytates in tropical regions, algae-based RPCs offering favorable energy density yet higher ash contents, and insect-based RPCs providing improved palatability and amino acid balance but variable chitin-associated digestibility. It is anticipated that 10–20% RPC substitution will achieve comparable average daily gain and feed conversion to soybean-based controls in broilers and pigs within temperate regions, while tropical and semi-arid regions may require formulation adjustments to offset digestibility losses and anti-nutritional effects. Digestibility meta-analysis is expected to reveal moderate to high standardized ileal amino acid digestibility (SID AA > 80% for lysine in algae RPCs; SID AA > 75% for methionine in insect RPCs) with region-driven heterogeneity. Environmental analyses are projected to show reductions in land use intensity but variable water footprints, contingent on region-specific water productivity and RPC production practices. The study contributes to knowledge by providing a comprehensive cross-regional comparison of RPC performance, integrating feed formulation economics, animal production outcomes, digestibility data, and environmental implications within a unified analytical framework. It clarifies the conditions under which RPCs can replace conventional proteins without compromising performance or sustainability, and identifies region-specific processing and formulation improvements required to maximize advantages. The main conclusion is that RPCs can be viable alternatives in diversified regional feed portfolios when tailored to local nutritional requirements, processing quality, and economic constraints. Recommendations include targeted optimization of RPC processing to reduce anti-nutritional factors, region-specific inclusion guidelines, investment in regional supply chains to ensure consistent quality, and policy incentives encouraging diversified protein sources to enhance resilience in livestock production systems.