Incorporation of functional feed ingredients to substitute antimicrobials in animal nutrition: Opportunities for livestock production in developing countries

Livestock including cattle, goats, sheep, pigs and poultry are kept under traditional farming systems producing manure, supporting crop production, insurance and financing emergency cash needs, and improving social status. The livestock feed resource base is mostly natural graze and crop residues whose quality and supply are dependent upon unreliable rainfall patterns. Due to rising demand for cropland, overgrazing, bush encroachment and bush burning, grazing supplies are being depleted. Grazing is supplemented using commercial feeds heavily infused with antibiotics contributing to antimicrobial resistance. Feed constitutes the largest expenditure, thus incorporating functional feed ingredients is favored. The study serves to increase farmers’ awareness to substituting antimicrobials with functional feed ingredients. A systematic review of literature was done and keywords related to animal nutrition, functional feeds and antimicrobial resistance were used to identify relevant articles. Results revealed that functional feeding of livestock offers a potential diversity to animal production systems and may increase profitability in animal husbandry ventures. Functional feed ingredients improve productivity and vigor by enhancing digestibility, preserving and stabilizing beneficial gut microflora, and having a favorable impact on the environment. Probiotics, plant phytogenic compounds, and prebiotics, have the potential to replace antimicrobials as environmentally-friendly therapeutics and growth promoters.