Antinutritional factors and contaminants in animal feeds and their detoxification: A review

Abstract

Animal feed, including herbage, may be contaminated with organic and inorganic compounds and with particulates. Organic chemicals comprise the largest group and include plant toxins, mycotoxins, antibiotics, prion proteins, animal toxins and pesticides. Inorganic compounds include heavy metals and radionuclides. Particulates such as weed seeds and certain bacterial pathogens are common contaminants of feed. The effects of feed contaminants and toxins range from reduced intake to reproductive dysfunction and increased incidence of bacterial diseases. Residues transferred to edible animal products represent another reason for concern. Comprehensive legislation is in place for the control of several of these chemical compounds and pathogens in feed. However, in many developing countries, including India, the statutory control of contaminants is at best rudimentary. Fortunately the chemical nature, mode of action and counteractive measures for many of substances have been well documented but the procedures for total elimination or destruction of toxins are not only cumbersome but also expensive making them practical. The adequacy of elimination of toxins by breeding strategies may not be compatible with high production. Satisfactory processing is essential for the profitable inclusion of some of the byproducts of novel oil seeds in livestock diets. Various chemicals were attempted for the removal of toxic components for upgrading the feedstuffs. These methods usually degrade the toxicants but these also cause substantial loss of nutrients as leaching. Moreover, chemical treatments are not used due to environmental concerns. Therefore, the scope for decontamination of feeds is limited and generally uneconomical and prevention is the most effective practical strategy. Detoxification was often achieved but economical feasibility remains questionable in many circumstances. Processing technologies that are economic and practical are urgently required. The alternative is to restrict the level of the inclusion of toxin containing feedstuffs such that the levels are within tolerable limits.