The biological effects of oxidative stress and associated free radicals on farm animal performance, productivity, and product quality may be managed via dietary interventions—specifically, the provision of feeds, supplements, and forages rich in antioxidants. To optimize this approach, it is important first to understand the development of free radicals and their contributions to oxidative stress in tissue systems of farm animals or the human body. The interactions between prooxidants and antioxidants will impact redox homeostasis and, therefore, the well-being of farm animals. The impact of free radical formation on the oxidation of lipids, proteins, DNA, and biologically important macromolecules will likewise impact animal performance, meat and milk quality, nutritional value, and longevity. Dietary antioxidants, endogenous antioxidants, and metal-binding proteins contribute to the ‘antioxidant defenses’ that control free radical formation within the biological systems. Different bioactive compounds of varying antioxidant potential and bio-accessibility may be sourced from tailored feeding systems. Informed and successful provision of dietary antioxidants can help alleviate oxidative stress. However, knowledge pertaining to farm animals, their unique biological systems, and the applications of novel feeds, specialized forages, bioactive compounds, etc., must be established. This review summarized current research to direct future studies towards more effective controls for free radical formation/oxidative stress in farm animals so that productivity and quality of meat and milk can be optimized.

Summary Spirulina (Athrospira sp.) is an edible microalga and a highly nutritious potential feed resource for many agriculturally important animal species. Research findings have associated Spirulina to improvements in animal growth, fertility, aesthetic and nutritional product quality. Spirulina intake has also been linked to an improvement in animal health and welfare. Its influence over animal development stems from its nutritive and protein‐rich composition, thus leading to an increased commercial production to meet consumer demand. Consequently, Spirulina is emerging as a cost‐effective means of improving animal productivity for a sustainable and viable food security future. However, our present knowledge of animal response to dietary Spirulina supplementation is relatively scanty and largely unknown. Therefore, the primary objective of this paper was to review past and current findings on the utilisation of Spirulina as a feed supplement and its impact on animal productivity and health. Only animals deemed to be of agricultural significance were investigated; hence, only ruminants, poultry, swine and rabbits and their responses to dietary Spirulina supplementation are covered.

The use of total volatile basic nitrogen (TVB‐N) as a quality parameter for fish is rapidly growing to include other types of meat. Investigations of meat quality have recently focused on TVB‐N as an index of freshness, but little is known on the biochemical pathways involved in its generation. Furthermore, TVB‐N and methylated amines have been reported to exert deterimental health effects, but the relationship between these compounds and human health has not been critically reviewed. Here, literature on the formative pathways of TVB‐N has been reviewed in depth. The association of methylated amines and human health has been critically evaluated. Interventions to mitigate the effects of TVB‐N on human health are discussed. TVB‐N levels in meat can be influenced by the diet of an animal, which calls for careful consideration when using TVB‐N thresholds for regulatory purposes. Bacterial contamination and temperature abuse contribute to significant levels of post‐mortem TVB‐N increases. Therefore, controlling spoilage factors through a good level of hygiene during processing and preservation techniques may contribute to a substantial reduction of TVB‐N. Trimethylamine (TMA) constitutes a significant part of TVB‐N. TMA and trimethylamine oxide (TMA‐N‐O) have been related to the pathogenesis of noncommunicable diseases, including atherosclerosis, cancers, and diabetes. Proposed methods for mitigation of TMA and TMA‐N‐O accumulation are discussed, which include a reduction in their daily dietary intake, control of internal production pathways by targeting gut microbiota, and inhibition of flavin monooxygenase 3 enzymes. The levels of TMA and TMA‐N‐O have significant health effects, and this should, therefore, be considered when evaluating meat quality and acceptability. Agreed international values for TVB‐N and TMA in meat products are required. The role of feed, gut microbiota, and translocation of methylated amines to muscles in farmed animals requires further investigation.