Reducing antibiotic growth promotors in animal feed calls for the development of new strategies to improve feed conversion (FCR) in poultry production systems. This represents unique opportunities to explore the biochemical and physiological sources of inter-animal variations associated with FCR. Research has demonstrated a genetic link between feed conversion ratio and mitochondrial ROS (reactive oxygen species) production at the cellular level in broilers. More recent studies indicate a positive relationship between increased anti-oxidative capacity in broilers induced by certain plant extracts in feed and improved FCR.
Relationship between FCR and antioxidative capacity
Feed efficiency has been heavily weighted in breeding objectives for meat producing poultry for over 40 years and as a result, major gains have been made. More recent investigations by a poultry science group from the University of Arkansas provide a picture of the basis of feed efficiency (FE) at the cellular level. Oxidative stress turned out to be a cellular activity affecting feed efficiency.
The studies showed that animals with higher feed efficiency had better mitochondrial function that included less mitochondrial ROS production and less oxidation of proteins. Although feed intake was not different between low and high FE broilers, high FE broilers gained more weight and feed conversion ratios were significantly different between high and low FE groups. The level of protein carbonyl, an indicator of protein oxidation, was higher in mitochondria isolated from breast muscle of low FE compared with high FE broilers, which indicated higher oxidative stress in low FE birds.
Building on the knowledge of the link between antioxidative capacity and improved FCR in broilers from genetic research, certain plant components could offer an additional and safe way to improve FCR by nutritional means.
Anti-oxidative power from plants
The exposure of plants to unfavourable environmental conditions increases the production of ROS, which uncontrolled leads to cell damage from oxidative stress. Consequently, it is essential for plants to have sophisticated ROS detoxification processes for protection of plant cells against the negative effects of ROS. Many herbs and spices contain high levels of components with strong antioxidative power, such as alkaloids and polyphenolic compounds including different types of phenolic terpenes, phenolic acids and flavonoids.
Nutritional boost for anti-oxidative capacity in birds
Recent studies carried out by the University in Athens confirmed that feeding a phytogenic formula containing certain phenolic terpenes and flavonoids to broilers significantly increased the antioxidative capacity in breast tissue, thigh, liver tissue and certain parts of the gut. Parameter for ROS scavenging activity, activity of antioxidative enzymes and reduced lipid peroxidation were significantly improved in those tissues. This study showed that there was a positive correlation between antioxidative capacity in the breast tissue of broilers and improvements in FCR (P<0.05). This indicates that feeding strategies for increased antioxidative capacity could support feed efficiency in broilers, which is subject to further research.
Benefits package from antioxidant plant components
Feeding strong antioxidative components from herbs and spices, such as certain phenolic terpenes and flavonoids offer an opportunity to naturally improve antioxidative capacity in broilers and thereby improve FCR for more profitable and sustainable production. The impact can be expected to be greater when birds are exposed to stressors such as heat, toxins and the likelihood for oxidative stress is high. Additional benefits from feeding these components may include better meat quality and stability. Cost-efficacy depends on finding the right composition, dosage and bioavailability.