Cinnamon is a natural additive with great potential for its use in poultry diets.
The demand for poultry meat has increased in recent years. Global poultry meat production reached approximately 137 million tonnes in 2020, making it the world’s most consumed meat.
Stressors such as excessive heat and overcrowding are considered major threats to poultry production due to their impacts on gut health and increased susceptibility to disease.
Previously, antibiotic growth promoters (AGPs) were used to control gastrointestinal pathogens and reduce the effects of stressors on bowel function.
- However, growing consumer awareness towards the adverse effects of antibiotics on human health, coupled with increasing bacterial resistance and food safety concerns, have led to bans on antibiotic use in poultry production.
Phytogenic additives (PA) have emerged as alternatives to AGPs and have great potential within the poultry industry. For example, it has been shown that under heat stress conditions in poultry, these can:
- Enhance immune function
- Exert beneficial effects on health performance
- Reduce stress response (Rashid y col., 2020).
The natural antioxidants found in many PAs have also been found to be effective in extending the shelf life of poultry meat, as well as improving its quality and acceptability.
- Natural
- Reduced toxicity
- Free of chemical residues
- Easy-availability
Natural plant products have been found to have beneficial effects, such as:
- Increased secretion of digestive enzymes
- Immunostimulant
- Bactericide
- Antiviral
- Antioxidant
Cinnamon is considered one of the most potent PAs, and has great potential for poultry use.
The effects of cinnamon on the intestinal health of birds are shown in Figure 1.
Figura 1.Effect of cinnamon on poultry intestinal health
Source: Taken from Akhtar Ali y col., 2021
Cinnamon
Cinnamon contains [register]several bioactive compounds including natural antioxidants, antimicrobials and anti-inflammatory components. Amongst which there are: volatile oils, flavonoids, curcuminoids, coumarins, tannins, alkaloids, xanthones, terpenoids, phenols and others (Liyanage et al., 2021).
- The concentration of volatile compounds in cinnamon essential oil (CEO) mainly depends on the part of the plant (leaves, bark, root, stem) from which it is extracted.
Cinnamaldehyde is the main CEO compound that is extracted from the bark. Meanwhile eugenol is the main compound extracted from the leaves.
The main bioactive compounds in cinnamon are cinnamaldehyde, cinnamate, and cinnamic acid, all of which play vital roles in various biological activities (Namazi et al., 2019).
The different essential oils that have been reported in cinnamon include:
- trans-cinnamaldehyde
- eugenol
- cinnamyl acetate
- L-borneol
- L-bornyl acetate
- β-cariofileno
- caryophyllene oxide
- E-nerolidol
- α-thujene
- α-cubebene
- terpinolene
- α-terpine
Cinnamon is high in polyphenols and anthocyanidins (procyanidins A and B).
Poultry gut health
The intestinal ecosystem plays a vital role in removing toxins and infectious agents from the intestinal tract of birds. Many factors influence the gut microbial ecosystem, including:
- Feed additives (phytobiotics, prebiotics, probiotics, feed enzymes, organic acids, etc.)
- Feed composition
- Genetics
- Heat stress
- Feeding practices within the poultry farm, amongst others.
The intestinal ecosystem of poultry consists of bacteria, protozoa and fungi in varying proportions. The concentration of microbiota varies along the intestinal tract, having greater numbers in the distal segments. The intestinal epithelium has tight junctions between cells that prevent the colonization of microorganisms while also participating in cell signaling.
Cinnamon use in poultry feed
Cinnamon is one of the PAs approved by the U.S. Food and Drug Administration for its inclusion in poultry feed.
The bioactive compounds in cinnamon have potent anti-inflammatory, antimicrobial and antioxidant properties with free radical scavenging actions and strong inhibitory effects on nitric oxide (NO) production by suppressing NFκβ activity (Zhu et al., 2020).
At the same time, the bioactive compounds in cinnamon can disrupt the growth of pathogenic microbes and stimulate the growth of commensal bacteria in the intestinal tract of poultry (Wenk, 2003).
Impact of cinnamon on nutrient digestibility
Cinnamaldehyde may also improve nutrient absorption by protecting gut morphology and integrity:
Cinnamaldehyde supplementation in the diet of broilers increased villus height in the duodenum and jejunum with an associated increase in nutrient absorption and digestion efficiency (Redondo et al., 2014).
Recent studies suggested that tannins (water-soluble phenolic compounds)found in cinnamon have a significant impact on poultry health and nutrition, as they can precipitate proteins in the gut (Cross et al., 2011).
- The apparent ileal digestibility of crude fat and amino acids (histidine, lysine, serine, phenylalanine, asparagine, and threonine) was significantly higher in cinnamaldehyde-supplemented groups (Jamroz et al., 2003).
Effects of cinnamon on intestinal microbiota
It is likely that desired optimal health and performance in birds can be achieved by modulating the gut microbiota.
- The cecum is densely populated by a number of bacteria that are primarily responsible for the fermentation of nutrients that are not absorbed in the ileum (Lee et al., 2017).
Dietary cinnamon promoted the growth of beneficial bacteria while reducing pathogenic bacterial load compared to control groups (Rashid et al., 2020). They found that dietary cinnamon increased the growth of Lactobacillus spp. while inhibiting Campylobacter spp. and E. coli in the ileum and cecum of poultry.
The production of SCFAs is attributed to the fermentation of Lactobacillus spp. which are responsible for the maintenance of the intestinal ecosystem and the prevention of pH-sensitive pathogenic bacteria.
The bioactive compounds in cinnamon have potential antimicrobial activities against
- Enterococcus faecalis
- Vibrio parahaemolyticus
- Pseudomonas aeruginosa
- Salmonella spp.
- Klebsiella pneumoniae
- Staphylococcus epidermis
- Staphylococcus aureus
- E. coli
Anthocyanins suppress the growth of pathogenic bacteria and improve the functionality of bird organs and can potentially enhance heat stress (Iqbal et al., 2020).
Flavonoids, including those found in cinnamon, act as antimicrobial agents in the gut of birds (Iqbal et al., 2020).
The ethanolic extract of cinnamon has strong antimicrobial activity against Salmonella aureus strains as reported by Bonilla and Sobral (2017).
Conclusions
The inclusion of cinnamon in poultry feed as a phytogenic additive has beneficial effects on nutrient digestibility, hypocholesterolemia, blood biochemistry profiles, gene expression, immunity and, in particular, on gut health. Alleviating the impacts of disease and environmental stressors.
Cinnamon supplementation in poultry feed mitigates the stress response by suppressing the NF-κβ pathway and increasing the expression of anti-inflammatory cytokines.
This review demonstrates that cinnamon can be used as a PA, in order to improve food safety, health and economic parameters in the poultry industry.
Source: Akhtar Ali y col., 2021
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