Alliaceae and animal health

Use of antibiotics in livestock

The use of antibiotics in livestock is essential for the treatment of most infectious diseases affecting livestock. In addition to their therapeutic use, antibiotics have been used in livestock for preventive purposes and as growth promoters, but the emergence of resistant bacteria has limited their use to stimulate growth and prevent undiagnosed diseases. Faced with this situation, farmers are demanding alternative methods to reduce the use of antibiotics without compromising the profitability and quality of their production.

Currently, there are several alternatives that allow to improve the health and well-being of animals, among which are probiotics, prebiotics, enzymes, organic acids and especially phytogenic compounds. Among the phytogenic products whose effectiveness has been more widely demonstrated by the research community are the derivatives of garlic and onion. Their use as medicinal plants dates back to the earliest days of mankind and in all known cultures.

There are numerous scientific studies in which it has been shown to be effective in the treatment of various infections and parasites, which together with its stimulating properties of the immune system and anti-inflammatory cause it to be considered among the compounds to promote animal health status and improve productive rates.

Benefits of using garlic and onion extracts

Changes in the gut microbiota weaken the mucosa by allowing bacteria to easily pass through. The organosulfur compounds (OSCs) found in garlic and onion have a direct effect on the microorganisms attached to the intestinal epithelium, so their use in livestock has multiple benefits:

I. Decrease in enteropathogens

The antimicrobial activity of OSCs has been demonstrated in many studies and has proven to be highly effective in reducing pathogenic bacteria of interest to livestock such as Salmonella, E. coli, Brachyspira, etc.. In addition, its mechanism of action is not only antibacterial, but also has a marked antiparasitic effect, mainly against coccidia of the genus Eimeria, one of the main causes of economic losses in farms.

Fig 1. The excretion of oocysts in brooilers infected with coccidia is significantly lower in those animals that consume additive feed with the thiosulfonates present in Garlicon (Kim et al. 2012).

II. Modulation of the gut microbiota

OSCs have been shown to act against enteropathogenic bacteria (Salmonella, E. coli, etc.) while respecting beneficial bacteria (Lactobacillus and Bifidobacterium), which contributes to the proper fermentation absorption of its derivatives, such as volatile fatty acids, vitamins and minerals (Hairstyle et al., 2013).

Fig. 2. Evolution of the different bacterial groups at intestinal level during the fattening and finishing phase after the addition of Garlicon to the diet of weaned piglets (day 0) until the end of the fattening phase (day 103). A decrease of enterobacteria, clostridia and salmonella is observed, while lactobacilli and bifidobacteria are maintained or increased. (Sanchez et al. 2020). # P<0.010; * P < 0.05; **P< 0.01; ***P< 0.001

III. Improvement of the intestinal epithelium

The use of OSCs found in garlic and onion increases the absorptive surface area and thickness of the intestinal mucosa. This improvement influences a variety of beneficial processes for the animal, such as nutrient absorption, defense against external pathogens, and correct inflammatory responses.

Fig. 3. The mucosal state of the colon of mice with colitis that consumed Garlicon is similar to that of healthy mice (negative control), unlike those animals with colitis that did not consume it (positive control) (Vezza et al., 2018).

IV. Modulation of the inflammatory response

OSCs have the ability to inhibit the excessive production of pro-inflammatory cytokines, thereby reducing intestinal inflammation that leads to dehydration, poor absorption of nutrients, and invasion by pathogenic microorganisms.

In addition, this reduction in inflammation extends to other areas of the body, helping to prevent airway obstruction or joint inflammation that limits the animal’s movement and food intake.

Fig. 4. Influence of OSCs on the production of pro-inflammatory cytokines in pig lung macrophages (Liu et al. 2012).

V. Improves defensive response

The principles assets present in garlic and onion has the ability to stimulate antibody production against specific antigens, this way stimulating the immune system of the animal.

Fig. 5. Stimulation of antibody production against coccidia thanks to the action of the active compounds present in Garlicon (Kim et al. 2012).

The benefits of these compounds and their scientifically proven efficacy indicate that, of all the existing phytogenic compounds, the use of Garlicon as an alternative to the use of antibiotics for prevention and growth promotion is the right choice.