The application of plant extracts in animal nutrition: a revolutionary force for natural health

Since the EU completely banned the use of antibiotics as growth promoters in 2006, the global demand for alternatives has become increasingly urgent. From livestock and poultry farming to pet health management, plant extracts have emerged as a type of efficient, safe, stable, and controllable feed additives, provide a green and sustainable solution for modern animal husbandry due to their characteristics of little side-effect, little drug-resistant, and low residue.

The Main Types and Active Ingredients of Plant Extracts

Plant extracts can be systematically classified according to source, composition and extraction process:

● According to plant part: Rhizomes (e.g. Astragalus, Glycyrrhiza), leaves (e.g. Tea, Rosemary), fruits (e.g. Citrus, Grape seeds), whole herbs (e.g. Echinacea, Mint).

● According to the extracted ingredients: polyphenols (flavonoids, tannins), terpenoids (essential oils, saponins), alkaloids (berberine, piperine), polysaccharides (astragalus polysaccharides, lentinuns polysaccharides).

● According to solubility: water-soluble extracts (polysaccharides, polyphenols), fat soluble extracts (essential oils, pigments).

Core active substances and their functions:

● Polyphenols: tea polyphenols (antioxidant), soy isoflavones (prebiotics), Proanthocyanidins (anti-inflammatory).

● Volatile oil: thymol (antimicrobial), carvacrol (growth promoter), eucalyptol (respiratory health).

● Polysaccharides: β- glucan (immune activation), fructooligosaccharides (prebiotic action), mannan oligosaccharide(pathogen adsorption).

Core Functions and Effects of Plant Extracts in Animal Feed

● Antibacterial, anti-inflammatory and immune-enhancing

Plant extracts achieve low-toxicity or non-toxic antibacterial effects by disrupting bacterial cell membranes, inhibiting enzyme activity, or interfering with the metabolism of pathogenic microorganisms. For example, Stephania extract can inhibit β-lactamase and Staphylococcus aureus, which is superior to ampicillin; Garlic extract prevents endometritis by inhibiting uterine pathogens. In the field of pets, Monk fruit extract can reduce the synthesis of inflammatory factors, while Oregano oil combined with antibiotics significantly improves the cure rate of escherichia coli. In addition, plant polysaccharides (e.g., astragalus polysaccharides) significantly enhance body immunity by activating macrophages and promoting the proliferation of T/B lymphocytes.

● Antioxidation and anti-stress

Flavonoids and polyphenols in plant extracts protect cells from oxidative damage by scavenging free radicals and decreasing lipid peroxidation. For example, tea polyphenols and proanthocyanidins can improve the activity of superoxide dismutase (SOD) and catalase (CAT), decrease reactive oxygen species. In studies on pet dogs, green tea polyphenols inhibited adipocyte differentiation and lowered the risk of obesity by regulating the expression of fat metabolism-related proteins. Meanwhile, in trials with laying hens, Artemisia extract significantly improved the antioxidant capacity of egg yolks and extended their shelf life.

● Intestinal health and microecological regulation

Plant extracts optimize the intestinal microbial communities by inhibiting harmful bacteria and promoting the proliferation of probiotics. For example, extracts from Cinnamomum plants can reduce the activity of urease and uricase, and reduce ammonia emissions. Yucca extracts and fructooligosaccharides (FOS) help regulate microbial balance in dogs and cats, reducing harmful metabolites such as ammonia and histamine. In addition, plant polysaccharides serve as substrates for microbial fermentation, producing short-chain fatty acids that promote the proliferation of intestinal epithelial cells and improve nutrient absorption efficiency. In piglet trials, a mixture of carvacrol and cinnamaldehyde significantly increased pepsin activity and reduced diarrhea.

● Promoting growth and feed conversion

Plant extracts promote animal growth by improving the palatability of feed, increasing the activity of digestive enzymes and regulating hormone secretion. For example, star anise essential oil significantly increases intestinal villus height and feed intake in animals; cinnamon extract delays intestinal lesions and improves feed utilisation. In studies on pet cats, proanthocyanidins inhibit fat cell proliferation and reduce body fat rate by regulating the fat metabolism-related genes.

Unique Applications of Plant Extracts in Animal Nutrition Products

● Livestock and poultry breeding: core technologies to replace antibiotics

Under the background of "antibiotic-free feed", plant extracts have become an important direction in antibiotic replacement technologies. For example, Eucommia ulmoides leaf extract, rich in chlorogenic acid and Eucommia flavonoids, can replace antibiotics to promote piglet growth; Dandelion extract enhances resistance to Newcastle disease virus in chicks, lowering mortality rates. In the productivity of laying hen, Lonicera japonica extracts and Turmeric extracts can reduce the rate of shell-less eggs and improve oviduct health. In addition, essential oils (oregano oil), alkaloids (berberine, artemisinin, sanguinarine) improve intestinal health by exerting antioxidant, antibacterial and antiparasitic functions. Heat-clearing herbal extracts (e.g. Scutellaria baicalensis extract, Honeysuckle extract) can effectively enhance the performance of heat-stressed cows.

● Pet nutrition: precise regulation of health indicators

Plant extracts have shown significant effects in addressing issues such as obesity and intestinal inflammation in pet dogs. Ginkgo biloba extract can reduce body weight and body fat rate in obese dogs. Proanthocyanidins inhibit fat cell proliferation by regulating the genes related to fat metabolism. In addition, yucca extract can modulate the gut microbiota of dogs and cats, reducing harmful metabolites (such as ammonia and histamine) and improving fecal odor. Pet food or snacks containing green tea polyphenols can inhibit the growth of harmful oral bacteria, reduce dental plaque and dental calculus, and prevent oral diseases like periodontitis. Plant extracts rich in vitamins and antioxidants, such as flaxseed extract, blueberry extract, and lecithin, provide nutrition for pet hair, making it softer and lustrous.

● Ruminants and aquaculture: emerging application fields

In ruminants, plant extracts (such as yucca saponins) can regulate rumen fermentation and improve nitrogen utilization. In aquaculture, Eucommia ulmoides leaves extracts can improve fish immunity and reduce mortality rates.

Application Challenges and Optimizing Strategies

● Existing technical bottlenecks

Palatability: Essential oils (e.g. oregano oil) may reduce pet food intake.

Incompatibility: High doses of tannins inhibit protease activity and reduce protein digestibility.

● Solutions and Development Tendency

Microencapsulation: Beta-cyclodextrin encapsulation of thymol reduces volatile losses by 70% and prolongs the duration of action.

Scientific Formula: The combination of curcumin and piperine increases bioavailability by 20 times.

Plant extracts have broad application prospects and great development potential in the fields of animal feed and health care. Through continuous research and practice, their application technologies will be continuously improved to provide strong support for promoting the green and sustainable development of animal husbandry and producing safe and high-quality food of animal origin. In the future, plant extracts are expected to play an more important role in the animal breeding industry.