INTRODUCTION
Pork meat is a highly demanded production worldwide, due to its rapid growth and good food conversion rate. The food for pigs represents between 60 and 70 % of total production costs (Caicedo and Caicedo 2021). In traditional pig farming, antibiotics and growth promoters were indiscriminately used, which gave rise to the appearance of resistant microorganisms and affected carcass quality (Rakotoharinome et al. 2014).
In this context, new research arises with natural additives from medicinal plants (phytobiotics), which allow the partial or total substitution of drugs in pigs diet. Beneficial bioactive compounds include carvacrol, thymol, γ-terpinene, p-cymene, sabinene, α-thujene, α-terpinene, linalool, eugenol, flavonoids, n-alkanes, sesquiterpenes, eugenol, coumarins, anthocyanidins, and saponins. However, for its implementation in the animal diet, some processing is necessary to improve the stability and quality of the product (Santamaría et al. 2015, Zaldumbide 2015, Carrión and García 2010 and Morejón 2016). The literature reports that the bioactive components of vegetables are supplied as essential oils, extracts and powders (Vázquez et al. 2013, Jaime et al. 2015 and Roura 2019).
These additives improve the taste of food, the secretion of digestive enzymes, gastric and intestinal motility, endocrine and immune stimulation, anti-inflammatory, antioxidant activity and, therefore, improvements in intake, digestibility, Food conversion and the animals weight are obtained (Gheisar and Kim 2017, Madrid et al. 2018 and Herrera and Trigueros 2019). In addition, they have great bactericidal potential against Enterococcus faecalis, Clostridium spp, Staphylococcus aureus, Escherichia coli and Salmonella spp (Ahmed et al. 2013 and Cárdenas 2014).
The increase in the palatability of diets is associated with the sensory characteristics that vegetable additives provide to pig food (Liptosa 2020). There are different products that act as antioxidants in the pig's gastrointestinal tract, able of delaying or preventing cell oxidation (Saldivar 2019). The microbial action is due to the pressure it exerts on the cell membrane, which gives place to imbalances that compromise the osmotic balance and that end with the lysis of the bacteria (Vásquez 2015 and Suryanarayana and Durga 2018). The health and integrity of the gastrointestinal tract is key in the productivity of animals; a healthy digestive tract will be one that maintains its structural and biochemical functionality, and that also has a balanced microbial population (Saldivar 2019). In fact, most antibodies are produced in the intestines, so a proper feeding management allows keeping the animal healthy (FAO 2016).
The objective of this study was to assess the use of phytobiotic additives (essential oils, powders and extracts) in the different stages of pig production.
PHYTOBIOTIC ADDITIVES FOR USE IN PIGS
At the international level, there are about 60 families of widely distributed plants, among which are: Compositae, Labiatae, Lauraceae, Myrtaceae, Pinaceae, Rosaceae, Rutaceae and Umbelliferae. Generally, they are families of plants that are found in temperate zones, such as Mediterranean and tropical countries. The active compounds of plants are in their leaves (basil, eucalyptus, peppermint, marjoram, mint, rosemary, sage, lemon balm), roots (angelica, saffron, turmeric, ginger, valerian), seeds (anise, dill, fennel, cumin), stem (cinnamon), flowers (lavender, chamomile, thyme, rose) and fruits(lemon, tangerine, orange, caraway, coriander, bay leaf, nutmeg, pepper), being stored in the secretory cells, cavities, carcass, epidermal cells or glandular trichomes that are obtained by means of steam distillation (Calsamiglia et al. 2017).
Martínez and Herradora (2019) state that 10 % of the plants that exist in the world can be considered medicinal, with many phytochemical properties. For many centuries they have been used to prevent or cure diseases that affect humans and animals. The secondary metabolites of plants are organic compounds, which are formed as a result of the main biosynthetic and metabolic ways. The presence and quantity of metabolites depends on the part of the plant that is used: stems, seeds, flowers, berries, bark or roots and both. In addition, its concentration can also be influenced by environmental conditions, the appearance of pests, as well as the sowing and harvesting season of the plant (Champagne and Boutry 2016).
In order to obtain these compounds, different methodologies are carried out for their use from the fragment of the plant. In the human and animal food industry, essential oils, powders and plant extracts are frequently used. The use of commercial or experimental phytobiotics for the pigs diet maintains a progressive rhythm, especially since the need to replace antibiotic growth promoters of synthetic origin was anticipated at the beginning of the 21st century, which began in 2006 in the European Union and, more recently, in countries such as United States and Mexico (Roura 2019). It should be noted that these additives do not have a withdrawal time, and do not generate residuality in the carcasses and, therefore, do not affect the health of consumers.
ESSENTIAL OILS
Essential oils (EO) are characterized by being aromatic substances, because their volatile components produce odors and flavors characteristic of plants (Arteaga et al. 2019). The EO contains highly volatile aromatic molecules such as (alkanes, alcohols, aldehydes, ketones, esters, and acids), monoterpenes, sesquiterpenes, and phenylpropanes. In addition, they contain compounds such as carvacrol, thymol, γ-terpinene, p-cymene, sabinene, α-thujene, α-terpinene, linalool and eugenol, depending on the plant species (Martínez et al. 2015).
A procedure for extracting EO consists of placing a 500 g sample of coarse air-dried powder (30 °C for 6 h) in the distiller, with a particle size <0.5 mm. The distillation process is carried out with a continuous flow of water steam (close to 100 °C). The process is stopped after 40 min, when it is observed that the oil volume readings remain constant. Later, the oil is separated and passed over anhydrous sodium sulfate. Then, it is passed through paper filter and kept at 4 °C in sealed vials in the dark up to 24 h, in order to ensure that oxidative degradation does not occur for their later use (Artega et al. 2019).
The supplementation of pigs diet with essential oils influences on the protection of the intestinal wall, and offers a line of defense against pathogens (Omonijo et al. 2018). The epithelial cells that make up the intestine wall need to be healthy to neutralize toxins and prevent pathogens from passing directly into the bloodstream (Jiménez 2015). As the antagonistic bacteria (Bifidobacterium and Lactobacillus) increase, they strengthen the intestinal wall and supply energy to the epithelial cells. Van and Van (2009) mentioned that EO inhibits the formation of flagella in Escherichia coli, which affects their growth and multiplication.
Hall et al. (2021) conducted a study in lactating sows supplemented with oregano EO. These authors obtained heavier piglets at one week of age, 10 weeks after weaning and at the slaughter time. Also, health records showed that piglets from litters supplemented with EO significantly reduced the incidence of therapeutic treatment and mortality. In another study, with male and female fattening pigs, the inclusion of oregano EO in the diet improved the productive yield and carcass characteristics of the animals (Janacua-Vidales et al. 2018).
Research concerning the use of EO in pig diets emphasizes its many benefits on food palatability, intestinal health, and animal productivity. Tables 1 and 2 show different commercial and experimental presentations of essential oils used in pigs.
Species (plant) | Used part | Commercial name | Trading house | Country | Composition | Category | Dose | Benefits | References |
---|---|---|---|---|---|---|---|---|---|
Oregano ( |
Leaves and flowers | Orevitol®-L | CKM | Peru |
Thymol and carvacrol |
Pre-weaning piglets Post- weaning piglets Pregnant and suckling sows |
150 to 500 mL/1000 L H2O. |
High biological activity Antimicrobial Blocks the coccidia cycle Renewal of the intestinal epithelium |
Baca and Ampuero (2019) |
Oregano ( |
Leaves and flowers | Regano 4XL | PREMIUM S.A. | Costa Rica |
Thymol and carvacrol |
Growing pigs Fattening pigs |
1.5 mL/kg of food |
Restorative of the intestinal biota Antioxidants Immunizer Weight gain promoter |
Jiménez (2015) |
Thyme ( |
Leaves and flowers | Aromex ®- YO | GmbH | Germany |
Thymol, carvacrol and flavonoids |
Growing pigs Fattening pigs |
Inclusion of 0.01 % in the diet |
Antiviral Antimicrobial Antioxidant Antiseptic |
Yan |
True cinnamon ( |
Leaf, seed and stem | Aromex ®- ME | GmbH | Germany |
N-alkanes, sesquiterpenesand oxigenated compounds such as hexanol, eugenol and mucilage |
Growing pigs Fattening pigs |
Inclusion of 0.01 % in the diet |
Reduces heat strees Antimicrobial Antioxidant |
Lan and Kim (2018) |
Oregano ( |
Leaves | Orego-Stim | Meriden Animal Health Ltd. | United Kingdom |
Carvacrol (81.92 %) and thymol (3.50 %). |
Pregnant sows Suckling sows |
15 g/kg of food |
Better piglet performance Decreased stress |
Tan |
Broccoli extract ( |
Different parts | Sipernat® | GmbH | Germany |
Terpenes, carvacrol, thymol and 1.8-cineole |
Post- weaning piglets |
150 mg/kg of food |
Antioxidant Antiviral Anti-inflammatory Immunomodulator |
Mueller |
Products | Stage | Indicators | References |
---|---|---|---|
Orevitol®-L 500 ppm | Post-weaning | Treatment days (12) Initial weight, kg (6.60) Final weight, kg (7.77) Daily food intake, kg (1.61) Food conversion, kg/kg (1.07) |
Baca and Ampuero (2019) |
Oregano essential oil 0.6 cm3/animal | Post- weaning | Treatment days (42) Initial average weight, kg (8.30) Final weight, kg (24.91) Daily weight gain, kg (0.38) |
Guerra |
Brocoli extract ( |
Post- weaning | Treatment days (28) Initial weight, kg (9.50) Final weight, kg (21) Daily food intake, kg (1.73) Daily weight gain, kg (0.76) Food conversion, kg/kg (1.41) |
Mueller |
Aromex ®- YO (thyme, rosemary, oregano, inclusion of 0.01 % in the diet | Growing | Treatment days (42) Initial average weight, kg (23.67) Weight gain, kg (25.66) Final average weight, kg (49.33) Food conversion, kg/kg (2.45) Total food intake, kg (63.04) |
Yan |
Aromex ®- ME (Original cinnamon, fenugreek, subterranean clover), inclusion of 0.01 % in the diet | Growing | Treatment days (42) Initial average weight, kg (24.08) Weight gain, kg (28.92) Final average weight, kg (53) Food conversion, kg/kg (2.26) Total food intake, kg (65.48) |
Lan and Kim (2018) |
Regano 4XL 1.5 mL/kg of food | Fattening | Treatments days (60) Initial weight, kg (55.76) Final weight, kg (112.86) Total food intake, kg (105) Food conversion, kg/kg (1.83) |
Jiménez (2015) |
Orego-Stim, inclusion of 15 g/kg of food | Pregnancy | Treatment days (115) Daily food intake, kg (2.50) Initial average weight, kg (234) Final average weight, kg (268.10) Average number of piglets born/sow (11.28) Average number of piglets alive/sow (11.16) Average number of piglets weaned/ sow (9.60) Weight of piglets at farrowing, kg (1.56) |
Tan |
VEGETABLE POWDERS
To obtain plant powders, the root, stem and foliage of plant species with medicinal potential, free of pests and diseases, are used (Granados-Echegoyen et al. 2016). A low-cost methodology consists on dehydrating the samples for 7 d in the shade on perforated cardboard plates, which are removed twice a day. Subsequently, they are placed in an oven, with air recirculation for 1 h at 60 °C (Salazar et al. 2019). Next, the samples are grinded in a parallel blade hammer mill, to 1 mm particle size (Más Toro et al. 2017). They are kept at room temperature in amber bottles to avoid loss of active substances due to light action (Yin et al. 1993).
The active substances present in the powder of medicinal plants have antibacterial, antiviral, antifungal, antitumor, anthelmintic, analgesic, anti-inflammatory, hypotensive and immunostimulant properties (Más Toro et al. 2017). By adding medicinal plant powders to the pigs diet in the digestive tract, the development of intestinal pathogens (E. coli, Bacteroides spp. and Clostridium spp) is inhibited and increases the beneficial microbial population that contributes to improving digestion and absorption of nutrients, with increased weight gain, as well as a decrease in diarrheal syndrome in post-weaning piglets (Segarra 2016).
Vegetable powders are easy to prepare, and special equipment is not required for their preparation, as is the case with EO. The use of vegetable powders can be a good alternative as an additive in pigs diet in order to reduce dependence on antibiotics and synthetic growth promoters, which cause resistance of pathogenic microbes and residuality on the carcass. Tables 3 and 4 show different vegetable powders used as additives in pig production.
Species (plant) | Used part | Presentation | Composition | Category | Dose | Benefits | References |
---|---|---|---|---|---|---|---|
Ginger( |
Rhizome | Pure powder |
Acids (linoleic, ascorbic) Shoagoles Gingerol Amino acids (arginine, niacin, threonine) |
Post-weaning piglets Growing pigs Fattening pigs |
Inclusion of 300 to 400 mg/kg of food |
Reduces parasitic, fungal and bacterial load Effect on intestinal microvilli |
Reyes (2015) |
Cashew ( |
Leaf | Mixed powder |
Quinones tripterpenes and steroids, free amino acids, reducing carbohydrates, phenols, tannins, anthocyanidins |
Post- weaning piglets |
Inclusion of 1% in the diet |
Nutraceutical properties (antibacterial, antioxidants and anti-inflammatory) Decreases the incidence of diarrhea |
Aroche-Ginarte |
Guava ( |
Leaf | Mixed powder |
Tannins, coumarins and anthocyanidins |
Pre and post weaning piglets |
Inclusion of 0.5 and 1 % in the diet |
Antidiarrheal Growth promoter Anti-inflammatory Antioxidant and antibacterial |
Más Toro |
Guava ( |
Leaf | Pure powder |
Polysaccharides, pectins, vitamins, steroids, glycosides, tannins, flavonoids and saponins |
Post-weaning piglets |
Inclusion of 1 g/100 g of food |
Antioxidant capacity Better intake Reduction of diarrhea |
Caicedo |
Garlic ( |
Bulb | Fermented powder |
Diallyl disulfide, allicin and allicin |
Fattening pigs |
Inclusion of 2 to 4g/kg of food |
Better yield Better marbling of meat Antimicrobial |
Yan |
Moringa ( |
Leaves and stem | Pure powder |
Phenols, flavonoids, proanthocyanidins and flavonols. |
Pregnant sows |
Inclusion of 8 % in the diet |
Better productive yield Antioxidant Higher protein level in colostrum |
Jia-Jie |
Red quebracho ( |
Stem | Pure powder |
Polyphenols, catenins |
Fattening pigs |
Inclusion of 500 g/t of food |
Bactericide Better intestinal integrity Better absortion of nutrients and drier feces |
Rojas (2016) |
Products | Stage | Indicators | References |
---|---|---|---|
Cashew leaves , inclusion of 1% in the diet | Pre-weaning | Treatment days (12) Initial weight, kg (5.0) Final weight, kg (6.6) Daily food intake, kg (0.05) Weight gain kg (1.60) Food conversion, kg/kg (1.51) |
Mas Toro |
Mixture of cashew leaves, guava and moringa, inclusion of 1 % in the diet | Post- weaning | Treatment days (42) Initial weight, kg (7.86) Final weight, kg (23.56) Daily food intake, kg (0.37) Daily weight gain, kg (0.37) Weight gain, kg (15.70) Food conversion , kg/kg (2.39) |
Aroche-Ginarte |
Guava leaf, inclusion of 1 g/100 g of food | Post-weaning | Treatment days (15) Initial weight, kg (9.17) Final weight, kg (13.52) Daily food intake, kg (0.35) Daily weight gain, kg (0.29) Weight gain, kg (4.35) Food conversion, kg/kg (1.35) |
Caicedo |
Dried ginger rhizome, inclusion of 400 mg/kg of food | Growing | Treatment days (70) Initial weight, kg (10.83) Final weight, kg (42.55) Daily weight gain, kg (0.45) Daily food intake, kg (1.01) Food conversion, kg/kg 2.21 Weight gain, kg (31.72) Total food intake , kg (70.28) |
Reyes (2015) |
Stem of red quebracho , inclusion of 500 g/t of food | Fattening | Treatment days (30) Initial weight, kg (73.61) Weight gain, kg (20.61) Daily weight gain, kg (0.68) Food conversion, kg/kg (3.02) Total food intake kg (62.22) Final weight, kg (94.22) |
Rojas (2016) |
Dried garlic, inclusion of 2 g/kg of food | Fattening | Treatment days (84) Initial weight, kg (55.91) Weight gain, kg (65) Daily weight gain, kg (0.77) Food conversion, kg/kg (2.25) Total food intake, kg (189) Final weight, kg (121.18) |
Yan |
Moringa leaf, inclusion of 8 % in the diet | Pregnancy | Treatment days (150) Food intake before mating kg/d/sow (2.50) Intake during pregnancy kg/d/sow (2.10) Average initial weight of sows, kg (140) Average number of piglets born /sow (13.50) Average number of piglets alive/sow (11.57) Litter weight at born, kg (19.16) Average weight of the piglet at born, kg (1.38) |
Jia-Jie |
VEGETABLE EXTRACTS
Plant extracts belong to the group of additives classified as aromatic and flavoring, which include all natural products and the corresponding synthetic products that can be used in all animal species, without limitation of age or dose. The use of macerates, decoction, infusion and boiled preparations is the most common way of taking advantage of plant resources to overcome various disorders such as rheumatism, diarrhea, diabetes mellitus, cough, bical ulcers, cholesterol reduction and as an antibacterial against Vibrio cholerae, Shigella flexneri, S. aureus, Salmonella spp., E. coli, Pseudomonas aeruginosa and Candida albicans (Gonçalves et al. 2008, Gutiérrez et al. 2008, Birdi et al. 2010, Metwally et al. 2010, Sanda et al. 2011, Shruthi et al. 2013 and Morais-Braga et a.l 2016).
Plant extracts are cheaper and more practical compared to powders and EO. They are easy to prepare and apply. Regarding the benefits obtained when using them, their stability and tolerance should be highlighted, since they can be used in all animal species, without restriction of age or product concentration (Hanczakowska and Swiatkiewicz 2012, García- Risco et al. 2015 and Santamaría et al. 2015).
Plant extracts are a good alternative for use as an additive in pig diets, since they are low cost and provide benefits in the sensory characteristics of the food, with the consequent increase in dry matter intake. The researches in pigs show that the use of plant extracts improves productive yield, digestibility of dry matter and protein. In addition, it provides anti-inflammatory and antimicrobial effects against various pathogens, with improvements in meat quality parameters (Isley et al. 2003, Liu et al. 2013, Devi et al. 2015 and Hanczakowska et al. 2015). Tables 5 and 6 show different studies with plant extracts for use in pigs.
Species (plant) | Used part | Commercial name | Trading house | Country | Composition | Category | Dose | Benefits | References |
---|---|---|---|---|---|---|---|---|---|
Mixture between Thyme ( |
Whole plant and seeds | Dysantic® | Vetanco | Argentina | Galactopyranose, thymol, carvacrol and flavonoids |
Post-weaning and growing pigs |
Inclusion of 0.1 and 0.2 % in the food |
Bactericide Viricide Inmune modulator Stability of the gastrointestinal biota |
Zamora (2018) |
Mixture of artichoke( |
Several parts | Protorgan® | GUWLAB | Mexico | Polyphenols, quercetins, apigenin, phytoestrogens | Fattening and growing pigs |
Inclusion of 0.1 and 0.15 % in the food |
Grow promoter Antioxidant Improved intake and weight gain |
Dávila-Ramírez |
Soapbark |
Leaves and flowers | Hibotek | CCLabs | Ecuador | Fatty acids Omega 3 vitamin E. Heterogeneous group of sterol glycosides and triterpenoids |
Growing and fattening pigs |
Inclusion of 150, 200, 250 and 300 p.p.m. in the food |
Grow promoter Environmental ammonia reducer Antibiotic action, Antiprotozoarica and Antifungal. |
De La Cueva (2013) |
Cinnamon |
Stem | Re ProPlus | PlusVet Animal Health | China | Plant extracts, organic acids, natural origin omega-3fatty acids and mycotoxin sequestrants. |
Pregnancy sows |
Inclusion of 10 g/sow/day |
Improved intestinal health Increased milk production Reduces the incidence of mastitis, metritis and agalactia Increased food intake during lactation |
PVAH (2019) |
Wild anise ( |
Leaves | Cooked extract of wild anise foliage | - | - | Polyphenols and tannins |
Post-weaning piglets |
Inclusion of 10 mL/100 g of food |
Improves food intake, weight gain, Food conversion and final weight. Decreases the incidence of diarrhea |
Caicedo |
Ginger ( |
Rhizome | Soapbark extract | - | - | Fatty acids, fiber, essential oils, amino acids and minerals. Aromatic principles: zingiberene bisabolene Punget principles: gingerols and shogaols |
Growing and fattening pigs |
Inclusion of 0.25, 0.5, 0.75 and 1 % in the food |
Acts as stimulant and antibacterial Improves digestion by increasing absorption Avoid respiratory problems Increases blood flow |
Segarra (2016) |
Spanish chestnut ( |
Leaves | Spanish chestnut extract | - | - | Heterogeneouspolymeric tannins formed by phenolic acids, in particular gallic acids, and simple sugars. |
Growing and fattening pigs |
Inclusion of 0.2% in the food |
Reduces oxidative stress Improve their productive performance Antimicrobial activity |
Aguirre-Meza |
Guava ( |
Leaf | Cooked extract of guava foliage | - | - | Polysaccharides, pectins, vitamins, steroids, glycosides, tannins, flavonoids and saponins |
Post-weaning pigs |
Inclusion of 10 mL/100 g of food |
Antioxidant capacity Improved intake, weight gain, Food conversion, final weight Reduction of diarrhea |
Caicedo |
Product | Stage | Indicators | References |
---|---|---|---|
Dysantic® (thyme), inclusion of 0.1 % in the diet | Pre- weaning | Treatment days (24) Initial weight, kg (6.68) Final weight, kg (8.96) Daily food intake, kg (0.28) Daily weight gain, kg (0.17) Food conversion, kg/kg (1.13) |
Zamora (2018) |
Wild anise, inclusion of 10 ml/100 g of food | Post-weaning | Treatment days (14) Initial weight, kg (6.06) Final weight, kg (8.94) Daily food intake, kg (0.34) Daily weight gain, kg (0.23) Weight gain, kg (2.88) Food conversion, kg/kg (1.71) |
Caicedo |
Hibotek (Soapbark), inclusion of 300 ppm in the diet | Growing | Treatment days (90) Initial weight, kg (15.22) Final weight, kg (73.82) Daily weight gain, kg (0.74) Daily food intake, kg (1.64) Food conversion, kg/kg (3.81) Weight gain, kg (58.60) Total food intake ,kg (147.64) |
De La Cueva (2013) |
Protorgan®, inclusion of 0.1% in the diet | Growing | Initial weight, kg (30) Final weight, kg (70) Daily food intake, kg (2.3) Food conversion, kg/kg (2.3) |
Dávila-Ramírez |
Ginger rhizome, inclusion of 0.75% in the diet | Growing | Treatment days (80) Initial weight, kg (17.45) Final weight, kg (82.5) Daily weight gain, kg (0.80) Daily food intake, kg (2.80) Food conversion, kg/kg (2.87) Weight gain, kg (65.05) Total food intake, kg (227.27) |
Segarra (2016) |
Spanish chestnut, inclusion of 0.2% in the diet | Fattening | Treatment days (40) Initial weight, kg (60.18) Weight gain, kg (27.99) Daily weight gain, kg (0.68) Food conversion, kg/kg (3.07) Final weight, kg (88.17) |
Aguirre-Meza |
Re ProPlus (cinnamon), inclusion of 10 g/day in the diet | Pregnancy | Pregnancy days (70) Treatment days (45) Average number of piglets born/sow (12.07) Average number of piglets alive/sow (11.37) Average weight of piglets at born, kg (1.04) |
PVAH (2019) |
CONCLUSIONS
The use of commercial and experimental phytobiotic additives constitutes an alternative to the excessive use of synthetic antibiotics, which act as growth promoters in pigs. These additives are supplied to animals as essential oils, powders and extracts to improve food intake, weight gain, Food conversion, final weight, carcass characteristics and reduce the incidence of diarrhea after weaning. The supplementation with phytobiotics in pigs diet is totally innocuous, that is, it does not have a withdrawal period, without wastes in tissues, and does not generate microbial resistance.