Dietary effects of a mix derived from oregano (Origanum vulgare L.) essential oil and sweet chestnut (Castanea sativa Mill.) wood extract on pig performance, oxidative status and pork quality traits

Effects of Dietary Lonicera flos and Sucutellaria baicalensis Mixed Extracts Supplementation on Reproductive Performance, Umbilical Cord Blood Parameters, Colostrum Ingredients and Immunoglobulin Contents of Late-Pregnant Sows

The present study aimed to determine the effects of dietary Lonicera flos and Sucutellaria baicalensis mixed extract (LSE) supplementation during the late-pregnancy period on the reproductive performance, umbilical cord blood hematological parameters, umbilical cord serum biochemical parameters, immune indices, hormone levels, colostrum ingredients, and immunoglobulin contents of sows. A total of 40 hybrid pregnant sows were randomly assigned to the control group (CON; sows fed a basal diet) and LSE group (LSE; sows fed a basal diet supplemented with 500 g/t PE). The results indicated that dietary LSE supplementation significantly increased (p < 0.05) the number of alive and healthy piglets and the litter weight at birth, and significantly increased (p < 0.05) the platelet counts in umbilical cord blood. Dietary LSE supplementation significantly increased (p < 0.05) the levels of prolactin (PRL) and growth hormone (GH), and the content of interleukin 2 (IL-2) in umbilical cord serum. Moreover, immunoglobulin A (IgA) and immunoglobulin M (IgM) in the colostrum were increased with PE supplementation (p < 0.05). In conclusion, dietary LSE supplementation in late-pregnancy sows could improve reproductive performance and colostrum quality, and could also regulate the levels of reproductive hormone in umbilical cord serum.

Phytogenic feed additives as natural antibiotic alternatives in animal health and production: A review of the literature of the last decade

The use of antibiotics in animal production raises great public safety concerns; therefore, there is an urgent need for the development of substitutes for antibiotics. In recent decades, plant-derived feed additives have been widely investigated as antibiotic alternatives for use in animal health and production because they exert multiple biological functions and are less likely to induce resistance development. This review summarizes the research history and classification of phytogenic feed additives and their main functions, potential modes of action, influencing factors, and potential negative effects. Further, we highlight the challenges in developing sustainable, safe, and affordable plant-derived antibiotic alternatives for use in livestock production.

A review on the alternatives to antibiotics and the treatment of antibiotic pollution: Current development and future prospects

Antibiotics, widely used in the fields of medicine, animal husbandry, aquaculture, and agriculture, pose a serious threat to the ecological environment and human health. To prevent antibiotic pollution, efforts have been made in recent years to explore alternative options for antibiotics in animal feed, but the effectiveness of these alternatives in replacing antibiotics is not thoroughly understood due to the variation from case to case. Furthermore, a systematic summary of the specific applications and limitations of antibiotic removal techniques in the environment is crucial for developing effective strategies to address antibiotic contamination. This comprehensive review summarized the current development and potential issues on different types of antibiotic substitutes, such as enzyme preparations, probiotics, and plant extracts. Meanwhile, the existing technologies for antibiotic residue removal were discussed under the scope of application and limitation. The present work aims to highlight the strategy of controlling antibiotics from the source and provide valuable insights for green and efficient antibiotic treatment.

Beneficial Effects of Castanea sativa Wood Extract on the Human Body and Possible Food and Pharmaceutical Applications

The aim of this review was to investigate the potential use of Castanea sativa wood extract as a food supplement and to evaluate its beneficial properties for human health. The results of the limited amount of studies suggest promising properties, including potential anti-inflammatory effects. The literature indicates that the extract, which is rich in bioactive compounds such as tannins, offers promising therapeutic possibilities for the treatment of conditions associated with chronic inflammation. Consequently, interest in its use in food and pharmaceuticals is growing. Phytochemical studies have reported antioxidant and antimicrobial activities, and anti-inflammatory, anticancer, hypolipidemic, hypoglycemic, and neuroprotective activities. A suitable extraction method and solvent is crucial for the isolation of bioactive compounds, being green extraction technologies outstanding for the industrial recovery of chestnut wood's bioactive compounds. Nevertheless, it is important to emphasize the importance of adhering to regulatory guidelines and obtaining the necessary approvals from regulatory authorities to ensure product safety and compliance. The regulation of herbal medicinal products with proven efficacy and traditional herbal medicinal products is well defined, monitored by authorized bodies, and subject to strict control measures. It is noteworthy that medicinal products are subject to stringent quality testing to ensure safety and efficacy in use, whereas there are no comparable regulatory standards and specific labeling requirements for dietary supplements. When using herbal products, compliance with established standards in health research is essential.

Performance and meat quality in pigs fed hydrolysable tannins from Tara spinosa

This study aimed to assess the effect of dietary tara (Tara spinosa (Feuillée ex Molina) Britton & Rose) hydrolysable tannins on performance and meat quality of finishing pigs. Twenty barrows (crossbred PIC × Piétrain; age: 125 ± 5 d; bodyweight: 60.8 ± 3.89 kg) were randomly assigned to two groups and fed ad libitum for 7 weeks a control diet (CON) or a diet supplemented with 10 g/kg of tara tannins (TAT), respectively. No differences (P > 0.10) on growth performance and carcass traits were observed between the two groups. Meat fatty acid profile was not affected (P > 0.10) by the diet, but the content of C22:5 n-3 tended to be lower (P = 0.079) in TAT pork. Dietary tannins tended to reduce (P = 0.095) meat cholesterol. The diet had no effect (P > 0.10) on fat-soluble antioxidant vitamins, hydrophilic antioxidant capacity, catalase activity, and glutathione peroxidase activity. Superoxide dismutase activity tended to be lower (P = 0.087) in TAT meat than in CON meat. Dietary tannins did not affect (P > 0.10) backfat and meat color development during 6 days of refrigerated storage, but TAT meat tended to be darker (P = 0.082). Meat from pigs fed tara tannins showed lower (P = 0.028) hydroperoxides content and a tendency toward lower conjugated dienes (P = 0.079) and malondialdehyde (P = 0.084) contents. Also, dietary tannins delayed lipid oxidation in meat subjected to oxidative challenges such as catalysis and cooking (P < 0.05). The positive effect of dietary tara hydrolysable tannins on lipid oxidation was likely due to their antioxidant and anti-inflammatory capacity, but it may have been mitigated by the high α-tocopherol content in meat.

Effect of Thyme (Thymus vulgaris L.) Used in Diets with Extruded Flaxseed on the Antioxidant and Lipid Profile of the Blood and Tissues of Fattening Pigs

Thyme has strong antioxidant properties and, therefore, can reduce the intensity of oxidative processes taking place in the body. The study aimed to assess whether the addition of thyme to diets for fattening pigs containing extruded flaxseeds, a source of n-3 PUFAs, which are particularly susceptible to oxidation, would have a positive effect on redox status and lipid metabolism. The experiment was conducted using 120 weaners (WBP × Neckar crosses) of about 30 kg BW, which were kept until the end of fattening (about 110 kg BW) and divided into three groups of 40 pigs. The control group received a diet with 4% extruded flaxseed. In groups T1 and T3, 1% or 3% of thyme was added to the basal diet. The introduction of 3% thyme resulted in a decrease in the total cholesterol level in the blood and the loin muscle. Moreover, an increase in SOD and CAT activity and a decrease in FRAP and LOOH was noted. Following supplementation with 3% thyme, the n-3 PUFA content and n-3/n-6 ratio increased, while the SFA content was significantly reduced. The results of the studies indicate that thyme has a positive effect on the redox status and lipid profile of the blood and muscles.

Sex Does Not Affect the Colour, Shear Stress, and Lipid Oxidation of Pork Meat, but Feed-Added Plant-Derived Extracts, Storage Time and Packaging Type Do

Essential plant oils added to products, packaging or animal feed are used as a method of preserving food quality because they extend the shelf-life of meat due their antioxidant and/or antimicrobial capacity. This action can be achieved with the correct packaging that preserves the meat's quality and safety. This study investigates the effects of plant-derived extracts (PDE) on the meat quality and shelf-life of pork packaged in vacuum or modified atmosphere packaging (MAP). Thirty-six barrows and thirty-six gilts were allocated into three experimental groups: the control, garlic extract (1 kg/ton of feed) and oregano-rosemary oil (2 kg/ton of feed) with the same base-diet. Two packaging were used: vacuum and a commercial MAP (70% O₂, 30% CO₂). The meat fat content, pH, colour, TBARS values and Warner-Bratzler shear stress were investigated. The sex of the animals did not affect any of the studied variables, whereas PDE affected some of the colour variables and the shear stress; both the packaging type and the storage time affected the colour variables, lipid oxidation and shear stress. Vacuum-packed meat was more stable in terms of colour, lipid oxidation and shear stress than MAP-packed meat.

RNA-Seq Study on the Longissimus thoracis Muscle of Italian Large White Pigs Fed Extruded Linseed with or without Antioxidants and Polyphenols

The addition of n-3 polyunsaturated fatty acids (n-3 PUFAs) to the swine diet increases their content in muscle cells, and the additional supplementation of antioxidants promotes their oxidative stability. However, to date, the functionality of these components within muscle tissue is not well understood. Using a published RNA-seq dataset and a selective workflow, the study aimed to find the differences in gene expression and investigate how differentially expressed genes (DEGs) were implicated in the cellular composition and metabolism of muscle tissue of 48 Italian Large White pigs under different dietary conditions. A functional enrichment analysis of DEGs, using Cytoscape, revealed that the diet enriched with extruded linseed and supplemented with vitamin E and selenium promoted a more rapid and massive immune system response because the overall function of muscle tissue was improved, while those enriched with extruded linseed and supplemented with grape skin and oregano extracts promoted the presence and oxidative stability of n-3 PUFAs, increasing the anti-inflammatory potential of the muscular tissue.

Incorporation of copaiba and oregano essential oils on the shelf life of fresh ground beef patties under display: Evaluation of their impact on quality parameters and sensory attributes

The preservative effect of the addition of different essential oils (copaiba and oregano) on meat quality parameters and sensorial acceptability was analyzed for fresh ground beef patties over 21 days of display. Five treatments were assessed: control (CON) without antioxidants; addition of the synthetic additive butylated hydroxytoluene (BHT); addition 0.05% of copaiba essential oil (CEO); 0.05% of oregano essential oil (OEO); or blend of 0.025% copaiba and 0.025% oregano essential oils (BEO). The lowest cooking losses and greatest tenderness (P <0.05) were reached with the blend (BEO). The inclusion of oregano essential oil presented a more intense chroma (P <0.05), with the best color retained during display. Oregano essential oil (OEO) and the blend (BEO) showed the highest antioxidant activity, reducing the lipid oxidation of beef patties during display (P < 0.05). Consumers preferred the odor of beef patties with essential oils (OEO and BEO) to the CON; however, the flavor from OEO had the lowest acceptability and the worst scores for overall acceptability (P < 0.05). Patties with the blend addition (BEO) were the best scored on overall acceptability assessments. In conclusion, the oregano and copaiba essential oils blend had a good preservative effect on fresh beef patties during display and increased sensory acceptability of the product, thus being a possible alternative for replacing synthetic compounds in processed foods.

Effect of dietary magnolia bark extract supplementation in finishing pigs on the oxidative stability of meat

BACKGROUND

Magnolia bark extract (MBE) is a natural supplement with antioxidant, anti-inflammatory, and antimicrobial activities. Its properties suggest that the dietary supplementation in livestock could improve the quality of products. Therefore, the aim of this study was to investigate, for the first time, the effect of dietary MBE supplementation (0.33 mg/kg) in finishing pigs on the oxidative stability of meat. Oxidative stability is of paramount importance for pork, as it affects storage, retail, and consumer acceptance. For the purpose, the fatty acid profile, cholesterol, fat-soluble vitamins, antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase), non-enzymatic antioxidant capacity (TEAC, FRAP, and Folin-Ciocalteu assays), color stability, and lipid stability of pork were assessed.

RESULTS

Concerning carcass characteristics, dietary MBE did not affect cold carcass yield, but reduced (P = 0.040) the chilling weight loss. The meat from pigs fed MBE had a lower (P = 0.031) lightness index than the control meat. No effect on intramuscular fat, cholesterol, and fatty acid profile was observed. Dietary MBE did not affect the content of vitamin E (α-tocopherol and γ-tocopherol) in pork, whereas it reduced (P = 0.021) the retinol content. The catalase activity was 18% higher (P = 0.008) in the meat from pigs fed MBE compared with the control group. The MBE supplementation reduced (P = 0.039) by 30% the thiobarbituric acid reactive substances (TBARS) in raw pork over 6 d of aerobic refrigerated storage. Instead, no effect on lipid oxidation was observed in cooked pork. Last, the meat from pigs fed MBE reduced Fe³⁺-ascorbate catalyzed lipid oxidation in muscle homogenates, with a lower (P = 0.034) TBARS value than the control group after 60 min of incubation.

CONCLUSIONS

Dietary MBE supplementation in finishing pigs delayed the lipid oxidation in raw meat. This effect was combined with an increased catalase concentration. These results suggest that dietary MBE could have implications for improving the shelf-life of pork.

Impact of Fennel Essential Oil as an Antibiotic Alternative in Rabbit Diet on Antioxidant Enzymes Levels, Growth Performance, and Meat Quality

In the current study, fennel essential oil was used as an antibiotic alternative compared to gentamycin for enhancing the expression of apoptosis genes and antioxidant enzymes in weaned rabbits as well as meat quality and growth performance. The gene expression of the cell lymphoma 2 (BAX and BCL2), caspase3 (CASP3), and glutathione peroxidase (GPX1) were estimated in the liver tissue using qRT-PCR. A total of 45 Moshtohor weaned male rabbits aged four weeks were randomly allocated to control, T1, and T2 treatment groups; each consisted of 15 weaned male rabbits with five replicates. Rabbits in the T1 and T2 groups were orally supplied with 1 mL fennel oil and 1 mL gentamycin, respectively. Weaned rabbits under different treatments showed increased body weight (BW) at 8 and 12 weeks of age and average daily gain (ADG) at 4-8 and 4-12 weeks of age compared to the control group. Compared to the controls, the weaned rabbits supplemented with fennel oil and gentamycin had lower total cholesterol, triglyceride, and MDA. In addition, villus length, mRNA of BAX, BCL2, Casp3, and GPX were increased in the different treatments compared to the control. Furthermore, the meat of these rabbits was less tender, had a lower aerobic plate count (APC), pH, and was brighter and redder in color than the control. Under the conditions of the present study, the supplementation of weaned Moshtohor rabbits with fennel oil as a natural alternative for gentamycin enhanced feed conversion and daily gain through enhancing villus length and mucus thickness. Additionally, fennel essential oil reduces oxidative stress by increasing the antioxidant enzymes.

Effects of Chinese wolfberry and astragalus extracts on growth performance, pork quality, and unsaturated fatty acid metabolism regulation in Tibetan fragrant pigs

We studied the effects of wolfberry and astragalus extract on the growth performance, carcass traits, and meat quality of Tibetan fragrant pigs, and we want to explain the mechanism of the difference from the level of RNA Seq. Twelve healthy 120-day-old Tibetan fragrant pigs weighing 35 ± 2 kg were divided randomly into two groups, each with six pigs. The control group was fed a basal diet, and the wolfberry and astragalus extract (WAE) group was fed a basal diet +1‰ of WAE. The experimental period was 90 days. Compared with the control group, the growth performance of the WAE group was significantly improved (p < .05), pork marble score significantly improved (p < .05), vitamin E content significantly increased (p < .05), unsaturated fatty acid content significantly increased (p < .05). A total of 256 differentially expressed genes were obtained by transcriptome sequencing, among which 114 were up-regulated and 142 were down-regulated. GO analysis showed that the differentially expressed genes were related to biological functions, such as monounsaturated fatty acid biosynthesis, fatty acid metabolism, lipoprotein decomposition, and lipase activity. Pathway analysis showed that these differentially expressed genes were mainly involved in unsaturated fatty acid biosynthesis regulation, glycerin metabolism, and lipopolysaccharide regulation in fat. WAE improved Tibetan fragrant pigs growth performance. By intervening in key genes related to fatty acid metabolism, the unsaturated fatty acid contents in pork were regulated, which improved the nutritional value of the pork.

Dietary ethanol extract of mango increases antioxidant activity of pork

Ethanol extract of mango seeds (EEMS) are composed of several polyphenolic compounds with considerable in vitro antioxidant activity that can be used in pig feed and may contribute positively to meat quality characteristics. The aim of this study was to evaluate the effect of EEMS as a source of antioxidants in growing-finishing pig diets on meat quality, lipid stability, sulfhydryl groups non-proteinaceous (SG-NP), total phenolic compounds, total antioxidant potential and total antioxidant activity of meat after 1 and 7 days of refrigeration storage. Thirty-two (60-day-old) barrows, weighing 20.20 ± 1.34 kg, were used in a randomized block design consisting of eight animals with four treatment regimens. Treatments consisted of: Control = no dietary antioxidant; butylated hydroxytoluene (BHT) = diet with 200 ppm BHT; EEMS200 = diet with 200 ppm EEMS; EEMS400 = diet with 400 ppm EEMS. At 145 days of age and average weight of 95.47 ± 6.19 kg, the animals were slaughtered and loin samples were collected and frozen before for qualitative analysis and evaluation of the effect of subsequent storage for 1 or 7 days at 8 °C on lipid stability, SG-NP, phenolic compounds, total antioxidant capacity and total antioxidant activity Meat from animals fed EEMS400 diet showed lower cooking loss (P < 0.0001) and higher non-protein sulfhydryl groups, phenolic compounds and total antioxidant activity at both 1 and 7 days of storage (P < 0.0001) compared to the other treatments. Greater antioxidant capacity was observed at 1 day storage in the meat of animals that consumed EEMS regardless of concentration when compared to the control group (P < 0.01). The dietary inclusion of EEMS to pig diets is more effective at 400 ppm in improving meat quality after cooking and antioxidant parameters of pork.

Review: Chestnut and quebracho tannins in pig nutrition: the effects on performance and intestinal health

Natural extracts are frequently adopted as a valuable alternative to antibiotics in intensive animal farming. Their diverse bioactive constituents such as phytosterols, glucosinolates, carotenoids and polyphenols have shown antioxidant, anti-inflammatory and antibacterial effects. Tannins are the largest class of polyphenol compounds of plant extracts, which can be classified into two hydrolysable or condensed subgroups. Poultry and swine nutrition are the most important sectors in which tannins have been used, firstly adopting tannin-rich feedstuffs and more recently, using tannin extracts from different plants. Several commercial products are available containing tannins extracted from the European chestnut tree (Castanea sativa Mill.) and the American quebracho (Schinopsis spp.). Tannins extracted from these plants have been applied on intensive swine farms due to their ability to improve animal performance and health. These positive and prominent effects are frequently associated with the antinutritional effects in reducing feed palatability, digestibility and protein utilization of feed. Some criticisms and contrasting results regarding pig performance and intestinal health have been reported. This paper provides an overview of the effects of chestnut and quebracho tannins on growth performance and intestinal health of pigs in order to clarify the appropriate dosage and response in the various physiological stages.

Plant-Derived Natural Antioxidants in Meat and Meat Products

The global meat industry is constantly evolving due to changes in consumer preferences, concerns and lifestyles, as well as monetary, geographical, political, cultural and religious factors. Part of this evolution is the introduction of synthetic antioxidants to increase meat and meat products' shelf-life, and reduce meat spoilage due to lipid and protein oxidation. The public perception that natural compounds are safer and healthier per se has motivated the meat industry to replace synthetic antioxidants with plant-derived ones in meat systems. Despite several promising results from in vitro and in situ studies, the effectiveness of plant-derived antioxidants against lipid and protein oxidation has not been fully documented. Moreover, the utility, usability, marketability and potential health benefits of natural antioxidants are not yet fully proven. The present review aims to (i) describe the major chemical groups of plant-derived antioxidants and their courses of action; (ii) present the application of spices, herbs and fruits as antioxidants in meat systems; and (iii) discuss the legislative framework, future trends, challenges and limitations that are expected to shape their acceptance and mass exploitation by the meat industry.

Pig feedstuff effect on the physicochemical and sensory properties of low-salt, dry-fermented sausages

This study investigates the effect of the addition of plant-derived extracts (control, garlic extract or a combination of carvacrol, thymol, cinnamic aldehyde and eugenol oils extracts) to pig feedstuff and the reduction in salt content (NaCl or a mixture 60:40 sodium chloride:potassium lactate) on some physicochemical characteristics and consumer acceptability of dry-fermented sausages. Six different batches were formulated. The pH, color, lipid oxidation, and microbial counts were measured, and a consumer home test was performed. Both the use of a plant-derived extract and salt type affected the dry-fermented sausage characteristics. The low-salt batches presented a lower pH and higher microbial counts than the control. The salt reduction affected the color but only in the oil batches, resulting in higher L* and lower a* values. The oil batches presented the highest TBAR values (>1 mg/kg), suggesting that antioxidant compounds present into the meat were not bioavailable on the sausages or were missed during the curing process. The use of plant-derived extracts affected to consumer acceptability, whereas salt replacement did not. Oil batches scored lower than the other. From the current results, the oil extract would not be a recommended additive in pig feedstuff, especially when a low-salt strategy will be employed.

Natural Phenolic Compounds for the Control of Oxidation, Bacterial Spoilage, and Foodborne Pathogens in Meat

Alternative technologies for long-term preservation, quality assurance, and safety of meat are continuously pursued by the food industry to satisfy the demands of modern consumers for nutritious and healthy meat-based products. Naturally occurring phenolic compounds are considered promising substances by the meat industry for their antioxidant and antimicrobial properties, while consumers seem to embrace them for their claimed health benefits. Despite the numerous in vitro and in situ studies demonstrating their beneficial effects against meat oxidation, spoilage, and foodborne pathogens, wide application and commercialization has not been yet achieved. Major obstacles are still the scarcity of legislative framework, the large variety of meat-based products and targeted pathogens, the limited number of case-specific application protocols and the questionable universal efficiency of the applied ones. The objectives of the present review are i) to summarize the current knowledge about the applications of naturally occurring phenols in meat and meat-based products, emphasizing the mechanisms, determinants, and spectrum of their antioxidant and antimicrobial activity; ii) to present state-of-the-art technologies utilized for the application of phenolic compounds in meat systems; and iii) to discuss relevant regulation, limitations, perspectives, and future challenges for their mass industrial use.

Natural Oregano Essential Oil May Replace Antibiotics in Lamb Diets: Effects on Meat Quality

A study was conducted to investigate the effect of oregano essential oil (OEO) and monensin sodium on the oxidative stability, colour, texture, and the fatty acid profile of lamb meat (m. Longissimus lumborum). Twenty Dorper x Pelibuey lambs were randomly divided into five treatments; control (CON), monensin sodium (SM, Rumensin 200® 33 mg/kg), a low level of OEO (LO, 0.2 g/kg dry matter (DM)), a medium level of OEO (MO, 0.3g/ kg DM), and a high level of OEO (HO, 0.4 g/kg DM). Dietary supplementation of OEO at any concentration lowered the compression strength in comparison with CON and SM. MO had the highest a* values (7.99) and fatty acid concentration (C16:1n7, C18:1n9c, C18:1n6c, C20:1n9, and C18:2n6c) during storage for 7 d at 3 °C. Lipid oxidation was not promoted (p > 0.05) by the moderated supplementation of oregano essential oil; however, OEO at 0.3 g/kg DM showed a slight lipid pro-oxidant effect. Dietary supplementation of MO and SM had the same effect on colour, tenderness, and the fatty acid profile of lamb (L. lumborum). It was demonstrated that oregano essential oil was beneficial for lambs feeding, and it could be a natural alternative to replace monensin in lamb diets with improvements in the quality of the meat.

Effects of dietary Origanum vulgare on gilthead seabream (Sparus aurata L.) immune and antioxidant status

Origanum sp. is a very common genus of aromatic plants worldwide distributed around the Mediterranean area and O. vulgare (oregano) is the most important species of this genus throughout the world. Due the known medicinal properties of oregano, the effect of diets enriched with 0% (control), 0.5% and 1% oregano leaves powder was studied on the growth, immune and antioxidant status of gilthead seabream (Sparus aurata L.). Fish fed with oregano 0.5% and 1% enriched diets improved both humoral (IgM and bactericidal activity in skin mucus and protease activity in serum) and cellular (head kidney leucocytes phagocytic ability) immunity at 15 and 30 days. Furthermore, the addition of oregano did not provoke any significant effect neither in the growth promotion nor in the liver antioxidant enzymes activity studied in the serum and skin mucus. The possibility of using O. vulgare as a functional additive to fish diet is discussed.

Oregano Feed Supplementation Affects Glycoconjugates Production in Swine Gut

Simple Summary

The European ban towards antibiotics is increasing the number of studies on the effects of feed additives, such as plant extracts, in order to enhance the health and welfare status of domestic animals intended for human consumption. Origanum vulgare possesses multiple pharmacological characteristics and its antioxidant and antibacterial properties are particularly interesting. Besides, a recent study aimed at evaluating the effects of oregano aqueous extract supplementation in poultry nutrition gave encouraging results regarding the secretion of glycoconjugates in the gut which increases tissue hydration and protects the intestinal mucosa from pathogenic bacteria, viruses, and parasites. Therefore, we investigated the effects of oregano feed supplementation on antioxidant and defense ability of pig gut. Our results showed that there was improved production of glycoconjugates in the duodenum and colon of pigs fed with supplementation of oregano aqueous extract, enhancing protection of the mucosa of these sections of the intestine. Also, we observed an enhanced antioxidant action in the two examined gut tract samples of the group supplemented with oregano. Findings can be used in further research to identify ways to improve endogenous defense ability with to reduce antibiotic use and prevent antimicrobial resistance.

Abstract

This study evaluated the effects of adding oregano aqueous extract (OAE) to the diet of pig slaughtered at finisher stage. Study was performed to identify glycoconjugates and evaluate the oxidative stress levels in the duodenum and colon intestinal tracts. Glycohistochemistry was performed by staining with Periodic acid–Schiff (PAS), Alcian blue (AB) pH 2.5, AB-PAS, AB pH 1, AB pH 0.5, low iron diamine, and high iron diamine. Serial sections were pre-treated with sialidase V before staining with AB pH 2.5 (Sial-AB) preceded or not by saponification. To study oxidative stress, an immunohistochemical analysis was applied to investigate the presence of the oxidative stress target molecule Bcl-2 Associate X protein (BAX). Findings show that oregano aqueous extract supplementation improves the production of the secretion glycoconjugates involved in direct and indirect defense, thus enhancing the protection of the pig intestinal mucosa. Moreover, the reduced BAX protein immunostaining observed in both duodenum and colon of swine of the oregano-supplemented group respect to that observed in the control group suggests an enhanced antioxidant action by oregano adding. Findings could be useful for other studies aiming to reduce antibiotic use and prevent antimicrobial resistance.

The effect of Goji berries (Lycium barbarum) dietary supplementation on rabbit meat quality

This study evaluated the effect of different dietary concentrations of Goji berries (GB) on the meat quality of rabbit. At weaning, 60 New Zealand male rabbits were assigned to three groups and fed with a commercial standard diet (C), C supplemented with 1% (LG) or 3% Goji berries (HG) until slaughter. Supplementation did not affect colour, water holding capacity, and tenderness but regression analyses showed linear relationships between pH (P < .05), Thiobarbituric Acid Reactive Substances (TBARS; P < .001), Oxygen Radical Absorbance Capacity (ORAC; P < .001), Redox Index (RI; P < .001), and phenolic content (P < .001) of Longissimus thoracis et lumborum muscle and the rate of GB in the feed. However, by pairwise comparisons emerged that acidification (pH: P < .05), antioxidant/oxidant status (TBARS, ORAC, RI; P < .001), and phenolic content (P < .01) of muscle significantly improved only in HG compared with C group. Then, a dose-dependent relation was found but only the higher dose of GB guaranteed an increase in protection against oxidative phenomena of meat.

Plant-Derived Extracts Feed-Addition and Packaging Type Influence Consumer Sensory Perception of Pork

This paper investigates whether the combination of the addition of extracts derived from plants (plants derived extracts, PDE) to pork feedstuff and the meat conservation conditions (packaging and time exposure) affect consumers' perception of pork quality, studied by means of visual appraisal, purchase intention and a home test. The three PDE groups were control, garlic extract and blended oil composed by carvacrol, timol, cynamic aldehide and eugenol extracts. Meat was packed in film, vacuum or modified atmosphere (MAP) packaging. A visual test was designed comprising a four-day storage step followed by a four-day exposure step in a refrigerated island display case. All studied effects influenced visual appraisal scores, being time exposure and packaging effects more noticeable than PDE or pig-sex effects. Meat from MAP scored higher than the rest. Scores decreased as exposure time increased, but this evolution was less perceptible in vacuum packaging and was faster for meat from the garlic group. Only gender affected the visual appraisal scores, with women scoring higher than men. Neither PDE addition nor pig sex affected to purchase intention whereas both exposure time and packaging type did. A maximum of 2 days of exposure would be recommended. In the home-test, meat from male pigs obtained higher scores than meat from female pigs, and none of the consumer-related effects influenced the given scores.

The influence of dietary chestnut and quebracho tannins mix on rabbit meat quality

Tannins were recently evaluated as feed additives in order to increase antioxidant compounds in animal diet, mainly to enhance resistance to lipid oxidation in meat. Rabbit meat is one of the most susceptible animal products, thus the main aim of this study was to evaluate the capacity of tannins to elongate shelf life of rabbit meat. Ninety hybrid rabbits were fed with three different diets: basal diet (control, C) and basal diet supplemented with 0.3% or 0.6% of tannins mix. Meat samples were refrigerated as raw at 4°C up to 11 days and analysed both as raw and cooked for physical-chemical characteristics, fatty acids profile, lipid oxidation and antioxidant capacity. Results showed that dietary tannins affected meat colour of raw samples (mostly yellowness). Lipid peroxidation (TBARS) of raw samples was lower in tannins group than C group; a further inhibition of peroxidation was showed also in cooked samples only by the highest dose of tannins mix. Moreover, antioxidant capacity (ABTS) of raw samples increased with the percentage of tannins. In conclusion, supplementation with 0.6% of tannins mix seems to positively affect the lipid peroxidation and antioxidant capacity of meat without modifying the intrinsic characteristics of rabbit meat.

Use of Selenium-enriched olive leaves in the feed of growing rabbits: Effect on oxidative status, mineral profile and Selenium speciation of Longissimus dorsi meat

In the present study the use of Selenium-fortified olive leaves as potential dietary source of Se in rabbit nutrition was evaluated. Sixty New Zealand White rabbits (35 days of age) were randomly assigned to the following dietary treatments: standard diet (C), and C supplemented with either 10% olive leaves (OL) or 10% Selenium-fortified olive leaves (SeOL; 100 mg/L of foliar spray sodium selenate solution). At 70 days of age, 10 rabbits per group were slaughtered and the oxidative status, mineral profile and Selenium speciation of Longissimus dorsi meat was analyzed. Meat of the SeOL group exhibited better oxidative status (lower TBARS, higher GPx and α-tocopherol values) and a 5-fold higher Se content compared to that of the other treatments. The main Se form was SeMet (7-fold higher in the SeOL group), followed by SeCys₂. The present trial demonstrates the possibility of using agro-industrial by-products as ingredients in rabbit feeds, thereby enriching meat bioactive compound content.

Supplementing Oregano Essential Oil in a Reduced-Protein Diet Improves Growth Performance and Nutrient Digestibility by Modulating Intestinal Bacteria, Intestinal Morphology, and Antioxidative Capacity of Growing-Finishing Pigs

This study investigated the effects of supplementing oregano essential oil (OEO) to a reduced-protein diet on growth performance, nutrient digestibility, intestinal bacteria, intestinal morphology, and antioxidative capacity of growing-finishing pigs. Forty-eight barrows were randomly allotted to four treatments including normal-protein diet (NPD), reduced-protein, amino acid-supplemented diet (RPD), the same RPD supplemented with chlortetracycline (RPA), and RPD supplemented with OEO (RPO). The data showed that dietary OEO supplementation increased the average daily gain of pigs compared with NPD and RPD. The gain:feed in RPO- and NPD-fed pigs was higher than those in RPD- and RPA-fed pigs. Increased average daily feed intake and 10th-rib backfat thickness were detected in RPA-fed pigs. Pigs fed the RPO had higher apparent total tract digestibility (ATTD) of crude protein than those fed the other diets. The RPD and RPA treatments showed reduced counts of Lactobacillus spp. in ileal digesta of pigs. The RPA and RPO treatments also showed lower Escherichia coli counts in ileal digesta than the NPD and RPD treatments. Dietary OEO supplementation increased villous height of the jejunum and the ileal and plasma total antioxidative capacity of pigs. In conclusion, dietary OEO supplementation could improve the growth performance and nutrient digestibility of pigs by modulating intestinal bacteria, intestinal morphology, and antioxidative capacity.

Dietary supplementation with Essential-oils-cobalt for improving growth performance, meat quality and skin cell capacity of goats

Essential oils (EO) are secondary metabolites usually made up of terpenoids and phenylpropanoids and have antimicrobial properties. However, the feeding effects of EO-Cobalt (EOC) on the performance of goats are largely unknown. Herein we investigated and reported the effects of dietary EOC (0, 52, and 91 mg daily) on fiber producing cashmere goats. We determined the resulting phenotypes including live growth, carcass weight, meat quality, and cashmere fiber traits. We show that dietary supplement of EOC significantly promoted average daily gain (P < 0.05), and significantly improved carcass weight, and meat and hair fiber quality (P < 0.05). We further conducted RNA-seq using skin and liver tissues from each group to assess the molecular mechanism conferring these phenotypic changes. A total of 191 differentially expressed genes were found in the skin tissues (0 vs 91 mg), while 1,127 DEGs were found in livers. Analyses of liver samples for differential gene action and functional prediction found that EOC stimulated physiological changes in the body’s immune system at both blood and cell levels. Our results demonstrated the potential of using EO-based feed ingredient to improve animal growth performance, meat quality and fiber quality, and further illustrated the molecular basis that contribute to phenotypes at physiological levels.

Potential of essential oils for poultry and pigs

The increasing pressure of abolishing and/or decreasing the use of antibiotics as antimicrobial growth promoters for livestock calls for alternative solutions to sustain the efficiency of current livestock production. Among the alternatives, essential oils have a great potential and are generally considered natural, less toxic, and free from residues. Essential oils have been proven in numerous in vitro studies to exert antimicrobial effects on various pathogens. The current review touched on the basics of essential oils, and the in vivo effects of essential oils on growth, intestinal microflora, anti-oxidation, immune functionality, meat qualities as well as the possible modes of action in poultry and pigs, and the future research areas were proposed.

Bioactive Compounds in Functional Meat Products

Meat and meat products are a good source of bioactive compounds with positive effect on human health such as vitamins, minerals, peptides or fatty acids. Growing food consumer awareness and intensified global meat producers competition puts pressure on creating new healthier meat products. In order to meet these expectations, producers use supplements with functional properties for animal diet and as direct additives for meat products. In the presented work seven groups of key functional constituents were chosen: (i) fatty acids; (ii) minerals; (iii) vitamins; (iv) plant antioxidants; (v) dietary fibers; (vi) probiotics and (vii) bioactive peptides. Each of them is discussed in term of their impact on human health as well as some quality attributes of the final products.

Effects of antioxidant mixtures in the diet of finishing pigs on the oxidative status and shelf life of longissimus dorsi muscle packaged under modified atmosphere

The effect of pig dietary supplementation with an antioxidant mixture (AOX), containing vitamin E and verbascoside, on animal oxidative status, meat quality parameters, and shelf life of the longissimus dorsi (LD) muscle was examined. Seventy pigs with an average live weight of 95.2 ± 1.2 kg were selected and assigned to 2 dietary treatments. The control (CTR) group was fed a commercial diet, and the AOX group was fed the same diet supplemented with the AOX, containing vitamin E and verbascoside from Verbenaceae extract, for 45 d before slaughter. At the beginning and at the end of the trial, blood samples were collected to determine oxidative status, using the Kit Radicaux Libres test. At slaughter, carcass weight was recorded and LD muscles from 10 pigs per treatment were sampled. Physical, chemical, microbiological, and sensory parameters and oxidative stability of LD muscle were assessed for up to 21 d of storage at 4°C under modified atmosphere packaging. Dietary AOX positively affected ( < 0.05) oxidative status and carcass dressing percentage. The oxidative and color stability of the LD muscle were improved ( < 0.05) in the AOX group compared with the control. The sensory shelf life revealed that at 15 d of storage, meat from the AOX group was comparable ( < 0.05) to the fresh meat in appearance and aroma. A lower ( < 0.05) spp. load was observed in the AOX samples than in the control samples. No other microbiological parameters were affected by dietary treatment. Overall, the present data showed that dietary AOX supplementation in pigs improved in vivo antioxidant status and exerted antioxidant and antimicrobial effects, thus enhancing the shelf life of raw pork under commercial conditions.

Effect of oregano essential oil and benzoic acid supplementation to a low-protein diet on meat quality, fatty acid composition, and lipid stability of longissimus thoracis muscle in pigs

BACKGROUND

Consumers are becoming increasingly interested in food containing appropriately high concentration of intramuscular fat (IMF) and polyunsaturated fatty acids (PUFA). The supplementation of feed with antioxidants decreases degradation of lipids in muscles thereby enhances nutritional and sensory properties of meat. Two experiments were conducted to determine the effects of adding oregano essential oil (OEO) and benzoic acid (BA) to low-protein, amino acid-supplemented diets on meat quality, sensory profile, fatty acid composition, and lipid oxidation of longissimus thoracis (LT) muscle in pigs.

METHODS

In Exp. 1, 21 barrows were housed in metabolism cages and randomly allotted to 1 of 3 diets. The three diets were normal protein diet (NPD), medium protein diet (MPD) and low protein diet (LPD) with 1% and 2% less than NPD, respectively. In Exp. 2, 36 barrows were randomly divided into three experimental groups, namely, NPD, LPD, and identical LPD supplemented with blends of OEO (250 mg/kg feed) and BA (1000 mg/kg feed) (LPOB) groups.

RESULTS

No significant effects of diets on meat quality were observed in Exp. 1. The b*45min, tenderness, and IMF content in LPD muscle were higher than those in NPD and LPOB muscle. The LT muscle in LPD group contained a higher percentage of oleic acid (C18:1n-9) and a lower percentage of linoleic acid (C18:2n-6) than those in NPD group. Dietary LPOB improved oxidative stability, total superoxide dismutase, and glutathione peroxidase but decreased drip loss in LT muscle.

CONCLUSIONS

These findings suggest that growing-finishing pigs fed with a low-protein, amino acid-supplemented diet show a high content of intramuscular fat in the longissimus thoracis muscle. Dietary LPOB enhances the anti-oxidative status by improving antioxidative capacity but deteriorates the sensory attributes by decreasing IMF content of meat.

Effect of oregano essential oil supplementation to a reduced-protein, amino acid-supplemented diet on meat quality, fatty acid composition, and oxidative stability of Longissimus thoracis muscle in growing-finishing pigs

This study investigated the effects of reduced-protein, amino acid-supplemented diet supplementation with oregano essential oil (OEO) in pigs, from growing period to slaughter, on the meat quality, fatty acid composition, and oxidative stability of Longissimus thoracis (LT) muscle. Thirty-six barrows were randomly divided into three experimental treatments, namely, normal protein diet (NPD), reduced-protein, amino acid-supplemented diet (RPD), and identical RPD supplemented (250mg/kg feed) with OEO (OEO) treatments. Dietary RPD and OEO increased the b*_45min, tenderness, overall acceptance, and intramuscular fat (IMF) content of pork compared with dietary NPD. The percentage of n-3 polyunsaturated fatty acid (n-3 PUFA) and the percentage of monounsaturated fatty acid in OEO muscle were higher and lower than those in RPD muscle, respectively. Dietary OEO improved oxidative stability, total antioxidative capacity, and catalase but decreased drip loss in LT muscle. Results indicated that dietary OEO enhanced the sensory attributes and anti-oxidative status of pork meat by improving IMF and n-3 PUFA proportion and antioxidative capacity.

Dietary integration with oregano (Origanum vulgare L.) essential oil improves growth rate and oxidative status in outdoor-reared, but not indoor-reared, pigs

The effects of a diet supplemented with oregano essential oil on performance, oxidative status, pork quality traits and sensorial properties were evaluated. In two studies, 72 pigs in indoor or outdoor conditions were assigned to either a control diet or an identical diet supplemented with 0.2% oregano essential oil. Pigs reared outdoor showed lower live weight, average daily gain and average gain:feed ratio compared to indoor pigs. The oregano supplementation improved the growth performance of the outdoor- but not the indoor-reared animals. The serum oxidative status was influenced by the diet. A higher oxidative stability was observed in the oregano-supplemented groups. As for the rearing conditions, the data suggest that after an initial adapting period, the free-range farming systems could be better tolerated by pigs. Meat derived from pigs reared outdoor showed higher pH and a* values. Lightness was influenced by both the diet and the rearing conditions. The control group reared indoor showed shear force values higher than both supplemented groups, while no differences were detected with the control group reared outdoor. In the consumer test performed under blind conditions, the oregano groups achieved higher consistency scores compared with the control. Under informed conditions, the meat derived from the oregano-supplemented pigs reared outdoor received the highest scores for consistency and overall liking regardless of the rearing system. The same result for the overall liking score was obtained in the expectation test. The data obtained showed that dietary oregano essential oil can be effective in reducing performance losses due to the outdoor-rearing system, increasing the oxidative status of the animal and oxidative stability of the meat, without modifying the meat quality traits and improving consumer perceptions of the meat quality.

Effect of pre- and post-weaning dietary supplementation with Digestarom® herbal formulation on rabbit carcass traits and meat quality

This study evaluated effects of Digestarom® (D) dietary inclusion before weaning (0-5weeks old; BW) and/or after weaning (5-12weeks old; AW) on growing rabbit carcass traits and meat quality. During BW, Pannon-Ka rabbits (does, kits) received two diets: a control diet (C) and one supplemented with 300mg Digestarom®/kg (D). At weaning, each group was divided into 3 dietary sub-groups: CC and DD received C and D diets from 5 to 12weeks of age, whereas DC was fed D from 5 to 8weeks and C from 8 to 12weeks of age (54 rabbits/group; AW). Rabbits were slaughtered at 12weeks of age. Digestarom® supplementation improved carcass yield and body mid part proportion only when administered BW. Rabbits fed D BW had higher hind leg meat cooking losses. Loin meat spiciness and rancidity increased with D both BW and AW. In conclusion, Digestarom(®) herbal formulation was ineffective in improving growing rabbit carcass traits or meat quality.

Effect of Dietary Treatment with Olive Oil By-Product (Olive Cake) on Physicochemical, Sensory and Microbial Characteristics of Beef During Storage

Several studies have demonstrated that the use of natural preservatives through animal diets could increase the shelf life of meat and meat products since many plant-derived substances show antioxidant and antimicrobial properties. The aim of this work was to study the effect of olive cake dietary supplementation on beef oxidative stability and antimicrobial activity during storage. Beef cattle were randomly divided into three homogeneous groups that were assigned to one of the three diets: a commercial unified based diet administered for 90 days until slaughter (CTR), CTR diet supplemented with 0.5% olive cake administered for 90 days until slaughter (OC1), and CTR diet supplemented with 0.5% olive cake and administered for 60 days followed by the administration of the CTR diet for 30 days until slaughter (OC2). Beefsteaks were overwrapped with oxygen-permeable packaging and analysed at four different storage times (zero, three, six and nine days). At the four sampling times considered from all of the samples, total viable count (TVC), Enterobacteriaceae counts, colour coordinates (CIE L*a*b* colour system), peroxide value (PV), thiobarbituric reactive substances (TBARs) determinations and descriptive sensory analyses were performed. No differences in TVC and Enterobacteriaceae count were detected among the groups over all of the sampling times considered. Differences were recorder among groups for PV, TBARS, colour and sensory analysis. The addition of olive cake in the animal diet had an effect on lipid oxidation reducing the level of PV, TBARS and retarding colour deterioration and the development of off odour in OC meat during storage.

Dietary Effects of Oregano (Origanum Vulgaris L.) Plant or Sweet Chestnut (Castanea Sativa Mill.) Wood Extracts on Microbiological, Chemico-Physical Characteristics and Lipid Oxidation of Cooked ham During Storage

The aim of this study was to evaluate the dietary effect of feeding pigs with diets enriched with sweet chestnut wood (Castanea sativa Mill.) or oregano (Origanum vulgaris L.) extract on the microbiological and chemical characteristics of cooked pork ham. Three groups of 10 pigs were fed with a control diet (CTRL), with the CTRL diet enriched with 0.2% of oregano extract (OR) and with the CTRL diet enriched with 0.2% of sweet chestnut wood extract (SCW), respectively. Six cooked hams per group were produced, sliced and packaged under a modified atmosphere (N2:CO2=80:20) and stored at refrigeration temperature (4±1°C). Three packages per cooked ham were sampled for analyses at three different storage times (0, 10 and 20 days). At day 0 time, antioxidant capacity of the products (ORAC_FL assay) and chemical composition were performed. At each sampling time, from all the samples the following analyses were performed: total microbial count (TMC), lactic acid bacteria count (LAB), Enterobacteriaceae count, Listeria monocytogenes, pH value, colour coordinates (L*, a*, b*), total basic volatile nitrogen (TBVN) and thiobarbituric reactive substances (TBARs) determinations. No differences in TMC, LAB and Enterobacteriaceae count, pH, TBVN, chemical composition and L* values were registered between the three groups at all the sampling times considered. No Listeria monocytogenes was detected in the samples tested. Significant differences were registered for ORAC_FL at 0 days, a* and b* values and TBARs value at 10 and 20 days of storage, with higher values for ORAC_FL, a* and b* values and lower values for TBARs in SCW and OR than CTRL. No antimicrobial effect could be recorded for OR and SCW but a higher oxidative stability, also highlighted by the colour maintenance, was observed in both OR and SCW.