Plant Feed Additives as Natural Alternatives to the Use of Synthetic Antioxidant Vitamins on Yield, Quality, and Oxidative Status of Poultry Products: A Review of the Literature of the Last 20 Years

From waste to value: Multi-omics reveal pomegranate peel addition improves corn silage antioxidant activity and reduces methane and nitrogen losses

Fermentation technology presents promising opportunities for food waste valorization. Pomegranate peel (PP), a food by-product, has potential applications in fermented feed. This study examined the effects of a 6% dry PP additive on the ensiling characteristics, antioxidant activity, metabolites, bacterial community, and in vitro ruminal fermentation, methane (CH4) emission of corn silage ensiled for 7 days and 60 days using microbiome and metabolome analyses. PP-treated silage inhibited (P < 0.05) protein degradation by reducing ammonia nitrogen and non-protein nitrogen concentrations during ensiling. The PP additive increased (P < 0.05) water-soluble carbohydrate content and reduced ethanol production in corn silage. Lactiplantibacillus dominated PP-treated silage at the initial ensiling stage, while Levilactobacillus prevailed at the final stage. Notably, the PP additive exhibited strong antioxidant activity by modulating antioxidant enzymes and flavonoid biosynthesis mediated by key metabolites (epigallocatechin and catechin). Correlation analysis identified Lactiplantibacillus, Citrobacter, Phytobacter and Burkholderia as key microbes in the production of antioxidant metabolites and enzymes in PP-treated silage. Additionally, PP supplementation reduced (P < 0.05) in vitro ruminal CH4 and nitrogen losses, while decreasing dry matter (DM) digestibility in corn silage. In summary, PP-treated corn silage enhanced antioxidant properties and reduced the nitrogen losses and in vitro ruminal CH4 emissions, but lowered DM digestibility. Thus, PP can be recommended as a silage additive, though the dry PP level should be lower than that used in this study.

Effects of Magnolia officinalis extract on the growth performance and immune function of weaned piglets

BACKGROUND

Magnolia officinalis is a medicinal herb known for its pharmacological properties and as a potential natural feed additive. We aimed to assess the effects of dietary Magnolia officinalis extract (MOE) on the growth performance and immune function of piglets, and explored the potential of MOE as a natural alternative to antibiotics for piglet nutrition during weaning.

RESULTS

Compared with the basal diet group (CK), the MOE diet significantly increased average daily feed intake and reduced diarrhea incidence and serum interleukin-6 (IL-6) levels. Compared with 0.1% MOE group, the 0.05% MOE group had lower diarrhea rates, eosinophils (EOS) count, EOS' percentage, and serum interleukin-4 levels. Compared with CK, 0.05% MOE supplementation in the diet could reduce the diarrhea incidence and the thymus index by elevating the levels of transforming growth factor-β (TGF-β) and interleukin-10 (IL-10) in the serum, jejunum, and ileum. Compared with the basal diet group, 0.05% MOE supplementation upregulated the mRNA expressions of IL-10 and TGF-β1 in the jejunum and ileum (P < 0.05) and those of IL-10, interleukin-1β (IL-1β), and interferon-γ (IFN-γ) in the thymus (P < 0.05). Moreover, 0.05% MOE increased the levels of butyric, isobutyric, isovaleric, and valeric acids in the colon.

CONCLUSIONS

MOE supplementation could modulate the immune status of animals, lower production costs, and contribute to more sustainable and ethical pig farming practices by promoting healthier growth and reducing disease susceptibility. Our findings offer a sustainable solution to antibiotic use in animal farming, addressing concerns about antibiotic resistance and food safety.

Effects of chlorogenic acid on productive and reproductive performances, egg quality, antioxidant functions, and intestinal microenvironment in aged breeder laying hens

This study investigated the effects of dietary chlorogenic acid (CGA) on the productive and reproductive performance, egg quality, antioxidant function, and intestinal microenvironment of laying hens. Thus, 162 healthy Hy-Line Brown breeding hens (63 weeks old) were randomly allocated to 3 groups, each receiving a basal diet plus supplementation: 0, 250, and 500 mg/kg CGA, respectively. Per the in vitro test, CGA had obvious inhibitory effects on Salmonella enteritis and avian pathogenic Escherichia coli and strong free radical scavenging ability. Per the breeder laying hen experiment, the CGA diets had no significant influence on egg production or reproductive performance (P < 0.05). Nevertheless, compared with the control diet, 250 mg/kg CGA significantly increased eggshell thickness, egg weight, yolk color, and Haugh unit (P < 0.05). Compared with the control diet and 500 mg/kg CGA, 250 mg/kg CGA significantly (P < 0.05) elevated antioxidant capacity by reducing serum malondialdehyde content, upregulating heme oxygenase-1, and downregulating heat shock proteins mRNA levels in the ileum. Compared with the control diet and 500 mg/kg CGA, 250 mg/kg CGA (P < 0.05) enhanced intestinal barrier function, shown by the upregulation of ileal Occludin and Mucin-2 mRNA levels; furthermore, 250 mg/kg CGA (P < 0.05) increased anti-apoptotic capacity by increasing B-cell leukemia/lymphoma 2 gene expression and downregulated Bcl2 Associated X mRNA levels in the liver and ileum of late breeder laying hens (P < 0.05). Lastly, 250 mg/kg CGA (P < 0.05) increased cecal g_CHKCI001 and short-chain fatty acid-producing bacteria g_Prevotellaceae UCG-001, positively related to gut health, and in the cecum, 500 mg/kg CGA significantly (P < 0.05) increased g_Shuttleworthia abundance, negatively related to gut health. Our findings suggest that dietary inclusion of 250 mg/kg CGA promotes egg quality, intestinal microbial composition, gut barrier integrity, and the antioxidant capacity of aged breeder laying hens.

Oxidative stress in poultry production

Oxidative stress (OS) is a major concern that impacts the overall health of chickens in modern production systems. It is characterized by an imbalance between antioxidant defence mechanisms and the production of reactive oxygen species (ROS). This literature review aims to provide a comprehensive overview of oxidative stress in poultry production, with an emphasis on its effects on growth performance, immune responses, and reproductive outcomes. This review highlights the intricate mechanisms underlying OS and discusses how various factors, including dietary components, genetic predispositions, and environmental stressors can exacerbate the production of ROS. Additionally, the impact of oxidative stress on the production performance and physiological systems of poultry is examined. The study also emphasizes the relationship between oxidative stress and poultry diseases, highlighting how impaired antioxidant defenses increase bird's susceptibility to infections. The review assesses the existing approaches to reducing oxidative stress in chickens in response to these challenges. This includes managing techniques to lower stress in the production environment, antioxidant supplements, and nutritional interventions. The effectiveness of naturally occurring antioxidants, including plant extracts, minerals, and vitamins to improve poultry resistance to oxidative damage is also examined. To improve the antioxidant defenses of poultry under stress conditions, the activation of cellular homeostatic networks termed vitagenes, such as Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) is necessary for the synthesis of protective factors that can counteract the increased production of ROS and RNS. Future studies into novel strategies for managing oxidative stress in chicken production would build on these research advances and the knowledge gaps identified in this review.

Antibiotics in avian care and husbandry-status and alternative antimicrobials

Undoubtedly, the discovery of antibiotics was one of the greatest milestones in the treatment of human and animal diseases. Due to their over-use mainly as antibiotic growth promoters (AGP) in livestock farming, antimicrobial resistance has been reported with increasing intensity, especially in the last decades. In order to reduce the scale of this phenomenon, initially in the Scandinavian countries and then throughout the entire European Union, a total ban on the use of AGP was introduced, moreover, a significant limitation in the use of these feed additives is now observed almost all over the world. The withdrawal of AGP from widespread use has prompted investigators to search for alternative strategies to maintain and stabilize the composition of the gut microbiota. These strategies include substances that are used in an attempt to stimulate the growth and activity of symbiotic bacteria living in the digestive tract of animals, as well as living microorganisms capable of colonizing the host’s gastrointestinal tract, which can positively affect the composition of the intestinal microbiota by exerting a number of pro-health effects, i.e., prebiotics and probiotics, respectively. In this review we also focused on plants/herbs derived products that are collectively known as phytobiotic.

Nutritional Composition and Bioactive Compounds of Basil, Thyme and Sage Plant Additives and Their Functionality on Broiler Thigh Meat Quality

Meat industries across the world are constantly focusing to find natural low-cost additives for the development of novel meat products to meet consumer demand for improving the health benefits. In this study, we investigated the chemical composition and the bioactive compounds of some herbal plants, namely basil, thyme, sage, and their functionality on broiler chicken thigh meat quality. Chemical composition, as well as total antioxidant activity, polyphenols, vitamin E lutein and zeaxanthin and the fatty acids of the plants, were analyzed. According to findings, total polyphenols was 21.53 mg gallic acid/g in basil, 31.73 mg gallic acid/g in thyme and 38.87 mg gallic acid/g in sage. The antioxidant capacity was 19.91 mM Trolox in basil, 54.09 mM Trolox in thyme and 54.09 mM Trolox in sage. Lutein and zeaxanthin from basil was 267.91 mg/kg, 535.79 mg/kg in thyme and 99.89 mg/kg, and vitamin E ranged from 291.71 mg/kg in basil to 379.37 mg/kg in thyme and 148.07 mg/kg in sage, respectively. After, we developed a trial on 120 unsexed broiler chickens (n = 30) which were separated into four groups with six replications of five chickens each: control (C); 1% basil (B); 1% thyme (T) and 1% sage (S). The B, T and S groups deposited significantly higher (p < 0.05) concentration of zinc, polyphenols, antioxidant capacity and vitamin E in meat samples compared with the C group. In the experimental groups, the proportion of total polyunsaturated fatty acids, the ratio of n-6 to n-3 fatty acids, and the ratio of polyunsaturated fatty acids to saturated fatty acids in the thigh muscles were significantly improved (p < 0.05). The tested plants exhibited a significant (p = 0.0007) hypocholesterolemic effect in the meat of the B (45.90 mg/g), T (41.60 mg/g) and S (48.80 mg/kg) experimental groups compared with the C (60.50 mg/g) group. These results support the application of the studied plants as natural sources of additives which could be effective in improving meat quality, from the human consumption perspective.

Long-term administration of a commercial supplement enriched with bioactive compounds does not affect feed intake, health status, and growth performances in beef cattle

Abstract. Feed additives including natural bioactive compounds (BCs) in combination with vitamin E (VitE) and organic Se could mitigate animal stress associated with intensive livestock farming due to their anti-inflammatory and antioxidant properties. Yeast and yeast derivate are included in feed additives as probiotic products and digestion promoters. Scutellaria baicalensis is a source of bioactive compounds and has been tested in monogastrics, exhibiting many immunostimulating and hepato-protective activities. However, the literature lacks information regarding S. baicalensis effects on beef cattle performance and health status. The aim of the present study was to evaluate the impact on beef cattle's feed intake, health and oxidative status, and growth performances of the inclusion of a commercial supplement (CS) containing VitE, organic Se, yeast derivate, and S. baicalensis extract during the fattening and finishing period. A total of 143 Charolaise male cattle were allotted into 12 pens of 11–12 animals each and assigned to a control (463.9±21.48 body weight – BW) or a treated (469.8±17.91 BW) group. Each group included two replicates of three pens. The treated groups were supplemented with 20 gCSanimal-1d-1. Feed intake was measured monthly on a pen base during two consecutive days. Total mixed ration and fecal samples were collected at three time points (monthly, from November to February) and pooled by replicate for the analyses to monitor digestibility. Blood samples were individually collected at the beginning and at the end of the trial for oxidative status and metabolic profile determination. Final BW and carcass weight were individually recorded to calculate average daily gain, feed conversion ratio, and carcass yield. Similar feed digestibility between groups were observed during the whole experiment. Feed intake, growth performances, final body weight, average daily gain, feed conversion rate, oxidative status, and metabolic profile were not affected by the dietary inclusion of the tested CS indicating no detrimental effect of the treatment. Different doses of this product should be tested in the future in order to provide a more complete report on the product efficacy.

Antioxidants in Animal Nutrition

Oxidative stress is an imbalance between the production of free radicals and their neutralization by the antioxidants' defenses [...].

Plant Feed Additives as Natural Alternatives to the Use of Synthetic Antioxidant Vitamins on Livestock Mammals' Performances, Health, and Oxidative Status: A Review of the Literature in the Last 20 Years

In the last two decades, the interest in natural plant feed additives (PFA) as alternatives to synthetic vitamins in livestock nutrition has increased. After a systematic review, a total of 19 peer-reviewed papers published between 2000 and 2020 were retained to evaluate the antioxidant effects of PFA compared to synthetic antioxidant vitamins (mainly vitamin E; VitE) in livestock nutrition. These studies demonstrated that PFAs could be as efficient as VitE in counteracting oxidative stress in pigs, rabbits, and ruminants. However, PFAs only positively affected animals’ growth performance and feed efficiency in some monogastric studies. The PFA can affect antioxidant enzyme activity in a dose- and method of administration-dependent manner. The antioxidant capacity of both PFA and VitE were depressed in cows fed with diets rich in polyunsaturated fatty acids. Variability among studies could be related to species differences. Despite the interest of the feed industry sector in PFA, there are still very few studies evaluating their antioxidant effect in species other than poultry.