Plant Feed Additives as Natural Alternatives to the Use of Synthetic Antioxidant Vitamins in Livestock Animal Products Yield, Quality, and Oxidative Status: A Review

Abstract

The interest for safe and natural foods of animal origin is currently increasing the use of plant feed additives (PFA) as antioxidants in animal nutrition. However, studies with livestock animals dealing with PFA as antioxidants are scarce. The aim of the present review was to evaluate the antioxidant impact of PFA compared with synthetic vitamins on animal food product yield and quality. For this purpose, peer-reviewed studies published between 2000 and 2020 were collected. Most papers were carried out on ruminants (n = 13), but PFA were also tested in swine (n = 6) and rabbits (n = 2). The inclusion of PFA in the diets of pigs, rabbits, and ruminants improved the products’ quality (including organoleptic characteristics and fatty acids profile), oxidative stability, and shelf life, with some impacts also on their yields. The effects of PFA are diverse but often comparable to those of the synthetic antioxidant vitamin E, suggesting their potential as an alternative to this vitamin within the diet.

The Inclusion of Alhagi maurorum in Growing Camel Diet: Effect on Performance, Liver-Related Blood Metabolites, and Antioxidant Status

“…The dynamic balance between oxidation and antioxidant activity in the circulatory system plays a critical role in the health and productive performance of livestock ( 47 ). The rich functional compounds in nature-derived feedstuffs make them an attractive component to improve the antioxidant status of animals, thereby improving the quality of products ( 47 – 49 ). Currently, consumers are interested in safe and natural foods of animal origin and in some cases, they are also willing to pay a premium price for them ( 49 ).…”

“…The rich functional compounds in nature-derived feedstuffs make them an attractive component to improve the antioxidant status of animals, thereby improving the quality of products ( 47 – 49 ). Currently, consumers are interested in safe and natural foods of animal origin and in some cases, they are also willing to pay a premium price for them ( 49 ). TAC reflects the cumulative effects of enzymatic and non-enzymatic antioxidants present in plasma and body fluids ( 47 , 48 ), whereas MDA is generated because of lipid peroxidation that could be measured as a biomarker of oxidative stress ( 47 ).…”

“…AM is rich in biologically active phytochemicals such as phenolics, flavonoids, alkaloids, and polysaccharides along with different essential minerals, proteins, and lipids, which has turned it into a powerful antioxidant ( 13 , 15 ). Natural plant feeds containing phenolic, flavonoid, and alkaloid substances can prevent peroxidation by scavenging free radicals or by activation of antioxidant enzymes such as glutathione reductase, GPx, and SOD ( 49 ). A study ( 52 ) reported that the aqueous extract of AM was appraised by reducing MDA levels using thiobarbituric acid assay.…”

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 swine, PFA has been mostly tested as alternatives to antimicrobials rather than as antioxidants, particularly after the ban of in-feed antibiotic use in 2006 [ 18 , 19 , 20 ], whereas in ruminants, PFA (usually essential oils) have been widely investigated as rumen modifiers [ 21 , 22 ]. Nevertheless, some trials comparing natural to synthetic antioxidants have also been conducted, in swine, rabbits, and ruminants, in order to assess their capacity in ameliorating products yield and quality [ 23 ]. However, only a few studies have been conducted in livestock to evaluate the antioxidant role of PFAs in comparison to synthetic molecules in affecting their performances.…”

Antioxidants in Animal Nutrition

“…The effects of natural extracts on product quality, oxidative stability, and shelf life in ruminants, swine, and rabbits have been reviewed. The authors reported that the effects of plant additives are different but similar to synthetic vitamin E, thus suggesting their role as possible natural substitutes [ 11 ]. The impact of plant additives in poultry nutrition has also been analyzed, based on the selection of literature published in the last 20 years [ 12 , 13 ].…”