The agro-food industry produces tons of waste at different stages in the food production process, creating a massive ecological crisis. If implemented, the use of fruit and vegetable by-products (FVBPs) in animal nutrition has the potential to lessen the environmental footprint of the food production chain, lower animal feeding costs, and improve the quality and sustainability of animal products. Recent research on the inclusion of FVBPs, naturally enriched with polyphenols, in the diets of small and large ruminants has shown some promising outcomes, which we discuss in this review. The effects of FVBPs on digestion, rumen fermentation, methane emissions, rumen liquor fatty acid profile, and milk production are examined. Due to the chemical composition and the presence of certain bioactive compounds, FVBPs are capable of influencing the ruminal and intestinal ecosystem through improved kinetics of fermentation. Several in vivo studies have demonstrated that the dietary inclusion of FVBPs resulted in improved milk production and composition without any negative effect on animal performance. Using FVBPs as an alternative to conventional feedstuffs may promote sustainable animal production and nutrition. However, it must be stressed that the efficacy of these feed supplements is conditional on the source, kind, and quantity employed.

Dietary supplementation with plant-based products may arise as part of an alternative strategy to using antibiotics as growth promoters in the poultry industry. Garlic powder (GP) possesses antimicrobial and antioxidant properties. The aim was to investigate the effect of dietary supplementation of GP on growth performance, carcass traits and meat quality of the Japanese quail. A total of 240, day-old mixed gender Japanese quail were assigned to 4 treatment groups, each group being replicated 4 times and containing 15 birds in each replication. Birds were provided with either a basal diet (control) or basal diet supplemented with 0.5%, 1% and 2% GP for 5 wk. At slaughter age, birds fed 1% GP had higher (P < 0.05) live weight and body weight gain when compared to the control. Supplementation with different levels of GP had no influence (P > 0.05) on feed intake, feed conversion ratio except 3rd wk, carcass traits and abdominal fat. Thiobarbituric acid, peroxide and pH values in breast meat of birds receiving GP (1% or 2%) after storage (0, 1, 3, 5, and 7 d) were lower (P < 0.05) than the birds in control. Furthermore, total psychrophilic bacteria count was lower in breast meat of birds supplemented with GP at any dose compared to the birds of control. Sensory characteristics such as color, aroma, juiciness and tenderness were observed significantly better (P < 0.05) in GP supplemented groups especially when fed 1% GP. In conclusion, supplementing the diet with 1% to 2% GP demonstrated growth-promoting effects and positively impacted meat quality, including sensory characteristics.

Public concern on the excessive use of synthetic food additives has raised a great interest to use natural products due to their potential in food and pharmacological industries. Nowadays, chemical food additives are questioned due to their contribution to the health risks and environmental impacts. Among natural additives, essential oils (EOs) are extracted from aromatic compounds and responsible for their biological activities namely antimicrobial and antioxidant capacity. Incorporation of bio-active compounds particularly EOs directly in food or edible/biodegradable food packaging seems to enhance the shelf life and quality characteristics of processed food and protect the consumers against oxidative and bacterial deterioration effects. However, inclusion of EOs in films/coatings for food packaging may put some effects on various properties (optic, tensile and etc.), which can affect the consumer acceptability. Their addition in food can cause some allergic and hypersensitivity reactions to the individuals who use them often. This paper aims to review the latest findings on the use of EOs incorporated with edible/biodegradable films and coatings to enhance the shelf life and quality of the food. Further investigations about essential oils are expected to clarify their exact action and build up their standard use in food industry.

Phytogenic feed additives have replaced the use of antibiotic growth promoters (AGP) in the diet of poultry particularly broiler chickens. Researchers are moving towards the use of natural products such as herbs, spices, plants and plant products, which possess influential effects on growth performance parameters, immune response and treatment of various diseases. Aloe vera is a well-known medicinal plant and is being used for commercial and therapeutic purposes such as antimicrobials, antitumor, anti-inflammatory, immunomodulator, wound healing, antioxidant and antiprotozoal agents. From a few last decades, the use of Aloe vera has been increased as a natural additive to broiler diet. Based on the review of literature, Aloe vera can improve immune response, growth performance in the broiler, as well as an excellent alternative of AGPs and anticoccidial drugs. It can be used for broiler diet in the form of gel, powder, ethanolic extract and aqueous extract. This review provides information about the use of Aloe vera in broiler production with reference to the effects on growth performance, immune system, intestinal microflora and coccidiosis in broiler chickens.

Brassica-derived feeds have been recognized for their economic and environmental benefits in ruminant nutrition. However, their utilization is constrained by the presence of glucosinolates and sulfur-containing compounds that exhibit both beneficial and adverse effects. This meta-analysis included 36 studies that evaluated the impact of glucosinolate intake on ruminant performance, nutrient digestibility, milk composition, and methane emissions. This analysis, conducted in accordance with PRISMA guidelines, revealed that glucosinolate supplementation resulted in a quadratic increase in milk urea nitrogen concentration (p = 0.017). Additionally, significant interactions between glucosinolate level and source influenced crude protein digestibility (p = 0.026). Milk composition parameters, including 4% fat-corrected milk, energy-corrected milk, milk protein, and lactose proportions, were significantly affected (p < 0.05). Furthermore, methane emissions (g/kg DMI) decreased quadratically with increasing glucosinolate intake (p = 0.003), with additional interactions observed between dietary treatments and animal species (p = 0.029). Propionate and isobutyrate concentrations increased in a quadratic and linear manner, respectively (p < 0.05). These findings suggest that glucosinolate-containing feed can enhance nutrient utilization and mitigate methane emissions in ruminants. However, the magnitude of these effects is dependent on the glucosinolate dosage, source, animal species, and dietary composition, necessitating further research to optimize their use in ruminant nutrition.

Genetically modified (GM) crops are being planted at large scale worldwide. In most of the countries, GM crops are processed into livestock feed. The land is used for cultivation of GM plants has been increased in recent years; in 2012 GM plants were grown on over 170 million hectares in 28 countries by 17.3 million farmers and extended to 185.1 million hectors in 2016 worldwide. GM plants have been used as feed for animals and the number of studies has proved their safety for animal and public health. This paper reviews the possible effects of GM crops on livestock, poultry, and aquatic animals by reviewing different type of studies, in which parameters such as performance, reproductive and health assessment were investigated. The most of peer-reviewed papers evaluating the effects of feeding animals with transgenic crops were based on GM plants with improved agronomic traits i.e. herbicide-tolerant plants and pets-tolerant plants; however, in some cases GM plants with boosted nutritional properties assessed. In most experiments, either Bt (Bacillus thuringiensis) maize, Roundup Ready (RR) soybean or both fed to animals. Measurable differences in various parameters were mostly observed in Bt maize and soybean fed separately or simultaneously to animals. In this review, scientific studies showing the effects of the use of GM products in the nutrition of domestic animals on performance, health and reproductive parameters are investigated.