Potential of phytogenics in filling gaps and removing traps for sustainable livestock production without antibiotics

Introduction Sustainable livestock production without antibiotics makes issues of pathogenic bacteria infections in farmed animals of utmost concern in situations of disease outbreaks that result in high mortality which subsequently affects profitability of production to farmers. According to reports, the long term and extensive use of antibiotics for veterinary purpose may eventually result in selection for the survival of resistant bacterial strain (Aarestrup 1999; Munk et al., 2018). Genes encoding for this resistance can also be transferred to other formerly susceptible bacteria, thereby posing a threat to both animal and human health (Munk et al., 2018). Ban on the use of in-feed antibiotics for farmed animals is a welcomed development with regards to antibiotic drug resistance in humans the consumers of farmed animals and their products. In the current era of antibiotic free animal production, medicinal plants and spices are being highlighted to fill gaps and remove traps for sustainable livestock resource development. Secondary plant metabolites such as tannins, saponins, flavonoids, anthraquinones and other compounds with antimicrobial, antibacterial, antifungal, antiviral and immune response inducing potential can successfully fill gaps in sustainable livestock resource development without antibiotic growth promoters. This will ultimately benefit both producers and consumers of animal products. Secondary metabolites such as tannins, polyphenols, flavonoids of plant origin with potential antimicrobial, anti-parasitic, anti-oxidant and anti-inflammatory (Wang et al 2008; Viveros et al., 2011 and Tosi et al., 2013; Brodowska, 2017) properties can be exploited in the livestock industry for sustainable production without antibiotics. In order to better understand these potentials of phytogenics, qualitative and quantitative analysis of the methanolic extract of O. gratissimum (lyn) was carried out using standard methods.