Feed Additive Potentials of Kola Nut, Bitter Kola, and Wonderful Kola: A Review

Abstract The chemical constituents of different types of kolas are beginning to gain attention as a natural feed additive because of safety risks, residues, and consumer dissatisfaction associated with the use of synthetic products. This review explores a diverse array of literature on the use of kola nut, bitter kola, and wonderful kola as feed additives from different sources such as Springer, PubMed, Scopus, Crossref, Google Scholar, Research Gate, and Index Copernicus Journals. The chemical composition of kola nut, bitter kola, and wonderful kola showed that they contained carbohydrate, ash, crude fiber, ether extract, crude protein, tannin, saponin, phytic acid, phenol, trypsin inhibitor, sterol, steroids, flavonoid, alkaloid, oxalate, caffeine, hydrogen cyanide, and vitamins in different proportions. These bioactive compounds gave the kolas phytogenic potentials as feed additives. The use of these kolas influenced growth response, especially weight gain and fed conversion ratio, nutrient digestibility, hematological parameters, serum biochemistry, antioxidant capacity, carcass weight, egg production, and spermatogenesis in broilers, layers, rabbits, and pigs differently. There is a dearth of information on the use of kola nut seed or pod in layers and pigs; bitter kola seed in pigs and wonderful kola seed in poultry and rabbits. More effort is still needed to determine the appropriate inclusion levels and fully elucidate their mode of action.