A review on practical applications of Citrus sinensis by-products and waste in poultry feeding

Abstract

In recent decades, in order to improve livestock and poultry performance, some compounds have been used as a feed additive and growth stimulator. Some of the most widely used growth stimulants have been antibiotics but, due to the harmful effects of antibiotic resistance and the limiting of their use, alternatives have been suggested such as probiotics, prebiotics, plant essential oils, essences and by-products. The orange is one of the earliest fruits used by humans. Orange by-products and waste are found extensively in some parts of the world. Orange waste contains ascorbic acid, phenolic compounds, coumarin and several volatile compounds, some producing orange aroma:aldehydes, esters, terpenes, alcohols, ketones, carotenoids (beta-carotene, lutein and beta-cryptoxanthin), nobilitin, pectin and bioflavonoids including hesperidine, naringenin and hysteritine. This paper reviews the practical applications of orange by-products and waste in poultry feeding. Advantages and disadvantages of effects of orange waste and by-products on poultry (broiler, laying hen, quail, etc.) performance, carcass components, immunity, blood constitutes, and gastrointestinal microflora are reviewed and discussed.