Supplementing the diet of dairy goats with dried orange pulp throughout lactation: II effect on milk fatty acids profile, phenolic compounds, fat-soluble vitamins and antioxidant capacity

Abstract

Although dried orange pulp (DOP) as a short-term dietary supplementation has been proven an effective substitute for cereals in goat diets–without impairing milk quality–there have been no studies considering its use over the full lactation period. This study evaluated replacing cereal with DOP in goat diets for the full 180-day lactation period on milk’s fatty acid (FA) and antioxidant composition. Payoya goats were assigned to three diet groups: a control group consuming a commercial concentrate with al-falfa hay as forage; a DOP40 or DOP80 group, wherein 40% or 80% of the cereal in the concentrate was replaced by DOP. The α-tocopherol and phenolic compounds levels and the antioxidant capacity in the milk increased as the DOP percentage increased. Including DOP might improve the FA indices of milk in the context of human health, especially when included at the end of lactation because it contributes to reducing the thrombogenicity index and increasing both the monounsaturated/saturated FA and poly-unsaturated/saturated FA indices and the amounts of indispensables α-C18:3 n-3 and C18:2 n-6 cis. Ulti-mately, DOP presents a plausible alternative to cereals in the diet of goats throughout lactation to improve the nutritional milk quality, especially the healthy antioxidant capacity.