Goats’ Feeding Supplementation with Acacia farnesiana Pods and Their Relationship with Milk Composition: Fatty Acids, Polyphenols, and Antioxidant Activity

SIMPLE SUMMARY: The study aimed to describe the fatty acids, polyphenols, and antioxidant activity of goat’s milk from five different feeding systems: Grazing; conventional diet; and conventional diet supplemented with 10, 20, and 30 percent of Acacia farnesiana pods. Conventional diet showed the highest content of polyunsaturated fatty acids while grazing showed the healthiest fatty acid profile. Similarly, grazing and A. farnesiana boosted the polyphenol content. A. farnesiana pod meal inclusion in the goats’ diets increased the selective presence of bioactive compounds and the antioxidant activity of goat’s milk while cholesterol content was reduced. ABSTRACT: Background: Research efforts have focused on the evaluation of the bioactive quality of animal products (milk, cheese, meat, and other by-products) contrasting various feeding strategies coming from different ecological zones. The study aimed to describe the fatty acids (FA), polyphenols (P), bioactive compounds (BC), and antioxidant activity (AA) of goat’s milk. Methods: Dairy goats were fed with five systems: (1) Grazing; (2) conventional diet (CD); (3) CD + 10% of Acacia farnesiana (AF) pods; (4) CD + 20% AF; and (5) CD + 30% AF. The fatty acid profile, health promoting and thrombogenic indexes were calculated. Milk extracts were evaluated by HPLC to determent phenolic compounds (gallic, caffeic, chlorogenic, and ferulic acids, catechin, epicatechin, and quercetin). Antioxidant activity of goat’s milk extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), oxygen radical absorbance capacity (ORAC), and the ferric reducing antioxidant power (FRAP) assays. Results: Conventional diet showed the highest content of polyunsaturated fatty acids while grazing showed the best n-6:n-3 and the linoleic:alpha linolenic acid ratio. Similarly, grazing and AF boosted the polyphenol content. Conclusions: Acacia farnesiana inclusion in the goats’ diets increased the presence of bioactive compounds and the antioxidant activity while diminishing the cholesterol content of goat’s milk.