Dietary supplementation of Aloe vera extract modulates rumen microbes and improves the functional food value of milk by altering phenolic content, antioxidant capacity, and fatty acid profile in lactating goats

Twenty-four cross-breed (Alpine x Beetal) lactating goats (average body weight: 37.5 +/- 2.7 kg and milk yield: 1.78 +/- 0.31 kg/day) were chosen for the ninety days duration of the experiment and divided into three groups following a completely randomized design. Group I acted as control (T-0) and received only a basal diet as per requirement, whereas group II (T-1) and group III (T-2) received basal diet added with Aloe vera extract at 2% and 4% of dry matter intake (DMI), respectively. Total phenolic compounds (TPC) and milk antioxidant status were higher (p < 0.05) in T-1 and T-2 than T-0. Relative abundance of methanogen, protozoa, Butyrivibrio proteoclasticus, and Ruminococcus flavefaciens in the rumen were lower, while Butyrivibrio fibrisolvens population was higher (p < 0.05) in T-2 and T-1 compared to T-0. Saturated fatty acids levels in milk were lower, whereas different polyunsaturated fatty acids levels were higher (p < 0.05) in T-1 and T-2 than T-0. Nutritional indices of milk increased in both supplemented groups. Overall, it may be concluded that dietary supplementation of Aloe vera extract at 2% and 4% of DMI may enhance the functional characteristics of milk by boosting TPC and antioxidant status, as well as the FA profile and nutritional quality indices of milk fat.