Hepatic and subcutaneous adipose tissue variations in transition dairy goats fed saturated or unsaturated fat supplemented diets

- Different fatty acids can affect fat mobilization with no effects on performance.
- Fish oil could reduce or delay adipose tissue fat mobilization during transition.
- Fish oil could improve hepatocyte adaptation to fat infiltration in dairy goats.

Biochemical and histological approaches were used to study the metabolic adaptations of transition dairy goats to dietary supplementation with saturated and unsaturated fatty acids. Twenty-three Alpine dairy goats were divided into three groups and fed a basal pre-kidding and lactation diet (C) or the same diet supplemented with fish oil (FO) or stearic acid (ST) starting 1 week before kidding until 21 days in milk (DIM). No differences were observed in milk production and composition. However, the serum non-esterified fatty acid (NEFA) and beta-hydroxybutyrate (BOHB) concentrations were changed over time by the treatments. The mean adipocyte area, measured on a subset of 12 goats, which included four subjects from each experimental group, decreased constantly in the C and ST groups from −7 to 21 days, while the FO group did not change between days 7 to 21. These results support the idea that FO is able to limit lipolysis, although the energy balance is still negative. No inflammatory processes were observed in the liver in accordance with the blood leukocytes trend, even if moderate to severe fatty changes in the liver were observed in the experimental goats. In the FO group, however, fatty infiltration appeared more severe and it occurred more gradually compared with the other diets. Overall, these results suggest an interesting ability of dietary lipid supplements to affect the fat mobilizing machinery; FO in particular seems able to reduce/delay fat mobilization and could improve hepatocyte adaptation to fatty infiltration, allowing the cells to better maintain their function.