Effect of hydrogenated palm oil dietary supplementation on milk yield and composition, fatty acids profile and Stearoyl-CoA desaturase expression in goat milk

Aim of this study was to investigate the effects of supplementing dairy goat diets with hydrogenated palm oil (HPO; 50 g/day/head) on milk yield and composition, and on milk fatty acids profile and Stearoyl-CoA desaturase gene expression. Compared with the control diet (C), supplementation with HPO increased milk yield and fat percentage. By contrast, milk protein percentage was not different between groups. Supplementation with HPO increased (P < 0.01) short and medium chain fatty acids, as well as C14:0 and C16:1 cis-9 acids (P < 0.05). Milk from control group showed significantly (P < 0.01) higher concentration of C18:0 and lower (P < 0.05) of cis-9 trans-11CLA. Concerning the desaturase index, the HPO addition sig- nificantly affected C16:1/C16:0 and cis-9 trans-11CLA/C18:1 trans-11 (P < 0.01) and C18:1/C18:0 (P < 0.05) ratios. The SCD gene expression (arbitrary units) was higher, even if not significantly, in the control com- pared to the treated group and in both groups decreased along the trial (May: 0.55 vs 0.41; June: 0.51 vs 0.38; July: 0.50 vs 0.37 for C and T group, respectively). Concerning health properties of milk, showing beneficial (CLAs and palmitoleic acid increase) and adverse (myristic acid increase) effect, our results suggest that further studies are needed to address a risk/benefit assessment of HPO supplementation in goats.