Effect of natural cashew nut shell liquid on lactation performance of dairy goats

This study aimed to evaluate the effects of cashew nut shell liquid (CNSL) levels in goats' diets on their performance and milk quality. We hypothesize that the inclusion of CNSL in lactating goats' diets may influence the biohydrogenation process, increasing the levels of CLA (i.e., C18:2-c9 t11 isomer) and its precursors (rumenic acid, C18:1-t11) in goat milk. Eight lactating Saanen goats were assigned to a replicated 4 × 4 Latin square design with four diets: a control diet with no inclusion of CNSL and diets with the inclusion of 5, 15 and 20 g of CNSL per kg/dry matter. Intake of major nutrients was not different between diets, and no difference was observed in apparent total-tract digestibility of nutrients, except that ether extract intake increased linearly (P < 0.001) with CNSL inclusion rate. Milk yield (2.39 kg/day) and milk composition were not affected by the inclusion of CNSL. The milk fatty acids (FAs) C18:1-t9 (P = 0.001) and C18:3-n3 (P = 0.007) presented higher concentrations in milk with CNSL inclusion. The partial sum of omega-3 FA (Σn3), PUFA/SFA ratio and n6:n3 and n3:n6 ratios showed linear responses (P < 0.05) with increasing levels of CNSL. In conclusion, the CNSL affected the milk lipid profile in a way that is favourable to human health. CNSL may be a viable strategy to enhance milk with bioactive FAs.