Metabolomic profile of goat milk associated with feed supplementation with Camelina sativa cake and Cynara cardunculus meal

The aim of the study was to evaluate changes in milk metabolomics in response to Camelina sativa cake and Cynara cardunculus meal supplementation in dairy goats. Eighteen primiparous and multiparous Alpine lactating goats were divided into 3 balanced groups according to parity number, milk production and days in milk (1.83, 2.23 kg, 273 DIM), and assigned randomly to 3 treatment groups. The treatment groups were: 200 g/d of camelina cake (CAM; n = 6), 200 g/d of Cynara cardunculus meal (CAR; n = 6), and control (CON, n = 6) receiving the standard diet without supplementation. The supplementation lasted 21 d. Milk yield and composition were measured weekly; milk samples for metabolomics analysis were collected at d 0 and d 21 and frozen at −80°C. Metabolomics analysis were performed by 1H NMR spectroscopy operating at 600 MHz. Productive data were analyzed by the Mixed Procedure for repeated measures of SAS. Metabolomics data were processed by the R program (ChemoSpec package) and MetaboAnalyst program. The multivariate analysis included the principal component analysis and partial least square–discriminant analysis to detect differences in the metabolome before and after the supplementation in the same animals. Feed supplementation had no effect (P > 0.10) on milk yield (CAM 1.19 ± 0.17, CAR 1.36 ± 0.17, CON 1.23 ± 0.17 kg/d) and composition (fat % CAM 6.21 ± 0.58, CAR 5.75 ± 0.58, CON 6.46 ± 0.58; protein % CAM 5.79 ± 0.49, CAR 5.11 ± 0.49, CON 5.55 ± 0.49) throughout the experiment. However, metabolomics profile of milk was affected by the experimental day (i.e., d 0 vs. 21). Compared with the CON diet, milk uridine, lecithin and ethanolamine decreased, whereas lactate and lactose increased when CAM and CAR were supplemented. There was no variation in milk metabolomics profile between CAM and CAR diets. In conclusion, feeding both camelina cake and Cynara cardunculus resulted in changes in metabolism that reflected in modified milk metabolomics profile. These findings would help in understanding the action mechanism of these feed supplements in dairy goats.