Impact of Pasture-Based Feeding on Terpene Profiles in Goat Milk

Regenerative agriculture (RA) is a system of agricultural practices that integrates livestock into holistic farming systems to restore ecosystems and improve soil health. Pasture diversity can influence the nutritional quality of animal products. Milk terpenes are bioactive compounds with antioxidant and anti-inflammatory activity that could also serve as biomarkers of animal diet. This study aimed to assess how RA pasture feeding practices influence the terpene profile of goat milk. Milk samples were collected from two farms: one with fully established RA practices (FARM-A, including cover cropping, rotational grazing) and another transitioning to RA (FARM-B). For FARM-B, milk was analysed before (goats mainly fed concentrate including alfalfa, maize, oat, wheat, beat pulp, sunflower meal, etc.) and after a grazing season (minimum of 5 days in pasture, 50% concentrate allowance plus pasture with ryegrass and a mixture of clovers). Terpenes were extracted by headspace solid-phase microextraction (HS-SPME) and analysed using gas chromatography-mass spectrometry (GC-MS), determining a total of eight terpenes: α-pinene, α-phellandrene, β-pinene, limonene, β-caryophyllene, p-cymene, α-copaene, and α-caryophyllene. Limonene, α-pinene, p-cymene, and β-caryophyllene were present in both farms. FARM-A samples also contained α-copaene, α-caryophyllene, and α-phellandrene, which were not present in FARM-B (both before and after RA pasture). FARM-B samples also contained β-pinene, which, along with p-cymene, significantly increased with grazing. Higher levels of α-pinene, α-copaene, α-caryophyllene, and β-caryophyllene were found for the pasture-fed goat milk of FARM-A compared with the samples before pasture of FARM-B. These findings suggest that a gradual transition from conventional feeding to grazing may be sufficient to increase terpene levels in goat milk. However, considering the small sample size and short duration of the study, further studies with larger sample sizes and longer feeding periods are required to confirm these observations.