Diet Supplementation with Hemp (Cannabis sativa L.) Inflorescences: Effects on Quanti-Qualitative Milk Yield and Fatty Acid Profile in Grazing Goats

Hemp (Cannabis sativa L.) is an annual plant belonging to the family of Cannabaceae with several varieties characterised by different fatty acid profiles, content in flavonoids, polyphenols and cannabinoid compounds. Hemp is mostly used in livestock nutrition as oil or as protein cake, not as inflorescences. The aim of this study was to evaluate the effect of dietary hemp inflorescences on milk yield and composition in grazing goats. Twenty goats (Camosciata delle Alpi), after kidding, were equally divided into two groups (G: Grazing and GH: grazing and hemp), homogeneous for milk yield in the previous lactation, parity and live weight. For three months, all goats were fed on a permanent pasture and received 700/head/day of concentrate (barley, oats and faba bean); diet of group GH was supplemented with 20 g/head/day of hemp inflorescences. Pasture DM intake was estimated according to previous research performed in the same area. In addition, goats’ body weight did not change along the trial meaning that their energy requirements were guaranteed. Individual milk yield was daily registered and samples collected every 20 days for chemical com-position (Milkoscan) and fatty acid profile (Gas Chromatography). The data were analysed by ANOVA (GLM procedure of SAS, 2000), for repeated measure. No significant differences were found for milk yield and chemical composition. Lauric acid (C12:0) was significantly higher in milk of group GH (4.83% vs 4.32%; P<0.01) as well as total conjugated linoleic acids (CLAs) (0.435% vs 0.417%; P<0.01).