Effect of including plantain in perennial ryegrass-white clover pasture offered to grazing dairy cows on milk composition and milk fatty acid and mineral concentrations

This study explored the effect of including plantain ( Plantago lanceolata L.; PL ) in perennial ryegrass ( Lolium perenne L.; PRG )-white clover ( Trifolium repens L.; WC ) pasture on the milk composition and milk fatty acid ( FA ) and mineral concentrations of spring-calving dairy cows. The treatments were PRG-WC ( G r C ) and PRG-WC-PL ( GCP ) pastures. Milk samples were obtained from dairy cows (n = 13 per treatment) during early (61 ± 12 d in milking; EL ) and late (214 ± 16 d in milking; LL ) lactation. Cows grazing GCP produced milk with a lower fat concentration. Milk lactose concentration was greater from cows grazing GCP in LL. Cows grazing GCP produced milk with greater concentrations of polyunsaturated FA (g 100 g milk −1 ) and α-linolenic acid (g 100 g milk fat −1 ). Treatment did not affect milk mineral concentrations in EL. In LL, cows grazing GCP produced milk with lower concentrations of calcium (−10 %) and magnesium (−7 %) compared with GrC. Including PL in a PRG-WC pasture for dairy cows can beneficially alter milk FA composition.