Comparison of nutrient and mineral content of herbage from pasture and fresh indoor feeding

Grazing and/or indoor feeding of fresh herbage are common feeding systems for dairy cows in Switzerland. In the framework of an on-farm dairy production system comparison, the nutrient and mineral content of herbage from pastures and for fresh indoor feeding were regularly analysed during two growing periods. Nutrient contents (crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), ethanol soluble carbohydrates (ESC)) were analysed by Near-infrared reflectance spectroscopy (NIRS) and the minerals calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sodium (Na), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) determined using an inductively coupled plasma optical emission spectrometer. Due to the different utilisation, herbage for fresh indoor feeding contained lower proportion of grasses (60 vs 70%) and herbs (6 vs 9%) but a higher content of legumes (34 vs 21%). The nutrient content was more variable throughout the growing period in the herbage for fresh indoor feeding. The differences in species composition and the generally lower growth stage resulted in significantly higher CP and lower ADF contents of the pasture herbage. Herbage for fresh indoor feeding showed higher contents of Ca and lower contents of P and Zn. The Mg content was similar and increased from spring to summer. The data demonstrates that herbage for fresh indoor feeding represents a valuable source of nutrients and minerals. Its contents, however, may fluctuate more strongly during the growing period as compared to herbage from pastures.