Within-year variation in pasture quality has implications for dairy cow nutrition

Within-year variation in herbage nutritive parameters (digestibility (DOMD), crude protein, soluble carbohydrate and fibre fractions) are described for pasture samples collected from four dairy farms with different soil and pasture characteristics. Samples were collected at 2- to 4weekly intervals to reflect material likely to be consumed by cows and analysed after freeze drying by near infrared spectrophotometry (NIRs). Results show large seasonal variations for most of the nutritive parameters (e.g., digestibility (655SO%), crude protein (13-32%), ADF (22-36%)). At times these values exceeded or were inadequate to meet the requirements of lactating cows. The implications of pasture quality data for dairy farm management and dairy cow productivity are discussed.