Pasture allowance, duration and lactation stage: effects on early lactation production

Spring grass availability can be a big challenge for Irish dairy farms due to limited over winter growth. The objective of this experiment was to determine the effect of pasture allowance (PA) offered for varying durations in early lactation on cumulative milk (MY) and milk solids yield (MSY), bodyweight and body condition score. Intake capacity (IC) was calculated for the control group (C) and they were offered a 100% PA. The remaining treatments were offered 60% PA for either two (×2) or six weeks (×6) from week one (E), three (M) and five (L) of experiment. All cows received 100% IC from week 11. After 10-weeks C had a greater MY than all treatments (+ 151 kg cow-1). The E60 × 2 and L60 × 2 treatments had similar 10-week MSY to C (121 kg cow-1), and C was higher than all other treatments (+ 11 kg cow- 1). Cumulative production at 33-weeks was higher for the C and E60 × 2 compared to L60 × 6. Despite immediate effects on milk production during periods of low grass availability, PA can be reduced with minimal effect on total lactation production with the exception of an extended restriction at peak milk production. However, other aspects of production need to be considered