Use of Irrigated Lucerne at Different Growth Stages II. Utilization for Milk Production

Lactating cows were assigned in a random block design to 6 treatments in a 3x2 factorial arrangement: 3 growth stages pre-bud (PB), 10% flower ( I OPP) and 50% flower (50PF), leaving 2 post-grazing residuals, high (HR) and low (LR).· Treatments were evaluated in 2 seasons, November-January (Sl) and January-March (S2). Forty-eight cows were used in each of the two seasons. During Sl milk production per cow (kg/day) was 20.0, 18,9 and 17.2 for PB, IOPF and 50PF for low residuals and 19.5; 19.8 and 20.3 for high residuals, respectively. For S2 milk production was lower but followed similar trends. Effect of growth stage, residual dry matter and season were significant (P<0.05). Milk production ranged from 11800 for 50PF (HR) to 15 900 kg/ha for PB (LR). Production/ha was lower with HR than with LR. The best treatment was used to develop a milk production system based on lucerne for grazing and haying, corn silage and concentrates.