In an italian ryegrasspasture under continuous stocking with sheep, biomass flows were estimated from2 to 20 October 1999. Treatments corresponded to four different sward heights(5, 10, 15 and 20 cm) maintained by variable stocking. The experimental designwas the randomized complete block design with three replicates. The fluxes weredefined by morphogenetic and structural variables obtained from measurementsperformed on marked tillers. During the period in which the intended sward heightswere established, significant effects in sward structure resulted in alterationson the biomass fluxes. The growth and intake fluxes showed a quadratic responsewith maximum values between 10 and 15 cm grazing heights, while the senescenceflux increased linearly with sward height. Maximum daily live weight gain andanimal yield per hectare were obtained within this interval, indicating thisinterval being the most appropriate to pasture management. The evaluation periodwas coincident with the floral induction phase, so the leaf lamina mass wasprogressively smaller and biomass fluxes showed a negative balance for all treatments.
