Grazing behaviour of young cattle around faecal pats

Young Holstein Friesian bulls grazed four mixed-contour paddocks for a duration of three days on ten occasions between December 2002 and March 2004. For the first seven grazing events, five faecal pats on both easy- (<25o) and steep-contoured land in each paddock were selected for monitoring herbage removal during the subsequent four to five grazing events. After each day of grazing, pasture height was measured at 5-cm intervals for 50 cm from the centre of each pat. The decrease in pasture height was converted to estimates of herbage dry matter removal. For the first three grazing events following pat deposition, avoidance of grazing herbage around pats was greatest on the first day of the three-day grazing duration. The mean distance of grazing from the centre of the pats was 21, 14, 10 and 7 cm for the first to fourth grazing events following deposition. Avoidance was greatest around pats that were deposited in late spring/early summer with little difference occurring between pats located on easy or steep land. Increased grazing pressure appeared to override the natural behaviour of young cattle to avoid grazing close to faecal pats. Grazing management of young cattle should ensure residuals of at least 1500 kg DM/ha in order to minimise the grazing of herbage surrounding faecal-pat areas which are highly contaminated with parasite larvae.