Abstract

Horses kept at pasture create focal areas with high-density of faeces (latrines), which under commercial conditions can account for 30% of total pasture area. This New Zealand study observed the utilisation of pasture, and establishment of lawns and roughs within one paddock, intensively grazed (semi-set-stocked) alternately by three herds of mixed-age (mature), predominately Standardbred, horses. The paddock was grazed by horses 480 of 730 days, with mean stocking density of four horses per ha (2148 kg live weight/ha). Median grazing duration was 44 days (IQR 37-47 days). The median overall pasture cover for the study period was 1114 kg DM/ha (range 496-2191 kg DM/ha), lawns was 683 kg DM/ha (range 389-1822 kg DM/ha), and roughs was 2058 (range 753-3971 kg DM/ha). There was a trend for greater post-grazing estimated pasture growth rates in roughs relative to the lawns (P=0.054). Latrine areas constituted a median 31% (IQR 24-33%) of available pasture area, with up to two faecal-piles/m2. The results of the current study suggest that intensive semi-set-stocked management promotes the establishment of easily identified latrine areas of moderate faecal-pile concentration. These data can contribute to modelling the nitrogen-holding capacity of the soil, nitrogen leaching and the efficient utilisation of pasture of grazing horses. Keywords: equine; faeces; nitrogen; pasture

BR, Adams, EK Gee, PJ Back, and CW Rogers

New Zealand Journal of Animal Science and Production, Volume 81, Online, 74-80, 2021