Studies on the Application of Cattle Slurry in Grassland III. Grazing preference as affected by application time of cattle slurry on pasture

This experiment was carried out to determine the effects of application time of cattle slurry ongrazing pasture on the grass growth. dry matter yield, nutritive value, animal preference, and efficiencyof pasture utilization. Four different application times of slurry(right now after grazing, 5th day, 10thday, and 15th day after grazing), and a no-slurry(control) plot were designed, 1991-1992.Annual application amount of slurry was 40 m3/ha, and slurry was applicated in spring(2 times),summer and autumn. Total NPK fertilizer applicated were same as 280, 200 and 240 kg/ha in alltreatment, respectively. The pasture was grazed with growing beef cattle(initia1 body wt.: ca. 250 kg)at every 30-35 cm of plant height.The grass height, dry matter yield, crude protein yield, and other nutritive value were not differentamong treatments. However, the animal preference and efficiency of pasture utilization showed significantdifference by application time of slurry.The highest grazing preference (1: the worst-9: the best), and utilization efficiency (0-100%) wereobserved by application time of right now after grazing (7.8, 76%), which was same to control(7.8,77 %), and followed by 5th day after grazing(7.3, 74%) and loth day after grazing(6.9, 71 %). But thepreference and pasture utilization were greatly decreased at application time of cattle slurry of 15th dayafter grazing(5.5, 60 %).From the above results, the optimum application time of cattle slurry on grazing pasture toenhance animal preference, and efficiency of pasture utilization was within 5 days after grazing (lessthan 13.6 cm of plant height), and within 10 days after grazing (less than 18.5 cm of plant height)at least.