Jackson J A, Hemken R W, Boling J A, Harmon R J, Buckner R C, Bush L P
J Anim Sci. 1984 May;58(5):1057-61. doi: 10.2527/jas1984.5851057x.
Seeds of the tall fescue ( Festuca arundinacea Schreb .) cultivars Kentucky 31 and an experimental ryegrass X tall fescue hybrid derivative strain (G1-307), and orchard grass (OG) seed were fed in a carrier diet to calves in controlled environmental rooms (31 to 32 C). Both tall fescue varieties produced symptoms of summer toxicosis in dairy steers. Total feed intake (P less than .01) and water intake (P less than .01) of calves were reduced by the tall fescue seed diets when compared with orchard grass. Steers fed G1-307 and Kentucky 31 tall fescue lost (NS) 17.5 and 7.8 kg of body weight, respectively, while those consuming orchard grass gained (P less than .01) 6.2 kg during the experiment. Rectal temperatures were lower (P less than .05) in the calves fed OG (39.4 C) when compared with those fed G1-307 (40.6 C) and Kentucky 31 (40.8 C) tall fescue seed, respectively. In a second trial Kentucky 31 seed was fed in a carrier diet to Holstein steers at graded levels of 0, 350, 700 and 1,050 g seed/d. Consumption of 700 and 1,050 g seed/d adversely affected performance of steers. Total feed intake was lower and water intake was reduced (P less than .05), with rectal temperatures being elevated (P less than .01) in these two groups when compared with 0- or 350-g treatments. No significant differences were detected in body weight changes in this trial. Respiration rates were not significantly affected in either trial. Results of these trials with the young bovine indicate that a toxic substance(s) is present in tall fescue seed.
将高羊茅（Festuca arundinacea Schreb.）品种肯塔基31号和一种试验性黑麦草×高羊茅杂交衍生菌株（G1 - 307）的种子，以及果园草（OG）种子，混入载体日粮中，喂给置于可控环境室（31至32摄氏度）的犊牛。两种高羊茅品种均使奶牛出现夏季中毒症状。与果园草相比，高羊茅种子日粮使犊牛的总采食量（P < 0.01）和饮水量（P < 0.01）降低。饲喂G1 - 307和肯塔基31号高羊茅的阉牛，体重分别减轻了17.5千克和7.8千克（无显著差异），而采食果园草的阉牛在试验期间体重增加了6.2千克（P < 0.01）。与分别饲喂G1 - 307（40.6摄氏度）和肯塔基31号（40.8摄氏度）高羊茅种子的犊牛相比，饲喂果园草的犊牛直肠温度较低（P < 0.05）（39.4摄氏度）。在第二项试验中，将肯塔基31号种子以0、350、700和1050克/天的分级水平混入载体日粮中，喂给荷斯坦阉牛。采食700克/天和1050克/天种子对阉牛的性能产生了不利影响。与0克或350克处理组相比，这两组的总采食量较低，饮水量减少（P < 0.05），直肠温度升高（P < 0.01）。在该试验中，体重变化未检测到显著差异。两项试验中的呼吸频率均未受到显著影响。这些针对幼牛的试验结果表明，高羊茅种子中存在一种有毒物质。
