Christen A M, Seoane J R, Leroux G D
Département de zootechnie, Université Laval, Cité Universitaire, Québec, Canada.
J Anim Sci. 1990 Oct;68(10):3350-9. doi: 10.2527/1990.68103350x.
Thirty-two wethers were used to compare the nutritive value of Climax timothy (Phleum pratense L.) and quackgrass (Agropyron repens L. Beauv.) harvested at two stages of maturity, joint and early heading, and fed as hay. Crude protein was higher for quackgrass than for timothy (P less than .01). As maturity advanced, CP decreased (P less than .01), but NDF and ADL increased (P less than .01). Dry matter intake was similar between species but decreased by 8% with increasing maturity (P less than .01). Intake of NDF (g/kg.75) was similar for all hays. With increasing plant maturity, apparent digestibility decreased, the effect being more pronounced for quackgrass. Apparent digestibilities of DM and energy were slightly higher (P less than .06) for timothy, and those of CP and hemicellulose were higher for quackgrass (P less than .01). Apparent digestibilities of NDF, ADF, ADL, crude fiber and cellulose were similar between species. Dry matter intake and digestibility were correlated negatively with the ADL/ADF ratio of the hay (r = -.99, P less than .01), whereas CP intake and CP digestibility were correlated with CP of the hay (r = .99, P less than .01). The Lucas test estimated true protein digestibility at 88.1% and metabolic fecal protein at 29.4 g per kg of DM intake. During the growth trial, DM intake was similar between hays, but ADG of sheep was lower (P less than .01) for those fed hays at early heading vs those receiving hays at the joint stage of maturity. The feed to gain ratio was slightly lower for hays at joint (P less than .08). Under the climatic conditions of the 1988 growing season, the nutritive value of quackgrass was similar to that of Climax timothy.
选用32只去势公绵羊，比较在拔节期和抽穗初期这两个成熟阶段收割并制成干草饲喂的Climax猫尾草（梯牧草，Phleum pratense L.）和偃麦草（Agropyron repens L. Beauv.）的营养价值。偃麦草的粗蛋白含量高于猫尾草（P < 0.01）。随着成熟度增加，粗蛋白含量下降（P < 0.01），但中性洗涤纤维和酸性洗涤木质素含量增加（P < 0.01）。两个品种之间的干物质采食量相似，但随着成熟度增加下降了8%（P < 0.01）。所有干草的中性洗涤纤维采食量（g/kg.75）相似。随着植株成熟度增加，表观消化率下降，偃麦草的这种影响更为明显。猫尾草的干物质和能量表观消化率略高（P < 0.06），偃麦草的粗蛋白和半纤维素表观消化率更高（P < 0.01）。两个品种之间中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素、粗纤维和纤维素的表观消化率相似。干物质采食量和消化率与干草的酸性洗涤木质素/酸性洗涤纤维比值呈负相关（r = -0.99，P < 0.01），而粗蛋白采食量和粗蛋白消化率与干草的粗蛋白含量呈正相关（r = 0.99，P < 0.01）。卢卡斯试验估计真蛋白消化率为88.1%，代谢粪蛋白为每千克干物质采食量29.4克。在生长试验期间，不同干草之间的干物质采食量相似，但与采食拔节期干草的绵羊相比，采食抽穗初期干草的绵羊平均日增重较低（P < 0.01）。拔节期干草的料重比略低（P < 0.08）。在1988年生长季节的气候条件下，偃麦草的营养价值与Climax猫尾草相似。
