Neel J P, Prigge E C, Townsend E C
Division of Animal and Veterinary Sciences, West Virginia University, Morgantown 26506-6108, USA.
J Anim Sci. 1995 Oct;73(10):3094-102. doi: 10.2527/1995.73103094x.
Four crossbred beef steers (392 kg BW) fitted with ruminal cannulas were used in a 4 x 4 Latin square experiment with treatments arranged in a 2 x 2 factorial to evaluate effects of forage species (F) and reconstitution (R) on apparent digestibility, ruminal kinetics, and digesta functional specific gravity (FSG). Dietary treatments were alfalfa (Medicago sativa L.) and timothy (Phleum pratense L.) hays (90% DM) and the same hays reconstituted with water to 38% DM. Apparent DM digestibility was unaffected by R or F. Proportion of ruminal digesta with a FSG of .9 to 1.1 or 1.1 to 1.2 decreased linearly (P < .05) after feeding, whereas the proportion with FSG > 1.2 increased linearly (P < .01). Reconstitution decreased (P < .10) the proportion of ruminal digesta with FSG of 1.1 to 1.2 and increased (P < .10) the proportion with a FSG > 1.2 compared with the hay diets. Reconstitution decreased digesta passage rate for timothy forage; no influence on passage rate for alfalfa was detected (F x R, P < .10). Ruminal DM pool was increased by reconstitution (P < .10). Inert particles of 1-mm length passed from the rumen at a faster rate (P < .05) than 3-mm particles. Inert particles with SG of 1.32 passed from the rumen at a faster rate (P < .05) in the reconstituted alfalfa than in the dry alfalfa diet but at a slower rate in the reconstituted timothy than in the dry timothy diet. These results suggest that factors other than SG of the digesta can have a profound effect on passage of forage particles from the rumen.
选用4头安装有瘤胃瘘管的杂交肉牛（体重392千克），进行4×4拉丁方试验，处理方式按2×2析因设计，以评估饲草种类（F）和复水（R）对表观消化率、瘤胃动力学及消化物功能比重（FSG）的影响。日粮处理包括苜蓿（紫花苜蓿）和猫尾草（梯牧草）干草（90%干物质），以及用水复水至38%干物质的相同干草。表观干物质消化率不受R或F的影响。采食后，FSG为0.9至1.1或1.1至1.2的瘤胃消化物比例呈线性下降（P<0.05），而FSG>1.2的比例呈线性增加（P<0.01）。与干草日粮相比，复水降低了FSG为1.1至1.2的瘤胃消化物比例（P<0.10），并增加了FSG>1.2的比例（P<0.10）。复水降低了猫尾草饲草的消化物通过率；未检测到对苜蓿通过率的影响（F×R，P<0.10）。复水增加了瘤胃干物质池（P<0.10）。1毫米长的惰性颗粒从瘤胃排出的速度比3毫米颗粒快（P<0.05）。SG为1.32的惰性颗粒在复水苜蓿中从瘤胃排出的速度比干苜蓿日粮快（P<0.05），但在复水猫尾草中比干猫尾草日粮慢。这些结果表明，除了消化物的SG外，其他因素可能对饲草颗粒从瘤胃的排出有深远影响。
