Whetsell M S, Prigge E C, Nestor E L
Division of Animal and Veterinary Sciences, West Virginia University, Morgantown 26505-6108, USA.
J Anim Sci. 2004 Jun;82(6):1806-17. doi: 10.2527/2004.8261806x.
To evaluate the influence of mass of ruminal contents on voluntary intake and ruminal function, five ruminally cannulated steers (550 kg) were fed an orchard grass hay diet ad libitum in a 5 x 5 Latin square experiment. The mass of ruminal contents was altered by adding varying weights of modified tennis balls to the rumen before the initiation of each 15-d experimental period. Treatments consisted of 50 balls with a specific gravity of 1.0, 1.1, 1.2, 1.3, or 1.4; the total weight of the balls was 7.45, 8.50, 9.25, 10.55, and 11.55 kg, respectively. Increasing the specific gravity of the balls added to the rumen decreased DMI and particle passage rate (P < 0.05) in a linear manner. A second experiment was conducted to evaluate the influence of mass of ruminal contents on voluntary intake and ruminal function of both forage and concentrate diets. Five ruminally cannulated steers (580 kg) were fed a 70% concentrate (DM basis) or an orchardgrass hay diet ad libitum in a 5 x 5 Latin square experiment. The mass of ruminal contents was altered as in the first experiment. Treatments consisted of 0 balls added to the rumen of steers fed concentrate diet (control), 75 balls with a specific gravity of 1.1 given to steers fed a concentrate diet, 75 balls with a specific gravity of 1.4 given to steers fed a concentrate diet, 75 balls with a specific gravity of 1.1 given to steers fed a hay diet, and 75 balls with a specific gravity of 1.4 given to steers fed hay diet. The addition of balls to the rumen of steers fed the concentrate diet decreased DMI (P < 0.05) compared with the 0-ball treatment, and increasing specific gravity of balls also decreased DMI (P < 0.01) for both concentrate and hay diets. Adding balls to the rumen of steers fed the concentrate diet decreased particle passage rate (P < 0.05), whereas increasing specific gravity of balls decreased particle passage rate for both concentrate and hay diet. The results of this study suggest that the density of ruminal digesta can have an influence on voluntary intake of both forage and concentrate diets.
为评估瘤胃内容物质量对采食量和瘤胃功能的影响，在一项5×5拉丁方试验中，给5头安装了瘤胃瘘管的阉牛（550千克）随意投喂果园草干草日粮。在每15天试验期开始前，通过向瘤胃中添加不同重量的改性网球来改变瘤胃内容物的质量。处理组包括添加比重为1.0、1.1、1.2、1.3或1.4的50个球；球的总重量分别为7.45、8.50、9.25、10.55和11.55千克。增加添加到瘤胃中的球的比重会使干物质采食量（DMI）和颗粒通过率呈线性下降（P<0.05）。进行了第二项试验，以评估瘤胃内容物质量对粗饲料和精饲料日粮的采食量和瘤胃功能的影响。在一项5×5拉丁方试验中，给5头安装了瘤胃瘘管的阉牛（580千克）随意投喂70%精饲料（以干物质计）或果园草干草日粮。瘤胃内容物的质量如第一项试验那样改变。处理组包括给饲喂精饲料日粮的阉牛瘤胃中不添加球（对照组）、给饲喂精饲料日粮的阉牛添加75个比重为1.1的球、给饲喂精饲料日粮的阉牛添加75个比重为1.4的球、给饲喂干草日粮的阉牛添加75个比重为1.1的球，以及给饲喂干草日粮的阉牛添加75个比重为1.4的球。与不添加球的处理组相比，给饲喂精饲料日粮的阉牛瘤胃中添加球会降低DMI（P<0.05），并且增加球的比重也会使精饲料和干草日粮的DMI降低（P<0.01）。给饲喂精饲料日粮的阉牛瘤胃中添加球会降低颗粒通过率（P<0.05），而增加球的比重会使精饲料和干草日粮的颗粒通过率降低。本研究结果表明，瘤胃消化物的密度会对粗饲料和精饲料日粮的采食量产生影响。
