Halachmi I, Maltz E, Livshin N, Antler A, Ben-Ghedalia D, Miron J
Institute of Agricultural Engineering, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel .
J Dairy Sci. 2004 Jul;87(7):2230-8. doi: 10.3168/jds.S0022-0302(04)70043-0.
Two total mixed rations (TMR) containing different proportions of roughage neutral detergent fiber (NDF) were fed to lactating cows under Israeli summer conditions, and the effects on feeding behavior and milk production were measured. Forty-two lactating cows were divided into 2 groups fed ad libitum a TMR containing either 18% NDF of roughage origin (control group) or only 12% roughage NDF, in which the corn silage component (16.5% of dry matter [DM]) was replaced with soy hulls (experiment group). This and additional adjustments in TMR were reflected in higher net energy for lactation and in vitro digestibility of the experimental TMR. Cow behavior was investigated at the feeding lane during June 2001; about 11,000 cow visits were analyzed. Feed intake per meal and average meal duration were significantly higher in the experiment group (1.51 kg of DM per meal and 12.1 min per meal, respectively) as compared with the control group (1.22 kg of DM per meal and 9.47 min per meal, respectively). However, number of meals per day recorded in the feeding lane was significantly higher in the control group (21.0 vs. 16.6 meals/d per cow). Distribution of meals and feed intake along the day depended more on management practices, such as milking and feed dispensing times, than on feed composition or weather conditions. These differences between groups were expressed in similar daily eating duration (approximately 200 min), and because the rate of feed consumption was similar for both treatments (approximately 127 g DM/min), the daily average DM intake was also similar (25.0 to 25.7 kg). However, NDF intake was higher in the experiment group. Consequently, the average milk yield was higher in the experimental group, and production of milk fat, 4% fat-corrected milk, and economically corrected milk were significantly higher in the experiment group than in the control group. Data imply that the experimental TMR containing only 12% NDF of roughage origin is more suitable for cows under hot climate conditions compared with the control TMR.
在以色列夏季条件下，给泌乳奶牛饲喂两种含有不同比例粗饲料中性洗涤纤维（NDF）的全混合日粮（TMR），并测定其对采食行为和产奶量的影响。42头泌乳奶牛被分为两组，自由采食含18%粗饲料来源NDF的TMR（对照组）或仅含12%粗饲料NDF的TMR，其中玉米青贮成分（干物质[DM]的16.5%）被大豆皮替代（实验组）。TMR的这种及其他调整反映在实验TMR较高的泌乳净能和体外消化率上。2001年６月在采食通道对奶牛行为进行了调查；分析了约11000次奶牛采食情况。与对照组（分别为每餐1.22 kg DM和9.47分钟）相比，实验组每餐采食量和平均采食持续时间显著更高（分别为每餐1.51 kg DM和12.1分钟）。然而，采食通道记录的对照组奶牛每日采食次数显著更高（每头奶牛21.0次对16.6次/天）。一天中采食次数和采食量的分布更多地取决于管理措施，如挤奶和投料时间，而非饲料组成或天气状况。两组之间的这些差异体现在相似的每日采食持续时间（约200分钟）上，并且由于两种处理的饲料消耗速率相似（约127 g DM/分钟），每日平均DM摄入量也相似（25.0至25.7 kg）。然而，实验组的NDF摄入量更高。因此，实验组的平均产奶量更高，实验组的乳脂、4%乳脂校正乳和经济校正乳产量显著高于对照组。数据表明，与对照TMR相比，仅含12%粗饲料来源NDF的实验TMR更适合炎热气候条件下的奶牛。
