Tolkamp B J, Schweitzer D P, Kyriazakis I
Animal Biology Division, Scottish Agricultural College, The King's Buildings, Edinburgh, United Kingdom.
J Dairy Sci. 2000 Sep;83(9):2057-68. doi: 10.3168/jds.S0022-0302(00)75087-9.
To determine whether visits or meals are the most biologically relevant unit of short-term feeding behavior, we analyzed 209,025 records of visits to feeders by 37 cows. Two feeds were used that differed in protein content. Cows were divided into control groups for the low and high protein feeds and a choice group that had access to both. Daily number of visits and intake per visit were very variable. Cows fed low protein feed had lowest daily intakes, but single-visit characteristics were poorly correlated with daily intake. The probability of cows ending a visit did not change greatly with visit length. Log-normal models were used to estimate individual meal criteria (44.7+/-2.1 min), and visits were grouped into meals. Meal duration (36.9+/-1.3 min) and daily number of meals (6.1+/-0.1) were not affected by treatment. Feeding rate and intake per meal were lowest for cows fed low protein feed. Meal size decreased systematically during the day. The probability of cows ending and starting a meal increased with meal length and interval between meals, as predicted by the satiety concept. Meals are, therefore, a biologically relevant unit of short-term feeding behavior and visits are not.
为了确定拜访或进食是否是短期采食行为最具生物学相关性的单位，我们分析了37头奶牛前往喂食器209,025次的记录。使用了两种蛋白质含量不同的饲料。奶牛被分为低蛋白饲料和高蛋白饲料的对照组以及可以获取两种饲料的选择组。每日的拜访次数和每次拜访的摄入量变化很大。喂食低蛋白饲料的奶牛每日摄入量最低，但单次拜访的特征与每日摄入量的相关性很差。奶牛结束一次拜访的概率不会随着拜访时长而发生很大变化。使用对数正态模型来估计个体进食标准（44.7±2.1分钟），并将拜访分组为进食。进食持续时间（36.9±1.3分钟）和每日进食次数（6.1±0.1）不受处理的影响。喂食低蛋白饲料的奶牛进食速度和每餐摄入量最低。每餐量在一天中系统性地减少。正如饱腹感概念所预测的那样，奶牛结束和开始进食的概率随着进食时长和两餐之间的间隔而增加。因此，进食是短期采食行为具有生物学相关性的单位，而拜访则不是。
