Savory C J
Physiol Behav. 1985 Dec;35(6):917-28. doi: 10.1016/0031-9384(85)90260-4.
With normal diets, removal of the crop in Japanese quail and domestic fowls caused reductions in mean meal lengths and sizes, and compensatory increases in meal frequencies, only in those (30-40%) birds that had previously eaten larger, less frequent meals. Sham operation had no such effect. Cropectomy had less effect on feeding activity parameters when quail were fed on a diluted (40% cellulose) diet, and had no effect on diurnal patterns of feeding with either undiluted or diluted food (all birds tending to eat more at the end of the day). This may have been because cropectomized birds could store food in the oesophagus in amounts similar to those previously stored in the crop. Cropectomy had no apparent long-term effect on food intake with undiluted diets, but may have suppressed it slightly with diluted food. In intact quail and fowls, with ad lib access to food when killed, crops were often found to be empty with undiluted food, but were rarely so with diluted food. Gizzards also tended to hold more with diluted food, but were never completely empty with any diet. The post-crop oesophagus and proventriculus were empty in nearly all birds. In quail fasted for two hours, then allowed to feed for 20 min and killed at intervals over a further two hours, maximum amounts of undiluted and diluted food in crops and gizzards were generally greater than in ad lib-fed quail. Crops and gizzards emptied faster with diluted than with undiluted food, but no gizzard was completely empty two hours after feeding. The results of these experiments indicate that, with normal diets, meal termination (satiety) during most of the day is associated with partial crop filling in (30-40%) birds that habitually eat larger, less frequent meals, and with varying degrees of gizzard filling in birds with smaller meals. Satiety involves more crop filling in more birds with diluted food, and this may also apply to other factors that cause increased feeding activity. Meal initiation (hunger) may be associated with partial gizzard emptying in all birds. At some stage towards the end of the day there is usually a conditioned change to cumulative filling of the crop with enough food to be processed overnight.
在正常饮食情况下，切除日本鹌鹑和家禽的嗉囊会导致平均进食时长和食量减少，而进食频率会有代偿性增加，不过只有那些（30 - 40%）之前进食量大、频率低的鸟类才会如此。假手术则没有这种效果。当鹌鹑食用稀释（40%纤维素）饮食时，嗉囊切除术对进食活动参数的影响较小，并且无论是未稀释还是稀释的食物，对其昼夜进食模式都没有影响（所有鸟类在一天结束时往往进食更多）。这可能是因为切除嗉囊的鸟类能够在食管中储存与之前在嗉囊中储存量相似的食物。嗉囊切除术对未稀释饮食的食物摄入量没有明显的长期影响，但对稀释食物的摄入量可能有轻微抑制作用。在完整的鹌鹑和家禽中，处死时若能随意获取食物，未稀释食物情况下嗉囊常常是空的，但稀释食物时很少如此。砂囊在食用稀释食物时也往往容纳更多食物，但无论何种饮食，砂囊都不会完全排空。几乎所有鸟类的嗉囊后食管和腺胃都是空的。将鹌鹑禁食两小时，然后允许其进食20分钟，并在接下来的两小时内每隔一段时间处死，其嗉囊和砂囊中未稀释和稀释食物的最大量通常比随意进食的鹌鹑更多。与未稀释食物相比，稀释食物时嗉囊和砂囊排空得更快，但进食两小时后没有砂囊会完全排空。这些实验结果表明，在正常饮食情况下，一天中大部分时间的进食终止（饱腹感）与（30 - 40%）习惯进食量大、频率低的鸟类嗉囊部分充盈有关，而进食量小的鸟类饱腹感则与不同程度的砂囊充盈有关。食用稀释食物时，更多鸟类的饱腹感涉及更多的嗉囊充盈，这也可能适用于其他导致进食活动增加的因素。进食开始（饥饿感）可能与所有鸟类砂囊部分排空有关。在一天快结束时的某个阶段，通常会有一个条件性变化，即嗉囊累积充盈足够的食物以便在夜间进行处理。
