Chagneau A M, Bessonneau D, Bouchot C, Lescoat P, Picard M, Lessire M
INRA Station de Recherches Avicoles, 37380 Nouzilly, France.
Poult Sci. 2006 Apr;85(4):808-15. doi: 10.1093/ps/85.4.808.
Three dietary compositions and 3 methods of pellet preparation were used in different choice situations to improve our understanding of the factors perceived by broiler chickens in the physical structure of their diet. Within the same visual field, broiler chickens were offered 8 microfeeders containing different pelleted feeds that could be reached from the same position of the bird. Chickens were daily tested during 5-min tests following a 45-min period of feed withdrawal, after adaptation to individual cages and experimental feeders. Two feeds (4 microfeeders/feed in alternate positions) were weighed prior to and after the test. Behavior of the chickens was videotaped during the test to count the number of pecks given to each microfeeder. In a first experiment, 2 feeds of distinct composition were either steam or cold-pelleted. The tests of choice were repeated daily from 22 to 25 and from 35 to 38 d of age on 96 male broiler chickens. Significant preferences were measured from the first test. Similar preferences were measured when chickens received the same choice or alternating choices from one test to another. Differences of feed intake between 2 feeds during 5 min were significantly correlated to differences of number of pecks (R2 = 0.85). In most cases, preferences were established within the first minute of pecking. Steam pellets were significantly preferred to cold pellets for one feed composition but not for the other. Preferences for compositions were consistent whatever the pellet preparation and probably associated with the color of the feeds. A second experiment confirmed that 38-d-old broiler chickens seemed to prefer light colors. Short-term preferences of a chicken for a feed were rather influenced by physical characteristics of feed particles (size, color, hardness) than by the origin of raw materials. Feed pecking may change because of feed composition itself, because of its consequences on color or texture cues, or both.
在不同的选择情境中，使用了三种日粮组成和三种制粒方法，以增进我们对肉鸡在日粮物理结构中所感知因素的理解。在同一视野内，向肉鸡提供8个微型喂食器，其中装有不同的颗粒饲料，肉鸡可从同一位置获取。在适应个体笼子和实验喂食器后，经过45分钟的禁食期，每天对肉鸡进行5分钟的测试。测试前和测试后对两种饲料（每种饲料在交替位置有4个微型喂食器）进行称重。在测试过程中对肉鸡的行为进行录像，以统计每个微型喂食器的啄食次数。在第一个实验中，两种不同组成的饲料分别进行蒸汽制粒或冷制粒。对96只雄性肉鸡在22至25日龄以及35至38日龄时每天重复进行选择测试。从第一次测试就测量到了显著的偏好。当肉鸡从一次测试到另一次测试接受相同选择或交替选择时，测量到了相似的偏好。两种饲料在5分钟内的采食量差异与啄食次数差异显著相关（R2 = 0.85）。在大多数情况下，偏好是在啄食的第一分钟内确立的。对于一种饲料组成，蒸汽颗粒明显比冷颗粒更受青睐，但另一种饲料组成则不然。无论制粒方式如何，对饲料组成的偏好都是一致的，并且可能与饲料颜色有关。第二个实验证实，38日龄的肉鸡似乎更喜欢浅色。肉鸡对一种饲料的短期偏好更多地受到饲料颗粒的物理特性（大小、颜色、硬度）影响，而不是原料来源。饲料啄食可能会因为饲料组成本身、其对颜色或质地线索的影响，或者两者兼而有之而发生变化。
