Latshaw J D, Moritz J S
Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA.
Poult Sci. 2009 Jan;88(1):98-105. doi: 10.3382/ps.2008-00161.
Broiler chickens were used to alter the partitioning of ME between maintenance and production. They were fed amounts of feed that ranged between ad libitum and 75 to 80% ad libitum each day from a BW of 1.1 to 2.2 kg. The experiment was done with 2 strains of broilers, both sexes, and 2 forms of feed (mash or pellets). Data were collected to determine live performance, digestibility of the feed, and carcass composition. The daily amount of feed did not affect the ME of the feed, but broilers fed limited amounts of feed gained less BW per day and had a larger feed:gain ratio. For most measurements, strain of broiler, sex, and form of feed also were significant factors. Because broilers that gained BW more slowly required more days to gain 1.1 kg and more feed during that time, a larger proportion of the energy was used for maintenance. The net energy theory proposes that heat increment, net energy for maintenance, and net energy for production are constants for a feed ingredient or feed. Results from the present research did not support the net energy theory. A different model was proposed that used ME as the basis for energy partitioning. Amounts of feed or energy per day had no effect on the ME content of the feed; however, amounts of energy consumed per day had dramatic effects on the proportion of the ME from each gram of feed that was used for maintenance, product, or heat increment. A model was developed that showed these effects and the feed:gain ratio over a wide range of daily energy intake.
使用肉鸡来改变代谢能（ME）在维持和生产之间的分配。从体重1.1至2.2千克起，它们每天的采食量在自由采食和自由采食量的75%至80%之间变化。该实验使用了2个品系的肉鸡、两种性别以及两种饲料形式（粉料或颗粒料）。收集数据以确定生长性能、饲料消化率和胴体组成。每日采食量不影响饲料的代谢能，但采食限量饲料的肉鸡每天增重较少，且料重比更大。对于大多数测定指标，肉鸡品系、性别和饲料形式也是显著因素。由于增重较慢的肉鸡达到1.1千克体重需要更多天数，在此期间需要更多饲料，因此较大比例的能量用于维持。净能理论提出，热增耗、维持净能和生产净能对于一种饲料原料或饲料来说是常量。本研究结果不支持净能理论。提出了一个以代谢能为能量分配基础的不同模型。每日采食量或能量对饲料的代谢能含量没有影响；然而，每日消耗的能量数量对每克饲料用于维持、生产或热增耗的代谢能比例有显著影响。开发了一个模型，该模型显示了这些影响以及在广泛的每日能量摄入量范围内的料重比。
