Zubair A K, Leeson S
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Poult Sci. 1994 Apr;73(4):529-38. doi: 10.3382/ps.0730529.
Two experiments were conducted with broilers to determine the effect of early feed restriction and realimentation on metabolic heat production and changes in sizes of digestive organs. An indirect open circuit calorimeter was used. Treatments were a full-fed control (FF) and a feed-restricted group (FR). Feed during the restriction period (6 to 12 d) for the FR birds was limited to 50% of voluntary feed intake of the FF birds. This was followed by realimentation period when all birds were provided feed for ad libitum consumption. The purpose of Experiment 1 was to measure basal metabolic rate (BMR), and Experiment 2 was designed to measure 36-h fasting metabolic rate (FMR), in both cases during time of restriction and realimentation. At the end of the 36-h unfed period, birds were killed and their digestive organs excised, blotted, and weighed. The FR birds showed significantly (P < .01) lower BMR compared with the FF birds during the restriction period. This lower BMR did not carry over into the refeeding period, when there was no difference between the two treatments. Thirty-six-hour FMR, like the BMR was also lower for FR compared with FF birds, but only during the period of restriction. Weights of digestive organs (expressed as a percentage of BW) during restriction were generally heavier for FR compared with FF birds. Measurements of organ weights taken during realimentation show significantly (P < .05) heavier liver and pancreas for FR compared with FF birds. Results of these experiments suggest that lower MR of "restricted-refed" birds does not play a role in the ability of the birds to show improved feed efficiency and growth compensation. Greater feed intake relative to BW and its associated digestive adaptations seem to be contributing factors to any growth compensation.
进行了两项试验，以确定早期限饲和恢复饲喂对肉鸡代谢产热及消化器官大小变化的影响。使用了间接开路式热量计。试验处理包括全喂饲对照组（FF）和限饲组（FR）。FR组鸡在限饲期（6至12日龄）的采食量限制为FF组鸡自由采食量的50%。之后是恢复饲喂期，此时所有鸡只均可自由采食。试验1的目的是测定基础代谢率（BMR），试验2旨在测定36小时禁食代谢率（FMR），均在限饲期和恢复饲喂期进行测定。在36小时未采食期结束时，宰杀鸡只，切除其消化器官，吸干水分并称重。在限饲期，FR组鸡的BMR显著低于FF组鸡（P < 0.01）。但这种较低的BMR在恢复饲喂期并未持续存在，此时两组处理之间没有差异。与FF组鸡相比，FR组鸡的36小时FMR在限饲期也较低，且仅在限饲期如此。在限饲期，FR组鸡的消化器官重量（以体重的百分比表示）通常比FF组鸡的重。在恢复饲喂期所测的器官重量显示，与FF组鸡相比，FR组鸡的肝脏和胰腺显著更重（P < 0.05）。这些试验结果表明，“限饲-恢复饲喂”鸡较低的代谢率在其提高饲料效率和生长补偿能力方面不起作用。相对于体重而言更大的采食量及其相关的消化适应性似乎是任何生长补偿的促成因素。
