Selection for growth rate, feed efficiency and body composition in mice.
Selection for growth rate, feed efficiency and body composition in mice.
复制标题
选择小鼠的生长速度、饲料效率和身体成分。
作者：
T. Sutherland;P. E. Biondini;G. Ward
生长速度和饲料利用率是肉畜生产中两个最重要的经济性状。在世界植物和动物蛋白质短缺的这些日子里，随着能源危机的逼近，通过加快生长速度来降低维持成本和通过提高植物饲料转化为动物蛋白质的效率来提高生长效率的必要性变得比以往任何时候都更加紧迫。已经报道了许多关于饲料转化效率的研究，这些研究涉及影响饲料转化效率的生理参数，并且可以想象这些生理参数可以显示遗传变异性。这些参数包括摄入的营养物质通过肠道吸收的效率（消化率），维持体重所需的能量（维持），吸收的营养物质转化为给定身体组织的效率，主要是蛋白质和脂肪，以及这两者沉积的相对效率。也许最重要的影响已被处理的饲料摄入量（食欲）的差异，和脂肪的比例瘦在组织中获得。也有许多关于生长速度和身体组成的单独研究，但很少有人试图将它们相互联系起来，或与影响效率的生理因素联系起来。本文试图综合我们的知识，通过处理上述生理特性和生长速度，饲料消耗量和身体组成这三个特性之间的相互关系，沿着的“综合特性”，通常称为饲料效率，在给定的时间段内体重增加的饲料消耗量的比例。将对已发表的结果进行回顾，并与我们在科罗拉多的小鼠实验室的结果进行比较。从小鼠到大型动物的预测将定期进行，以了解在经济规模上可能提供什么见解。
ROWTH rate and efficiency of feed utilization are two of the most economically important characters in the production of meat animals. In these days of world shortage of both plant and animal protein, and with an energy crisis looming on the horizon, the necessity both to reduce maintenance costs by speeding up growth rate and to improve the efficiency of growth by improving the efficiency of conversion of plant feed to animal protein, has become more urgent than ever. Many studies have been reported on efficiency of feed conversion, dealing with the physiological parameters which affect it and which could conceivably show genetic variability. These parameters include the efficiency with which ingested nutrients are absorbed through the gut (Digestibility), the energy required to maintain body weight (Maintenance), and the efficiency with which absorbed nutrients are converted into a given body tissue, principally protein and fat, and the relative efficiencies of the deposition of these two. Perhaps the most important influences treated have been the differences in feed intake (appetite), and the ratio of fat to lean in the tissue gained. Many individual studies have also been carried out on growth rate and body composition, but few have attempted to relate these to each other or to the physiological factors affecting efficiency. The present paper attempts to synthesize our knowledge by treating the physiological characters mentioned above and the interrelationships among the three characters of growth rate, feed consumption, and composition of the body, along with the “synthetic character” generally called feed efficiency, the ratio of gain in weight of body to the amount of feed consumed over a given period of time. A review of published results will be presented and compared to the results from our own mouse laboratory in Colorado. Projections from mice to large animals will be made periodically to see what insights may be offered on an economic scale.