The Development of Feeding Standards for Livestock
When writing of the historical development of a scientific concept, it is essential to give at least a general picture of the scientific ideas invoived.
A brief account of these ideas will, therefore, be given first. If feeding stuffs are to be used to their full advantage, then it is essential for us to know something of their relative merits and of their effects upon the animal. Further, if they are to be quantitatively compared with each other, their value must be first expressed in terms of some unit, and their quantitative effect on the animal must also be measurable in these same units. Thus three feeding stuffs may contain x, y, and z units of nutrient material per hundred pounds respectively, whilst a cow may require m units of nutrient material to keep it alive and p units of material per gallon of milk. From this knowledge of the three feeding stuffs and the requirements of the cow, we should be able to decide theoretically on a suitable mixture of these feeding stuffs for the cow. Clearly this idea can be extended to all feeding stuffs and to all classes of product, such as eggs and meat. The historical development of feeding standards has therefore gone hand in hand with the nutritional evaluation of feeding stuffs, and both have progressed in the light of an ever growing knowledge of physiology and biochemistry.