More information on the Open Book is available. Copyright 1981, the National Academy Press. Keywords, machine extracted. Top 50 words repeated twice, next 100 once, plus phrases. OCR for page 51 Nutritional Err.
Efficiency is the comparison of output to input.
There are numerous schemes for measuring efficiency of converting ingested foodstuffs to animal product. For example, dry matter content of both feedstuffs and animal product are highly variable, which may result in from 3 to 25 units of feed by weight required to produce a unit of body weight gain. However, feed to gain ratio is an accepted way of describing total efficiency and is a useful term in practical situations since ultimately it is weight of feed that must be grown or purchased and fed and weight of product sold. Seasonal variation in com- position of expelled product such as butterfat content of milk are well known. However, when all factors are considered, environment has little ef fect on partial efficiency.