It should be borne in mind that the above figures express 

 only net energy and not protein value. If protein is needed to 

 balance the ration, it can be purchased most economically in the 

 high-grade protein concentrates, such as cottonseed meal, gluten 

 feed, distillers' dried grains and the like. 



4. Ntitriiive Ratio of Cattle Feeds. 



The numerical relation which the digestible protein bears to 

 the other digestible organic nutrients (fiber, extract matter and 

 fat^) is termed the nutritive ratio of the feed or ration. One 

 hundred pounds of timothy hay has, for example, 3 parts of 

 digestible protein to 47.3 parts of other digestible nutrients, 

 or as 1 is to 15.8. This is termed a A^ery wide nutritive ratio. 

 One hundred pounds of gluten feed contains 22.3 parts of digestible 

 protein to 58.6 parts of other digestible nutrients, or as 1 is to 2.6. 

 This may be termed a very narrow nutritive ratio or proportion. 

 All feeds having a nutritive ratio of 1 to 5 or less may be said to 

 have narrow ratios, those from 1 to 5 to 1 to 8 a medium ratio, 

 and above 1 to 8 a wide ratio. 



The cereals and other non-leguminous coarse fodders have 

 medium to wide ratios, and the leguminous coarse fodders, 

 medium ratios and the leguminous seeds and most concentrated 

 by-products narrow ratios. 



5. Combining Coarse and Concentrated Feeds (Balanced Rations). 



Desirable rations for dairy stock should possess (a) palata- 

 bility, (b) sufficient bulk, and (c) 1 part of protein to 5.5 to 7 

 parts of the other digestible organic nutrients. If the ratio is 

 much narrower than 1 to 5.5, the ration is likely to be too stimu- 

 lating for continuous feeding, and the animal is likely to become 

 thin in flesh. If the ratio is much wider than 1 to 7, the tendency 

 will be for the animal to put on fat rather than to give milk. 

 In both cases the ration may be said to be out of balance. 



For both economical and physiological reasons it is necessary 

 that a considerable portion of the daily ration of the dairy animal 

 should be composed of coarse fodder or roughage, because such 

 materials are easily and cheaply produced on the farm, and 

 because the digestive tract of the bovine is especially suited to 

 utilize them. Most of these home-grown coarse feeds, however, 

 are very high in carbohydrates, low in protein, and have a rela- 

 tively low digestibility. It is necessary, theiefore, to supplement 

 them to an extent with the cereal grains, which, though relatively 

 low in protein, are very digestible; and with the concentrated 

 by-products which, in addition to a relativel}^ high digestibility, 

 are quite rich in protein. A single illustration will make this 



^ The fat is converted into the energy equivalent of the starch or fiber by multiplying 

 by 2.2; thus, 3 per cent of fat would have an energy equivalent of 6.6 per cent or parts of starch. 



