CALCULATING FEEDING RATIONS 97 



fat. He then allowed certain amounts of these nutrients in 

 the ration, additional to that for maintenance, based on each 

 pound of milk of definite butter-fat composition. The stand- 

 ard proposed by Haecker was a great step forward, but 

 some investigators after extensive trials came to the con- 

 clusion that the nutrients recommended fell a trifle short of 

 real requirements. Haecker's table was changed slightly by 

 Savage, who approved of the maintenance standard, but 

 who increased the percentage of protein required, from 18 

 to 20 per cent. Savage also combined the total nutrients, 

 instead of computing carbohydrates and fat separately. In 

 their modified form of the Wolff-Lehmann standard, Henry 

 and Morrison arrange for dairy cattle by adopting the 

 quantities of protein given in both Haecker and Savage 

 standards, as for example 0.054 0.065 digestible protein for 

 milk with 4.0 per cent fat. In this case, Haecker recom- 

 mends 0.054 pound protein to be fed for each pound of 4.0 

 per cent milk produced, while Savage recommends 0.065 

 pound. The person figuring out a ration for a dairy cow 

 will do well to see that the feed contains enough protein 

 to come within the variations of the standard and the ad- 

 justment of this nutrient may well receive first consideration. 

 There is no fixed standard for dry matter adopted in this 

 case, but cows producing one pound of fat a day should 

 receive from 21 to 25 pounds of dry matter for 1,000 pounds 

 live weight. 



A reference to Table B, Appendix, will show the modi- 

 fied Wolff-Lehmann standard given by Henry and Mor- 

 rison.* The method of computing the amounts of dry 

 matter, digestible protein and total digestible nutrients, 

 applies the same in this case as in the example given with 

 beef cattle. One must make a special computation, how- 

 ever, to establish one's standard, based on the number of 

 pounds of milk daily, and its fat content, as previously 

 stated. This is determined as follows: 



*Feeds and Feeding, 1917. 

 4 



