POULTRY-CRAFT. 117 



the standard is much greater in warm weather than in cold. Computations 

 for summer rations, in the hottest weather, would, without doubt, sometimes 

 show nutritive ratio as narrow as 1:4, and potential energy as low as 50 ; 

 but not very often. Computations of good winter rations, for rather cold 

 houses, would rarely show values exceeding those of the average fattening 

 ration. 



157. The Balance of the Ration. It is clear that a ration can be exactly 

 balanced only at rare intervals, and then, as it were, only for the instant. Then 

 if the ration is sufficient in quantity, there must be excess of either one kind of 

 elements or the other. For economic reasons it is desirable that the excess be 

 of the cheaper elements the carbohydrates. The ration should always be a 

 little wide, rather than a little narrow. 



158. Examples in Balancing Rations: 



(i). To compute the values of the ration described in ^[146 (2) : 

 Corn contains (see table, ^[ 153) 10.4% protein, 70.3% carbohydrates, 5% 

 fat; wheat, 11.9% protein, 71.9% carbohydrates, 2.1% fat; bran, 15.4% 

 protein, 53.9% carbohydrates, 4% fat; beef scraps, 58% protein, 32.9% fat; 

 then 



Protein Carbohydrates Fats 



Ibs. Ibs. Ibs. 



94 Ibs. corn contain 9.77 66.08 4.7 



106 Ibs. oats contain 12.5 63.28 5.3 



100 Ibs. bran contain 15.4 53.9 4. 



12 Ibs. beef scraps contain 6.96 .... 3.94 



312 Ibs. mixture contain 44-63 183.26 17-94 



and the nutritive ratio of the mash is : 



44.63 : (17.94X2.5)4-183.26 = i : 5.1 ; 

 and potential energy for 312 Ibs. is : 



( 1 7.94X16 X264)+[ (44.63X183.26) 16X116] = 494.208 calories, 

 and potential energy per oz. is 99 calories. 



The computation of the whole grain given in this ration gives : 



Protein Carbohydrates Fats 



Ibs. Ibs. Ibs. 



120 Ibs. wheat contain 14.28 86.40 2.52 



64 Ibs. oats contain 7.55 38.20 3.2 



120 Ibs. buckwheat contain 12. 77*4 2.64 



56 Ibs. corn contain 5.82 39.36 2.8 



360 Ibs. mixture contain 39-6.5 241.36 11.16 



Nutritive ratio, i : 6.8 ; potential energy, 95 calories per ounce. 



