CHAPTER XIV 

 DIGESTIBILITY AND NUTRITIVE RATIO 



The leading quality of f eedstuffs is digestibility. All nutri- 

 ents taken into the body are not digested, nor is there a 100 

 per cent, of any nutrients digested. 



The percentage feed nutrients capable of being digested and 

 assimilated varies from 98 per cent, in the case of cows' milk 

 and eggs to less than 50 per cent, in the case of wheat and oat 

 straw. 



Grains rank higher in digestibility than coarse roughage. 

 Thus, 40 to 80 per cent, protein in coarse fodder may be 

 capable of being digested, while only 30 to 68 per cent, of the 

 crude fiber is available. 



Digestibility of fats and oils vary greatly, ranging from 90 

 per cent, in some cereals to as low as 30 per cent, in some kinds 

 of straw. 



At times cut or ground alfalfa or clover is used in compound- 

 ing the dry mashes for poultry. It has been determined that 

 the degree of maturity affects the digestibility of plants. In 

 one experiment conducted with cattle it was found that in clover 

 cut while just coming in bloom 71 per cent, of the protein was 

 digested. If cut and cured in full bloom but 65 per cent, was 

 digested, and if cut toward the end of blooming only 59 per 

 cent, could be digested. 



Trials with animals have been conducted in feeding a 

 -protein diet exclusively. The results were an increased decom- 

 position of the protein in the body as the quantity was in- 

 creased and the excess does not go to form flesh. Protein 

 consumption in the body is apparently, in part, dependent 

 upon the condition of the animal's body as a result of previous 

 feeding. Voit showed by experiments that fat when fed alone 

 does not decrease protein consumption in the body. Carbo- 

 hydrates, when fed alone, have the same effect as fat — that is, 



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