380 FEEDS AND FEEDING, ABRIDGED 



crude fiber take place. The food remains in the crop too short a 

 time for any appreciable digestion there thru bacterial action, such as 

 occurs in the paunch of ruminants, and little bacterial action takes 

 place in the large intestine. Due to this, crude fiber has little value for 

 poultry, but serves simply to give bulk to the ration. Hence, the feed 

 of poultry must be more concentrated in character than that for other 

 farm stock. 



Digestibility of feeds by poultry. — Since the urine is not voided sep- 

 arately by poultry, digestion trials can not be conducted satisfactorily 

 in the same manner as with other animals. In general, the digestibility 

 of feeds by poultry resembles that of swine, tho poultry digest even 

 less fiber. The digestibility of grain for poultry is not increased by 

 grinding, as all seeds are ground fine in the gizzard, if grit is available. 



Feeding standards and nutrient requirements of poultry. — Owing 

 to the fact that satisfactory digestion coefficients have .not been obtained 

 for poultry, our knowledge of their actual nutrient requirements is 

 less definite than for other classes of stock. "Wheeler of the New 

 York (Geneva) Station ± has presented the most complete standards 

 which have yet been advanced. These, converted to the same terms 

 as the Modified Wolff-Lehmann Standards, are given in Appendix 

 Table V. It will be noted that poultry require a much larger amount 

 of nutrients per 1,000 lbs. live weight than do the other farm animals. 

 This is due to their small size and the consequent greater radiation 

 of heat from the body, and to their high body temperature and great 

 activity. No .figures are given for the amount of total dry matter, 

 but, as mentioned previously, on account of the nature of their diges- 

 tive tract, rations for poultry must be more concentrated than for 

 other stock, even swine. 



The nutritive ratios recommended for growing chicks and for lay- 

 ing hens are narrower than for nearly all other classes of farm animals. 

 This is because chicks and other young poultry grow very rapidly in 

 proportion to their size and hence store large amounts of protein 

 in their bodies. Laying hens require a narrow nutritive ratio be- 

 cause they are yielding a product very high in protein. Eggs con- 

 tain about 65.9 per ct. water, 12.8 per ct. crude protein, 10.6 per 

 ct. fat, and 10.7 per ct. mineral matter. The protein thus forms 

 about 38 per ct. of the total dry matter. On account of these facts, 

 rations for growing and laying poultry should contain a rather 

 larger proportion of protein-rich feeds than for other farm animals. 

 For fattening poultry less protein is needed and the nutritive ratio 

 may range from about 1 : 6.2 for young birds which are still growing 

 to 1 : 8 for mature poultry. 



i Jordan, The Feeding of Animals, pp. 393-5. 



