Aug. i6, I9IS Prickly-Pears as a Feed for Dairy Cows 



421 



Table XI. — Comparison of estimated and actual coefficients of digestion for dairy 



cows — Continued 



COMPARISON OF HAY, GRAIN, AND MEDIUM AND HEAVY RATIONS OF PRICKLY-PEAR 



It will be observed from this table that when hay and grain were fed 

 the actual coefficient for organic matter exceeded the estimated by 2.08 

 per cent, and that when hay, grain, and a moderate quantity of prickly- 

 pear (60 pounds per day) were fed the actual exceeded the estimated by 

 1.85 per cent. These results indicate that prickly-pear in moderate 

 amounts has little effect on the digestibility of the other organic ingre- 

 dients of the ration. The effect of a large ration of prickly-pear (105 to 

 120 pounds) as compared with a medium ration will be seen from the 

 results with cows 11 and i. When fed the medium ration, the actual 

 exceeded the estimated coefficient by 0.55 per cent; when fed the large 

 ration, the actual was 2.62 per cent less than the estimate. These figures 

 indicate that a large amount of prickly-pear in the ration depressed the 

 coefficient of digestion. 



The results of the writers' digestion trials with prickly-pear as the 

 sole feed agree fairly well with those obtained by Hare (7). The trials 

 reported in this paper show a less efficient digestion of dry matter, fiber, 

 nitrogen-free extract, ether extract, and organic matter, but a more 

 efficient digestion of ash and especially of protein. In general, the 

 coefficients of digestion secured by Hare are greater than those obtained 

 in the trials of the writers (Table XII). 



Table XII. — Comparison of digestion coefficients of prickly-pear with those of pre- 



vious trials 



96502°— 15 4 



