68 



MANUAL OF MILK PRODUCTS 



titrated simultaneously. The test covered three periods. 

 During Period I both cows were fed a ration containing about 

 forty pounds of silage a day, which they had been receiving for 

 five months or more. In Period II Naomi's Beauty was fed 

 on the silage ration, while Ethel's Fancy received a ration with- 

 out silage. During Period III the ration was changed for both, 

 Ethel's Fancy going back to the silage; while Naomi's Beauty 

 received none. The results are given below. 



Result of Acidity Test 



Period 



Length of Feeding 

 Period 



Number 



of 

 Samples 



Naomi's Beauty 



Ethel's Fancy 



Silage 



No Silage 



Silage 



No Silage 



I 



II 



III 



Up to May 13th 

 May 13th to 20th 

 May 20th to 27th 



3 

 4 



9 



per ct. 



0.11 

 0.11 



0.13 



per ct. 



0.16 

 0.19 



per ct. 



0.19 



" As may be seen from these figures, there was apparently a 

 slight increase in acidity when the cows were ' taken off ' a silage 

 ration, but the difference is so small that it may probably be 

 attributed to chance variations. There is a much more notice- 

 able difference between individual cows, as is shown by the fol- 

 lowing analyses, all on silage rations : ' Brownie,' average of six 

 analyses, 0.19 per cent; 'Molly 2d,' average of six analyses, 

 0.185 per cent; 'Naomi's Beauty,' average of seven analyses, 

 0.11 per cent; and 'Ethel's Fancy,' average of twelve analyses, 

 0.175 per cent. The mixed milk of the herd of twenty-five cows 

 on grass (May 25th to 27th) showed as an average of six analyses 

 0.175 per cent of acidity." 



