148 CLEAN MILK 



the cows themselves. While it would be impossible for any one 

 to make much profit in milk at less than 2 cents a quart, yet it may- 

 be accepted that, unless a cow comes up to a certain standard in re- 

 gard to quantity and quality of milk, it is unprofitable to keep her, 

 and the sooner that cow and her owner are parted the better. Just 

 what that standard should be will depend somewhat on local con- 

 ditions, and prices of food, and milk; but, in a general way, the 

 cow that will not average about 10 quarts daily during 10 months- 

 of the year (6,000 lbs. annually), and whose milk falls much be- 

 low 4 per cent, fat, on the average (unless the quantity is very 

 large), will not pay to keep. In this region, there are many herds- 

 of grade Holsteins, containing as many as 80 to 120 heads, which. 

 average 16 quarts and over per cow during the summer months — 

 on pasture alone — in the rich valley lands. In order to determine 

 whether individual cows are profitable, the farmer must weigh 

 the daily amount and test the butter fat of each cow's (see p. 322) 

 milk at frequent intervals. Each cow's milk should be weighed 

 separately, directly the cow is milked, by hanging the milk pail on 

 a balance scale (the Chatillon balance, costing about $3.00 at any 

 dairy supply house, is the best) and recording the weight on a 

 record sheet which is gotten up for this purpose (see Appendix, 

 p. 322.) The record sheet should be kept near the weighing balance 

 in a room devoted to this purpose in the barn. To determine the 

 percentage of fat in the milk, a composite sample — that is, a sample 

 of a mixture of the same quantity of night's and morning's milk of 

 each cow for three days — should be examined by the Babcock test at 

 the beginning and end of each month. The composite sample is ob- 

 tained by pouring the fresh milk from one pail to another, and 

 from the mixed milk one should remove a gill with a long-handled 

 dipper at each milking. The gill is placed in a clean labelled and 

 covered Mason glass jar, which is shaken each time a new sample 

 is added. Fifteen drops of formalin or half a powdered B. & W- 

 corrosive sublimate tablet will preserve the samples for days, and 



