468 Value of Records of Milk Yield of Cows, [sept., 



which systematically give a low yield or produce milk of low 

 quality, and, by disposing of them, prevent the loss due to 

 maintaining cows that are not worth their keep. Where 

 milk is made into butter, the importance of obtaining a high 

 percentage of fat in the milk is obvious, while to the breeder 

 the practice of milk-testing is perhaps even more important, 

 as by this means he can select his best cows for breeding 

 purposes. 



Simple Records of Milk Yields. — A record of the yield of 

 milk in its simplest form is not difficult to keep, and the small 

 amount of time and trouble involved is well repaid by the 

 value of the information obtained. All that is required is a 

 spring balance to which a pail can be hung. The milk of 

 each cow can thus be easily weighed, and should then be noted 

 on a sheet ruled for the purpose and fastened up in some 

 convenient position. The weight of the pail should be de- 

 ducted, but balances can be obtained with dials on which 

 the weight of the pail is allowed for. If this record is kept 

 systematically, an accurate account of the yield of each cow 

 will be obtained. Its value lies in the fact that though in a 

 general way farmers are able to distinguish between the good 

 and bad milkers in their herds, a difference of 100 or even 

 200 gallons is not so easily appreciated when spread over the 

 whole period of lactation. A difference of 100 gallons at 6Jd. 

 per gallon represents 54s., and it is probably not too much 

 to say that cows in the same herd frequently differ in their 

 annual production by as much as without their owner 

 being aware of it. 



If the trouble of weighing the milk of each cow daily is 

 felt to be too great, an approximately accurate result can be 

 obtained by doing it once a week, and multiplying the result 

 by 7. Experiments made in Lancashire and in the United 

 States have shown that the error is not likely to be more 

 than 3 per cent. 



Testing the Milk for Butter-fat. — Although a careful record 

 of the milk yield is of considerable value, it is advisable that 

 the milk-seller should also know the percentage of butter-fat 

 in the milk of his cows. In the vast majority of cases the j 

 milk given by the cows of this country exceeds in butter-fat 

 and other milk solids the percentage specified in the Sale 



