VERMONT DAIRYMEN'S ASSOCIATION. 81 



quantity. Why should we expect a cow or herd of cows al- 

 ways to give week after week, the same quality of milk? 

 Milk making- is the cow's work, just as agricultural investi- 

 gation and teaching and executive duties are my work, and 

 the sundry farming operations, your work. Do we always 

 work as well one day as another whether we feel well or 

 ill? Though in the best of health do we do the same 

 amount of work each day? Why should we expect a cow to do 

 the same day after day? Her work is expressed by the milk 

 she makes, and, largely, by the per cent of fat she puts into 

 that milk. We should not expect of her what we ourselves 

 cannot do. 



STAGE OF LACTATION. 



The stage of lactation is another reason why Smith's milk 

 differs from Jones'. It is well known that cows tend to better 

 the quality of their milk as they progress in lactation. Inves- 

 tigation has shown that cows differ greatly in this matter. 

 Some vary but slightly and others largely as they pass from 

 freshness to stripping. A farrow cow goes dry giving milk 

 but little richer than when she came in; a pregnant cow go- 

 ing drj T usually gives considerably richer milk than when she 

 came in. Experiment has shown, moreover, , that on the av- 

 erage the increase from calving to drying-off approximates 

 1.25 per cent fat, that is to say a milk testing 4 per cent 

 at calving may test 5.25 per cent of fat at stripping. Smith's 

 milk may be made largely by strippers, while Jones' cows may 

 be mostly fresh in milk. 



It is now generally understood that the quality of the milk 

 of the same herd varies decidedly from day to day, from milk- 

 ing to milking, and that, in order to represent correctly the 

 weekly or monthly quality, it is necessary to take a composite 

 sample. It will sometimes happen, however, that even when 

 composite samples are used tests may vary one week with an- 

 other fifty, sixty or seventy points. I believe it is the duty of the 

 creamery management in such case to verify the result by re- 

 test. Many patrons have an exaggerated idea as to this matter. 

 For instance, a few years ago a creamery patron told me that 

 he was being defrauded, that his test at the creamery one 

 month was 3.90 and the next month 3.85. These five points, 

 0.05 per cent, seemed to him enormous. No operator can take 

 the same test in the same Babcock bottle and always read it 

 twice alike. Two-tenths of one per cent is not a wide differ- 

 ence between two tests, and three-tenths of one per cent as 

 between one month and another, even when the cows are in 

 full flow, is hardly a wide enough variation for cavil; more 



