212 ANNUAL, REPORT OP THE OfE. Doc. 



I. VARIATIONS IN TESTS BETWEEN INDIVIDUAL PATRONS. 



1st. Why does SmiWs milk or creaTn test differ from that of 

 Jones'? Dillereiices of breed, individuality, food, nervous excite- 

 ment, environment, weather, tlie stage of lactation, and the manage- 

 ment of the creaming devices may influence the result. Let us 

 sketch some of these. 



BREED. 



Every observing dairyman appreciates that differences in cattle, 

 due to the character of their breeding, are such that some cows give 

 richer milk than others. The Channel Island cows have been bred 

 through many scores of years with a specific purpose in view, to 

 make a high grade milk; and, on the other hand, the cattle of Hol- 

 land and Scotland have been bred generation after generation more 

 particularly to make a large quantity of milk. While there are ex- 

 ceptions to every rule, still, speaking broadly. Jerseys and Guern- 

 seys give richer milk, than do cows of other breeds. Smith's test 

 cutranks Jones' because long lines of breeding with a definite aim 

 in view have implanted in his animals a tendency toward making a 

 better grade of milk than can Jones' cows. 



INDIVIDUALITY. 



While the differences in breed are frequently concerned in the test 

 ^ariations as between one patron and another, the individuality of 

 the animal is often quite as important. There are families within 

 breeds. The cows of some families give relatively rich milk, and 

 others in other families relatively poor milk. The type of cow and> 

 The relationship of the performance is all important. As nothing 

 here is differently built than a dissimilar, the conformation of the 

 cows to that type which long years of efficiency has produced is a 

 measurable factor in the estimation of breeding work. 



FOOD. 



He who looks to food to grade up the quality of milk looks in vain. 

 Food variations raaj' increase the quantity of milk but seldom if 

 ever bring about permanent changes in quality. If a cow is fed a 

 very scant ration she may alter more or less the qualitj' of milk 

 given; but when a cow is changed from a good, palatable, plenteous 

 ration to another of similar grade, but differently made up, no ma- 

 terial change in the quality of the milk is likely to follow, providedi 

 the rations are normal. We have been trying for years at our sta- 

 tion to persuade cows to change the quality of their milk, but at no 

 time and in no way have we brought about a permanent change. 

 When we have fed fat (vegetable oils, like corn cottonseed, linseed 

 and palm oils, etc.), to the cow we have changed the quality of the 



