FEEDING DAIRY CATTLE 



235 



cows were separated into three groups of the same number of cows 

 within each of the dairy breeds represented, Holstein, Jersey, and 

 Guernsey, according to their production of butter fat; the data 

 for the different groups have been combined and are given in the 

 following table : " 



Returns from Cows of Different Producing Powers 



While the difference in the average production of butter fat by 

 groups 1 and 3 amounted to 190.2 pounds, or 56 per cent, calculated 

 on the production of group 3, the cost of feed for the two groups 

 increased only 20 per cent, and that of total number of feed units 

 18 per cent. The differences in net returns (the value of products 

 above cost of feed), on the other hand, amounted to 108 per cent, 

 and 100 feed units produced 31 to 32 per cent more butter fat or 

 value of products in case of group 1 compared with group 3; that 

 is, the best cows made the largest production at a relatively much 

 lower feed cost; hence the percentage increase in the net returns 

 secured was much greater than that in butter fat, viz., 108 per 

 cent above that for the lowest lot. The number of feed units con- 

 sumed in the rations fed was increased by only 18 per cent, and 

 the efficiency of the rations calculated per 100 feed units was 

 increased by over 30 per cent. . 



The same lesson is taught still more strikingly by the results 

 obtained with the best ten and the poorest ten cows in the competi- 

 tion (Fig. 45) ; the feed of the former cost $114.66 per head for 

 the year, while the net returns were $124.29, or 52 per cent; the 

 feed of the latter cost $61.10, and the net returns were $14.89, or 

 only 20 per cent. 



The preceding results were obtained with excellent dairy cows, 

 of families that had been bred persistently for a large milk pro- 

 duction for many generations. Cows of this type respond to 

 heavier feeding by an increased milk production; other cows of 

 different breeding, or bred for beef production, would gain in body 



11 Wisconsin Bulletin 226, p. 22. 



