236 PRODUCTIVE FEEDING OF FARM ANIMALS 



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 difference 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; 



NET RETURNS j \jjjj^^y h enco -(-he percentage in- 

 crease in the net returns 

 secured was much greater 

 than that in butter fat, 

 BEST TEN cows POOREST TEN cows viz., 108 per cent above 



FIQ. 46. The areas of the circle represent the that f Or the lowest lot. 

 average values of the products from the best ten or 



the poorest ten cows in the Wisconsin Dairy Cow The number 01 ICed Units 

 Competition, 1909-11. (Wisconsin Station.) -. . ., , . 



consumed in the rations 



fed was increased by only 18 per cent, and the efficiency of the rations 

 calculated per 1 00 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. 46) ; 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 results 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 will respond to 

 heavier feeding by an increased milk production up to the extent of 

 their capacity; other cows of different breeding, or bred for beef 

 production, would gain in body flesh by such feeding, and their milk 

 production would be likely to suffer if forced by liberal feeding 

 (Fig. 45). Nearly all dairy herds that have not been carefully 

 culled will contain a considerable proportion of the latter kind of 

 cows; in feeding a herd the individual cows must, therefore, be 

 carefully watched lest they be fattened by the system of feeding 

 adopted, instead of increasing in their milk production. Regular 

 weighing of cows, at least once a month, is a valuable aid in the man- 

 agement of a dairy herd, as it furnishes definite information as to 

 changes in the body weight of individual cows that may occur. 



