216 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



first lactation period required a great deal of feed for body- 

 growth, consequently her returns are not as great as her dam's. 

 The other heifers show a considerable increase in net returns 

 over their dams. This increase ranges from $6.80 to $22.38 

 when the best records are compared and the average net returns 

 per lactation are $7.70 to $12.28 more than that of their dams. 



In the case of the first generation Guernsey grades it will 

 be noticed that three of the four have thus far produced less 

 than their dams. By way of explanation, it may be stated that 

 lack of maturity of the heifers at the time records were made is 

 no doubt a factor of great importance, as is the fact that the 

 scrub cows Nos. 6, 33, and 53, the dams of these three heifers, 

 have the highest average records of any of the scrubs with 

 daughters by purebred bulls. However, it is evident that a much 

 greater factor is the variation in the ability of different sires 

 within a breed to transmit dairy qualities. Heifers Nos. Sy and 

 no were sired by a Guernsey bull loaned to the station before 

 a Guernsey herd was owned by the college. Unfortunately rec- 

 ords of his purebred daughters as compared with their dams 

 are not available. However, the best record we have had from 

 a first generation heifer was made by No. 175. As a two-year- 

 old this heifer produced 6078.5 pounds of milk and 310.95 

 pounds of fat, or 3049.9 pounds, or 101% more milk and 161 

 pounds, or 107% more fat, and $24.48 more profit than her 

 dam's best record. This halfblood Guernsey was sired by our 

 present herd bull and her record compared to the other first 

 generation Guernsey grades clearly indicates that variation in 

 the ability of sires to transmit dairy qualities is a factor of im- 

 portance and worthy of close study by the man selecting a sire 

 when the bull is to be used on a scrub herd, as well as when 

 selection is made for a high grade or purebred herd. 



The one first generation Jersey grade that has freshened to 

 date shows a good increase over her dam in butterfat produc- 

 tion, in spite of the fact that her dam was one of the two scrub 

 cows that came to the college when four years of age and has 

 made comparatively good records. 



The question naturally arises in the mind of the practical 

 dairy farmer as to whether or not the bulls used on these scrub 

 cows were high priced animals and therefore beyond his reach. 



