510 GENETICS IN RELATION TO AGRICULTURE 
more the decisive standard of excellence, a fact which is reflected in the 
establishment of advanced registry records by pure-bred dairy cattle 
associations for those animals which prove of superior performing or 
breeding ability. Many experiment stations have enthusiastically 
recommended the use of pure-bred sires in building up dairy herds, 
a few have conducted investigations for the purpose of determining 
precisely how much improvement may be expected from the use of 
such sires. An investigation of this kind at the Iowa Station has pro- 
ceeded far enough to warrant a preliminary report. For this investiga- 
tion seven cows, six heifers, and one young bull were purchased in an 
isolated region of Arkansas where it was practically certain that no 
pure-bred bulls had ever been used. These were developed at the 
station, and their records are available for comparison with those of 
their daughters which have been sired by Guernsey, Holstein-Friesian, 
or Jersey bulls. In Fig. 196 are shown the results of grading two gen- 
erations to pure bred Hol- 
Taste LXVIII.—Comparison or a Scrus Cow, stein-Friesian bulls. The 
No. 52, wirh Her Daveuter, No. 69, Srrep first generation of grading 
BY A HousTsIn-FreIsian Buuu (Data of 
has given a heifer which is 
Kildee and McCandlish) g Tr ich 1 
intermediate in most char- 
Pounds | Pounds | | Net acters between its dam and 
pala ilu _ the general type of Hol- 
52 6 | Ave. | 3,856.4 | 174.53] g19.29 Steln-Friesian cow. She, 
Best | 4,588.4 | 201.67| 16.27 however, lacks the char- 
acteristic color markings of 
69 4 Ave. | 5,757.4 | 242.31] 31.57 the MHolstein-Friesian, a 
Best | 6,822.8 | 283.75) 38.65 fact which obscures some- 
what her resemblance to 
No. of 
pice lactation 
periods 
Per cent. in-| Ave. 49.3 | 38.8 63.7 ‘ 
crease of daugh-| Best 48.7| 40.7 ? that breed’s type. The 
ter over dam second generation calf, her 
daughter, however, pos- 
sesses characteristic Hol- 
stein-Friesian markings and would pass for a very fair-specimen of the 
breed. The important consideration, however, is the comparative 
excellence of these animals in milk and butter fat production. The 
data relative to this question are given in Table LXVIII. The most 
notable feature in these records is the increase of 64 per cent. in average 
net returns. 
Table LXIX has-been so compiled from the data of Kildee and Mc- 
Candlish as to give a general résumé of their investigations. The cows 
have been divided into three lots according to the kind of sire used in 
grading. In the first lot scrub cows are compared with their daughters 
which were sired by a Holstein-Friesian bull; in the second lot the scrubs 
Digitized by Microsoft® 
