6 BULLETIN 29, POETO RICO EXPERIMENT STATION. 
sionally mark the body. Among some breeders black muzzles, 
tongue, and switch are preferred. The average of the 12,258 cows 
in the United States that had completed yearly records for the reg- 
ister of merit up to October 20, 1919, is 7,931 pounds of milk test- 
ing 5.35 per cent. The milk contains a high percentage of total 
solids, especially butterfat, 4.5 to 6 per cent of fat being not unusual. 
The butter records are correspondingly large, from 350 to 400 pounds 
of butter being annually produced by each milking animal. Buyers 
from all parts of the world go to the island of Jersey to purchase 
these cattle and willingly pay high prices for the best animals. 
GUERNSEYS. 
Guernsey, which is 4 by 9 miles in extent and the second largest of 
the Channel Islands, is the home of the Guernsey cattle, the origin 
and history of which are the same as those of the Jersey breed. 
The Guernseys have been kept a distinct breed for many years by 
the exclusion from the island of all other cattle. 
The Guernsey is larger than the Jersey and is stronger boned. 
The average weight of mature cows is about 1,000 pounds. The 
Guernsey is light in color, white and yellow predominating. (PI. II, 
Fig. 1.) Darker shades are occasionally found on some of the cows 
and commonly on the bulls. This breed is somewhat like the Porto 
Eican cattle in conformation, size, and color. The Jersej^s and the 
Guernseys have short hair and have been developed in a mild climate. 
Both do well in Porto Rico except for attacks of tick fever. The 
Guernsey is a high producer of milk, which is nearly as rich in 
butterfat as is that yielded by the Jersey. The average production 
of 8,896 cows in the United States that had completed a year's rec- 
ord for advanced register to January 15, 1920, is 9,030.5 pounds 
of milk testing 5.015 per cent. 
AYRSHIRES. 
The Ayrshire breed originated in the county of Ayr, in south- 
western Scotland. It is only within the last hundred years, how- 
ever, that these cattle have become so distinct in their characteristics 
as to be considered a breed. Doubtless the breed as it is to-dav 
is the result of infusions of blood from the cattle of England, Hol- 
land, and the Channel Islands. In color the cattle vary from med- 
ium red to dark mahogany-brown and white, either of which may 
predominate. They are not as gentle as the Jersey cattle. They 
are somewhat less readily acclimated to tropical conditions because 
they are a distinctly northern breed. 
The Ayrshire cow varies in weight from 900 to 1,300 pounds, the 
average weight being 1,100 pounds at maturity. Ayrshires are 
£ood milkers, and the average of 3,319 cows and heifers in the 
