18 BULLETIN 20, PORTO RICO EXPERIMENT STATION. 
a good foundation stock that is acclimated and immune to tick fever. 
(PL I, Fig. 2.) The small yields and low tests of some of the other 
cows conclusively show the necessity of eliminating all unprofitable 
animals. The increased yields of herds Xos. 5, 6, and 7 show what 
ran be accomplished by improving the breed. A good purebred sire, 
the best that can be afforded, will do much to improve the uniformity 
and quality of the milk yield of the progeny. 
SUMMARY. 
Cattle should have a larger and better place in the agriculture 
of Porto Rico than is now the case. They provide a large amount 
of food in the form of beef, milk, cream, and cheese, and the cost 
of their upkeep is relatively small. Every farm, no matter how 
small, should keep at least one cow. Even one cow will utilize what 
are now waste products of the farm, give milk for the family, and 
add to the family income by her yield of marketable dairy products. 
Cattle help to conserve the fertility of the soil by returning to it 
in the form of manure a large percentage of the fertilizing con- 
stituents in the feed. The fertility thus utilized considerably lessens 
the cost and upkeep of the animals. 
Porto Rico should produce a large number of fine dairy cattle, 
since it is possible to produce large yields of elephant grass, velvet 
beans, and other forage crops that are greatly relished by such cattle. 
There is still room for improvement in forage production, how- 
ever, and grasses that are rich in quality as well as abundant in 
quantity should be more extensively grown. Improved grasses 
should be planted on all the idle lands of the island. The increased 
yields will help to build up the animal industry of the country be- 
cause more cattle will likely be raised by the owners of lands grow- 
ing the nutritious grasses. When one farmer puts his idle land to 
work and gets good results in the form of good yielding crops and 
cattle, other farmers will be influenced to do the same and the com- 
munity will be thus benefited. 
Porto Rico has a good foundation in her native stock, but the 
cattle should be bred for some special purpose. Although the dairy 
cow now brings a greater return for the amount of money expended 
on her than any other farm animal, such cows should l}e bred with 
a view to increasing the quantity and quality of the milk yield. 
The native herd can be improved by the introduction of new blood. 
Good sires should be purchased for this purpose, but until the tick 
is eradicated cattle from the North should be handled with great 
care, because they are very susceptible to tick fever and soon suc- 
cumb. When an importation is made, only purebred animals of 
the highest type should be purchased. Until the tick has been 
