FEEDING DAIRY CATTLE 123 



Sufficient data are not at hand for the Guernsey and 

 Ayrshire breeds, but they fall between the two breeds given. 



It is well to breed the heifer sp that she will come into 

 milk at 24 to 26 months of age if a Jersey or Guernsey, and at 

 28 to 30 months if a Holstein or an Ayrshire, the variations 

 suggested being made to allow for the size of the animal. 



T le milking tendency of the cow when mature is not in- 

 fluei iced to any appreciable extent by any ordinary variations 

 in the ration fed during the growing period. The dairy 

 cha] acteristic of a cow is a matter of inheritance and does 

 not ,eem to be influenced to any great extent by over- or under- 

 feed ng when a heifer. In experiments by the author with 

 ovei 40 animals some of the best milk producers, as well as 

 some of the worst, were in a group fed excessively from birth 

 to first calving. Another group receiving a light ration up 

 to calving time showed the same variation in quality. 1 



114. Salt Requirements. All animals that consume large 

 quantities of vegetable food require salt. It is not merely 

 an appetizer but a necessity. Animals that live upon meat 

 do not have this craving. A cow kept without salt shows 

 a strong craving for it during the first few weeks, then quiets 

 down into an emaciated condition of low vitality, which will 

 result in a complete breakdown after several months. 



The amount of salt needed varies with the amount of feed 

 consumed. A dry cow needs about .75 ounce per day. The 

 cow in milk needs the same amount for maintenance and 

 in addition about .6 ounce per day for each 20 pounds of 

 milk. The amount required therefore for cows yielding from 

 20 to 30 pounds of milk per day is about 1.5 ounces. Salt 

 ma}- be supplied by mixing the proper amount regularly in 

 the feed or it may be placed where the animal can have access 



1 Missouri Agricultural Experiment Station, Bulletin 135. 



