Studies in Milk Secretion. 



527 



son to her three-year-old performance, Belle's production when 



two years old is over 2,000 pounds less in milk and about five 

 pounds less in total butter fat. This great difference is occa- 

 sioned by Belle averaging about one per cent higher in fat than 

 her dam. Ruby produced 8,448 pounds of milk as a two-year-old 

 and had she averaged the same per cent of fat as when three 

 years old. Belle's record for butter fat at the same age would 

 have exceeded hers by twenty pounds. 



99. — Kate daughter of Ruby at two years of age. 



The longest single period of lactation was that of Glista 

 Netherland for 73 weeks. This was her first lactation and dur- 

 ing this time she produced 14780 pounds of milk containing 

 474.64 pounds of butter-fat. A comparison of her record with 

 that of Glista 4th will be of interest, since they are practically 

 of the same age and are very closely related, both being by the 

 same sire and Glista 4th's dam is Glista Netherland's grand dam. 

 Glista 4th has had four calves; been in milk a total of 174 

 weeks and produced 31601.75 pounds of milk and 1057.35 pounds 



