244 



Bulletin 397 



TABLE 23. Relation of Age to Milk Production 

 (Averages of 14 cows for 8 lactations) 



Lactation 



I 



2 

 3 

 4 

 5 

 6 



7 



Milk 



production 



(pounds) 



7,511-9 

 7,266.9 

 9,179-8 

 8,961.2 

 9,529-8 

 9 , 62 1 - 1 

 10,399.6 

 11,123.9 



Number 

 of days 

 milked 



345 - 1 

 289.1 

 3312 



321.5 

 308.4 

 318.2 



327-7 

 352-0 



Number 



of days 



dry 



54 

 55 

 50 

 54 

 50 

 66 

 66 

 59 



Per cent of 

 maximum 

 production 



68 

 65 

 83 

 81 

 86 

 86 



'93 

 100 



TABLE 24. Relation of Age to Milk Production 

 (Averages of 9 cows for 9 lactations) 



Lactation 



Milk 



production 



(pounds) 



Number 

 of days 

 inilked 



Number 



of days 



dry 



Per cent of 

 maximum 

 production 



I 



2 

 3 

 4 

 5 

 6 



7 

 8 



9 



7,706.5 

 8 , 302 . o 

 9,163.0 



9,492.7 

 10,578.9 

 10,276.3 

 11,433-0 

 12,153-9 

 II ,241 .0 



335 

 303 

 319 

 332 

 316 



309 

 344 

 345 

 344 



59-4 

 51 I 



48.7 



52.4 

 48.0 



62.4 



68.0 



67.2 



35-9 



63 



68 



75 

 78 

 87 

 85 

 94 

 100 

 92 



TABLE 25. Relation of Age to Milk Production 

 (Averages of 4 cows for 10 lactations) 



354 



