380 



Feeds and Feeding. 



albumin show little change. Those who let the calf have the first 

 milk drawn and reserve the strippings keep the richest milk. (299) 

 598. Effects of age. Wing of the Cornell Station 1 recorded the 

 following yields of 8 cows beginning as 2-yr.-olds and extending thru 

 their fourth lactation period: 



Effects of age on the yield and composition of milk. 



The average yield of the 2-yr.-old heifers in their first lactation 

 period was 6,022 Ibs. of milk and 215 Ibs. of fat. With succeeding 

 years up to the fifth there was an increase of both milk and fat, the 

 increase being small after the third lactation period. Ranking the 

 fourth lactation period at 100, the milk yield for the heifer period 

 was 76 per ct. 



Thorne of the Ohio Station 2 found the cow the most economical 

 producer at 7 years of age, slowly declining thereafter. Beach of 

 the Connecticut Station 3 places the yield of heifers at 70 per ct. of 

 that of mature cows. Dairymen usually rate 2 heifers equal to 1 

 cow, which is reasonable because of the extra expense of care and 

 keep. The milk of the heifer is usually slightly richer than when 

 she becomes a mature cow, but because of the greater quantity the 

 mature cow yields more fat. 



599. Effect of advancing lactation. Woll of the Wisconsin Sta- 

 tion* has condensed, in the table on the next page, the findings of the 

 New York (Geneva) Station with 14 cows of 6 breeds, giving the 

 dry matter consumed and the yields of milk and fat, month by 

 month, from freshening until the cows went dry. 



The table shows that immediately after freshening the cow gives 

 richer milk than later. It then grows poorer for a month or two, 

 and after that slowly increases in richness until she becomes dry. 

 We further learn that during the first month after a cow freshens a 

 given quantity of feed gives greater returns in milk product than 



Bui. 169. 



Rpt. 1893. 



Bui. 29. 



Bui. 116. 



