TWO SYSTEMS OF FEEDING DAIRY COWS 13 

 Table 9. — Data Respecting Reproduction. 



High Roughage Low Roughage 

 Group Group 



Days after calving before 



Appearance of first heat days 53 35 



Next conception days 142 105 



Regularity of oestrum : 



Good per cent 33 75 



Fair per cent 45 25 



Poor per cent 22 



Number of services required 1.3 1.3 



Percentage of breedings from one service 69 70 



Irregularities: 



Retained placenta 3 



Abortion 1 (a) I (b) 



Other 1(c) I {d) 



(a) At 7 months. 



(b) At 6 J months. 



(c) 1 rase of cervicitis. 



(d) 1 case of chronic metritis. 



It is evident that the low roughage group was somewhat nearer normal in its 

 reproductive function than the high roughage group. This was true especially with 

 regard to the cycle of oestrum and the length of time from calving to the next 

 conception. The condition and weight at birth of the calves produced by both 

 groups is summarized in Table 10. 



Table 10. — Data on Calves Dropped During the Experiment. 



High Roughage Low Roughage 



Group Group 



Sex distribution : 



Male per cent 84.6 60.0 



Female per cent 15.4 40.0 



Average weight at birth * pounds 98 98 



Condition at birth : 



Very good per cent 31 20 



Good per cent 61 60 



P'air per cent 8 20 



*Corrected for unequal sex distribution; the average birth weight of all Holstein bull calves 

 dropped in the station herd over a long period of years is 8 per cent higher than the average birth 

 weight of Holstein heifer calves dropped in the herd for the same period. 



Twenty-eight calves are represented in the summary in Table 10, thirteen in the 

 high roughage group and fifteen in the low roughage group. Average birth weight 

 was the same in both groups. At first glance it would seem, from the standpoint 

 of condition at birth, that the calves in the high roughage group were on the whole 

 more vigorous. However, it must be pointed out that all the "fair" individuals 

 were heifers. It is common knowledge that bulls, as a rule, are more vigorous when 

 born than heifers are, and part of the difference in this respect can probably be 

 charged to the larger number of heifers in the low roughage group. 



