168 Essay on the Interpretation of Alilk Records. 



The following diagram, obtained in the preliminary in- 

 vestigation, should perhaps also be given. It gives the increase 

 in lactation totals with age for the same 110 cows, also the 

 increase in calendar year totals for another 125 cows. (A few 

 cows appear in both curves.) 



Fig. 6. — Increase in Yield with first 6 Calves, &c. 



Lactation Totals. 

 [110 Cows.] 



Calendar Year 

 Totals. 

 [125 Cows.] 

 N.B. — Calendar 

 years begin 

 from next 1st 

 October after 

 birth of first 

 calf. 



The most regular curve is given by the R.M., the mode of 

 which does not appear to be reached until the sixth calf. The 

 increase is very slight however after the fourth calf, and for a 

 standard figure representing the mature inherent capability of 

 a cow the average of the fourth, fifth and sixth R.M. has been 

 taken. It has been termed the standard R.M. or R.M.g. The 

 mode of the curve has not been chosen because comparatively 

 few cows are kept after the sixth calf, and it was thought such 

 a figure would give a misleadingly large indication of the yield 

 the owner might expect to get in practice. 



Constants given by the R. M. curve are as follows : — 



