C. Crowther and H. E. Woodman 



49 



nitrogen deficit, whereas Cow C still retained a positive nitrogen-balance. 

 If the nitrogen-balances throughout w'ere plotted graphically against the 

 days of duration of the trial, it would be found that the curves for the 



Table IV. 



Summarji of nilro(/en-balances during period of pregnancy of Cow D. 



(Days 36G-575.) 



Daily ration: 



Gorv C (to day 558): 20 lb. seeds hay* (average dry matter per day = 7340 gm.). 

 Cow D (to day 407): 20 lb. seeds hay (average dry matter per day = 7250 gm.). 



(Day 408-562); 21 lb. seeds haj' (average dry matter per day = 7740 gin.). 



Cow C 



Cow D 



Period 



in 

 days 



,366-383 



387-407 



41(5-432 



436-153 



457-474 



478^95 



499-523 



534-558§ 



562-575 



N con- 

 sumed 

 (average 

 per day) 



gm. 

 143-7 

 144-6 

 1.36-8 

 138-9 

 1.50-2 

 152-6 

 149-1 

 145-2 

 146-6 



Total N 



voided 



(average 



per day) 



gm. 

 132-8 

 131-8 

 129-9 

 1441 

 160-0 

 154-8 

 161-6 

 148-4 

 141-6 



Mean 



daily 



nitrogen- 



balance 



gm. 

 -1-10-9 

 4-12-8 

 -I- 6-9 



- 5-2 



- 9-8 



- 2-2 

 -12-5 



- 3-2 

 + 5-0 



Change 

 in 



weight 

 fur 



period-l- 

 ib. 



4-32 



- % 



+ H 



-m 



+ 5J 



-m 



- 3s 

 -1-20 



N con- Total N Mean 



sumed voided daily 



(average (average nitrogen - 



per day) per day) balance 



gm. 

 143-7 

 144-6 

 143-6 

 14.5-8 

 1.57-7 

 160-2 

 156-6 

 145-6 

 149-4 



gm. 

 148-6 

 145-7 

 144-5 

 143-8 

 15.5-9 

 1.5.5-1 

 154-7 

 140-8 

 131-4 



:m. 

 4-9 

 1-1 

 0-9 

 20 

 1-8 

 5-1 

 1-9 

 4-8 



-1-18-0 



Change 



in 

 weight 



for 

 periodj 



lb. 

 -13| 



-Hl2f 

 + 25i 

 -F21i 

 -1-19 

 ■t-22 

 + 26i 

 4-104 

 •fl5S 



Condensed summary. 

 CowC 



CowD 



Number of 



analytical 



days 



174 

 428 



Total N 

 consumed 



gm. 

 25,309 

 62,925 



Total N 

 retained 

 or lost 



gm. 

 - 50 

 -t-816 



Nett change 

 in live- 

 weight 



lb. 

 -18J 



4-9111 



Total N 

 consumed 



gm. 

 24,019 



Total N 

 retained 

 or lost 



gm. 

 4-386 



Nett change 

 in live- 

 weight 



lb. 

 4-139-4 



* From day 562 started feeding new consignment of hay. This proved poorer in nitro- 

 gen and ration for days 562 to 575 was consequently altered, and average consumption 

 as follows: 



Cow C: 21-4 lb. hay 4- -43 lb. linseed cake ( =87.50 gm. dry matter per day). 

 Cow D: 21-8 lb. hay 4- -43 lb. linseed cake ( =8920 gm. dry matter per day). 



t Weight of Cow C at beginning of period, 1378 lb. 



X Weight of Cow D at beginning of period, 1407 lb. 



§ The records for Cow D in this period relate only to days 534-544. This cow was 

 withdrawn from trial between days 544 and 558 on a"count of slightly swollen hocks. 



II Does not include weight changes from August 29 to October 31, 1919, during which 

 period no determinations of nitrogen-balance were made. 



two cows intersect shortly after service of Cow D ; previous to this, the 



curves run approximately parallel. Thus, on a diet more than sufficient 



for its protein requirements in the ante-pregnant period, Cow D, as a 



Journ. of Agric. Sci. xii 4 



