774 EXPERIMENT STATION RECORD. [Vol.40 



In the Holstein-Friesian Advanced Register prior to May 1, 1915, the author 

 finds records of 1,295 cows that completed a year's test during the same lacta- 

 tion in which they satisfied advanced registry requirements for a 7-day test. 

 The records of this group of cows are submitted to statistical study. Tables 

 and graphs are given showing the relation between pounds of fat and percentage 

 of fat. In the semiofficial records there is a steady uniform increase in fat 

 percentage with increased fat production. In the "day records there is a simi- 

 lar increase in percentage between the 8 and the 24-lh. records, hut a sharp 

 and abnormal rise in percentage occurs for the higher records. The mean fat 

 pen ei the 7-day tests was 3.679±0.01 and that of the year t< 



3.434±0.006. Considering the small probable errors, this difference is of uu- 

 doubted significance. The 7-day percentage recori also distinctly more 



variable than the year records, the standard deviations being, respectively, 

 0.526±0.007 and O.S17±0.004 The correlation between amounts of milk i 

 duced during the 7-day test and during the S66 days was found to be 0.702 tO.01, 

 while | rrelatlon between the official and semiofficial amounts of butter fat 



was 0.703±0.01. Although these correlations are high, it la d out that 



5 an- not high enough for correlations between two measurements of tbe 

 same thing. Taking all the data into account, the author concludes that the 

 7-day I - - tory Index of a cow's annual production of butler 



fat. 



Short discussions are given of the 80-day test and of the 8-months-after- 

 calving 7-day test, in 1,300 records where official 7-day and 30-day tests w< 



ipleted, the tat percental higher in the former than in the latter 



throughout the range of production, the dii e being somewhat in 



the case ol the higher records Onlj 2 ords were available for the pur- 



pos mparing the 7-daj test at the beginning of lactation and after 



lapse QthS. Iu the Cfl he late test had a higher 



percentage of fal than the early test, but the condition I in the higher 



records. 



Ten vital questions regarding test work i HoUU in 1 rit Han Wot hi. U\ 

 {1919), No. 7, pp. 519-5^ figs. 8).— The editors of the EoUtein Frii riam 



World propounded 10 questions concerning the value of the 7-daj r Hol- 



ein cattle as a measure ..f productive capacity basis tor I ra- 



tions and as a factor in the advancement of the breed.. Answers arc lure sum- 

 marized from II. II. Wing, H. 11. Dean, 0. F.rf, O. Larsen, <;. ll. True, and K. B 

 Musser. Considerable skepticism is shown as to the value of the test All seem 

 to think that the test will eventually be abandoned, hut only <;. II. True advi t 9 

 Its Immediate discard. 



The Wisconsin Register of Production, C. W. Tuaires [Hoard's Dairyman, 

 57 (1919). No. IS, pp. 646, 6J,7, fig. /).— Report is made of the tirst year's opera- 

 tion of the Wisconsin Register of Production, a scheme for giving official 

 nition to high producing cows in Wisconsin cow test associatons l and 



carried out by the Wisconsin Dairymen's Association In cooperation with t tie 

 University of Wisconsin. The s.de requirement tor entrj is a record of : 

 lbs. of butter fat In a year, there being no sliding scale for age or breeding 

 During the year the cows satisfying the requirement numbered _'T1. of wanes 

 81 were registered as pure-bred Holsteins, Guernseys, or Jerseys, ami l"> are de- 

 scribed as natives. The average milk production was 9,181.6 lbs., and the a-.cr 

 age butter fat record 407.48 lbs. 



Water requirements for milk production. A (\ IfcOAStntBBB fend W 

 Gaessleb {Jovr. Dairy 8oi., 2 (1919). No. i. pp ; 8). This pap. r reports sa 

 periments at the Iowa ESxperlmenl station to determine, U possible, the amount 

 of water in addition to that iu the feed required b] cows foi mil* production 



