74 EXPERIMENT STATION RECORD. [Vol. 43 



New Zealiind certilieate-ol-i-ecord system lor pure-bred dairy cows in 191!). A 

 total of 1.200 certiticates have \y^en granted. 



Investigation into milk yield of Ayrshire cows, J. F. Tocher {Trans. 

 Hiyhlaml nud Agr. fe'oc. Scot., 5. set:, 31 (1919), pp. 237-256, fif/n. 7).— This is 

 a preliminary report of a statistical analysis of the manuscript records of the 

 Scottish Midi Records Association for the years 1911 and 1912. Tables and 

 diagrams are presented to show the relationships of (1) yield of milk and per- 

 centage of fat, (2) length of lactation and yield of milk, (3) age of cow and 

 yield of nulk, (4) age of cow and percentage of fat, and (5) season of year 

 when i)arturition took place and yield of milk. 



The maximum amount of milk per lactation and the minimum percentage of 

 fat occurred at the age of about 10 years. Cows calving from August to No- 

 vember produced more milk per lactation than those calving during other 

 months, but the difference was due entirely to a longer average lactation period. 



A table showing the frequency distribution of milk yields indicates that half 

 the cows produced more than 6,000 lbs. of milk and 2 per cent more than 10,000 

 lbs. A frequency table for fat percentages based on this investigation is given 

 in the paper noted below. 



Variations in the composition of milk, J. P. Tocher (Scot. Jour. Agr., 2 

 (1919), No. 3, pp. 3J{3-,i53). — In 384 mixed-herd samples of nulk collected under 

 the author's supervision the average fat percentage was 3.495 with a standard 

 deviation of 0.549. The average percentage of solids-not-fat was 8.85 with a 

 standard deviation of 0.375. In over 11,000 lactation records of Ayrshire cows 

 collected by the Scottish Milk Records Association (see above) the mean per- 

 centage of fat was 3.727 anti the standard deviation 0.324. 



" The results of this paper show that the prescribed minima for butter fat 

 [3 per cent] and for solids-not-fat [8.5 per cent] are artificial in character, 

 and are based neither on the real minima found to exist for these constituents 

 nor on an adequate study of the natural variations occurring in genuine milk." 



The Irish milk supply, L. Smith-Goruon {Better Business, 5 {1919), No. 1, 

 pp. 11S6). — A series of notes on the sanitary quality, prices, and quantity of 

 the market milk sold in Ireland. In addition to poor quality and high price 

 there appears to be an actual scarcity of milk due to decrease in the number 

 of cows, low average yields, and a wider use of milk for making butter, con- 

 densed milk, and milk powder. Legislation is recommended similar to the 

 Ontario Milk Act (1911) giving full powers to local authorities both for super- 

 vision and for trading. 



Milk products in America and Europe, W. Dempster {Neiv Zeal. Jour. 

 Ayr.. 20 {1920), No. 2, pp. 91-109; also in New Zeal. Dairyman, 2k {1920), No. 6, 

 pp. 27, 28, 30, 33, 35, 36, 38, Jfi. ^2).— This is a discussion of the extent of pro- 

 duction, uses, and probable future uses throughout the world of milk powder, 

 condensed milk, milk sugar, and casein. It is based upon the author's linowl- 

 edge of the milk products industries in New Zealand and on data collected in 

 the course of an otJicial visit to the United States, Canada, England, and 

 Holland, of which an account is given. 



Production and prices of milk and of its chief derivatives {Internatl. 

 Inst. Agr. [Roine], Bur. Statis. Doc. Leaflets, 3 {1919), No. 2, pp. 17-39).— A 

 compilation of available statistics as to the production of milk, butter, and 

 cheese in the principal countries of the world, with information as to prices 

 in local mai'kets. 



The trade in milk and its derivatives {Internatl. Inst. Agr. [Rome^, Bur. 

 Statis. Doc. Leaflets, 3 {1919), No. 2, pp. 40-51). — Tabulated data are given as 

 to the imports and exports of milk (fresh, condensed, dried etc.), cream, 

 butter, and cheese by countries for the years 1913 to 1917. 



