DAIRY FARMING — DAIRYING. 89 



the churnability of the ripened cream was nearly 3 per cent greater 

 than that of the sweet cream. Experiments were also made with cream 

 of different fat content and from different kinds of cows. The results 

 of these experiments, which are not detailed in the abstract, showed 

 that under some circumstances the effect of the size of the fat globules 

 on churning may be obliterated by other conditions. A fat content 

 of the cream too high or too low to be advantageous diminishes the 

 churnability in a greater degree than large fat globules increase it. 

 The viscosity of the cream also had a very marked effect on the 

 churning. 



An accountis also given of von Stoekhauseifs investigations (E. S. R., 

 9, p. 1087). 



Effect of period of lactation on milk and quality of butter, 

 G. L. McKay and J. W. Wilson (Iowa Sta. Bui. 36, pp. 865-867). — 

 In continuation of previous work (E. S. E., 9, p. 91) a test was made 

 with two lots of 4 and 7 cows, respectively, to study the effect of the 

 period of lactation upon milk yield and the.quality of butter. The first 

 lot averaged sixty-two days since calving, and the second lot one hun- 

 dred and ninety-five days. The two lots were fed, under like con- 

 ditions, the same rations of sheaf oats, clover hay, corn, barley meal, 

 and sugar beets. The total milk yield in fifteen days from lot 1 was 

 972 pounds, and from lot 2, 88(i pounds. The milk from each cow T was 

 kept separate, the cream was removed by a separator, and the butter 

 was made and handled by the same methods. The butter was judged 

 by an expert, and no difference was observed as due to a difference in 

 the period of lactation. 



The authors believe that the trouble experienced with cream from 

 cows in an advanced stage of lactation is due to the fact that the cows 

 are not fed a sufficiently succulent ration. As the period of lactation 

 advances the fat globules in the milk become smaller and the cream 

 more viscous. Succulent food, it is stated, will cause a more abundant 

 secretion of milk furnishing less viscous cream. The authors also 

 advise the addition of sour milk to start the ripening of the cream. 

 This insures a rapid development of lactic-acid fermentation, and 

 retards the growth of undesirable microorganisms. When the cream 

 is properly ripened they believe no difficulty will be experienced in 

 churning it. 



Investigations on the utilization of casein, Backhaus (Ber. 

 Landw. Inst. Univ. Konigsberg, 2 (1807), pp. 1-11). — The author points 

 out that the fat of milk sells for about twice as much as the casein, 

 although the relative nutritive value of fat to protein is given by Kouig 

 as 3 :5 for human food and by Kfihn as 2.5 : 6 for animal nutrition. The 

 author believes that in the interest of dairying some means should be 

 found for utilizing the casein more profitably. The uses to which 

 casein has already been put in the industries and as a food for man and 

 animals are noted. 



