SCIENCE. 



[Vol. XIV. No. 357 



SCIENCE; 



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INFLUENCE OF FOOD, ANIMAL IDIOSYNCRASY, AND 

 BREED ON THE COMPOSITION OF BUTTER.' 



One of the fundamental principles of dairying is regard for the 

 influence which the care of the animal, supervision of the milking, 

 separation of the cream, ripening of the cream, churning and wash- 

 ing, have on the quality of butter for table use. These processes 

 also, together with the method of packing, have a notable influence 

 upon the preservation of the butter in a sweet state. The discus- 

 sion of the above problems, however, is a thing for the practical 

 dairyman rather than the chemist. The chemical composition of 

 butter-fat, as influenced by the character of food rec'eived by the 

 animal, the race of the animal, and the peculiarities of the animal, 

 has hitherto been little studied from a chemical point of view. To 

 the latter subject I propose to devote the following paper. 



Late in February this year, I received a letter from Professor 

 H. H. Harrington, chemist of the E.xperimental Station of Texas, 

 accompanied by two samples of butter, which he asked me to ex- 

 amine. The following extract from Professor Harrington's letter 

 will indicate the motive which led him to send the samples : — 



"Some work in our laboratory indicates that volatile acids from 

 the cottonseed butter are much lower than has been generally sup- 

 posed. I send two samples of butter, — one from coltonseed feed, 

 and the other from feed containing no cottonseed. If you can do 



1 Abstract of a paper by H. W. Wiley, read before the Society for the Promotion 

 of Agricultural Science at its annual meeting held in Toronto, Canada, Aug. 26, 27, 



me the favor of analyzing this butter, I shall send more samples 

 from the same cows on the same feed. We hope in the near future 

 to follow up these analyses with complete analyses of butter from 

 different feeds, feeding two cows on cottonseed, and then changing 

 them to other feed." 



The samples sent by Mr. Harrington were small, and a complete 

 analysis could not be made ; but the results obtained are of such 

 interest that I will communicate them at the present time, and call 

 attention to the peculiarities noticed. 



Volatile acids, No. cc N-io BaOoHj for 5 grams 



Percentage of iodine absorbed 



Melting-point 



Reduction of silver by Bechi 



The most remarkable points connected with the analyses are as- 

 follows : I. The low percentage of volatile acids in butter from 

 cottonseed; 2. The phenomenally high melting-point of the butter 

 from cottonseed ; 3. The persistence of the reducing agent of the 

 butter from cottonseed, as indicated by its action upon nitrate of 

 silver. 



The melting-point of the butter is higher than that of pure lard. 

 The particular point to be noticed in this matter is, that in butter- 

 designed for consumption in Southern countries, or produced in 

 Southern countries, the mixture of cottonseed with the feed of 

 cows will tend to raise the melting-point of the butter, and render 

 it more suitable for consumption in hot climates. 



The persistence of the reducing agent is also a matter of interest.. 

 It has passed, in the samples examined, through the digestive or- 

 ganism of the cow, and has re-appeared in the butter with almost 

 undiminished activity. The selective action of the digestive organs^ 

 on the different glycerides contained in the food of the animal is. 

 also a matter of importance. It would be expected a prioi'i that 

 the butter from a cow fed largely on cottonseed-oil would contaiiv 

 more oleine and have a lower melting-point than if ordinary food 

 were used. On the contrary, it is seen that either the more solid 

 glycerides have been absorbed during the process of digestion, or 

 that the oleine has undergone some distinct change in the digestive 

 organism by which it has assimilated the qualities of the other 

 glycerides. 



From an analytical point of view, the results are of great impor- 

 tance, since they show that a butter derived from a cow fed on 

 cottonseed-meal or one excreting a fat of unusual quality might be 

 condemned as adulterated when judged alone by the amount of 

 \olatiIe acids present. Since cottonseed-meal is destined to ^e a 

 cattle-food of great importance, especially in the southern part of 

 the United States, this is a fact of the greatest interest to analysts. 

 The observation of Mayer, soon to be mentioned, that the specific 

 gravity of butter-fat varies with its content of volatile acids, I have 

 also verified in some cases by the determination of the specific 

 gravity of samples of butter-fat taken from the milk of the same 

 cows kept on the same food, but taken the following day after the 

 samples mentioned. The specific gravity for the cotton-meal 

 fed sample was .8929 at 99° ; that for the ordinary fed sample. 

 .8991 at 99°. 



Professor Mayer's experiments were made on a single cow of a 

 North Holland breed. From time to time during the progress of 

 the experiments the original food was used, in order to see what 

 effect the period of lactation would produce. The cow was fed 

 for twelve days on each separate ration before the samples were 

 taken. After two days more, another set of samples was taken,, 

 and then the food changed for a new experiment. 



In the butter-fat the melting and solidifying points were taken,, 

 and the volatile acids determined according to the method of 

 Reichert. The specific gravity was also determined by the West- 

 phal method at 100°. 



The rations of the cow were composed of the following ma- 



