14 MASS. EXPERIMENT STATION BULLETIN 441 



under adverse weather conditions. Furthermore, most of the growers have found 

 it necessary to make an additional application of 500 to 700 pounds of a complete 

 fertilizer during late May to replace excessive leaching losses by spring ri^ins and 

 to supply readily available plant food to the crop during a time when it is making 

 a steady and rapid growth. 



The results of last year's trial indicate that more efficient use of commercial 

 fertilizer could be made by split application, consisting of 1000 pounds per acre 

 of 5-8-7, broadcast and disked in prior to planting; 500 to 700 pounds per acre 

 about the middle of May; and 500 pounds more about the first part of June. This 

 would insure a steady supply of abundant plant food with a minimum loss through 

 leaching and should entail no extra labor inasmuch as there are available fertilizer 

 distributers which can be attached to powered onion cultivators. 



DEPARTMENT OF ANIMAL HUSBANDRY 

 Victor A. Rice in Chaige 



A Study of the Mineral Elements of Cows' Milk. (J. G. Archibald.) The 

 work with cobalt has been completed, at least insofar as the present development 

 of the project is concerned; and the results have been published in the Journal of 

 Dairy Science Vol. 30, No. 5, May 1947. The following is quoted from the article: 



Cobaltous acetate was fed as a supplement (500 mg. daily) to the 

 rations of eight cows for a period of two months by the double reversal 

 method and the milk was analyzed for cobalt. The results revealed that 

 feeding the supplement consistently raised the amount of cobalt in the 

 milk. The average increase was four-fold. The milk from cows re- 

 ceiving the supplement averaged 2.4 micrograms of cobalt per liter in 

 contrast with 0.6 micrograms per liter when the cows were on the con- 

 trol ration. 



The obvious possible significance of these results lies in their applica- 

 tion to calf nutrition. In our experience, young stock have showed 

 greater susceptibility to the nutritional anemia which is characteristic 

 of cobalt deficiency than older cattle have. In the light of these results, 

 it would seem that in areas where cobalt deficiency is common, the re- 

 quirements of calves for this element might most naturally and logically 

 be supplied through the milk of cows whose rations have been fortified 

 with supplemental cobalt. 



Interest in this work has been shown recently on the part of the indusrial 

 processors of milk. One firm states that in connection with their "use of milk 

 products as fermentation media, . . . very small concentrations of the so-called 

 trace elements are of great importance." Cobalt is stressed by them as one of 

 the principal elements in this connection. 



The element nickel will be investigated during the winter of 1947-48. 



A Study of Quality in Roughage: Composition, Palatability, and Nutiitive 

 Value of Hays as Affected by Curing, Harvesting, and Storing Procedures. (J . G. 



Archibald, M. L. Blaisdell, and H. N. Stapleton.) Preliminary studies with the 

 1945 and 1946 hay crop indicate marked differences in the composit'on of different 

 lots of hay, especially with respect to their Content of protein, sugar, and carotene. 

 These differences are thought to be due to such variables as weather during the 

 growing period and at curing time, kind of crop, and methods of harvesting and 

 storing. Their significance with regard to palatability and nutritive value of 

 the hay produced is, in our present state of knowledge, pretty largely a matter of 

 conjecture. Existing knowledge on the subject is fragmentary, inconclusive, and 

 even contradictory. It is the aim of this project to obtain authentic information. 

 Work has just been begun and results are not as yet available. 



