148 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



fact that it is no lono;er necessary to supply the War Department, 

 which required large quantities during the war. 



The tuberculin and mallein prepared and distributed by the labora- 

 tories (hiring- the liscal year could not possibly have been purchased 

 on the market even under the most favorable circumstances for loss 

 than $75,000. In addition to this very considerable saving in money 

 the bureau has been able to assure the purity and strength of these 

 products used in its official testing for the eradication of tuberculosis 

 and glanders. 



OTHER WORK. 



The assistant chief of the Biochemic Division is a member of the 

 Insecticide and Fungicide Board and has given a large part of his 

 time to the work of that board. In its cooperative work with the 

 board the division analyzed 123 samples of insecticides intended for 

 use on domestic animals, and 82 of the preparations were found to be 

 misbranded or adulterated. The infractions of the law were for 

 the most part technical errors which resulted apparently, as a rule, 

 from ignorance of the law. 



ZOOLOGICAL DIVISION. 



The investigation of parasitic diseases of animals and the study, 

 collection, and determination of animal parasites have been continued 

 in the Zoological Division under Dr. B. H. Ransom, chief. 



ROUNDWORMS OF SHEEP. 



The principal experiments at the bureau farm near Vienna, Va., 

 were designed to test the possibility of rearing lambs to marketable 

 size without loss from stomach worms by changing them every three 

 weeks during the grazing season to fresh pasture (forage fields on 

 which a crop had been grown since their previous occupancy by 

 sheep, and which had not been occupied by sheep since the preceding 

 autumn). Shortly after lambing the ewes were dosed with copper- 

 sulphate solution. The ewes and lambs were kept together in stables 

 until the flock was turned out to pasture and thereafter also at night. 

 One lot of lambs was pastured with the ewes, the other separately. 

 The latter, however, were turned back into the stable with the ewes 

 during a portion of each day for nursing as well as being stabled 

 with them at night. Both lots of lambs were dosed with copper- 

 sulphate solution when weaned, and both were thereafter kept en- 

 tirely separate from the ewes, but were moved to fresh pasture at 

 the same intervals after weaning as before ; that is, every three weeks. 

 There was no loss among the lambs that were pastured with the ewes. 

 They made a stronger growth than the other lot, although they did 

 not escape considerable infestation with stomach worms. The lambs 

 that were pastured separately from the ewes became only very 

 slightly infested with stomach worms. Their failure to make the 

 growth that the others did is probably to be attributed to the inter- 

 ference with nursing involved in keeping them separated from the 

 ewes a considerable portion of each day. 



Old sheep and yearlings, as in former years, have been kept in 

 good condition without special precautions as to the presence of 



