fi Lancaster Farming, Saturday, August 2. 19(H) Breakthrough in Marek's Disease Studies Reported By Merck Sharp & Dohme Researchers Itesc.nch .it the Meick Sharp A. Dohnu* Research L'aboi atones is utilizing two important bieak thloughs in the study of Maiek’s disease This disease costs Unit ed States poultiy pioduceis an estimated 200 million dollars a year. These cutical bieak- Ihioughs arc the ability to grow the herpesvirus associated with Maiek’s disease in tissue culture cells, and the development of simple serologic tests Because of these advances, scientists now have the tools necessary foi lap id advancement in the contiol of the disease, tepoiled Di Theo doie A Maag, supeivisor of ic seaich in avian leukosis at Mei cl. Dr Maag has wntlen about Maiek’s disease in the cunent issue of The Merck Agncultuial Memo, published as a seivice to animal agucultuie bv Feed Pio ducts, Meick Chemical Division Marek’s disease is essentially a ccnglomeiation of tumoious like disoideis of joung buds Skin, neives. livei spleen, kidney, heait and muscle aie involved Although tumois and associated conditions aie comparatively new pioblems to the broiler in dustiy, they aie now the major disease of broilei, as well as le placement bads, bieedei or lay ei opeiations Marek leseaich at Merck be gan several yeais ago when in vestigatois worked with a bi oil er from Delmaiva They isolat ed a strain, now known as MSD 1, which showed only neural and skin lesions Investigatois hoping to isolate the disease-causing agents be lieve that a heipesvuus is closely associated with Maiek’s disease A lew reseai chei*s‘, including Dr Maag, believe that at least one other virus is involved Accoiding to Dr Maag’s article in the Agricultural Memo, Mai ek’s disease may be at least two disease syndiomes One is mfiam matoiy, seen as uncomplicated netve and skin lesions The sec ond is lymphoprolifeiative, and is lecognized by neoplastic-like lesions of the kidney, livei, sp'een, gonads, muscle and heait Susceptibility appeals to be diffeient for each bleed, and the method of infection may also differ Bad-to-bud tiansmission is P'obably limited to close con tacts and lesults mainly fiom m Hunter Safety Requirement The Pennsylvania Game Com mission this week again lemmd ec youths of the hunter safety tiaimng lequnemenl foi pinch asing a hunting license Aitei September 1 1969 no limiting license shall be issued tc anv pei son undei the age of si'ieen vear= unless he p e=enl' 3 evidence that he has held o .untmg hcen-e i==ued b' the 1 i common..edGh o f Pennsylvania O) anothei state map or yea’ oi a ceitifiCdte sho.vmc ih<.‘ ‘he. , ; outh hdS satisfactory comnlet a hunter safety comm surh a.