New calcium sources used in pig feeding.

Three types o f marble waste ( Sohodol and type “M dry”) as well as Borsec t ravert in waste were tested as die tary calcium sources for growing p igs compared to the feed grade l imestone from Basarabi – Constan a. 86 hybrid (Large White × Peri Synthe tic Line 345) pig lets wi th 9 .55 kg average ini t ia l weight were assigned to f ive groups di f feren tia ted by the calcium source. The calc ium conten t of the marble and travert in waste supplied by S.C. Marmura SA Bucharest ranged between 35.37-38.27%, compared to 38% calc ium in feed grade l imestone. The same calcium leve l was suppl ied to a l l f ive groups, i rrespect ive o f the source . Sl igh tly lower average da ily weight gains were ob tained in the treated groups compared to the l imestone group , but the di f ferences were not sign if icant . Feed convers ion rat io was simi lar. Serum and bone calc ium leve ls were similar wi th the contro l group, part icu larly when waste from n ic marble and Borsec t ravert in were used.