[Nutritive antibiotics and biostimulant preparations in the rations of swine for fattening].

Two experiments were carried out with sows for fattening having a body weight of 20 to 100 kg. The following nutritive antibiotics were tested -- bacipharmin -- 10% (PRB), zinkbacitracin -- 10% (UFRJ), vitamycin 3 (USSR), nitrovin (Peizun, USA) and mekadox -- 5% (USA). It was established that the stimulating effect of these antibiotics was manifested during the first fattening period -- up to 60 kg body weight, when the average daily increment of the experimental groups treated with bacipharmin, zink bacitracin and nictrovin in the I experiment was 7--15% higher and in the II experiment in which zink bacitracin, vitamycin 3, nitrovin and mekadox were added -- 8--14% higher as compared to the control groups. During the second period of fattening (60--100kg) no effect of the same nutritive antibiotics was observed, with the exception of the vitamycin treated group. In both experiments an economy of combined fodder per 1 kg body weight was realized in the experimental groups. Application of nutritive antibiotics and biostimulators during the second period is economically unexpedient. The antibiotics tested have no negative effect on carcass slaughter characteristics and on the chemical composition of meat. No residual substances of the nutritive antibiotics tested were detected on the second day following slaughter in the meat group treated with mekadox, since no sows of this group were slaughtered.