Treatment, control and/or prevention of respiratory and enteric diseases caused by microorganisms sensitive to the action of lincomycin and/or spectinomycin, improving the growth rate and feed conversion. Pigs: Salmonellosis, enteritis by E. coli, swine dysentery, mycoplasmal enzootic pneumonia, porcine colitis, porcine proliferative enteropathy (ileitis). Mastitis-metritis-agalactia syndrome. Poultry: Chronic respiratory disease (mycoplasmosis), air sacculitis and infectious sinusitis, salmonellosis, enteritis associated to E. coli and to Clostridium perfringens.