[Studies on the modification of sexual and breeding maturity in swine using gonadotrophic hormone preparations].

Injection of low doses of PMSG-HCG gonadotrophin mixes to intensively raised prepuberal gilts, aged six months, stimulated sexual juvenile development prior to breeding use, the average being 255 days. First insemination of the test animals, following synchronisation of oestrus or ovulation, increased live births by 0.5 piglets per litter over the untreated controls. More controlled production experiments to test the new bioengineering approach are in preparation.