UBS has slashed target prices across the mining sector after downgrading its gold and silver price forecasts for 2014 and 2015.The bank said it now sees few positive catalysts for precious metal prices over the medium term, with the Federal Reserve expected to start tapering quantitative easing in January. Gold is losing its safe-haven demand and physical buying has its limits, it added.UBS has revised its 2014 gold price forecast down by 9% to $1,200 an ounce and slashed its silver forecasts for 2014 and 2015 by 18% and 13%, respectively. It said that prices will "remain subdued for four+ years"."The diversified miners are only marginally affected (earnings per share downgrades of 0-2%), while the platinum names suffer from lower gold revenues. "We still prefer companies with low unit costs, good capital discipline & strong cash-flow growth, with Rio Tinto and BHP Billiton our top picks."Meanwhile, the bank downgraded its rating for Hochschild Mining, saying that share price upside could be capped if lower gold and silver prices persist "as HOC is operationally leveraged and its net debt is set to increase in FY14 and FY15".UBS made the following changes to target prices/ratings:Antofagasta: target price cut from 870p to 845p, 'neutral' rating kept.Aquarius Platinum: target price cut from 44p to 43p, 'neutral' rating kept.Fresnillo: target cut from 1,150p to 1,100p, 'buy' rating kept.Hochschild Mining: target cut from 200p to 150p, rating downgraded from 'buy' to 'neutral'.Kazakhmys: target cut from 240p to 235p, 'neutral' rating kept.Lonmin: target cut from 335p to 325p, 'neutral' rating kept.Rio Tinto: target cut from 3,620p to 3,610p, 'buy' rating kept.BC