Zinc prices were higher by 0.48per cent to Rs 186.80 per kg in futures trade Wednesday as speculators built up fresh positions, taking positive cues from spot market on rising demand.At the Multi Commodity Exchange, zinc for delivery in the current month traded 90 paise, or 0.48 per cent, higher at Rs 186.80 per kg in business turnover of 836 lots.Marketmen said fresh positions built up by participants due to pick up in demand in the domestic spot market, led to the rise in zinc futures.