''It may have been that recent rains have led to lower slaughter rates, and so to entice farmers back to market processors have had to lift prices,'' Mr Penny said.
Underlying demand was ''solid'' and the fact processors were willing to pay higher prices indicated they had the ability to pass that cost on.
Mr Penny highlighted the Chinese and US markets in particular, describing them as ''robust'', not only delivering higher prices but also increases in their respective lamb import volumes.
''We expect lamb prices to remain very strong over the remainder of this season and to also start the new season at healthy levels.
''However, the growing risk of a global trade war could put a damper on prices later in the year,'' Mr Penny said.
Wool prices had also lifted 1.5% but dairy prices had slid 0.6% because of lower whole milk powder and milk fat prices.