LAMB prices firmed again last week, making the decision of forward contracts versus playing the spot market this winter more difficult for producers.

In West Australian saleyards, lamb prices in the past fortnight have hit 500c/kg carcass weight.

Lamb prices nationally are now at their highest level since September last year.

The forward-contract prices, however, could be playing a role in the dearer trend by boosting demand for lambs to feed.

This week Meat and Livestock Australia said the market was being driven from the bottom.

"There has been increasing competition between processors and restockers on better quality drafts of light and trade weights and this has placed upward pressure on prices," it said.

Feedback from agents and farmers on the forward contracts remains mixed, with some vowing to stick to the auction system and others stating that a guaranteed price of 450c/kg couldn't be overlooked.

Meanwhile, results from opening stud bull sales raise questions about the state of the southern cow herd and the attitude of farmers towards the beef industry.

In the past fortnight, studs of every colour - Angus, Hereford and Charolais - struggled to clear bulls, even at the reserve prices of $2000 to $2500.

It suggests that either there are too many bulls being produced, or people are not upgrading to new genetics in a depressed beef market that lacks the pricing systems to reward better-performing stock.

Stalwart stud breeder Don Lawson, who watched his son Tom's on-farm sale of Paringa Charolais bulls last week, is convinced that industry groups such as ABARE have underestimated the severe cull in breeding numbers.

"The official figure is about an 8 per cent fall in cow numbers, but talking to stock agents it would be more like 30 per cent in some areas," Mr Lawson said.

As cow numbers have fallen, many people are believed to be breeding their own bulls and selling a few each year.