The Chicago Board of Trade cancelled farm commodity futures trade today because of a malfunction in the computerized price reporting system.

It marked the first time since the computer system was installed more than 10 yearsago that a breakdown cancelled trading. There have been numerous delays in trading, however, because of temporary mechanical failures.

There was no trading in wheat corn, oats, soyabean meal or oil futures. Trade in silver plywood, gold, iced broilers and GNMA futures opened at 12.30 p.m. CDT and lasted until the normal closing or about an hour later.

The exchange's director said thay today would not be considered a business day for purposes of deliveries and tenders against May contracts. Variable price limits which would have applied to all delivery month in soybeans and meal will apply Tuesday.

The limited trading in iced broiler futures left prices closed about half a cent highter.

On the Chicago Mercantile Exchange, pork belly futures advanced by allowable daily limits of 200 points or 2 cents a pound. Demand was inspired by a higher crash market and constructive storage figures.

Live hog futures advanced the limit of $1.50 a hundredweight. Higher cash prices and a lighter than expected hog run were trading factors.

Live cattle futures prices rose 65 cents. A light slaughter Friday and an unexpected lightcattle run Tuesday contributed to the demand.