KANSAS CITY (Dow Jones)--Seasonal price patterns point to price declines for beef and pork going into the summer months, and many market analysts say they expect the patterns to follow through this year.

One cattle market analyst said to beware of the seasonals this year, because tighter supplies may make prices move differently than seasonal charts might predict.

Bob Brown, a private market analyst in Oklahoma, though, said that seasonal charts were the best way to formulate opinions of future price behavior, since no one can predict the future.

The U.S. Department of Agriculture's reported wholesale prices for beef and pork began to slide last week. The composite value for choice beef cuts was $171.40 per hundredweight on May 11, and the top for pork cutout values was $91.81 on May 14.

Since then, beef has come off 2.19% to $167.65 on Thursday. Pork declined 5% to $87.21 on Wednesday. Pork values bounced $0.55 on Thursday to $87.76, but many market analysts saw this as a short-term bounce in an otherwise downward trend.

Brown pointed out that pork prices spiked last week as buyers sought out loins, butts and ribs for weekly grocery specials through the Memorial Day holiday weekend. He saw prices this week coming back into line after the spike.

Brown also said that for this week, pork prices moved higher in nine out of the last 10 years. Next week shows seasonal declines, with three of 10 years showing increases and seven showing weakness. The generally weak tone then holds for another three weeks, he said.

Daniel Bluntzer, livestock market analyst for Frontier Risk Management, said beef prices had reached historically very high levels, so it was time for it to retreat as it did this week. Also, the seasonal shift into lower price trends usually begins in early to mid-May, so this year's turn is a little later than the average.

In nine of 10 years, beef prices go down into July, Bluntzer said. This is a function of the seasonal production cycles of cattle where more and larger cattle are presented to the packer for slaughter, resulting in more beef production. This happens just as the weather begins to heat up and consumer appetites decline because of hot weather.

Cattle/Hog Slaughters

This week's cattle slaughter was estimated at 681,000 head, compared with 671,000 a week ago and 685,000 a year ago. Year-to-date cattle slaughter is up 1.2% from a year ago.

The week's hog slaughter estimate was 2.016 million head, compared with 1.948 million a week ago and 2.066 million a year ago. For the year, hog slaughter is off 4.2%.

Total Meat Production

The USDA estimated total beef, pork and lamb production for the week at 928 million pounds. Last week's output was 907 million pounds, and the year-ago figure was 950.6 million pounds. Year-to-date combined meat output is down 2.7%.

Broiler/fryer slaughter for the week was estimated at 161.500 million head, compared with 165.664 million a week ago and 159.312 million a year ago.

-By Lester Aldrich, Dow Jones Newswires; 913-322-5179; lester.aldrich@dowjones.com