'Price Fatigue' Hurting Beef Sales-Tyson  CHICAGO (Reuters) - Tyson Foods Inc &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=TSN.N target=/stocks/quickinfo/fullquote"&gt;TSN.N&lt;/A&gt;., the world's  largest meat company, said on Thursday that high beef prices  may have consumers shifting to pork and chicken, but its beef  segment should do well later this year.