Big and cattle farmers have seen a sharp drop in prices within the last few months, a result of large supplies and a higher slaughter rate than anticipated.

Spring-finished cattle price highs were near $138 per live hundredweight, but recently fell to $115, a $23 plunge, according to Chris Hurt, an agricultural economics professor at Purdue University.

The story is similar for hogs, he said.

After seeing yearly highs at $81 for a national lean price in the third week of June, prices have dropped $20, or 25 percent, in the past two months, Hurt noted.

Among the pressures: declining restaurant traffic as retailers increase prepared food offerings priced at a fraction of the cost of dining out, lower costs for food prepared at home versus rising costs for food consumed away from home,...