Tyson Foods Inc, the biggest U.S. meat processor, reported a 28.6% rise in quarterly profit, helped by higher exports of beef and pork and lower livestock costs.

Net income attributable to Tyson rose to $593 million, or $1.59 per share, in the first quarter ended Dec. 31, from $461 million, or $1.15 per share, a year earlier.

Sales rose marginally to $9.18 billion from $9.15 billion.

Tyson's shares were up 7.8% at $70.50 in premarket trading on Monday.