Cal-Maine Foods has booked a 39% drop in second-quarter earnings, as revenue growth failed to offset higher costs.

The company said earnings dipped to US$14.3m in the quarter to 1 December, down from $23.3m in the comparable period of last year. Sales were up 13% to $328.9m.

Cal-Maine was hit by the spiking cost of corn and soybean meal, its main feed ingredients. The company added that it expects feed prices to remain high and volatile for the rest of the fiscal year.