US meat producer Tyson Foods said strong demand for chicken and pork offset the loss of beef exports due to a case of mad cow disease in the country.

Tyson said sales rose to $6.15bn from $5.85bn helped by the popularity of high-protein diets, as net profit increased to $119m from $72m.

The company's beef unit had an operating loss of $2m compared with last year’s profit of $6m.

Chicken sales rose $2.05bn helped by double-digit increases in foodservice, retail and export sales.