Retail segment net sales increased $30.3 million, or 23%, to $162.5 million. Volume increased 13% as strong growth in shipments of premium and mainstream branded offerings, which have historically comprised approximately 40% of the segment’s volume, was partially offset by a decline in shipments of private label products, which reflects incremental losses of certain low-margin private label business. Price/mix increased 10 percent, largely driven by favorable mix from higher sales of branded products.
Net sales in our Other segment increased $0.3 million, or 1%, to $35.3 million, as favorable price/mix more than offset lower volumes in our vegetable business.
Gross Profit and Product Contribution Margin
Gross profit declined $53.7 million, or 21%, to $196.7 million in the third quarter of fiscal 2021. The decline was driven by lower sales and higher manufacturing and distribution costs. These higher costs were largely due to incremental costs and inefficiencies related to the pandemic’s disruptive effect on our production, transportation, and warehousing operations. We also incurred higher costs in the quarter related to capital, repair and maintenance activities that we delayed at the onset of the pandemic. In addition, higher manufacturing costs reflected input cost inflation. The decline in gross profit was partially offset by a $7.5 million change in unrealized mark-to-market adjustments associated with commodity hedging contracts, which includes a $7.2 million gain in the current quarter, compared with a $0.3 million loss related to these items in the prior year quarter.
Lamb Weston’s overall product contribution margin, defined as gross profit less advertising and promotion expenses, declined $52.5 million, or 22%, to $191.3 million. The decline was largely due to lower sales and higher manufacturing and distribution costs (as described above).
Global segment product contribution margin declined $30.0 million, or 27%, to $79.3 million. Higher manufacturing and distribution costs, as well as unfavorable mix, drove the decline. Global segment cost of sales was $398.2 million, up 6% compared to the third quarter of fiscal 2020, primarily due to higher manufacturing and distribution costs.
Foodservice segment product contribution margin declined $29.6 million, or 30%, to $70.2 million. Lower sales volumes, higher manufacturing and distribution costs, and unfavorable mix drove the decline, partially offset by favorable price. Cost of sales was $147.9 million, down 18% compared to the third quarter of fiscal 2020, due to lower sales volumes, partially offset by higher manufacturing and distribution costs.
Retail segment product contribution margin increased $4.3 million, or 15%, to $33.1 million. Favorable mix drove the increase, partially offset by higher manufacturing and distribution costs, and an $0.8 million increase in advertising and promotional expenses. Cost of sales was $126.4 million, up 25% compared to the third quarter of fiscal 2020, primarily due to higher sales volume and higher manufacturing and distribution costs.
Other segment product contribution margin increased $2.8 million, or 47%, to $8.7 million. These amounts include a $4.3 million gain related to unrealized mark-to-market adjustments and realized settlements associated with commodity hedging contracts in the third quarter of fiscal 2021, and a $0.7 million loss related to the contracts in the prior year period. Excluding these adjustments, Other segment product contribution margin decreased $2.2 million due to higher manufacturing and distribution costs, partially offset by favorable price/mix in our vegetable business.
Selling, General and Administrative Expenses
Compared with the prior-year period, SG&A expenses increased $8.2 million, or 9%, to $96.1 million. The increase was largely due to investments to improve our manufacturing and supply chain operations over the long term, and to a lesser extent, our information technology infrastructure, which included approximately $1 million of non-recurring expenses, primarily related to consulting expenses associated with a new enterprise resource planning (“ERP”) system. The increase in SG&A was partially offset by cost management efforts.