ROME, May 6 (Xinhua) -- World food commodity prices decreased slightly in April, a month after they hit record highs as the Russia-Ukraine conflict continued, the United Nations Food and Agriculture Organization (FAO) reported on Friday.

The FAO Food Price Index averaged 158.5 points in April, down 0.8 percent from its record high in March.

The monthly index of food commodity prices, released by the Rome-based agency, showed "modest" declines in two of five sub-indexes that pushed the overall index lower.

Among the sub-indexes, grain and cereals prices -- the largest components of the index -- slipped 0.4 percent, due mostly to increased corn exports from South America. Pressure on wheat prices remained high due to the Ukraine crisis and supply issues from the United States. Rice prices were higher due to increased demand in Asia and poor weather in rice-growing areas in the Americas, according to the FAO.

Prices for vegetable oils fell 5.7 percent as supplies in key areas rose to meet demand.

Other sub-indexes climbed from their highs in March. Dairy prices rose 0.9 percent due to supply shortfalls in Europe and Oceania. Meat prices climbed 2.2 percent, pushed by rising prices of poultry, pig and bovine meat, and sugar prices were 3.3 percent higher.

The FAO Food Price Index is based on worldwide prices for 23 food commodity categories covering prices for 73 different products compared to a baseline year.