SEOUL, Jan. 20 (Xinhua) -- South Korea's livestock number largely fell in the fourth quarter on the back of concerns about avian influenza and higher production costs, statistical office data showed Friday.

The number of broiler chickens raised here was 88,713,000 during the October-December quarter, down 5.2 percent from a year earlier, according to Statistics Korea.

The reduction was attributed to the lingering worry about the spread of avian influenza in some regions and higher chick prices.

The number of ducks tumbled 11.2 percent to 5,994,000 amid concerns about the bird flu, but the reading for layer chickens grew 2.2 percent to 74,188,000 in the fourth quarter.

The number of milk cows shrank 2.7 percent to 390,000 on higher product costs, but the figure for beef cattle rose 2.9 percent to 3,694,000 due to demand for cattle being 24 months or older.

The number of pigs shed 0.8 percent to 11,124,000 in the cited quarter.