LONG-CHAIN FATTY ACID DIGESTION IN LACTATING COWS FED FRESH GRASS FROM SPRING TO AUTUMN

Abstract

Lactating cows were fed fresh ryegrass. The long-chain fatty acid balance in the rumen was negative (− 15.7–32.6% of intake) in primary growth and leafy regrowths, and positive (+ 11.2–20.2%) in stemmy regrowth (P < 0.05). Their apparent intestinal absorption rose during the grazing season from 59.3 to 89.9% (P < 0.05). Key words: Fatty acids, digestion, cows, ryegrass, season