Effect of concentrate type on rumen fermentation and milk production of cows at pasture.

Abstract The experiment was conducted with 15 Autumn-calving Holstein–Friesian cows, three of which were fitted with rumen cannula, that were allowed to access a perennial timothy and meadow fescue sward between 10 June and 12 August 1996. The control treatment (C) consisted of pasture alone. For the other two treatments, cows were fed 4 kg per day of either a concentrate supplement consisting of barley (B) or a treatment (M) containing (g/kg) barley (200), oats (200), wheat bran (220), wheat (110), wheat syrup (60) and molassed sugar beet pulp (200). The experiment was carried out as a replicated ( n =5) 3×3 Latin square design. The grazing area was divided into 15 paddocks and cows were grazed on a 1 to 2-day rotation. There was no treatment effect on rumen pH but the molar proportion of acetic acid in rumen fluid was higher ( p p p p p p