Effects of including chopped alfalfa hay in barley-based total mixed rations on production and rumen fermentation of lactating dairy cows

Alfalfa silage [13.6% dry matter (DM)] was replaced with chopped alfalfa hay in barley silage and barley-grain-based total mixed rations. This replacement increased DM from 45.2 to 54.9%, decreased physical effective fibre, determined as the proportion of the DM passing through the 8- and 19-min screens of the Penn State Particle Separator multiplied by dietary neutral detergent fibre (peNDF), from 21.9 to 16.2% DM, increased dry matter intake from 19.1 to 21.2 kg d(-1), numerically reduced milk protein yield from 1.01 to 0.93 kg d(-1), but did not affect milk yield, milk fat, rumen pH, and rumen ammonia.