Short-term response in solids-not-fat to grain fed in addition to molasses for dairy cows grazing tropical pastures

Abstract

Holstein-Friesian cows in mid to late lactation grazed tropical grass-legume pastures with no supplement (C); 2.7 kg DM molasses/cow.day (M); or 2.6 kg DM molasses + 2.5 kg DM grain/cow.day (MG). Daily milk yields over the 8 week experimental period were 10.4, 11.2 and 12.9 kg/cow for C, M and MG. The MG supplementation increased solids-not-fat (SNF), protein and lactose percentages in milk, with average SNF values of 8.02, 8.10 and 8.24% (P<0.05), and lactose values 4.46,4.50 and 4.58% (P<0.057), for weeks 5-8; and average protein values for weeks 1-8 of 2.96, 3.02 and 3.10% (P<0.05) for C, M and MG, respectively. Molasses alone did not substantially increase the protein and lactose content of milk, but additional energy in the form of maize increased these values. If SNF percentages in milk were low, maize plus molasses feeding did not improve the quality to the legal minimum of 8.5% in 8 weeks.