ChileanJAR

An experiment was carried out at La Platina Regional Research Center, Santiago, Chile, in order to determine the level of milk yield that can be achieved when alfalfa soilage is the only feeding. source to dairy cows. The treatments were: T₁ =young alfalfa soiling (plus minerals) as the only feed; and T₂ = young alfalfa soiling plus enough concentrate to reach the yield potential of the cows. Cows fed only with young alfalfa (20-25% bud) yielded 22.9 and 18.2 L of non-corrected and 4% fat-corrected milk (FCM), respectively, during the first 20 weeks of lactation. During this period, the daily intake in T₁ was 3.18 kg d.m./100 kg live weight. Theoretically, milk yield seems to be restricted by the energy level in the diet, since the intake of such nutrient might be enough for only 19.9 and 17.2 L of non-corrected and FCM, respectively. On the other hand, there was a surplus of protein enough to produce 43.9 and 38.0 L of non-corrected and FCM, respectively. In the treatment of soilage plus concentrate, the energy intake was 42% higher than in soilage alone. Non-corrected milk yield was significantly higher in such treatment, but the fat content of the milk decreased importantly; thus the FCM yield was only 8 higher (P > 0,05) in T₂ than in T₁.