[Feed intake and milk production in dairy cows fed whole fat soybeans]

In two experiments (E 1, E 2) two different basic diets were fed to 36 diary cows with addition of 1 or 2 kg of full fat soya beans (SB) or without SB for six weeks. The cows were fed individually. The basic diet consisted of 49% grass silage, 23% maize silage and 21% hay, supplemented with 7% manioc (% DM) in E 1 and of grass, supplemented with 2.0 kg maize silage, 3.0 kg hay and 1.5 kg manioc (kg DM/cow.d) in E 2. The basic diet used in E 1 and the grass in E 2 were offered ad libitum. Further a mixture of 1 kg SB, soya bean meal and manioc (Treatment 1), a mixture of 2 kg SB and manioc (Treatment 2) and a mixture of soya bean meal and manioc (Treatment 3, control), respectively, was supplemented to achieve diets with equivalent concentrations of energy and protein. Depending on the daily milk yield a concentrate was fed to high yielding cows (> 21.5 kg milk in E 1 and > 25.0 kg milk in E 2, respectively). The addition of 1 kg SB increased the forage intake in both experiments by 1.2-1.5 kg DM/cow.d significantly, while the addition of 2 kg SB increased the forage intake only in E1 to the same extent. The mean total DMI was 19.2 kg in E 1 and 17.7 kg in E 2, respectively. The daily milk yield was not influenced by addition of SB. The average milk yield was 28.8 kg and 26.7 kg in E 1 and E 2, respectively. The milk fat content increased significantly in E 1 by 0.3-0.4% with no respect to the amount of the supplied SB (4.11% vs. 3.74%). In E 2 the milk fat content increased only slightly (3.84% vs. 3.74%). Milk protein content was not influenced in E 1, but decreased in E 2 after addition of 2 kg SB.