Investigations on the replacement of maize products in rations for dairy cows and fattening bulls

Abstract

For different reasons as for example the occurrence of pests like Diabrotica virgifera there may be a shortage in availability of maize products for ruminant feeding. Therefore, different feeding studies on replacement of maize products in rations for dairy cows and fattening bulls were conducted as a part of the “Diabrotica research programme” set up by the federal government of Germany and the federal state of Bavaria. The main focus was set to on suitability of alfalfa as well as grass silage as a roughage source for dairy cows and fattening bulls. It is shown that partial replacement of maize silage by these products allows producing at high production level in Simmental cows and fattening bulls. A decisive advantage is the possibility to reduce the portion of protein concentrates like soybean or rape meal in the diets. Moreover, other beneficial aspects for ruminant feeding such as the high structural value of alfalfa silage are discussed. In ruminant feeding, corn is used as an energy rich dietary component. As a part of the programme a dairy cow feeding trial was conducted to evaluate whether replacement of corn by wheat is a promising possibility to reduce portion of maize products in ruminant diets. Results of the study demonstrate the limits of these feeding strategies, especially in maize silage based diets high in energy concentration and in the concentration of soluble carbohydrates. In these diets, concentrations of degradable starch and sugar are often near or above the maximum recommended amounts. For these reasons use of corn as a source of undegradable starch is preferable to the use of other cereals to prevent conditions that promote rumen acidosis.

Keywords

• dairy cows
• fattening bulls
• roughage source
• starch source