[Problems in the energy and nutritional requirements of feeding and welfare of food producing animals].
The efforts in optimizing feeding conditions of food producing animals in the past were focussed primarily on promoting performance and/or the products' quality (MEYER 1997). In spite of great success in this direction various risks occur due to the conflict between the increased requirements on the one hand and the species typical demands on the other (for example: need of roughage as well as of concentrates with high energy and nutrient density in ruminants). Especially in feeding high yielding dairy cows the conflict is obvious: Even in the case, that high amounts of concentrates are fed it becomes more and more difficult to meet the energy requirement when the milk yield exceeds 40 kg milk per day (FLACHOWSKY a. LEBZIEN 1997). A negative energy balance is accompanied by a forced predisposition for ketosis and infertility (KRUIP 1996). Insufficient proportions of roughage in those rations predispose the animals for rumen acidosis and associated problems (health of claws etc.) as well as for displacement of abomasum. Thereby in feeding high yielding dairy cows there is only the choice between different risks due to the fact that the feed intake capacity did not increase to the same extent as the milk production did. In fattening calves the use of roughage (in Germany required by law) is on debate in this direction (necessary to avoid disturbances in the behaviour). Further problems in feeding animals according to their species typical demands are related to the established conditions of housing, feeding and water supply (risks of mechanization and automatization due to potential disfunction). The generally increased feeding intensity results--for example in poultry--in a higher frequency of skeleton diseases; the more and more specialized pig production (separate units for piglet production, rearing units, fattening units) is accompanied by increased changes in diets and techniques of feed and water supply, to that the animals have to be accustomed, too. The science of animal nutrition gets more and more involved in questions on the species depending requirements that guarantee a physiological development of the animal, health and normal behaviour. There is an increased need to create and evaluate parameters that can be used for characterization animals' well-being related to different feeding strategies. Without any doubts it is a special task to veterinary nutritionists to point out risks, problems, conflicting aims when the feeding intensity is forced continuously. The slogan "back to nature" is too simple and does not correspond to the complexity of efforts which are suitable and necessary to meet animals' energy and nutrient requirements as well as demands of animals' welfare. Eventually it is helpful to remember sometimes the limits set up by the biology and physiology when feeding intensity or techniques are on debate.
Kamphues
J
J
Institut für Tierernährung, Tierärztlichen Hochschule Hannover.
D000821:Animal Feed; D000827:Animal Welfare; D000818:Animals; D000829:Animals, Domestic; D004734:Energy Metabolism; D008460:Meat; D009751:Nutritional Requirements
Probleme der art- und bedarfsgerechten Fütterung landwirtschaftlicher Nutztiere.