Feeding experiments



  • A knowledge of the quantitative needs of the body for the nutrients and the relative value of feeds as source of these nutrients is the basis of scientifc feeding, which has been gained gradually by means of research and experience over many years.
  • An understanding of the methods by which it has been attained and which are still being employed to augument it is essential for the student of nutrition.
  • Trial and error were the means by which the art of feeding animals was originally developed.
  • Feeding experiments have been carried out with farm animals during the past two centuries to compare the value of different feeds or combination of feeds.
  • More recently feeding studies have been conducted with laboratory animals, fish, primates and even humans to determine the value and utilisation of individual feeds and the nutritional adequacy or safety of different diets.
  • The feed given to animals are first chemically analysed for its composition and later to find out its utilization in the animals, feeding experiments are conducted.
  • Usually in feeding experiments the value of feed is compared to that of another feed whose efficiency is¬†known.
  • The qualitative value of feed is expressed as digestibility, metabolizability or its effect on production like weight gain, milk production, egg production etc.
  • In large animals it is difficult to measure the composition of the whole animals, wherein nitrogen balance trials are conducted, to indirectly measure the nitrogen retention. The combined use of digestion studies, slaughter experiments or balance studies along with feeding trials to measure the intake, absorption and retention of specific nutrients add greatly to the amount of information obtained.

Feeding trial or experiment

  • It is a record of the results produced in terms of growth, milk production, or nitrogen balance etc from a given feed or ration.

Variations in feeding experiments

    • Genetic
    • Environmental
    • Age
  • To minimize the uncontrolled variations, experiments are statistically designed.

Guidelines for the design of feeding experiments

  • Diets: The experimental diets must be similar in terms of ingredients, except for the ingredient which is to be tested.
  • Animals: Should be of similar age, size and sex .
  • Statistical design:
    • Randomization of animals of same age and size into different groups.
    • Whenever group feeding is done, replication of the group is important.

Experimental design

  • Completely Randomized Design (CRD)
  • Randomized Block Design (RBD)
  • Latin Square Design
  • Factorial design

The different feeding experiments are:

Last modified: Friday, 30 March 2012, 9:33 AM