What is “scientifically proven”?

This link is to a book that discussed "what is scientifically proven" .... although this particular book related to human nutrition and health,  the basic principles of “scientifically proven” remain the same no matter which specie or subject under discussion.

Quoting the above reference: A “scientific” experiment is one where you take a set of circumstances, purposefully change only ONE variable, run the experiment and observe what happens. If anything interesting or unusual happens, then you look for a reason. Since all of the VARIABLES were “controlled,” the most likely suspect as to the CAUSE of the observed change is the one variable that you purposefully changed.   That’s science.

When first entering the ostrich industry back in 1994 wanting to learn more, the words "scientifically proven" was continually used - but when one examined what was being said, it quickly became obvious that there was nothing scientifically proven as it applied to ostrich production.  Another word heard repeatedly was “replicable”.   Of course important, but the variables must be understood in order to ensure an experiment is replicable under the same given conditions.

The success of the other livestock industries over the past decades is a result of the very high volumes of production that have enabled management to control the variables. Until it is possible to control variables, the only meaningful studies that can be carried out are those that set benchmark figures to enable further studies to be evaluated as we develop volume and in a position to eliminate the variables.

What exactly are these “variables”?

What is a “Variable” when conducting any experiment or trial?
A variable in this context is any change however small that variable may appear to be.  This will include such things as:

  • The genetic heritage of the livestock – includes not only the breed, type, origin, but also the management and nutritional history of the genetic lines/parentage.
  • Environment – includes management systems, climate, housing, pens, stress exposure
  • When discussing nutrition – includes not only the nutrient levels of each ration, but also the sources of those nutrients,  the precision of manufacture, feeding times and feeding rates/consumption.

In 2002 there was a proposal for a comparative study by the vet for the Klein Karroo Group.  The aim of the study was to compare baby chick liver colours.  Many chicks in South Africa were hatched with livers of a bright yellow colour which Blue Mountain was suggesting was a clear indicator of nutritional deficiencies in breeder nutrition and a contributory cause to the high levels of chick mortality experienced by South Africa ostrich farmers.

The full proposal can be viewed here.  For the purpose of a discussion on variables, I will copy here only the suggested parameters that clearly rendered any such study of absolutely no value to the industry and their producers.  It must be remembered that this proposal was made at a time when production levels were generally extremely low and there was a study on examining the causes of high levels of chick mortality underway.   The principal motivation for the study was to monitor the colour of chick livers at hatch and alterations as the chicks transferred from yolk sac dependency to full external feed intake.

Material
1.  10 chicks each from breeders fed on two different commercial breeder rations. Hatched artificially. Raised according to one protocol.
2.  10 chicks from breeders in on veld pasture. Hatched artificially or by parents and raised on veld.

oudtshoorn veldt

Figure 1 - Oudtshoorn Breeders in the South African Veld in the Oudtshoorn Region

As proposed this study was meaningless because there were far too many variables on a very limited number of chicks.   The proposer clearly did not have a basic understanding of the variables that would have an influence on the results.   The only variable referenced as a control was that the chicks in Group 1 should be reared according to the same protocol.

All Chicks suggested in the study:
No reference was made to ensure the performance history and nutritional history of the parents was known.  As this was a study designed to compare the livers of the chicks, for it to have any true meaning it was essential to ensure the exact nutrient consumption of the breeders and then the chicks while growing was known.  Liver condition (along with all internal organ development) is directly affected by the nutrients fed to the breeders producing the eggs.

Group 1 Chicks:
Most commercial rations in South Africa contain variables from batch to batch and the labelling regulations did not require feed ingredients to be listed and contained minimal nutritional information.

Group 2 Chicks:
For those of you not familiar with South Africa, the Veld is pasture area around Oudtshoorn.  Those second group of chicks would be from breeders running in this area.  Most farmers running breeders in this way also supplemented with either home produced rations made up including a commercial vitamin/mineral/amino acid premix or a commercial breeder ration.

When our industry achieves the high volumes of the mainstream livestock industries, it will then be possible to correctly control variables – including genetics.   In ostrich this would be chicks from a batch of eggs from comparative breeder pairs.   The breeders’ full production, management, nutritional, environmental and genetic history would also be on record.

One comment

  1. […] Here we discussed Variables when scientifically evaluating diets of ostrich.   Reference was made to Veldt Pasture. Note there was no definitive definition provided for Veld pasture. […]

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