Project without external funding

Use of roughage (silages, ryegrass, Jerusalem artichoke, and turnip) during vegetation course in year round free range production of fattening pigs (Raufutter Schweine Freiland)

Project Details
Project duration: 03/200602/2008


The research project was conducted to assess intake of different
roughages by fattening pigs in free range systems by using titan dioxide
as marker and in vitro methods to determine the apparent digestibility.
In four fattening periods pigs of the experimental treatments had free
access to the field crops while concentrate was reduced by 15% (starting
period) resp. 30% (finishing period) compared to the control
Mean daily live-weight gains (dlwg) in the different
fattening periods varied markedly between and within treatments. Pigs
with access to Jerusalem artichoke gained clearly higher dlwg compared
to the control treatments while access to the other roughages was only
partly suited to compensate for the reduced concentrate. In general,
carcasses were characterized by a high lean meat percentage.

Investigations on the digestibility of roughages by using three
different in vitro methods (enzymatic incubation, fermentation, and
pre-treatment before fermentation) gained similar results. Hence, all
methods seem to be appropriate tools to assess roughages.
With a
mean value of 41.2% ± 5.1% faeces contained a very high concentration
of crude ash. High correspondence of the noble earth element patterns
between faeces and soil samples indicate that the concentration of crude
ash in faeces originated nearly exclusively from the incorporated soil.
Analysis of titan dioxide in faeces after Kjeldahl-disintegration did
not led to valid results. These were obtained after a repeated
disintegration of samples after exposure to pressure and measuring with
Due to the high amounts of incorporated soil elements and
the interference with titan dioxide it is concluded that the use of
titan dioxide does not allow drawing valid conclusions with regard to
feed intake and that titan dioxide is not an appropriate marker under
free range conditions. Potential risks with respect to the food safety
issue when pigs are kept on soils possibly loaded with residues need
further investigations.

Research Areas



Last updated on 2019-05-07 at 17:15