Investigation of the suitability of alternative turkey origins for an organic farming system (organic turkeys)
Project Leader: Dr. Olschewsky, Anna; Prof. Dr. Knierim, Ute
Project participants: Prof. Dr. Riehn, Katharina
Project description:
Although the proportion of organic turkey farming in Germany is comparatively low at less
than 2%, the sector is attracting attention, particularly
due to the use of fast-growing conventional lines and
sometimes high prevalence of various performance- and
husbandry-related diseases. To date,
little information is available on the extent of these
problems in alternative slower-growing turkey breeds.
The present
study therefore examined the results of slower
growing turkey breeds under organic practice conditions
in terms of behavior, health, meat quality and performance
. The strains Hockenhull Black (robust with
reduced performance potential) and Hockenhull Large Bronze (suitable for
free-range farming with similar performance to Kelly BBB) were compared with the
reference genetics Kelly BBB, which is already used more frequently as a slower-growing genetics
. The rearing and fattening of around 2 x 50
cockerels per genetics in three runs (844 animals in total) on a
biodynamic practice farm in a mobile barn were scientifically monitored from 2015
to 2018 with the following investigations:
continuous documentation of mortality and causes of death;
recording of the length of use of certain housing areas by means of direct
and video observation with instantaneous scan sampling, scoring of
plumage and skin condition as an indicator of feather pecking, cannibalism
and social conflicts, as well as recording of walking ability,
leg position and foot condition in the 7th, 16th and 25th week., 16th and 25th
week of life. After partial slaughter in the 17th, 20th and 25th
week of life, the condition of the foot pads and thoracic
skin on the carcass and the presence of injuries and scratches were assessed. In addition,
live and carcass weights,
weights of valuable cuts, pH values, drip juice losses and
blood points were recorded at these times. In addition, daily weight gains and
feed conversion were calculated. The data were analysed for possible effects of
"genetics" and "week of life" and their interaction with linear or
generalized linear mixed models and
effect sizes were calculated. Some of the data were analyzed using non-
parametric methods due to small
sample sizes or violations of the normal distribution.
As a result, only a few
significant differences with mainly small effect sizes
were found between the genetics. Exceptions were a significantly
worse leg health in Hockenhull Bronze, an increased occurrence
of breast blisters in Kelly BBB and a high proportion of
footpad lesions in Hockenhull Black. However, the latter were characterized
by low mortality, fewer
leg deformities and a reduced injury rate. Overall, the
injury prevalence rates were for the most part lower than in
comparative studies. It can therefore be concluded that both
the two alternative origins and the reference genetics can be reared and fattened under
organic practice conditions with 100% organic feeding and
good management in such a way that an acceptable to good status
in terms of behavior, health and meat quality is achieved with
comparatively high performance.
The project was funded by the Landwirtschaftliche Rentenbank.
Publications: