After a period of four years the performance data has been updated.
The target performance data of all main
products of the
LOHMANN breeding programme have been elevated considerably
for the last time in 2008. Then, for the first
time separate performance standards for
alternative housing systems were introduced in order to adjust to the changed
general conditions due to barn, aviary and
free-range systems. Since 2008, the performance standards have not been changed.
In the meantime, however, thanks to genetic progress as well as improved housing
and management conditions increasingly
better performances have been achieved
in commercial farms. This applies both to
housing in conventional cage systems still
common in non-EU countries and to enriched cages within the European Union
and alternative systems. An adjustment
to the target performances is not carried
out every year.
The genetically determined
improvement has been accumulated over
the past four years and after that, the new
performance target was defined, which
will now again last for some time.
Improvement of the laying persistency
Especially after the 50th week of life the productivity of the hens has improved. This is
a logical consequence of the high selection priority set on the main breeding goal
of laying persistency for saleable eggs. The
better persistency at the end of the laying
cycle as well as the continuously improved
egg quality (breaking strength) lead to an
increased productivity of the flocks providing saleable eggs.
This allows for an extended housing period (without moulting) resulting in reduced costs per pullet
and egg and thus, offers an economic advantage for the egg producer. Under the
common practical conditions, housing periods become increasingly longer: Flocks
producing more than the 80 weeks stated
in the former standards as the end of the
production cycle are no longer a rarity.
For
this reason, the performance standards
for production in cage systems were extended from 80 to 90 weeks. In alternative
systems depopulation takes place averagely earlier than in cage systems, thus the
performance standards for this production
system was only extended up to 85 weeks.
The daily feed intake has not been
changed genetically. Today, the hens are
able to produce a higher egg mass with
the same amount of feed, which is ascribed to the improved feed efficiency.
The balanced breeding strategy aiming
at an improved feed conversion led to increased production efficiency at the same
feed requirement and a still sufficient feed
intake capacity.
New international standards for cage systems
Due to the ban on conventional cage systems in the EU, especially in Western and
Northern Europe the traditional cages
have not been replaced with enriched
cages but with barn, aviary and free-range
systems allowing the hens an increased
physical activity. The results with field flocks in such management systems are
often lower compared to cage systems.
Not only a lower egg number, but also a
reduced egg weight can be observed in
comparison with cage systems. This fact
has been considered in the new data and
an egg weight curve corresponding to the
management system has been defined as
a standard.
New standards for alternative management systems (barn, free-range
and aviary systems)
The standards of
LOHMANN TIERZUCHT
laying hens both for cage and alternative
systems have been defined in such a way
that the production target is achieved at
average management and environmental conditions. They do not represent the
maximum attainable results respective
to the genetic potential. We know that
the genetic potential of laying hens of
all strains is considerably higher than our
field-related performance standards.
At this point, we cannot predict when the
next adjustment of the targets will be carried out.
LOHMANN TIERZUCHT invests a
lot of work and capital in order to sustainably achieve further genetic progress also
in the future. Not only with regard to the
economically most important characteristics as laying performance and feed conversion, but also in a further improved egg
quality (shell stability, shell colour) and survival rate.
Even after many generations of intensive
selection, the genetic parameters (heritability) still indicate that additional progress
in performance is possible. For sure, the
biological limit of one egg per day is approaching and is already attained by many
hens in the phase of the laying peak. Nevertheless, there still is a lot of potential for
further improvement of persistency and
shell stability for the future genetic enhancement of laying hens from the
LOHMANN TIERZUCHT breeding programmes.
Dr. Matthias Schmutz, Genetics