In which direction is layer breeding heading in major areas? LOHMANN
TIERZUCHT’s geneticists Prof. Dr. Rudolf Preisinger and Dr. Wiebke Icken give
clear answers to seven current questions.
1. Are there differences in the breeding
of layers determined for barn and free
range systems?
LOHMANN TIERZUCHT continues to focus
its activities on the essential characteristics
such as high laying performance, good feed
conversion, market compliant egg weight
as well as excellent shell and egg quality.
However, in these management systems,
the behaviour of the hens is of higher importance than in cage systems.
The particular suitability for barn and free
range systems comprises of characteristics such as stability of plumage, low tendency for feather pecking and cannibalism,
spreading in the house system, good usage
of free range and nest acceptance, meaning
less floor eggs. Additionally, hens in barn
and free range systems have to cope with greater environmental and stress influences
and in case of suboptimal feeding, have to
show high metabolic stability.
2. How can the behavioural characteristics mentioned above be monitored in
breeding work?
Reliable data obtained from an environment which is similar to practical farming
conditions, are an indispensable precondition. This means that the hens monitored
must be managed in large groups, but
nevertheless the performance and behaviour of each individual hen can be analysed.
At LOHMANN TIERZUCHT, performance and
behavioural data are recorded with the aid
of the so-called Weihenstephan Funnel Box
based on transponder technology. This enables the automatic and individual recording
of nest visits, nest occupation time, oviposition time and number of eggs. Due to the
transponders ensuring the identification of
each single laying hen, the period of time
spent in the free range can also be logged.
3. Is the heritability of behavioural characteristics high enough for successful
breeding?
The characteristics nest acceptance and
laying performance are recorded with the
Weihenstephan Funnel Box in the common selection criterion “Number of saleable nest eggs”
Eggs which are laid on the floor will not be
taken into account as being saleable eggs,
thus reducing the laying performance.. The
heritability lies on a mid-range level and
thus, can be well treated in breeding. The
heritability estimates of free-range usage
also lies on the mid-range level. However,
it correlates negatively to the laying performance – hens showing a high laying performance spend less time in the free-range
area.
4. To which extent does house management influence the hens’ behaviour?
Training and management decisively influence nest acceptance. Fostering the
hens’ activity by means of a corresponding rearing, a timely house change into
the production house as well as the design
and arrangement of the laying nests are
among the most important aspects in order to minimize the number of floor eggs.
To a great extent, feather pecking and cannibalism depend on the house management. Here, principal starting points are the
choice of lighting, an adapted lighting programme and feeding in line with demand.
5. What are the main differences
between white and brown hens, especially in terms of their suitability for
alternative management?
The behaviour of white and brown laying hens is considerably different. While
the white Leghorn hen seems to beanxious and hectic, the brown hen is characterized by a calmer and calm behaviour,
which sometimes even affects the nest acceptance negatively. Results obtained by the
Weihenstephan Funnel Box have shown that
compared to the LOHMANN LSL hen, the
LOHMANN BROWN hen starts earlier in
the day with oviposition. Furthermore,
LOHMANN LSL hens spend a much shorter
period of time while visiting nests during the
day and stay notably longer in the nest per
visit.
For management purposes, it can
be deduced from these results, a
stock of LOHMANN LSL hens having the same size as one of LOHMANN
BROWN hens, should be provided with
more nest spaces in order to avoid floor
eggs. In optimum management, both
hens are equally suitable for alternative
systems. The decisive factors for choosing the right hen are the national market
situation and the consumers’ preferences.
6. Can a worldwide operating company
such as LOHMANN TIERZUCHT meet
the different requirements for laying
hens?
Basically, the different selection criteria are
integrated in an overall breeding value index. This index evaluates the single criteria
with regard to their controllability through
breeding as well as their economic and
market relevant importance.
LOHMANN TIERZUCHT offers five basic
pedigrees of which the single selection
criteria are prioritised differently. Lets take
for example, a robust, brown-feathered
hen with relatively big eggs the LOHMANN
TRADITION. Unlike the LOHMANN BROWN
hen, she has a lower egg rate and higher
feed consumption.
The individual countries of the world focus on different criteria. Japan, a country
in which eggs are also eaten raw, has the
highest demands where egg quality is concerned. Canada would like to have white
eggs whereas. Spain prefers having brown
eggs and eggs which are as big as possible.
India is a market for small, white-coloured
eggs. Cream-coloured eggs are also very
popular in Japan and China, whereas these
eggs are not saleable in Europe. Last but
not also least, hens have to prove themselves in the most various climatic regions
worldwide and under differing management conditions.
7. To what extent have new, geneticbased breeding methods been already
integrated in layer breeding?
At the moment, intensive research is being carried out in terms of marker-assisted
selection, for example, as part of the
project Synbreed, in which LOHMANN
TIERZUCHT is also involved. Marker-assisted
selection aims at analysing several patches
of the genome for small differences, which
when combined, can provide an indication
of performance respective of important
breeding criteria. In the meantime, research
has already identified 600,000 chicken
markers. However, a single patch can at the
same time have a positive effect on one
characteristic and a negative on another.
When it comes to performance and quality criteria, the combination of all patches
provides the genetic predisposition.
In conducting blood sample analysis,
marker-assisted selection will facilitate the
selection of males and hens already during rearing. Thus, a first selection without efficiency testing can be carried out
earlier and more targeted, which again
shortens the generation interval and increases the breeding progress. In addition,
selection will become more efficient where
vitality and susceptibility to diseases are
concerned.
A successful example for the use of genetic
analysis in layer breeding is the exclusion of
the “genetic defect for fishy egg” tainting
brown layer lines.” LOHMANN TIERZUCHT
owns the European patent for this.